Properties of fish myofibrillar protein film incorporated with catechin-Kradon extract

Food Packaging and Shelf Life 13 (2017) 56–65

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Properties of fish myofibrillar protein film incorporated with catechinKradon extract ⁎

Pimonpan Kaewprachua, Natthakan Rungraenga, , Kazufumi Osakob, Saroat Rawdkuena, a b

MARK

⁎

Food Technology Program, School of Agro-Industry, Mae Fah Luang University, Muang, Chiang Rai, 57100, Thailand Department of Food Science and Technology, Tokyo University of Marine Science and Technology, Tokyo 108-8477, Japan

A R T I C L E I N F O

A B S T R A C T

Keywords: Active film Antimicrobial Catechin Fish myofibrillar protein Careya sphaerica Roxb.

Properties of fish myofibrillar protein (FMP) films incorporated with catechin-Kradon extract (Careya sphaerica Roxb.) (CK) were investigated. The incorporation less than 9 mg/ml of CK improved tensile strength, but this slightly declined when increasing the concentration (P < 0.05). Significant decreases for elongation at break (51.38–132.76%), transparency (3.35–3.88), and water vapor permeability (1.56 − 2.08 × 10−9 g m−1 s−1 Pa−1) were observed when the concentration of CK increased (P < 0.05). Nevertheless, film thickness (11.45–19.48 μm), solubility (18.82–38.30%), and antioxidant activity increased markedly as the level of CK increased (P < 0.05). FMP films with CK added possessed low L* value but high a* and b* values, and they exhibited excellent UV light barrier properties. However, the only antimicrobial activity that was observed was against Vibrio parahaemolyticus. According to these findings, FMP films incorporated with 9 mg/ml of CK have potential for being used as active packaging.

1. Introduction Quality and appearance of food is very important for consumers. Food quality changes easily and quickly due to microbial and chemical degradation and this can happen during handling, transportation, and storage (Saghir, Wagner, & Elmadfa, 2005). The oxidation reaction of lipid is the main cause of spoilage. Therefore, preventing microbiological and chemical deteriorations are critical challenges for the food industry. Several innovative packaging techniques have been produced with the goal of both maintaining the quality and prolonging the shelf life of foods. Packaging is used for protecting the food from the outside environmental and preventing contamination. In recent years, so-called active packaging has emerged as an alternative method for protecting food. Antimicrobial and/or antioxidant packaging are the main systems that effectively kill or suppress microbial growth and delay the oxidation of pigments and lipids present in food (Kaewprachu & Rawdkuen, 2016). This technology actually incorporates active agents into the packaging materials, which provides antimicrobial and/or antioxidant properties that do not exist in traditional packaging. Recently, many studies have focused on active agents from natural sources. Non-natural synthetic chemical agents, such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), and tertiary butylhydroquinone (TBHQ) are suspected of carcinogenic potential and

⁎

toxicity, which is a clear concern for human health. Many studies found that TBHQ promoted carcinogenesis in animal model and cell culture. This is because its genotoxic and cytotoxic properties (Hirose, Yada, Hakoi, Takahashi, & Ito, 1993; Negar, Susan, & Ayman, 2007). So, its use is restricted as it is considered as a food additive. There are many natural possibilities such as plants or herb extracts. Many have been effectively incorporated into biodegradable films. Some include catechin-lysozyme (Rawdkuen, Suthiluk, Kamhangwong, & Benjakul, 2012), longan seed extract (Sai-Ut, Benjakul, & Rawdkuen, 2015), pomegranate peel extract (Emam-Djomeh, Moghaddam, & Ardakani, 2015), honeysuckle flower extract (Wang, Wang, Tong, & Zhou, 2017), coconut husk extract (Nagarajan, Benjakul, Prodpran, & Songtipya 2015), and basil leaf essential oil (Arfat, Benjakul, Prodpran, Sumpavapol, & Songtipya 2014). Kradon (Careya sphaerica Roxb.) is very common in the North and Northeastern part of Thailand. Lupeol, taraxerol, β-sitosterol, and quercetin are the main phenolic compounds found in Kradon leaves (Maisuthisakul, 2012). Kradon extract has been noted for high antioxidant activity (Maisuthisakul & Pongsawatmanit, 2005; Sriket, 2014) and antimicrobial activity (Daduang, Vichitphan, Daduang, Hongsprabhas, & Boonsiri, 2011; Panomket, Wanram, & Srivoramas, 2011). The preparation and utilization of Kradon extract containing phenolic compounds could provide a high value-added potential for those leaves. Green tea extract has been utilized widely as an active

Corresponding authors. E-mail addresses: [email protected] (N. Rungraeng), [email protected] (S. Rawdkuen).

http://dx.doi.org/10.1016/j.fpsl.2017.07.003 Received 4 April 2017; Received in revised form 24 July 2017; Accepted 27 July 2017 2214-2894/ © 2017 Elsevier Ltd. All rights reserved.

