- Email: [email protected]
Improvement of resveratrol release performance and stability in extruded microparticle by the α-amylase incorporation
Journal of Food Engineering 274 (2020) 109842
Contents lists available at ScienceDirect
Journal of Food Engineering journal homepage: http://www.elsevier.com/locate/jfoodeng
Improvement of resveratrol release performance and stability in extruded microparticle by the α-amylase incorporation Shanfeng Chen, Jinhuan Zong, Lijun Jiang, Chengye Ma, Hongjun Li, Dongliang Zhang * School of Agricultural Engineering and Food Science, Shandong University of Technology, No. 266 Xincun Road, Zhangdian District, Zibo, Shandong Province, China
A R T I C L E I N F O
A B S T R A C T
Keywords: Microparticle Sustained-released α-Amylase Corn starch
Delivery of biological active substances with the sustained-release microcapsule is a common practice in the food industry. There were many kinds of methods to prepare the sustained-release microparticle, however their portability was the obvious shortcoming. This study presented a simple preparation process of microparticle (particle) with the extruded starch as wall material, resveratrol as the core material and the thermostable α-amylase as the release-improvement reagent (ESRA). The extruded microparticle containing starch and resveratrol (ESR) performed 58.2% release ratio of resveratrol within 5 days water immersion, whereas the α-amylase improved the release performance of the ESRA with 86.7% release ratio of resveratrol. Resveratrol release induced by the disintegration of microparticle was in accord with the size decrease observed by the particle size analyser. Lightstability of incorporated resveratrol was increased, but the extrusion package had no contribution in improving the thermostability of resveratrol. FT-IR, XRD and SEM were employed to investigate the change of molecular link between resveratrol and starch, crystal collapses of starch and microparticle morphology. This preparation process had a broader range of application, which could embed the solid powder and liquid compounds.
1. Introduction Microcapsules is the most common method for the delivery with the improvement of the stability or sustained-release characteristics of the bioactive ingredients (Huang et al., 2015; Ravanfar et al., 2018). Many kinds of microcapsule preparation techniques were investigated due to the advantage of microencapsulation. Spray drying, a common tech nique used for microencapsulation of food ingredients, is a simple inexpensive method in which either proteins or polysaccharides or a combination of both as the shell (Anwar and Kunz, 2011). Complex coacervation, another common technique, possesses series of distinct strengths including oxidation retarding, heat-resistance and controlled-release (Chang et al., 2016). Nevertheless, many techniques have their own drawbacks in the food and drug industry due to the non-food grade materials, expensive materials, complex preparation process, high preparation temperature or instability production (Ros sier-Miranda et al., 2012). Extrusion process for making micro encapsulated ferrous fumarate could prevent the interaction between ferrous fumarate and iodine, and it is also used for encapsulation of the
herbicide EPTC (S-ethyl dipropylacarbamothioate) in starch. However, the release rate, an important index for the utilization, is not included in these documents (Li et al., 2010; Trimnell et al., 2010). Several studies evaluated food-grade biopolymers to produce mi crocapsules with high stability (Dimantov et al., 2004; Livney and Garti, 2008; Wan et al., 2015). A potential alternative for commonly used coatings is starch with denaturation, modification or pretreatment. Extrusion is a highly integrated process with many unique advantages for encapsulation applications. Encapsulation of functional hydrophobic components into starch based matrices via extrusion processing is a promising area which has gained growing interest by food industry as well as by chemical, pharmaceutical, and medical industries (Ahmad et al., 2016; Emin and Schuchmann, 2013). Starch is converted into a homogenous molten state in the extrusion process, which conversion encompasses various structural changes, such as granules disruption, crystals melting and molecule entanglement (Ming et al., 2011). This molecule entanglement affords the approach for the incorporation and sustained-release of the ingredient. The sustained-release, resistance and stability of the microcapsule have been investigated; nevertheless, the
Abbreviations: ESRA, extruded the mixture of starch, resveratrol and thermostable α-amylas; ESR, extruded the mixture of starch and resveratrol. * Corresponding author. E-mail address: [email protected] (D. Zhang). https://doi.org/10.1016/j.jfoodeng.2019.109842 Received 24 July 2019; Received in revised form 25 November 2019; Accepted 25 November 2019 Available online 26 November 2019 0260-8774/© 2019 Elsevier Ltd. All rights reserved.
S. Chen et al.
Journal of Food Engineering 274 (2020) 109842
Fig. 1. Release performance of microparticles, standard curve of resveratrol, and stability of resveratrol powder and microparticles. A, the release of encapsulated resveratrol with and without amylase (ESR and ESRA). B, lightstability of resveratrol powder, encapsulated resveratrol with and without amylase (RP, ESR and ESRA). C, thermostability of resveratrol powder, encapsulated resveratrol with and without amylase (RP, ESR and ESRA). D, standard curve of resveratrol (Same symbol represent significantly different value at p � 0.05).
incorporation rarely considers the release ratio of core material. Hollow microcapsule was used to improve the release ratio of incorporated ingredient, and the addition of reagent promoting the disintegration of microcapsule was also an alternative method. The study presented a simple preparation of microparticle with the extruded starch as wall material, resveratrol as the core material and the thermostable α-amylase as the release-improvement reagent of resveratrol.
temperature (50, 55, 60, 65 � C for the four parts starting from the feed part) and 110 rpm screw speed, and then the microparticle was obtained (extruded the mixture of starch, resveratrol and thermostable α-amylas, ESRA). The α-amylase was excluded in the ESR group (extruded the mixture of starch and resveratrol). The extrudate was smashed by using ultra-micro pulveriser, and microparticle with 0.15–1 mm diameter was selected.
2. Materials and methods
2.3. Release ratio of microparticle
2.1. Materials
The microparticle (10 g) was dispersed in 400 mL water and settled in a light-tight refrigerator at 5 � C. The suspension solution was shaken, 100 mL supernatant was taken out after 1 h settlement, and then the same volume of water was added. The supernatant was used in the following detection after centrifugation at 400 rpm for 5 min. This procedure was performed once a day for 5 days. Experiment was repeated three times, and the standard deviation and significant differ ence were calculated by the Microsoft excel. Resveratrol content was measured using a spectrophotometer (Microplate Reader, Thermo Fisher Scientific, USA) at 308 nm, and different concentrations of resveratrol solution were employed to draw the standard curve (Fig. 1D).
Thermostable α-amylase (CAS, 9001-19-8, 51 kDa, 40000 u/g, Sol qrbio Life Science Co. Ltd., Beijing, China), corn starch (Food Degree, 10.2% water content, Shandong Hengren Food Industry co. LTD, Shandong, China), resveratrol (CAS, 501-36-0, Macklin Reagent Co. Ltd., Shanghai, China) and distilled water (Made by Shandong Univer sity of Technology laboratory) were used. 2.2. Preparation of microparticle Parameters of home-made single-screw extruder are shown as following, 79 mm diameter of barrel bore, 77 mm outer diameter of extruder screw, 16.4:1 length-to-diameter (LID) ratio of extruder screw, and 10 mm diameter bore in conical tapered dies. A temperature control facility (in four separate zones) and a digital display of torque (T, %) are equipped in extruder, and the temperature of four barrel sections is adjustable between 0 and 300 � C. A twin-screw volumetric gravity feeder was adopted in this extruder to feed the material with 100 kg/h constant feed speed (Supplementary Fig. 1). Mixture including 10 kg corn starch (water content was adjusted to 24%), 10 g resveratrol and 5 g α-amylase was extruded with 65 � C barrel
2.4. Light and thermal stability of resveratrol powder and microparticle Resveratrol powder (1 g), ESRA (1 g), and ESR (1 g) were tiled in a plate (9 cm diameter) and exposed under the illumination source of a suntest chamber (Weihuang, Shanghai, China) with a xenon arc lamp (the irradiation energy was set at 30 � 1.1 W m 2). Three kinds of powder were taken and dispersed in 80% ethanol and diluted by certain volume of water (the absorbance at the range of 0.1–1.2 to detect the concentration of resveratrol. Consequently, the residual ratio of 2
S. Chen et al.
Journal of Food Engineering 274 (2020) 109842
Fig. 2. Granularity variation of the microparticles in release process. A, granularity of ESR and ESRA microparticles at the beginning of water immersion. B, granularity of ESR and ESRA microparticles within 5 h of water immersion. C, granularity of ESR and ESRA microparticles within 3 days of water immersion. C, granularity of ESR and ESRA microparticles within 5 days of water immersion.
resveratrol was calculated by the following equation.
argon atmosphere. All samples were examined by an accelerating voltage of 5 kV.
Residual ratio of resveratrol ¼ ðresidual amount = original amountÞ � 100%
2.8. X-ray diffraction (XRD) detection
Three kinds of samples (1 g for each sample) was loaded in a 50 mL plastic tube and heated at 50 � C for 5 days. The content and the residual ratio of resveratrol were detected every day following the abovementioned detection method.
The samples with the same pretreatment as item 2.7 were employed in the X-ray scattering measurement with an X-ray diffractometer (D8ADVANCE, Bruker AXS, Germany), a copper tube at 35 kV and a Cu radiation at 0.154 nm wavelength. Diffractograms were obtained by scanning from 3� to 50� at 0.5� /min with a step size of 0.02 (Hui et al., 2007).
2.5. Particle size variation of the microparticle in release process The particle size of microparticles was measured by the Mal vern2000 laser diffraction particle size analyser. Microparticle (2.5 g) was dispersed into 1 L water, and settled in light-tight refrigerator at 5 � C. The particle size of microparticle was measured at the 0 h, the fifth hour, the third day and the fifth day of water immersion.
2.9. Fourier transforms infrared spectroscopy (FT-IR) The FT-IR spectra of the samples (with the same pretreatment as 2.7) were recorded by a Nicolet 5700 spectrophotometer (Thermo Nicolet 5700, USA). The powdered samples were mixed with an analytical grade KBr and then pressed into discs. The spectra of the samples were recorded in the region of 400–4000 cm 1.
2.6. Crystal morphology of cross-polarization (polarization microscope) Suspension containing 400 mL water and 10 g microparticle was settled in light-tight refrigerator at 5 � C, and taken out at the beginning and 5 days of water immersion. Sediment was placed in glass slide with water and covered with coverslip (Cai et al., 2014b). Crosspolarization, an index of the starch crystal structure, was observed with a polarization microscope (Nikon 50i microscopy, Japan).
3. Results and discussion 3.1. Release ratio, light stability and thermo stability of microparticle Considering the sustained release also referred to the release rate and ratio of core material, thermostable α-amylase was used to improve both characteristics of microparticle by its amylolytic ability. The release rate of resveratrol within first 24 h was higher than the following days in the release process of ESR and ESRA, and a stable release rate of resveratrol was observed in the ESR suspension (Fig. 1A). The gelatinisation of starch in extrusion process accelerated the enzyme hydrolysis at the first day, while the additional crystal structure of the starch had a negative
2.7. Scanning electron microscopy (SEM) Sediment in item 2.6 was freeze-dried (Yamato, DC401, Japan) and observed using SEM with an FEI Sirion 200 microscope (PHILIPS Ltd., Netherlands). The sediment was placed on a metal stub with a doublesided adhesive tape and then coated under vacuum with gold in an 3
S. Chen et al.
Journal of Food Engineering 274 (2020) 109842
of ESR was d (0.5) ¼ 498.766 μm and ESRA was d (0.5) ¼ 415.446 μm (Fig. 2A). Disintegrated particles in the α-amylase addition group (ESRA) were described in Fig. 2B with d (0.5) ¼ 29.147 μm after 5 h water immersion, and the ESR possessed the slightly inflated particles with d (0.5) ¼ 527.051 μm. The absence of enzyme was responsible for the low gelatinisation degree of ESR. The enlarged particle size was probably caused by the water absorption of starch crystal and the gelatinised starch around starch crystal (Fig. 2B) (Evans and Lips, 2010). The particle size was continued to be diminished with d (0.5) ¼ 321.195 μm in ESR and d (0.5) ¼ 25.939 μm in ESRA after 3 days water immersion, nevertheless, d (0.5) ¼ 270.639 μm of ESR and d (0.5) ¼ 24.759 μm of ESRA were measured at 5 days of water immersion. A slight change of ESRA particle size (Fig. 2C and D) between 3 and 5 days of water immersion demonstrated that the releasing amount of resver atrol barely increased, this result was coincided with the releasing amount in Fig. 1A. The size of starch crystal (d (0.5) ¼ 15.835 μm) was different from the particle size of ESRA, this difference was possibly induced by the water absorption and swelling of starch crystal (Tester and Morrison, 1994; Witono et al., 2014). 3.3. Crystal morphology (polarization microscope) Approximate size of the ESR (arrow in Fig. 3A1) and the ESRA (arrow in Fig. 3C1 was observed by using a polarization microscope, by contrast, the ESR still maintained an intact particle shape after 5 days of immersion (arrow in Fig. 3B1). The morphology and number of starch crystal represented the degree of starch gelatinisation and denaturation (Cai et al., 2014a; Jenkins and Donald, 1997). Gelatinisation and entanglement of starch packaged the crystal, which formed the intact structure that blocked the dissolution and breakdown of microparticles and postponed the release of resveratrol. The extrusion destroyed the crystal structure by the gelatinisation, which could be revealed by the disappearance of crosspolarization (Doublier et al., 1987; Liu et al., 2010). The addition of the α-amylase intensified the denaturation of starch chain, the decomposition of starch granule and the dissolution of gelatinised microparticle. Moreover, the enzyme promoted the breakdown of ESRA inducing the scatter of starch crystal, the separation of crosspolarization and the disappearance of a portion of crosspolarization (arrows in Fig. 3D1 and D2). The cross polarization also disappeared in some gelatinised starch particles (ar rowheads in Fig. 3D1 and D2). An amount of starch crystal with cross-polarization was annotated in ESR (arrows in Fig. 3A2, B2 and C2), the microparticles were intact and could hardly release the core material (resveratrol).
Fig. 3. Crystal morphology of cross-polarization. A, ESR microparticles (A1 was amplified 40 times, A2 was amplified 100 times). B, ESR microparticles within 5 days of water immersion (B1 was amplified 40 times, B2 was amplified 100 times). C, ESRA microparticles (C1 was amplified 40 times, C2 was amplified 100 times). D, ESRA microparticles within 5 days of water immersion (D1 was amplified 100 times, D2 was amplified 200 times).
effect on the release rate of resveratrol following days. Approximately 40% resveratrol was released at the beginning of the water immersion both in the encapsulated samples with and without α-amylase. The addition of α-amylase improved the release of resveratrol up to 86.7% total release ratio within five days water immersion. Despite of the release amount of ESR was less than ESRA, the ESR was still a desirable microparticle on account of its 58.2% resveratrol release rate within 5 days. The denatured starch packaging and entangling the resveratrol in extrusion induced the remarkable improvement of resveratrol photo stability (Fig. 1B), and the interaction between denatured starch and resveratrol had no effect on the thermostability of samples (Figure C). Light absorbance of starch improved the photostability of resveratrol remarkably. Gelatinised starch generated by the hydrolysis of α-amylase in ESRA that exhibited the stronger photoprotection function than ESR demonstrating that the packaging function of gelatinised starch played the dominant role in the improvement of resveratrol photostability (Fig. 1C) (Feng et al., 2011; Lee and Kim, 2010; Wang et al., 2016).