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agent for the preparation of active films (Rawdkuen et al., 2012; Siripatrawan & Harte, 2010). Catechins are the main phenolic compound that are mostly found in tea, and they have shown to inhibit a wide range of microorganisms as well as to have good antioxidant activity (Almajano, Carbó, Jiménez, & Gordon, 2008; Oh, Jo, Cho, Kim, & Han, 2013). Traditional packaging is normally made up from petroleum-based polymeric materials. They have been continuously used because of their inexpensive, lightweight, durability, and functional advantages (such as thermosealability, microwavability, and optical properties) (Marsh& Bugusu, 2007). On the other hand, these materials are not easy to degrade and generate much heat and exhaust gases when burned, thus posing a negative impact on environmental. In addition, a variety of byproduct from agricultural or marine sources has been utilized frequently to manufacture biodegradable film. Protein is the most commonly used material for producing biodegradable based films due to film-forming ability, high nutritional value, and abundance. The myofibrillar proteins from fish muscle particularly have been used effectively as a starting material (Nie, Gong, Wang, & Meng, 2015). Biodegradable film developed from fish myofibrillar protein (FMP) showed to be slightly transparent and had colorless characteristics with an excellent UV light barrier when compared to a commercial wrap film (polyvinyl chloride) (Kaewprachu, Osako, Benjakul, & Rawdkuen, 2016a). Rostamzad, Paighambari, Shabanpour, Ojagh, and Mousavi (2016) suggested that FMP film had potential to be used for producing active packaging. Phenolic compounds have been reported to interact with proteins via hydrophobic interactions, hydrogen bonding, ionic bonds, and covalent bonds (Hoque, Benjakul, & Prodpran, 2011; Mekoue Nguela, PoncetLegrand, Sieczkowski, & Vernhet, 2016; Wu et al., 2013). The aromatics rings of polyphenol would combine with hydrophobic sites of proteins, such as pyrrolidine rings of prolyl residues, via hydrophobic interactions, while hydrogen bonding occurs between H-acceptor sites of the proteins and the hydroxyl groups of the polyphenol (Bourvellec & Renard, 2012; Ozdal, Capanoglu, & Altay, 2013). Moreover, under alkaline conditions with the presence of oxygen, oxidized polyphenols (quinone) could react with lysine, methionine, cysteine, and tryptophan residues in protein molecules (Liu, Ma, McClements, & Gao, 2017; Nie, Zhao, Wang, & Meng, 2017; Strauss & Gibson, 2004). This reaction can be induced the formation of covalent CeN and CeS bonds via cross-linking, which are more thermally stable and rigid than other interactions (Prodpran, Benjakul, & Phatcharat, 2012). Adding catechin and Kradon extract to act as the active agents to inhibit microbial growth and retard the oxidation of lipids may affect the overall functional properties of the FMP film. Incorporating active agents at appropriate amounts can provide antimicrobial and antioxidant properties with only a small change to the functional properties of film. Therefore, the objective of this investigation was to study the properties of FMP films contained the combination of catechin-Kradon extract (CK) at different concentrations (0–12 mg/ml). Their properties were compared with a low density polyethylene (LDPE) wrap film.

from a patient and provided by Tokyo Metropolitan Institute of Public Health, Tokyo, Japan. 2.2. Preparation of Kradon extract Kradon leaves (Careya sphaerica Roxb.) were obtained from a local market in Chiang Rai, Thailand. They were subjected to liquid nitrogen and then stored in a plastic bag at −20 °C for further extraction. To prepare the Kradon extract, 1 g of frozen Kradon leaves containing 69.44% moisture content were combined with distilled water using a sample to water ratio of 1:32 (w/v). After stirring for 30 s, the mixture was then subjected to extraction using a household microwave (LG Thailand Co. Ltd., Bangkok, Thailand) at 500 W for 62 s (Dahmoune, Nayak, Moussi, Remini, & Madani, 2015). The extract was filtered and the supernatant was then collected. Finally, the supernatant was subjected to freeze drying. The extract was subsequently referred to as “Kradon extract”. 2.3. Preparation of fish myofibrillar protein (FMP) Fresh tilapia (Orcochromis niloticus) (400–500 g/fish) was purchased from a local market in Chiang Rai, Thailand. It was washed, fileted, and minced uniformly. FMP was prepared as described in Kaewprachu et al. (2016a). The minced fish was added with five volumes of 50 mM NaCl. After homogenization (11,000 rpm for 2 min), the mixture was then centrifuged at 10,000 × g for 10 min at 4 °C and filtered through cheese cloth. The washed mince was collected and re-washed twice. After that, the FMP was dried in a freeze dyer, packed under vacuum conditions, and stored in freezer (−20 °C) for further analysis. 2.4. Preparation of fish myofibrillar protein film incorporated with catechin-Kradon extract Firstly, a film-forming solution (FFS) was prepared as described in Kaewprachu et al. (2016a). FMP 1% (w/v) was added with the distilled water, followed by homogenization at 11,000 rpm for 1 min, and the pH was adjusted to 11 using 1 N NaOH. It was centrifuged at 3000 × g at room temperature for 10 min. The supernatant was then collected. Glycerol at 25% (w/w, based on protein content) was used as a plasticizer and stirred at room temperature for 30 min. After stirring, MTGase (2% w/w, based on protein content), for use as a cross-linker, was added into the mixture and stirred continuously for 30 min to obtain the FFS. Prior to incorporating active agents, the combination of catechinKradon extract solution (CK) was prepared by dissolving catechin in 60% ethanol while the Kradon extract was dissolved in distilled water. The catechin solution was added to the Kradon extract solution in a ratio of 1:1. It was then incorporated into FFS in order to obtain final concentrations of 0, 3, 6, 9, and 12 mg/ml and was continuously stirred at room temperature for 1 h. The bubbles contained FFS were eliminated by a hybrid mixer (HM-500; Keyence Co., Tokyo, Japan) for 10 min. Finally, the de-aerated FFS (4 ± 0.01 g) was casted onto a rimmed silicone resin plate (50 × 50 mm) and dried for 24 h at 25 ± 0.5 °C and 50 ± 5% relative humidity (RH). The obtained dry films were manually peeled and conditioned at 50 ± 5% RH at 25 °C for 48 h, prior to be tested.

2. Materials and methods 2.1. Chemicals and microbials Catechin hydrate (C1251), 2,2-diphenyl-1-picryl hydrazyl (DPPH), and 2,4,6-tripyridyl-s-triazine (TPTZ) were purchased from SigmaAldrich (St. Louis, MO, USA). 6-hydroxy-2,5,7,8-tetramethylchroman2-carboxylic acid (Trolox) was purchased from Calibiochem (Darmstadt, Germany). Microbial transglutaminase (MTGase) (Activa TG-K: 100 activity units per gram) was supplied by Ajinomoto Co. Inc. (Tokyo, Japan). All other reagents used were of analytical grade. Salmonella Typhimurium ATCC 13311, Staphylococcus aureus ATCC 12600 and Listeria monocytogenes CIP 107776 were obtained from Laboratory of Food Microbiology, Tokyo University of Marine Science and Technology, Tokyo, Japan. Vibrio parahaemolyticus was isolated

2.5. Film properties determinations 2.5.1. Film thickness The film thickness was measured by using a dial-type thickness gauge (Series 7300; Mitsutoyo Co., Kanagawa, Japan). 6 random locations around each of the 10 film samples were used for determining thickness. 57

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were dried at 105 °C for 24 h to obtain the dry un-dissolved debris film matter. The film solubility was calculated by the weight of the dry matter of un-dissolved debris subtracted from the initial weight of the dry matter and expressed as the percentage of total weight. Experiment was conducted in triplicate.

2.5.2. Mechanical properties A Tensipresser (TTP-50BX II, Takemoto Electric Inc., Tokyo, Japan) was used for testing tensile strength and elongation at break of a film sample according to the ASTM D 882-97 (American Society for Testing & Materials, 1999). The film sample was cut into 2 cm wide and 5 cm long and then placed between 30 mm of initial grip separation with a cross-head speed of 1 mm/s. Measurement was examined until the films were disrupted.

2.5.8. Water vapor permeability (WVP) The films’ WVP was performed using a modified ASTM standard method (American Society for Testing & Materials, 1989) as described by in Kaewprachu et al. (2016b). A film sample was cut into a circle of 70 mm in diameter. The condition of testing was performed at 30 °C at 50 ± 5% RH. The weight of glass cup was noted at 1 h interval over a period of 8 h. Experiments were conducted in triplicate and expressed as g m−1 s−1 Pa−1.

2.5.3. Film appearance, colors, light transmittance, and transparency Appearance of all films was evaluated by using a Fujifilm Finepix S4900 digital camera (Fujifilm Thailand Co. Ltd., Bangkok, Thailand). The color of the film was determined by using a Color Reader (CR13, Konica Minolta Inc., Japan). Color attributes were expressed as L* (lightness), a* (redness/greenness), and b* (yellowness/blueness) value. A film sample was cut to a rectangular shape (40 × 40 mm) and analyzed the light transmission of the films at the wavelength between 200 and 800 nm using a UV spectrophotometer (UV-1800, Shimadzu Co., Kyoto, Japan) (Kaewprachu, Osako, Benjakul, Tongdeesoontorn, & Rawdkuen, 2016b). A film sample was cut to a rectangular shape (40 × 40 mm) and measured the light transmission at 600 nm by using spectrophotometer. The transparency value of the film was calculated by the following Eq. (1) (Han & Floros, 1997): Transparency = −log T600/x

2.5.9. Antioxidant properties of the films Film extract solution was prepared as described in Tongnuanchan, Benjakul, and Prodpran (2012). The film (25 mg) was added with 3 ml of distilled water. After stirring for 3 h, the mixtures were centrifuged at 3000 × g for 10 min and the supernatant obtained was then determined for DPPH radical scavenging activity and ferric reducing antioxidant power. 2.5.9.1. DPPH radical scavenging activity. The film extract solution (1.5 ml) was added to 0.15 mM 2,2-diphenyl-1-picryl hydrazyl (DPPH) in 95% ethanol (1.5 ml), followed by mixing and then kept in the dark for 30 min at room temperature (Tongnuanchan et al., 2012). The DPPH assay solution was recorded the absorbance at 517 nm using a spectrophotometer. The films’ antioxidant activity was expressed as the percentage of DPPH radical scavenging activity.