3.4. SEM Extrusion induced the denaturation and gelatinisation of the mixture facilitating the formation of tight structure of extruded starch (ESR and ESRA) (Al-Rabadi et al., 2011; Chen and Rizvi, 2006; Chuang and Yeh, 2004). Nevertheless, α-amylase in ESRA enhanced the starch gelatini sation that eliminated the generated holes (arrows in Fig. 4C1, C2 and C3) in ESR by the incomplete gelatinisation (arrowheads in Fig. 4A1, A2 and A3). The appearances such as the holes in ESR and the tight struc ture of ESRA revealed that the α-amylase contributed to the gelatinisa tion and package ability of starch. The loose structure and small size of microparticles were identified in ESRA with water immersion, which suggested that the embedded α-amylase enhanced the gelatinisation in extrusion and hydrolysation function of α-amylase was responsible for the loose morphology of microparticle (Fig. 4D1, D2 and D3). The gelatinised starch produced by the extrusion, enhanced by α-amylase and settled among the starch crystal was easily hydrolysed by enzyme resulting in the breakdown of microparticle and the acceleration of resveratrol release (Waterschoot et al., 2015). The holes were generated in the ESR with water immersion, and bulky granules still existed in the enzyme-absent group (arrow heads in Fig. 4B1, B2 and B3).
3.2. Particle size variation of the microparticle in release process Microparticle was dispersed in water, and the change of particle size was measured by the laser particle analyser at the 0 h, the fifth hour, the third day and the fifth day of water immersion (Fig. 2). The result showed that the particle of ESR and ESRA to water im mersion was large and intact at the beginning showing the particle size 4
S. Chen et al.
Journal of Food Engineering 274 (2020) 109842
Fig. 4. Morphology of microparticles observed using SEM. A, ESR microparticles (Bars in A1, A2 and A3 were 200, 100 and 20 μm, respectively). B, ESR micro particles within 5 days of water immersion (Bars in B1, B2 and B3 were 200, 100 and 20 μm, respectively). C, ESRA microparticles (Bars in C1, C2 and C3 were 200, 100 and 20 μm, respectively). D, ESRA microparticles within 5 days of water immersion (Bars in D1, D2 and D3 were 200, 100 and 20 μm, respectively).
other apparent peak was found in the lines of ESR-1 and ESRA-1, so the characteristic peaks of resveratrol monomer were eliminated by the convolution of starch chain (Fig. 5ESR-1 and ESRA-1). Multiple characteristic peaks of starch crystal in the ESRA-2 at 2θ of 13.04� , 15.04� , 17.3� , 18.16� , 19.92� and 22.92� indicated that starch crystal was the main content in the ESRA within 5 days of water im mersion (Fig. 5 ESRA-2). This result also suggested that the micropar ticle barely contained resveratrol after 5 days release, and the package of starch crystal by the starch amorphous state probably decreased the crystal characteristics of starch. Moreover, water absorption that
Fig. 5. XRD detection. ESR-1, ESRA-1 were the microparticles without water immersion. ESR-2, ESRA-2 were microparticles with 5 days of water immersion.
3.5. XRD detection Further insights into the impact of enzyme addition on the structure and gelatinisation of the extruded mixture were investigated using XRD analysis. A previous study of extruded corn starch stated two distinct diffraction peaks at approximately 2θ of 13� and 20� (Artz et al., 2010; Basto et al., 2016; Ye et al., 2018). The coincident result was also observed in the ESR and ESRA with peaks at 2θ of 13.04� and 19.92� . No
Fig. 6. FT-IR. ESR-1, ESRA-1 were the microparticles without water immer sion. ESR-2, ESRA-2 were microparticles with 5 days of water immersion. 5
S. Chen et al.
Journal of Food Engineering 274 (2020) 109842
occurred in ESR intensified the disappearance of crystal peak induced no apparent peak in line of ESR-2 (Fig. 5ESR-2). Most of the embedded resveratrol in gelatinised starch hardly escaped from the unbroken ESR particle within 5 days of water immersion. The α-amylase addition of ESRA possessed the opposite result caused by the hydrolysation function of this enzyme.
the packaging function of starch significantly improved the photo stability of resveratrol. ESRA was easily hydrolysed and had a consid erable release ratio, whereas ESR obtained the opposite characteristics. That is the α-amylase changed particle size, altered the mechanism of resveratrol release and improved resveratrol release ratio. The ESR group had an acceptable release ratio in the chasing period, and these two kinds of solid microparticle had clear advantages in transportation, preservation and utilization.
3.6. Fourier transforms infrared spectroscopy (FT-IR) The characteristic spectral region of starch at 750-1000 cm 1 was the same between the two groups with water immersion (Fig. 6ESR-2 and ESRA-2). A similar line trend was also found in groups without water immersion (Fig. 6ESR-1 and ESRA-1), thus the water immersion that induced the breakdown of microparticles was a cause for the difference between groups with and without water immersion. Curve variation at 1025.994–1155.152 cm 1 attributed to C–O bond stretching of C–O–C in ESRA with water immersion was apparently different from in the variation of other groups (Fig. 6ESRA-2). The dissolution of hydrolysed and gelatinised starch in water caused the sharp peaks (Yang et al., 2007). Absorption bands at 1417.423 and –C 1644.982 cm 1 of microparticles were attributed to the conjugated C– stretching vibration that ascribed to the aromatic ring skeletal of resveratrol (Shi et al., 2008), and the weakened peaks of conjugated – C stretching vibration accounted for the low content and high release C– amount of resveratrol in ESRA group (Fig. 6ESRA-2). The vibration of conjugate double bonds of benzene ring at 2094.315 cm 1disappeared in the line of ESRA-2 suggesting that the α-amylase facilitated the release of resveratrol and the encapsulation function of starch on the resveratrol was weakened. The absorption band at 2927.412 cm 1could be assigned to the vi bration of the symmetrical –CH2 stretching vibration, asymmetrical –CH2 stretching vibration and asymmetrical –CH3 vibration of starch. It was slightly broadened in ESRA-1 by the gelatinisation and entangle ment of starch that was reinforced by the addition of enzyme (rectangle in Fig. 6ESRA-1). These entanglement and package functions protected the resveratrol from the light. The extrusion resulted in the stretch of helical structure, the decomposition of starch and the generation of low molecular weight substance, which complicated the microparticles and flattened the absorption bands of –OH vibration at around 3367.103 cm 1 (Fig. 6 ESR-1 and ESRA-1). This changed absorption brand of –OH vibration also suggested that the hydrogen bond was attributed to the intramolecular connection and the connection between starch and resveratrol indicating that the resveratrol was packaged in starch by the hydrogen bonds (Li et al., 2016). More flat peaks observed in groups without water immersion than other two groups specified that the more hydrogen bonds formed during the extrusion. Water dissolution removed the denatured starch and hydrolysate, and then sharp peaks appeared in ESR-2 and ESRA-2. The α-amylase addition in ESRA with water immersion accelerated the resveratrol release and the dissolution of starch crystal which led to the narrow peak (Fig. 6ESRA-2).