(1)

where T600 is transmittance (%) at 600 nm and x is the film thickness (mm). 2.5.4. Differential scanning calorimetry (DSC) A differential scanning calorimeter (DSC-50, Shimadzu Co., Kyoto, Japan) was used examined to the films’ thermal properties (Cerqueira, Costa, Fuciños, Pastrana, & Vicente, 2014). Each film sample (10–12 mg) was weighed, placed into a DSC pan, and then sealed. Measurements were tested at temperature between 25 and 180 °C with a heating rate of 10 °C/min.

2.5.9.2. Ferric reducing antioxidant power. Acetate buffer (300 mM, pH 3.6), 10 mM TPTZ (2,4,6-tripyridyl-s-triazine) solution in 40 mM HCl, and 20 mM FeCl3·6H2O solution were mixed at the ratio of 10:1:1 to obtain a fresh working FRAP solution. The film extract solution (150 μl) was added to the FRAP solution (2850 μl) and then incubated at 37 °C for 30 min (Tongnuanchan et al., 2012). The FRAP assay solution was examined the absorbance at 593 nm using a spectrophotometer. Ferrous sulfate ranging from 0 to 1000 μM was used for preparing the standard curve. The FRAP activity was expressed as mmol ferrous sulfate equivalent/g dried film.

2.5.5. Fourier transform infrared spectroscopy A FT-IR spectrometer (Nicolet 6700, Thermo Scientific Inc, USA) was used for analyzing FT-TR spectra of a film sample. The scan was performed at room temperature in a spectral range varying from 4000 to 650 cm−1 with a resolution 4 cm−1 and 64 scans (Kaewprachu et al., 2016b). All of the data treatments were evaluated with Omnic 6.0 software (Thermo-Nicolet, Madison, Wis., USA).

2.5.10. Antimicrobial activity Antimicrobial activity of the film samples was performed using the agar diffusion method described in Rawdkuen, Sai-Ut, and Benjakul (2010). S. Typhimurium, V. parahaemolyticus, S. aureus and L. monocytogenes were cultured into Muller-Hinton (MH) broth and incubated in a shaker incubator at 37 °C for 18–24 h. A loopful of the microorganisms working stocks were streaked onto MH agar plate and further incubated at 37 °C for 18–24 h to obtain single colony. The optical density of the cultures was adjusted to 0.5 McFarland turbidity standards with 0.85% normal saline and then inoculated on MH agar plates using a sterile swab. A film sample was cut to a circular shape (6 mm in diameter) and then placed on a Muller-Hinton (MH) agar surface, which has been inoculated with microorganisms. Ampicillin (10 μg/disc) and tetracycline (30 μg/disc) were used in this study as antibiotics for the strains tested. After incubation (37 °C for 18–24 h), the plate was investigated for inhibition zones on the film discs. Experiments were carried out in triplicate.

2.5.6. Moisture content of films Moisture content was determined following AOAC (2011) standard methods. The sampled film was cut into 2 × 2 cm, dried in an oven at 105 °C for 24 h, and then weighed. Experiment was repeated three times. The moisture content of the film was calculated by the following Eq. (2): Moisture content (%) = [(Mi − Mf)/Mi] × 100

(2)

where Mi and Mf are initial weight of the film and the weight of film after drying, respectively. 2.5.7. Film solubility The films’ solubility was assessed following the method as described in Sai-Ut et al. (2015). The sampled film was cut to a rectangular shape (20 × 20 mm) and dried at 105 °C for 24 h. After drying, the film was placed in a 50 ml centrifuge tube containing 10 ml of distilled water. The mixture was shaken continuously by using a shaker (seesaw BC700; Bio Craft Co., Japan) for 24 h. The un-dissolved debris was filtered through a filter paper (Advantec, Tokyo, Japan). The obtained pellets

2.6. Statistical analysis Analysis of variance (ANOVA) was used for statistical analysis and the differences between means were carried out by Duncan’s Multiple Range Tests. SPSS package (SPSS 16.0 for window, SPSS Inc., Chicago, IL) was used as a tool for statistical analysis. 58

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Table 1 Thickness, mechanical properties, and thermal properties of FMP films incorporated with a combination of catechin-Kradon extract at different concentrations in comparison with commercial wrap film (LDPE). CK (mg/mL)

Thickness (μm)

TS (MPa)

EAB (%)

Thermal properties ΔH (J/g)

Tm (°C) Control 3 6 9 12 LDPE

c

11.45 ± 1.03 11.45 ± 1.03c 12.45 ± 1.59c 15.55 ± 1.03b 19.48 ± 0.64a 9.70 ± 0.48d

c

b

8.80 ± 0.29 9.91 ± 0.29b 10.31 ± 0.44b 9.64 ± 0.98b 6.53 ± 0.59d 11.40 ± 0.18a

132.76 ± 4.87 90.82 ± 5.09c 79.32 ± 4.65cd 75.19 ± 3.62d 51.38 ± 6.11e 622.67 ± 22.03a

d

99.37 ± 1.41 103.44 ± 0.80c 106.19 ± 2.28c 113.12 ± 1.05b 113.52 ± 0.71b 122.54 ± 0.02a

4.68 ± 0.89e 6.63 ± 0.38e 17.62 ± 1.61d 31.59 ± 1.89c 44.19 ± 2.50b 105.08 ± 4.47a

Value are given as mean ± SD from n = 10 determination of thickness; n = 5 determination of mechanical properties; n = 3 determination of thermal properties. Different superscripts in each column are significantly difference (P < 0.05). CK: catechin-Kradone extract, TS: tensile strength, EAB: elongation at break, LDPE: low density polyethylene.

3. Results and discussion

The EAB value clearly reduced with the addition of CK at a level of 3–12 mg/ml (P < 0.05). This indicates that the CK produced increased rigidity in the film. In general, increased TS is accompanied with decreased EAB value. Furthermore, the protein-polyphenol interactions may also reduce the effect of plasticizers, leading to film strength. Consequently, the film became less flexible. Decreases in EAB have been reported in sodium caseinate films enriched with pomegranate peel extract (Emam-Djomeh et al., 2015) and gelatin film incorporated with green tea extract (Wu et al., 2013). Concentrations of CK have shown to be crucial for strength and flexibility in FMP based film. The LDPE film exhibited higher TS than the developed films by about 1–2 times while the EAB value of the developed films were still less flexible than the control LDPE film by around 78–91%. In addition, the developed films showed poorer mechanical properties, especially in EAB, compared to the control. The desired strength and flexibility of films depends on their application, distribution, and handling. It also depends on the way the packaged foods are stored. For example, film with high flexibility (EAB) is more suitable for wrapping than a plastic bag (Kaewprachu et al., 2016b). According to these findings, it can be concluded that addition of CK significant affected the FMP films’ mechanical properties by increased TS to some extent and decreased EAB.

3.1. Films thickness The thickness values of the developed film were ranged between 11.45 and 19.48 μm while the thickness of LDPE film was 9.70 μm (Table 1). The thickness of the film contained CK increased as the amount increased. No changes in the film thickness were observed in the control FMP film and the FMP film contained 3–6 mg/ml CK (P > 0.05). However, the film enriched with CK at a level of 9–12 mg/ ml showed significant difference in film thickness (P < 0.05). This could be explained by increased viscosity of FFS when adding CK. However, the thickness value in this study was lower than those reported in Nie et al. (2015). They reported that the thickness of green tea polyphenol contained FMP films (0, 30, and 50 g/kg) to be in the range of 60–72 μm. Emam-Djomeh et al. (2015) reported that pomegranate peel extract added sodium casinate films led to higher in the film thickness (54–61 μm). The developed FMP films in this study showed a greater thickness value of around 15 to 50% when compared with the LDPE film. According to Pavlath and Orts (2009), the thickness of film is typically less than 0.3 mm. This suggests that the incorporation of CK, especially at higher concentrations, is more likely responsible for the thickness of the developed films. In general, thickness has effects for other mechanical properties such as optical and barrier properties.

3.3. Films appearance, colors, light transmission, and transparency The appearance of FMP film incorporated with different concentrations of CK as compared with LDPE film is shown in Fig. 1. The film specimens were visually homogenous with a smooth surface. However, the FMP films containing the highest amount of CK exhibited slightly roughness surface. The overall appearance of the FMP film was affected by the incorporation of CK, no matter what concentration was used. The control film was slightly clear and transparent without any color. The film incorporated with CK was slightly yellow to orange, and then became a darker yellow to orange when the concentration of CK was increased. This result coincided with the color and transparency results that will be later reported. These findings show that FMP films incorporated with CK, especially at high levels, may be limited in their applications. The color attributes of FMP film without the addition of CK were closer to the LDPE film (Fig. 1). The incorporation of CK affected the film’s color as indicated by the decreased lightness value (95.01–88.92) with the coincidental increases in redness (−0.68 to 4.84) and yellowness values (4.70–18.10) as the CK concentrations increased from 3 to 12 mg/ml (P < 0.05). The high redness and yellowness value was probably due to the natural pigment present in catechin or Kradon extract. Chlorophylls and carotenoids are plant pigments that can contribute to the color of tea leaves (Loranty, Rembiałkowska, Rosa, & Bennett, 2010). In addition, the lowering in lightness might be helpful to prevent food deterioration. Change in the film’s color were also observed in betel leaves extract added sago starch film (Nouri & Nafchi, 2014), chitosan film containing Eucalyptus globulus