Acknowledgement This work was supported by the Shandong Provincial Natural Sci ence Foundation, China (ZR2017MC073). Appendix A. Supplementary data Supplementary data to this article can be found online at https://doi. org/10.1016/j.jfoodeng.2019.109842. Credit author statement Shanfeng Chen: Methodology, Conceptualization, WritingReviewEditing. Jinhuan Zong: Writing-Original draft manuscript, Investigation, Data curation. Lijun Jiang: Software, Validation. Chengye Ma: Visualization, Software, Formal analysis. Hongjun Li: Project administration, Resources. Dongliang Zhang: Supervision, Project administration, Resources. References Ahmad, M., Qureshi, S., Maqsood, S., Gani, A., Masoodi, F.A., 2016. Micro-encapsulation of folic acid using horse chestnut starch and β-cyclodextrin: microcapsule characterization, release behavior & antioxidant potential during GI tract conditions. Food Hydrocolloids 66. Al-Rabadi, G.J., Torley, P.J., Williams, B.A., Bryden, W.L., Gidley, M.J., 2011. Particle size of milled barley and sorghum and physico-chemical properties of grain following extrusion. J. Food Eng. 103 (4), 464–472. Anwar, S.H., Kunz, B., 2011. The influence of drying methods on the stabilization of fish oil microcapsules: comparison of spray granulation, spray drying, and freeze drying. J. Food Eng. 105 (2), 367–378. Artz, W.E., Warren, C., Villota, R., 2010. Twin-screw extrusion modification of a corn fiber and corn starch extruded blend. J. Food Sci. 55 (3), 746–754. Basto, G.J., Carvalho, C.W.P., Soares, A.G., Costa, H.T.G.B., Ch� avez, D.W.H., Godoy, R.L. d.O., Pacheco, S., 2016. Physicochemical properties and carotenoid content of extruded and non-extruded corn and peach palm (Bactris gasipaes, Kunth). LWT Food Sci. Technol. (Lebensmittel-Wissenschaft -Technol.) 69, 312–318. Cai, C., Cai, J., Man, J., Yang, Y., Wang, Z., Wei, C., 2014. Allomorph distribution and granule structure of lotus rhizome C-type starch during gelatinization. Food Chem. 142 (3), 408–415. Cai, J., Cai, C., Man, J., Yang, Y., Zhang, F., Wei, C., 2014. Crystalline and structural properties of acid-modified lotus rhizome C-type starch. Carbohydr. Polym. 102 (1), 799–807. Chang, C., Varankovich, N., Nickerson, M.T., 2016. Microencapsulation of canola oil by lentil protein isolate-based wall materials. Food Chem. 212, 264–273. Chen, K.H., Rizvi, S.S.H., 2006. Rheology and expansion of starch-water-CO2 mixtures with controlled gelatinization by supercritical fluid extrusion. Int. J. Food Prop. 9 (4), 863–876. Chuang, C.C., Yeh, A.I., 2004. Effect of screw profile on residence time distribution and starch gelatinization of rice flour during single screw extrusion cooking. J. Food Eng. 63 (1), 21–31. Dimantov, A., Greenberg, M., Kesselman, E., Shimoni, E., 2004. Study of high amylose corn starch as food grade enteric coating in a microcapsule model system. Innov. Food Sci. Emerg. Technol. 5 (1), 93–100. Doublier, J.L., Paton, D., Llamas, G., 1987. A rehological investigation of oat starch pastes. Cereal Chem. 64 (1), 21–26. Emin, M.A., Schuchmann, H.P., 2013. Analysis of the dispersive mixing efficiency in a twin-screw extrusion processing of starch based matrix. J. Food Eng. 115 (1), 132–143. Evans, I.D., Lips, A., 2010. Viscoelasticity OF gelatinized starch dispersions. J. Texture Stud. 23 (1), 69–86. Feng, Q.J., Xiao, Z.G., Zheng, G.Z., Wei, X., Hong-Jian, Y.E., 2011. Study on the gelatinization of corn starch by enzyme-added extrusion at low temperature. Science & Technology of Food Industry 32 (8), 287-286. Huang, Y., Zhou, Y., Huang, J., Zhu, C., Chen, M., Pan, X., Wu, C., 2015. Metoprolol tartrate sustained-release binary matrix microspheres for oral administration produced by novel ultra-fine particle processing system. Powder Technol. 285, 44–50.
4. Conclusion Starch was converted into a homogenous molten state in extrusion process, and the ingredients (resveratrol and α-amylase) were also included in this process. This conversion may encompass various changes, such as the package of resveratrol and the molecular tangle between each other. The preparation of extruded starch microparticle containing resveratrol and α-amylase was studied to simplify the resveratrol encapsulation and give more lightstability to the active ingredient (resveratrol). The release rate of resveratrol within the first 24 h was higher than the following 4 days in ESRA, and the stable release rate of resveratrol was observed in ESR. The addition of α-amylase improved the release ratio of ESRA with 86.7% resveratrol release ratio within 5 chasing days, however, the microparticle without enzyme was also feasible with its total release ratio of 58.2%. Light absorbance and 6
S. Chen et al.
Journal of Food Engineering 274 (2020) 109842
Hui, C., Xu, K., Xue, D., Song, C., Zhang, W., Wang, P., 2007. Synthesis of dodecenyl succinic anhydride (DDSA) corn starch. Food Res. Int. 40 (2), 232–238. Jenkins, P.J., Donald, A.M., 1997. Breakdown of crystal structure in potato starch during gelatinization. J. Appl. Polym. Sci. 66 (2), 225–232. Lee, Y.C., Kim, K.T., 2010. Gelatinization and liquefaction of starch with a heat stable α-amylase. J. Food Sci. 55 (5), 1365–1366. Li, W., Li, C., Gu, Z., Qiu, Y., Cheng, L., Hong, Y., Li, Z., 2016. Retrogradation behavior of corn starch treated with 1,4-α-glucan branching enzyme. Food Chem. 203, 308–313. Li, Y.O., Diosady, L.L., Wesley, A.S., 2010. Iodine stability in iodized salt dual fortified with microencapsulated ferrous fumarate made by an extrusion-based encapsulation process. J. Food Eng. 99 (2), 232–238. Liu, P.L., Zhang, B.S., Shen, Q., Hu, X.S., Li, W.H., 2010. Preparation and structure analysis of noncrystalline granular starch. Int. J. Food Eng. 6 (4), 61–64. Livney, Y.D., Garti, N., 2008. Complexes and conjugates of biopolymers for delivery of bioactive ingredients via food. Delivery & Controlled Release of Bioactives in Foods & Nutraceuticals 234–250. Ming, L.I., Peng, L., Wei, Z., Long, Y.U., Xie, F., Huayin, P.U., Liu, H., Ling, C., 2011. Extrusion processing and characterization of edible starch films with different amylose contents. J. Food Eng. 106 (1), 95–101. Ravanfar, R., Comunian, T.A., Abbaspourrad, A., 2018. Thermoresponsive, waterdispersible microcapsules with a lipid-polysaccharide shell to protect heat-sensitive colorants. Food Hydrocolloids 81, 419–428. Rossier-Miranda, F.J., Schro€ en, K., Boom, R., 2012. Microcapsule production by an hybrid colloidosome-layer-by-layer technique. Food Hydrocolloids 27 (1), 119–125.
Shi, G., Rao, L., Yu, H., Xiang, H., Yang, H., Ji, R., 2008. Stabilization and encapsulation of photosensitive resveratrol within yeast cell. Int. J. Pharm. 349 (1), 83–93. Tester, R.F., Morrison, W.R., 1994. Properties of damaged starch granules. V. Composition and swelling of fractions of wheat starch in water at various temperatures. J. Cereal Sci. 20 (2), 175–181. Trimnell, D., Carr, M.E., Doane, W.M., 2010. Encapsulation of EPTC in starch by twin~ screw extrusion. Starch - StA¤rke 43 (4), 146–151. Wan, Z.L., Guo, J., Yang, X.Q., 2015. Plant protein-based delivery systems for bioactive ingredients in foods. Food & Function 6 (9), 2876–2889. Wang, P., Fu, Y., Wang, L., Saleh, A.S.M., Cao, H., Xiao, Z., 2016. Effect of enrichment with stabilized rice bran and extrusion process on gelatinization and retrogradation properties of rice starch. Starch - St€ arke 69. Waterschoot, J., Gomand, S.V., Delcour, J.A., Goderis, B., 2015. Direct evidence for the non-additive gelatinization in binary starch blends: a case study on potato starch mixed with rice or maize starches. Food Hydrocolloids 50, 137–144. Witono, J.R., Noordergraaf, I.W., Heeres, H.J., Janssen, L.P., 2014. Water absorption, retention and the swelling characteristics of cassava starch grafted with polyacrylic acid. Carbohydr. Polym. 103 (103), 325–332. Yang, J.-H., Yu, J.-G., Feng, Y., Ma, X.-F., 2007. Study on the properties of ethylenebisformamide plasticized corn starch (EPTPS) with various original water contents of corn starch. Carbohydr. Polym. 69 (2), 256–261. Ye, J., Liu, C., Luo, S., Hu, X., McClements, D.J., 2018. Modification of the digestibility of extruded rice starch by enzyme treatment (β-amylolysis): an in vitro study. Food Res. Int. 111, 590–596.