3.2. Mechanical properties The mechanical properties of the developed films were affected by the addition of CK (P < 0.05) (Table 1). Increased tensile strength (TS) with decreased elongation at break (EAB) were pronounced in films incorporated with CK, indicating that CK led to a inflexible film. When CK was incorporated into FFS, the TS of the films increased markedly and reached the highest value of 10.31 MPa when CK was added to a level of 6 mg/ml (P < 0.05). However, the TS decreased gradually when increasing the amount of CK from 9 to 12 mg/ml (P < 0.05). This suggested that CK induced the formation of protein-polyphenol interactions, resulting in the film strengthening. Hoque et al. (2011) reported increased TS in gelatin film incorporated with cinnamon, clove, and star anise extracts via hydrogen bonds and protein-polyphenol hydrophobic interactions. In the present study, decreased pH of the FFS was observed when the concentration of CK increased. It is well known that FMP cannot form film around isoelectric points (pI) due to lowered protein solubility. Therefore, the incorporation of CK, especially at higher amounts, more likely provided the pH of FFS to be close to the pI, leading to protein coagulation rather than dispersion in FFS. Decreased FMP solubility resulted in the formation of a weak structure in the film. As a consequence, the film had low TS value (Table 1). This is consistent with Wang, Hu, Ma, and Wang (2016) who reported that the incorporation of chestnut (Castanea mollissima) bur extracts to soy protein isolate film led to decrease in the TS above a certain limit. 59

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Fig. 1. Film appearance of FMP films incorporated with a combination of catechin-Kradon extract at different concentrations in comparison with commercial wrap film (LDPE). The numbers designate concentrations of catechin-Kradon extract (mg/ml).

concentrations used. Li, Miao, Wu, Chen, and Zhang (2014) reported that changes of the films’ light transmission might be because phenolic compounds contain a lot of benzene rings, which OH groups and C]O groups could be enhanced the n → π* absorption in the range of 200–400 nm. Bitencourt, Fávaro-Trindade, Sobral, and Carvalho (2014) also reported that gelatin film containing curcuma extract exhibited low light transmission in the UV range. They suggested that unsaturated bonds (many double bonds) contained in curcumin structure is responsible for UV light absorption. In this study suggest that film incorporated with CK was more sufficient in blocking the UV and visible light transmission than the control and LDPE films. Therefore, FMP films incorporated with CK can be beneficial for food packaging applications, especially high lipid-based foods, in order to retard lipid oxidation. These conditions serve to protect the food products against physical and chemical changes and prolong shelf life. This is consistent with Wang et al. (2016) who found no light transmission at UV ranges in soy protein isolate film incorporated with chestnut bur extracts. Unripe banana starch/solid lipid microparticles films incorporated with ascorbic acid showed low transmission in UV and visible ranges (Sartori & Menegalli, 2016). In the visible ranges (400–800 nm), light transmission for the control film, for the FMP film added with 3 mg/ml of CK, and for the LDPE film, all showed to be above 80%. However, FMP films enriched with CK, especially at higher concentrations, had light transmission

essential oil (Hafsa et al., 2016), and chestnut bur extracts contained soy protein isolate film (Wang et al., 2016). Based on these findings, the color of the FMP based film was influenced by the source as well as the amount of active compound added into FFS. Although, the color of the developed film could influence consumer perception, there are beneficial effects reported here in terms of the antioxidant and antimicrobial properties that do not exist in the traditional packaging. Light transmission of FMP films enriched with various the levels of CK concentration is presented in Table 2. The UV light transmission ranged from 0 to 87.4%, while the visible light transmission ranged from 73.0 to 86.5%, 0.2 to 81.9%, and 88.6 to 92.2% for the control film, FMP films incorporated with CK, and LDPE film, respectively. It is clearly marked that FMP films incorporated with and without CK have very good barrier properties for preventing light transmission in the stated UV ranges, while the LDPE film has poorer barrier properties. It well known that proteins have excellent UV blocking properties due to their light absorption ability by the carbonyl groups of peptide bonds, the aromatic amino acids, and the disulfide bonds which in the range of 190–210, 250–320, and 250–300 nm, respectively (Kowalczyk & Biendl, 2016). Decreased UV and visible light transmission were observed in films added with CK at a level of 3 to 12 mg/ml, compared to the control film. Furthermore, no light transmission in the UV ranges (200–280 nm) was observed in the films when CK was incorporated, irrespective of the

Table 2 Light transmission and transparency of FMP films incorporated with a combination of catechin-Kradon extract at different concentrations in comparison with commercial wrap film (LDPE). CK (mg/mL)