7
Contents lists available at ScienceDirect
Journal of Food Engineering journal homepage: http://www.elsevier.com/locate/jfoodeng
Improvement of resveratrol release performance and stability in extruded microparticle by the α-amylase incorporation Shanfeng Chen, Jinhuan Zong, Lijun Jiang, Chengye Ma, Hongjun Li, Dongliang Zhang * School of Agricultural Engineering and Food Science, Shandong University of Technology, No. 266 Xincun Road, Zhangdian District, Zibo, Shandong Province, China
A R T I C L E I N F O
A B S T R A C T
Keywords: Microparticle Sustained-released α-Amylase Corn starch
Delivery of biological active substances with the sustained-release microcapsule is a common practice in the food industry. There were many kinds of methods to prepare the sustained-release microparticle, however their portability was the obvious shortcoming. This study presented a simple preparation process of microparticle (particle) with the extruded starch as wall material, resveratrol as the core material and the thermostable α-amylase as the release-improvement reagent (ESRA). The extruded microparticle containing starch and resveratrol (ESR) performed 58.2% release ratio of resveratrol within 5 days water immersion, whereas the α-amylase improved the release performance of the ESRA with 86.7% release ratio of resveratrol. Resveratrol release induced by the disintegration of microparticle was in accord with the size decrease observed by the particle size analyser. Lightstability of incorporated resveratrol was increased, but the extrusion package had no contribution in improving the thermostability of resveratrol. FT-IR, XRD and SEM were employed to investigate the change of molecular link between resveratrol and starch, crystal collapses of starch and microparticle morphology. This preparation process had a broader range of application, which could embed the solid powder and liquid compounds.
1. Introduction Microcapsules is the most common method for the delivery with the improvement of the stability or sustained-release characteristics of the bioactive ingredients (Huang et al., 2015; Ravanfar et al., 2018). Many kinds of microcapsule preparation techniques were investigated due to the advantage of microencapsulation. Spray drying, a common tech nique used for microencapsulation of food ingredients, is a simple inexpensive method in which either proteins or polysaccharides or a combination of both as the shell (Anwar and Kunz, 2011). Complex coacervation, another common technique, possesses series of distinct strengths including oxidation retarding, heat-resistance and controlled-release (Chang et al., 2016). Nevertheless, many techniques have their own drawbacks in the food and drug industry due to the non-food grade materials, expensive materials, complex preparation process, high preparation temperature or instability production (Ros sier-Miranda et al., 2012). Extrusion process for making micro encapsulated ferrous fumarate could prevent the interaction between ferrous fumarate and iodine, and it is also used for encapsulation of the
herbicide EPTC (S-ethyl dipropylacarbamothioate) in starch. However, the release rate, an important index for the utilization, is not included in these documents (Li et al., 2010; Trimnell et al., 2010). Several studies evaluated food-grade biopolymers to produce mi crocapsules with high stability (Dimantov et al., 2004; Livney and Garti, 2008; Wan et al., 2015). A potential alternative for commonly used coatings is starch with denaturation, modification or pretreatment. Extrusion is a highly integrated process with many unique advantages for encapsulation applications. Encapsulation of functional hydrophobic components into starch based matrices via extrusion processing is a promising area which has gained growing interest by food industry as well as by chemical, pharmaceutical, and medical industries (Ahmad et al., 2016; Emin and Schuchmann, 2013). Starch is converted into a homogenous molten state in the extrusion process, which conversion encompasses various structural changes, such as granules disruption, crystals melting and molecule entanglement (Ming et al., 2011). This molecule entanglement affords the approach for the incorporation and sustained-release of the ingredient. The sustained-release, resistance and stability of the microcapsule have been investigated; nevertheless, the
Abbreviations: ESRA, extruded the mixture of starch, resveratrol and thermostable α-amylas; ESR, extruded the mixture of starch and resveratrol. * Corresponding author. E-mail address: [email protected] (D. Zhang). https://doi.org/10.1016/j.jfoodeng.2019.109842 Received 24 July 2019; Received in revised form 25 November 2019; Accepted 25 November 2019 Available online 26 November 2019 0260-8774/© 2019 Elsevier Ltd. All rights reserved.
S. Chen et al.
Journal of Food Engineering 274 (2020) 109842
Fig. 1. Release performance of microparticles, standard curve of resveratrol, and stability of resveratrol powder and microparticles. A, the release of encapsulated resveratrol with and without amylase (ESR and ESRA). B, lightstability of resveratrol powder, encapsulated resveratrol with and without amylase (RP, ESR and ESRA). C, thermostability of resveratrol powder, encapsulated resveratrol with and without amylase (RP, ESR and ESRA). D, standard curve of resveratrol (Same symbol represent significantly different value at p � 0.05).
incorporation rarely considers the release ratio of core material. Hollow microcapsule was used to improve the release ratio of incorporated ingredient, and the addition of reagent promoting the disintegration of microcapsule was also an alternative method. The study presented a simple preparation of microparticle with the extruded starch as wall material, resveratrol as the core material and the thermostable α-amylase as the release-improvement reagent of resveratrol.
temperature (50, 55, 60, 65 � C for the four parts starting from the feed part) and 110 rpm screw speed, and then the microparticle was obtained (extruded the mixture of starch, resveratrol and thermostable α-amylas, ESRA). The α-amylase was excluded in the ESR group (extruded the mixture of starch and resveratrol). The extrudate was smashed by using ultra-micro pulveriser, and microparticle with 0.15–1 mm diameter was selected.
2. Materials and methods
2.3. Release ratio of microparticle
2.1. Materials
The microparticle (10 g) was dispersed in 400 mL water and settled in a light-tight refrigerator at 5 � C. The suspension solution was shaken, 100 mL supernatant was taken out after 1 h settlement, and then the same volume of water was added. The supernatant was used in the following detection after centrifugation at 400 rpm for 5 min. This procedure was performed once a day for 5 days. Experiment was repeated three times, and the standard deviation and significant differ ence were calculated by the Microsoft excel. Resveratrol content was measured using a spectrophotometer (Microplate Reader, Thermo Fisher Scientific, USA) at 308 nm, and different concentrations of resveratrol solution were employed to draw the standard curve (Fig. 1D).
Thermostable α-amylase (CAS, 9001-19-8, 51 kDa, 40000 u/g, Sol qrbio Life Science Co. Ltd., Beijing, China), corn starch (Food Degree, 10.2% water content, Shandong Hengren Food Industry co. LTD, Shandong, China), resveratrol (CAS, 501-36-0, Macklin Reagent Co. Ltd., Shanghai, China) and distilled water (Made by Shandong Univer sity of Technology laboratory) were used. 2.2. Preparation of microparticle Parameters of home-made single-screw extruder are shown as following, 79 mm diameter of barrel bore, 77 mm outer diameter of extruder screw, 16.4:1 length-to-diameter (LID) ratio of extruder screw, and 10 mm diameter bore in conical tapered dies. A temperature control facility (in four separate zones) and a digital display of torque (T, %) are equipped in extruder, and the temperature of four barrel sections is adjustable between 0 and 300 � C. A twin-screw volumetric gravity feeder was adopted in this extruder to feed the material with 100 kg/h constant feed speed (Supplementary Fig. 1). Mixture including 10 kg corn starch (water content was adjusted to 24%), 10 g resveratrol and 5 g α-amylase was extruded with 65 � C barrel
2.4. Light and thermal stability of resveratrol powder and microparticle Resveratrol powder (1 g), ESRA (1 g), and ESR (1 g) were tiled in a plate (9 cm diameter) and exposed under the illumination source of a suntest chamber (Weihuang, Shanghai, China) with a xenon arc lamp (the irradiation energy was set at 30 � 1.1 W m 2). Three kinds of powder were taken and dispersed in 80% ethanol and diluted by certain volume of water (the absorbance at the range of 0.1–1.2 to detect the concentration of resveratrol. Consequently, the residual ratio of 2
S. Chen et al.
Journal of Food Engineering 274 (2020) 109842
Fig. 2. Granularity variation of the microparticles in release process. A, granularity of ESR and ESRA microparticles at the beginning of water immersion. B, granularity of ESR and ESRA microparticles within 5 h of water immersion. C, granularity of ESR and ESRA microparticles within 3 days of water immersion. C, granularity of ESR and ESRA microparticles within 5 days of water immersion.
resveratrol was calculated by the following equation.
argon atmosphere. All samples were examined by an accelerating voltage of 5 kV.