Control 3 6 9 12 LDPE

Transparency*

Transmittance (%T) at wavelength (nm) 200

280

350

400

500

600

700

800

0.00 0.00 0.00 0.00 0.00 73.60

9.74 0.00 0.00 0.00 0.00 87.37

73.00 2.22 1.52 0.56 0.20 88.57

77.88 39.14 39.12 30.92 19.52 89.77

82.56 62.12 60.46 50.74 35.86 90.30

84.72 76.62 70.60 59.02 43.10 90.77

85.78 80.36 73.40 61.08 45.36 91.60

86.52 81.96 74.88 62.46 46.42 92.23

Different superscripts in each column are significantly difference (P < 0.05). CK: catechin-Kradone extract, LDPE: low density polyethylene. * Values are mean ± SD of 3 independent determinations.

60

3.88 3.84 3.76 3.56 3.35 3.97

± ± ± ± ± ±

0.002b 0.001c 0.008d 0.004e 0.003f 0.003a

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flexibility reported earlier. An amide-A peak was found at 3274 cm−1 (NH-stretching). An amide-B peak was also observed at 2918 cm−1 (CeH stretching) (Aewsiri, Benjakul, & Visessanguan, 2009). The amide-A peak shifted from the wavenumber of 3274 for the control FMP film to 3273–3269 cm−1 for the CK contained films. This suggests that the incorporation of CK might induce the cross-linking of FMP, thus favoring the interaction between FMP-phenolic compounds, which are present in CK, or FMP-phenolic compounds-MTGase. The shift of the vibrational peak to a lower wavenumber was observed when the NH group present in FMP interacted with the OH group of CK through hydrogen bonding (Bitencourt et al., 2014; Wu et al., 2013). According to Hoque et al. (2011), protein cross-linking led to higher diffraction of film, which affects the obtained spectra. However, this result was not consistent with Wang et al. (2016) who found that amide-A of the chestnut bur extract contained soy protein isolate films was shifted to high wavenumber. They suggested that a lower formation of hydrogen bonds but had other interactions occurred such as hydrophobic interactions. Kadam, Pankaj, Tiwari, Cullen, and O’Donnell (2015) reported that plant extract polyphenols can form both covalent and hydrogen bonding, consequently occupy the functional groups (such as C]O and NeH) of biopolymer matrix. According to these findings, the CK added FFS could induce the cross-linking between FMP-phenolic compoundMTGase in the film network, which is indicated by the changes in FT-IR spectra and functional properties.

below 80%. This may be because the film incorporated with CK appeared yellow to orange and not transparent to the human eyes. The light transmission in the visible ranges (400–800 nm) is greater than 80% (Schmid, Sängerlaub, Wege, & Stäbler, 2014) and it means that the film is transparent to the human eye. The transparency of the film is an important property for food application as it affects the product appearance and use as a see-through packaging material. The transparency values of the FMP films incorporated with CK at a level of 0–12 mg/ml and LDPE film were 3.35–3.88 and 3.97, respectively (Table 2). Changes in transparency were noticeable in all of the films (P < 0.05). A lowered transparency was found when the level of CK concentration was increased. This is consistent with Emam-Djomeh et al. (2015) and Wang et al. (2016) who reported that sodium casinate films and soy protein isolate films exhibited less transparency when increasing the levels of pomegranate peel extract and chestnut bur extract, respectively. Therefore, inclusion of CK into FMP films could affect the films’ transparency by lowering the transparency value, resulted in limiting their applications. 3.4. Film thermal properties The melting temperature (Tm) and enthalpy (ΔH) of FMP films incorporated with different concentrations of CK as compared to LDPE film are shown in Table 1. Tm and ΔH of the FMP films incorporated with CK were in the range of 99.37–113.52 °C and 4.68–44.19 J/g, respectively. The Tm of the films indicated the temperature caused a disruption of the polymer interaction that formed during film preparation. Changes in Tm and ΔH values were observed in the control films and FMP film incorporated with CK, regardless of the level of CK concentrations used (P < 0.05). In the present study, a continuous increase in Tm and ΔH was observed when increasing the level of CK. The increases in Tm and ΔH of the developed films might be due to greater inter-chain interactions between the FMP and the phenolic compounds in CK. This occurred most likely via non-disulfide covalent bond, which restricted molecular movement in the films and strengthened the film network. Higher ΔH was also needed to destroy the film network. According to Yan, Li, Zhao, and Yi (2011), change in thermal stability is a good indicator of protein-phenol interactions; moreover, an increase in Tm reflects a rise in the average number of cross-linking junctions per molecule. This result was not agreement with Kim, Yang, Lee, Beak, and Song (2017) who found that inclusion of hibiscus extract into red ginseng residue protein film could decrease ΔH of red ginseng residue protein film due to less formation of hydrogen bonding between protein and hibiscus extract. However, no changes in Tm for the film added with 3 and 6 mg/ml of CK. There was also no change in the film containing 9 and 12 mg/ml (P > 0.05) CK. In brief, the incorporation of CK has a pronounced affect the FMP films’ thermal property. Nie et al. (2015) concluded that higher amounts of bonding between protein and phenol led to more compact and stable structure. Thus, the films’ thermal stability was enhanced.