Residual ratio of resveratrol ¼ ðresidual amount = original amountÞ � 100%
2.8. X-ray diffraction (XRD) detection
Three kinds of samples (1 g for each sample) was loaded in a 50 mL plastic tube and heated at 50 � C for 5 days. The content and the residual ratio of resveratrol were detected every day following the abovementioned detection method.
The samples with the same pretreatment as item 2.7 were employed in the X-ray scattering measurement with an X-ray diffractometer (D8ADVANCE, Bruker AXS, Germany), a copper tube at 35 kV and a Cu radiation at 0.154 nm wavelength. Diffractograms were obtained by scanning from 3� to 50� at 0.5� /min with a step size of 0.02 (Hui et al., 2007).
2.5. Particle size variation of the microparticle in release process The particle size of microparticles was measured by the Mal vern2000 laser diffraction particle size analyser. Microparticle (2.5 g) was dispersed into 1 L water, and settled in light-tight refrigerator at 5 � C. The particle size of microparticle was measured at the 0 h, the fifth hour, the third day and the fifth day of water immersion.
2.9. Fourier transforms infrared spectroscopy (FT-IR) The FT-IR spectra of the samples (with the same pretreatment as 2.7) were recorded by a Nicolet 5700 spectrophotometer (Thermo Nicolet 5700, USA). The powdered samples were mixed with an analytical grade KBr and then pressed into discs. The spectra of the samples were recorded in the region of 400–4000 cm 1.
2.6. Crystal morphology of cross-polarization (polarization microscope) Suspension containing 400 mL water and 10 g microparticle was settled in light-tight refrigerator at 5 � C, and taken out at the beginning and 5 days of water immersion. Sediment was placed in glass slide with water and covered with coverslip (Cai et al., 2014b). Crosspolarization, an index of the starch crystal structure, was observed with a polarization microscope (Nikon 50i microscopy, Japan).
3. Results and discussion 3.1. Release ratio, light stability and thermo stability of microparticle Considering the sustained release also referred to the release rate and ratio of core material, thermostable α-amylase was used to improve both characteristics of microparticle by its amylolytic ability. The release rate of resveratrol within first 24 h was higher than the following days in the release process of ESR and ESRA, and a stable release rate of resveratrol was observed in the ESR suspension (Fig. 1A). The gelatinisation of starch in extrusion process accelerated the enzyme hydrolysis at the first day, while the additional crystal structure of the starch had a negative
2.7. Scanning electron microscopy (SEM) Sediment in item 2.6 was freeze-dried (Yamato, DC401, Japan) and observed using SEM with an FEI Sirion 200 microscope (PHILIPS Ltd., Netherlands). The sediment was placed on a metal stub with a doublesided adhesive tape and then coated under vacuum with gold in an 3
S. Chen et al.
Journal of Food Engineering 274 (2020) 109842
of ESR was d (0.5) ¼ 498.766 μm and ESRA was d (0.5) ¼ 415.446 μm (Fig. 2A). Disintegrated particles in the α-amylase addition group (ESRA) were described in Fig. 2B with d (0.5) ¼ 29.147 μm after 5 h water immersion, and the ESR possessed the slightly inflated particles with d (0.5) ¼ 527.051 μm. The absence of enzyme was responsible for the low gelatinisation degree of ESR. The enlarged particle size was probably caused by the water absorption of starch crystal and the gelatinised starch around starch crystal (Fig. 2B) (Evans and Lips, 2010). The particle size was continued to be diminished with d (0.5) ¼ 321.195 μm in ESR and d (0.5) ¼ 25.939 μm in ESRA after 3 days water immersion, nevertheless, d (0.5) ¼ 270.639 μm of ESR and d (0.5) ¼ 24.759 μm of ESRA were measured at 5 days of water immersion. A slight change of ESRA particle size (Fig. 2C and D) between 3 and 5 days of water immersion demonstrated that the releasing amount of resver atrol barely increased, this result was coincided with the releasing amount in Fig. 1A. The size of starch crystal (d (0.5) ¼ 15.835 μm) was different from the particle size of ESRA, this difference was possibly induced by the water absorption and swelling of starch crystal (Tester and Morrison, 1994; Witono et al., 2014). 3.3. Crystal morphology (polarization microscope) Approximate size of the ESR (arrow in Fig. 3A1) and the ESRA (arrow in Fig. 3C1 was observed by using a polarization microscope, by contrast, the ESR still maintained an intact particle shape after 5 days of immersion (arrow in Fig. 3B1). The morphology and number of starch crystal represented the degree of starch gelatinisation and denaturation (Cai et al., 2014a; Jenkins and Donald, 1997). Gelatinisation and entanglement of starch packaged the crystal, which formed the intact structure that blocked the dissolution and breakdown of microparticles and postponed the release of resveratrol. The extrusion destroyed the crystal structure by the gelatinisation, which could be revealed by the disappearance of crosspolarization (Doublier et al., 1987; Liu et al., 2010). The addition of the α-amylase intensified the denaturation of starch chain, the decomposition of starch granule and the dissolution of gelatinised microparticle. Moreover, the enzyme promoted the breakdown of ESRA inducing the scatter of starch crystal, the separation of crosspolarization and the disappearance of a portion of crosspolarization (arrows in Fig. 3D1 and D2). The cross polarization also disappeared in some gelatinised starch particles (ar rowheads in Fig. 3D1 and D2). An amount of starch crystal with cross-polarization was annotated in ESR (arrows in Fig. 3A2, B2 and C2), the microparticles were intact and could hardly release the core material (resveratrol).
Fig. 3. Crystal morphology of cross-polarization. A, ESR microparticles (A1 was amplified 40 times, A2 was amplified 100 times). B, ESR microparticles within 5 days of water immersion (B1 was amplified 40 times, B2 was amplified 100 times). C, ESRA microparticles (C1 was amplified 40 times, C2 was amplified 100 times). D, ESRA microparticles within 5 days of water immersion (D1 was amplified 100 times, D2 was amplified 200 times).
effect on the release rate of resveratrol following days. Approximately 40% resveratrol was released at the beginning of the water immersion both in the encapsulated samples with and without α-amylase. The addition of α-amylase improved the release of resveratrol up to 86.7% total release ratio within five days water immersion. Despite of the release amount of ESR was less than ESRA, the ESR was still a desirable microparticle on account of its 58.2% resveratrol release rate within 5 days. The denatured starch packaging and entangling the resveratrol in extrusion induced the remarkable improvement of resveratrol photo stability (Fig. 1B), and the interaction between denatured starch and resveratrol had no effect on the thermostability of samples (Figure C). Light absorbance of starch improved the photostability of resveratrol remarkably. Gelatinised starch generated by the hydrolysis of α-amylase in ESRA that exhibited the stronger photoprotection function than ESR demonstrating that the packaging function of gelatinised starch played the dominant role in the improvement of resveratrol photostability (Fig. 1C) (Feng et al., 2011; Lee and Kim, 2010; Wang et al., 2016).
3.4. SEM Extrusion induced the denaturation and gelatinisation of the mixture facilitating the formation of tight structure of extruded starch (ESR and ESRA) (Al-Rabadi et al., 2011; Chen and Rizvi, 2006; Chuang and Yeh, 2004). Nevertheless, α-amylase in ESRA enhanced the starch gelatini sation that eliminated the generated holes (arrows in Fig. 4C1, C2 and C3) in ESR by the incomplete gelatinisation (arrowheads in Fig. 4A1, A2 and A3). The appearances such as the holes in ESR and the tight struc ture of ESRA revealed that the α-amylase contributed to the gelatinisa tion and package ability of starch. The loose structure and small size of microparticles were identified in ESRA with water immersion, which suggested that the embedded α-amylase enhanced the gelatinisation in extrusion and hydrolysation function of α-amylase was responsible for the loose morphology of microparticle (Fig. 4D1, D2 and D3). The gelatinised starch produced by the extrusion, enhanced by α-amylase and settled among the starch crystal was easily hydrolysed by enzyme resulting in the breakdown of microparticle and the acceleration of resveratrol release (Waterschoot et al., 2015). The holes were generated in the ESR with water immersion, and bulky granules still existed in the enzyme-absent group (arrow heads in Fig. 4B1, B2 and B3).
3.2. Particle size variation of the microparticle in release process Microparticle was dispersed in water, and the change of particle size was measured by the laser particle analyser at the 0 h, the fifth hour, the third day and the fifth day of water immersion (Fig. 2). The result showed that the particle of ESR and ESRA to water im mersion was large and intact at the beginning showing the particle size 4
S. Chen et al.
Journal of Food Engineering 274 (2020) 109842
Fig. 4. Morphology of microparticles observed using SEM. A, ESR microparticles (Bars in A1, A2 and A3 were 200, 100 and 20 μm, respectively). B, ESR micro particles within 5 days of water immersion (Bars in B1, B2 and B3 were 200, 100 and 20 μm, respectively). C, ESRA microparticles (Bars in C1, C2 and C3 were 200, 100 and 20 μm, respectively). D, ESRA microparticles within 5 days of water immersion (Bars in D1, D2 and D3 were 200, 100 and 20 μm, respectively).
other apparent peak was found in the lines of ESR-1 and ESRA-1, so the characteristic peaks of resveratrol monomer were eliminated by the convolution of starch chain (Fig. 5ESR-1 and ESRA-1). Multiple characteristic peaks of starch crystal in the ESRA-2 at 2θ of 13.04� , 15.04� , 17.3� , 18.16� , 19.92� and 22.92� indicated that starch crystal was the main content in the ESRA within 5 days of water im mersion (Fig. 5 ESRA-2). This result also suggested that the micropar ticle barely contained resveratrol after 5 days release, and the package of starch crystal by the starch amorphous state probably decreased the crystal characteristics of starch. Moreover, water absorption that
Fig. 5. XRD detection. ESR-1, ESRA-1 were the microparticles without water immersion. ESR-2, ESRA-2 were microparticles with 5 days of water immersion.
3.5. XRD detection Further insights into the impact of enzyme addition on the structure and gelatinisation of the extruded mixture were investigated using XRD analysis. A previous study of extruded corn starch stated two distinct diffraction peaks at approximately 2θ of 13� and 20� (Artz et al., 2010; Basto et al., 2016; Ye et al., 2018). The coincident result was also observed in the ESR and ESRA with peaks at 2θ of 13.04� and 19.92� . No
Fig. 6. FT-IR. ESR-1, ESRA-1 were the microparticles without water immer sion. ESR-2, ESRA-2 were microparticles with 5 days of water immersion. 5
S. Chen et al.
Journal of Food Engineering 274 (2020) 109842
occurred in ESR intensified the disappearance of crystal peak induced no apparent peak in line of ESR-2 (Fig. 5ESR-2). Most of the embedded resveratrol in gelatinised starch hardly escaped from the unbroken ESR particle within 5 days of water immersion. The α-amylase addition of ESRA possessed the opposite result caused by the hydrolysation function of this enzyme.
the packaging function of starch significantly improved the photo stability of resveratrol. ESRA was easily hydrolysed and had a consid erable release ratio, whereas ESR obtained the opposite characteristics. That is the α-amylase changed particle size, altered the mechanism of resveratrol release and improved resveratrol release ratio. The ESR group had an acceptable release ratio in the chasing period, and these two kinds of solid microparticle had clear advantages in transportation, preservation and utilization.
3.6. Fourier transforms infrared spectroscopy (FT-IR) The characteristic spectral region of starch at 750-1000 cm 1 was the same between the two groups with water immersion (Fig. 6ESR-2 and ESRA-2). A similar line trend was also found in groups without water immersion (Fig. 6ESR-1 and ESRA-1), thus the water immersion that induced the breakdown of microparticles was a cause for the difference between groups with and without water immersion. Curve variation at 1025.994–1155.152 cm 1 attributed to C–O bond stretching of C–O–C in ESRA with water immersion was apparently different from in the variation of other groups (Fig. 6ESRA-2). The dissolution of hydrolysed and gelatinised starch in water caused the sharp peaks (Yang et al., 2007). Absorption bands at 1417.423 and –C 1644.982 cm 1 of microparticles were attributed to the conjugated C– stretching vibration that ascribed to the aromatic ring skeletal of resveratrol (Shi et al., 2008), and the weakened peaks of conjugated – C stretching vibration accounted for the low content and high release C– amount of resveratrol in ESRA group (Fig. 6ESRA-2). The vibration of conjugate double bonds of benzene ring at 2094.315 cm 1disappeared in the line of ESRA-2 suggesting that the α-amylase facilitated the release of resveratrol and the encapsulation function of starch on the resveratrol was weakened. The absorption band at 2927.412 cm 1could be assigned to the vi bration of the symmetrical –CH2 stretching vibration, asymmetrical –CH2 stretching vibration and asymmetrical –CH3 vibration of starch. It was slightly broadened in ESRA-1 by the gelatinisation and entangle ment of starch that was reinforced by the addition of enzyme (rectangle in Fig. 6ESRA-1). These entanglement and package functions protected the resveratrol from the light. The extrusion resulted in the stretch of helical structure, the decomposition of starch and the generation of low molecular weight substance, which complicated the microparticles and flattened the absorption bands of –OH vibration at around 3367.103 cm 1 (Fig. 6 ESR-1 and ESRA-1). This changed absorption brand of –OH vibration also suggested that the hydrogen bond was attributed to the intramolecular connection and the connection between starch and resveratrol indicating that the resveratrol was packaged in starch by the hydrogen bonds (Li et al., 2016). More flat peaks observed in groups without water immersion than other two groups specified that the more hydrogen bonds formed during the extrusion. Water dissolution removed the denatured starch and hydrolysate, and then sharp peaks appeared in ESR-2 and ESRA-2. The α-amylase addition in ESRA with water immersion accelerated the resveratrol release and the dissolution of starch crystal which led to the narrow peak (Fig. 6ESRA-2).
Acknowledgement This work was supported by the Shandong Provincial Natural Sci ence Foundation, China (ZR2017MC073). Appendix A. Supplementary data Supplementary data to this article can be found online at https://doi. org/10.1016/j.jfoodeng.2019.109842. Credit author statement Shanfeng Chen: Methodology, Conceptualization, WritingReviewEditing. Jinhuan Zong: Writing-Original draft manuscript, Investigation, Data curation. Lijun Jiang: Software, Validation. Chengye Ma: Visualization, Software, Formal analysis. Hongjun Li: Project administration, Resources. Dongliang Zhang: Supervision, Project administration, Resources. References Ahmad, M., Qureshi, S., Maqsood, S., Gani, A., Masoodi, F.A., 2016. Micro-encapsulation of folic acid using horse chestnut starch and β-cyclodextrin: microcapsule characterization, release behavior & antioxidant potential during GI tract conditions. Food Hydrocolloids 66. Al-Rabadi, G.J., Torley, P.J., Williams, B.A., Bryden, W.L., Gidley, M.J., 2011. Particle size of milled barley and sorghum and physico-chemical properties of grain following extrusion. J. Food Eng. 103 (4), 464–472. Anwar, S.H., Kunz, B., 2011. The influence of drying methods on the stabilization of fish oil microcapsules: comparison of spray granulation, spray drying, and freeze drying. J. Food Eng. 105 (2), 367–378. Artz, W.E., Warren, C., Villota, R., 2010. Twin-screw extrusion modification of a corn fiber and corn starch extruded blend. J. Food Sci. 55 (3), 746–754. Basto, G.J., Carvalho, C.W.P., Soares, A.G., Costa, H.T.G.B., Ch� avez, D.W.H., Godoy, R.L. d.O., Pacheco, S., 2016. Physicochemical properties and carotenoid content of extruded and non-extruded corn and peach palm (Bactris gasipaes, Kunth). LWT Food Sci. Technol. (Lebensmittel-Wissenschaft -Technol.) 69, 312–318. Cai, C., Cai, J., Man, J., Yang, Y., Wang, Z., Wei, C., 2014. Allomorph distribution and granule structure of lotus rhizome C-type starch during gelatinization. Food Chem. 142 (3), 408–415. Cai, J., Cai, C., Man, J., Yang, Y., Zhang, F., Wei, C., 2014. Crystalline and structural properties of acid-modified lotus rhizome C-type starch. Carbohydr. Polym. 102 (1), 799–807. Chang, C., Varankovich, N., Nickerson, M.T., 2016. Microencapsulation of canola oil by lentil protein isolate-based wall materials. Food Chem. 212, 264–273. Chen, K.H., Rizvi, S.S.H., 2006. Rheology and expansion of starch-water-CO2 mixtures with controlled gelatinization by supercritical fluid extrusion. Int. J. Food Prop. 9 (4), 863–876. Chuang, C.C., Yeh, A.I., 2004. Effect of screw profile on residence time distribution and starch gelatinization of rice flour during single screw extrusion cooking. J. Food Eng. 63 (1), 21–31. Dimantov, A., Greenberg, M., Kesselman, E., Shimoni, E., 2004. Study of high amylose corn starch as food grade enteric coating in a microcapsule model system. Innov. Food Sci. Emerg. Technol. 5 (1), 93–100. Doublier, J.L., Paton, D., Llamas, G., 1987. A rehological investigation of oat starch pastes. Cereal Chem. 64 (1), 21–26. Emin, M.A., Schuchmann, H.P., 2013. Analysis of the dispersive mixing efficiency in a twin-screw extrusion processing of starch based matrix. J. Food Eng. 115 (1), 132–143. Evans, I.D., Lips, A., 2010. Viscoelasticity OF gelatinized starch dispersions. J. Texture Stud. 23 (1), 69–86. Feng, Q.J., Xiao, Z.G., Zheng, G.Z., Wei, X., Hong-Jian, Y.E., 2011. Study on the gelatinization of corn starch by enzyme-added extrusion at low temperature. Science & Technology of Food Industry 32 (8), 287-286. Huang, Y., Zhou, Y., Huang, J., Zhu, C., Chen, M., Pan, X., Wu, C., 2015. Metoprolol tartrate sustained-release binary matrix microspheres for oral administration produced by novel ultra-fine particle processing system. Powder Technol. 285, 44–50.
4. Conclusion Starch was converted into a homogenous molten state in extrusion process, and the ingredients (resveratrol and α-amylase) were also included in this process. This conversion may encompass various changes, such as the package of resveratrol and the molecular tangle between each other. The preparation of extruded starch microparticle containing resveratrol and α-amylase was studied to simplify the resveratrol encapsulation and give more lightstability to the active ingredient (resveratrol). The release rate of resveratrol within the first 24 h was higher than the following 4 days in ESRA, and the stable release rate of resveratrol was observed in ESR. The addition of α-amylase improved the release ratio of ESRA with 86.7% resveratrol release ratio within 5 chasing days, however, the microparticle without enzyme was also feasible with its total release ratio of 58.2%. Light absorbance and 6
S. Chen et al.
Journal of Food Engineering 274 (2020) 109842
Hui, C., Xu, K., Xue, D., Song, C., Zhang, W., Wang, P., 2007. Synthesis of dodecenyl succinic anhydride (DDSA) corn starch. Food Res. Int. 40 (2), 232–238. Jenkins, P.J., Donald, A.M., 1997. Breakdown of crystal structure in potato starch during gelatinization. J. Appl. Polym. Sci. 66 (2), 225–232. Lee, Y.C., Kim, K.T., 2010. Gelatinization and liquefaction of starch with a heat stable α-amylase. J. Food Sci. 55 (5), 1365–1366. Li, W., Li, C., Gu, Z., Qiu, Y., Cheng, L., Hong, Y., Li, Z., 2016. Retrogradation behavior of corn starch treated with 1,4-α-glucan branching enzyme. Food Chem. 203, 308–313. Li, Y.O., Diosady, L.L., Wesley, A.S., 2010. Iodine stability in iodized salt dual fortified with microencapsulated ferrous fumarate made by an extrusion-based encapsulation process. J. Food Eng. 99 (2), 232–238. Liu, P.L., Zhang, B.S., Shen, Q., Hu, X.S., Li, W.H., 2010. Preparation and structure analysis of noncrystalline granular starch. Int. J. Food Eng. 6 (4), 61–64. Livney, Y.D., Garti, N., 2008. Complexes and conjugates of biopolymers for delivery of bioactive ingredients via food. Delivery & Controlled Release of Bioactives in Foods & Nutraceuticals 234–250. Ming, L.I., Peng, L., Wei, Z., Long, Y.U., Xie, F., Huayin, P.U., Liu, H., Ling, C., 2011. Extrusion processing and characterization of edible starch films with different amylose contents. J. Food Eng. 106 (1), 95–101. Ravanfar, R., Comunian, T.A., Abbaspourrad, A., 2018. Thermoresponsive, waterdispersible microcapsules with a lipid-polysaccharide shell to protect heat-sensitive colorants. Food Hydrocolloids 81, 419–428. Rossier-Miranda, F.J., Schro€ en, K., Boom, R., 2012. Microcapsule production by an hybrid colloidosome-layer-by-layer technique. Food Hydrocolloids 27 (1), 119–125.
Shi, G., Rao, L., Yu, H., Xiang, H., Yang, H., Ji, R., 2008. Stabilization and encapsulation of photosensitive resveratrol within yeast cell. Int. J. Pharm. 349 (1), 83–93. Tester, R.F., Morrison, W.R., 1994. Properties of damaged starch granules. V. Composition and swelling of fractions of wheat starch in water at various temperatures. J. Cereal Sci. 20 (2), 175–181. Trimnell, D., Carr, M.E., Doane, W.M., 2010. Encapsulation of EPTC in starch by twin~ screw extrusion. Starch - StA¤rke 43 (4), 146–151. Wan, Z.L., Guo, J., Yang, X.Q., 2015. Plant protein-based delivery systems for bioactive ingredients in foods. Food & Function 6 (9), 2876–2889. Wang, P., Fu, Y., Wang, L., Saleh, A.S.M., Cao, H., Xiao, Z., 2016. Effect of enrichment with stabilized rice bran and extrusion process on gelatinization and retrogradation properties of rice starch. Starch - St€ arke 69. Waterschoot, J., Gomand, S.V., Delcour, J.A., Goderis, B., 2015. Direct evidence for the non-additive gelatinization in binary starch blends: a case study on potato starch mixed with rice or maize starches. Food Hydrocolloids 50, 137–144. Witono, J.R., Noordergraaf, I.W., Heeres, H.J., Janssen, L.P., 2014. Water absorption, retention and the swelling characteristics of cassava starch grafted with polyacrylic acid. Carbohydr. Polym. 103 (103), 325–332. Yang, J.-H., Yu, J.-G., Feng, Y., Ma, X.-F., 2007. Study on the properties of ethylenebisformamide plasticized corn starch (EPTPS) with various original water contents of corn starch. Carbohydr. Polym. 69 (2), 256–261. Ye, J., Liu, C., Luo, S., Hu, X., McClements, D.J., 2018. Modification of the digestibility of extruded rice starch by enzyme treatment (β-amylolysis): an in vitro study. Food Res. Int. 111, 590–596.
7