3.6. Moisture content The developed FMP films’ moisture content was affected by the incorporation of CK (P < 0.05) (Table 3). The moisture content of the experimental films gradually decreased with increasing concentrations of CK. This might be because interactions were induced between protein and the phenolic compounds present in CK. Thus, there was a reduction of hydrophilic groups available that would restrict the proteinwater interactions via hydrogen bonding. As a consequence, the moisture content of the films decreased. Furthermore, hydrophobic bonds were established via protein-polyphenol interactions, resulting in a reduction of film moisture content. Similar trends have been presented for cassava starch film incorporated with yerba mate extract (Jaramillo, Seligra, Goyanes, Bernal, & Fama, 2015) and chitosan film containing honeysuckle flower extract (Wang et al., 2017). However, Nie et al. (2015) reported that the moisture content of myofibrillar protein film increased as the concentration of grape seed procyanidins or green tea polyphenol increased from 0 to 50 g/kg. In their study, they concluded that the hydrophilic character of grape seed procyanidins, or green tea polyphenol, led to higher in the hygroscopic characteristics of films. According to Verbeek and Bier (2011), moisture content directly affects the protein films’ mechanical properties because of their characteristic hydrophilicity. Typically, films that contain high amounts of water have high flexibility and low strength. Moreover, films with high moisture content, if used for application, can cause microbial growth on the surface of packaged food.

3.5. FT-IR spectroscopy 3.7. Films solubility The spectra of the FMP films displayed major bands at 1645 and 1539 cm−1, indicates for amide-I (C]O stretching) and amide-II (NeH bending and CeN stretching) (Kaewprachu et al., 2016a) (Fig. 2). Limpan, Prodpran, Benjakul, and Prasarpran (2010) found amide-I and amide-II peaks at 1646 and 1547 cm−1, respectively. The peak was found at wavenumber of 1042 cm−1 might be associated to the interactions between the asymmetric stretching vibrations of film structure and OH group of plasticizer (probably by means of hydrogen bond) (Bergo & Sobral, 2007; Wu et al., 2013). When the concentration of CK increased, the wavenumbers of the peak shifted from 1042 for the control FMP film to 1031 cm−1 for the CK contained films. This might be because the CK affected the interaction between the film structure and the plasticizer. This result coincides with the decreased film

From the visual observation, the experimental films maintained their integrity after a 24 h dip in water. The developed FMP films’ solubility was in the range of 18.82–38.30%, while the LDPE film could not soluble in water (Table 3). Significant differences in film solubility were observed between the films incorporated with CK and the control film, irrespective of concentrations of CK used (P < 0.05). Increase in film solubility was noted as the level of CK concentrations increased (P < 0.05). The highest amount of CK addition showed to be the maximum in film solubility value (38.30%), while the minimum film solubility value was noted in the control FMP film (18.82%). Although, the interactions of protein-polyphenol were expected to reduce the films’ solubility, it seems that the film solubility is the measurement of 61

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Fig. 2. FT-IR spectra of FMP films incorporated with a combination of catechin-Kradon extract at different concentrations. The numbers designate concentrations of catechin-Kradon extract (mg/ml).

application of the film to food products may need water insolubility to improve the integrity of the packaged product.

Table 3 Moisture content, film solubility and water vapor permeability (WVP) of FMP films incorporated with a combination of catechin-Kradon extract at different concentrations in comparison with commercial wrap film (LDPE). CK (mg/mL)

Moisture content (%)

Control 3 6 9 12 LDPE

30.20 26.28 24.99 18.88 16.23 ND

± ± ± ± ±

1.10a 1.26ab 2.26b 5.09c 0.62c

Film solubility (%) 18.82 21.17 27.35 33.14 38.30 ND

± ± ± ± ±

1.56e 0.67d 0.27c 1.55b 1.16a

3.8. Water vapor permeability

WVP (×10−9 g m−1 s−1 Pa−1) 2.08 1.86 1.72 1.66 1.56 0.04

± ± ± ± ± ±

Changes in WVP were noted in the FMP films incorporated with CK, in comparison with the control FMP film, regardless of concentrations of CK used (P < 0.05) (Table 3). The developed films’ WVP was from 1.56 − 2.08 × 10−9 g m−1 s−1 Pa−1. Among the FMP films, the maximum WVP value was noted in the control FMP film, while the minimum WVP value was noted in the FMP film enriched with the maximum level of CK (12 mg/ml). The WVP of FMP films was slightly decreased when increasing the level of CK concentration (P < 0.05). This suggests that CK induced the protein-polyphenol interactions through hydrogen bonding as well as through hydrophobic interactions, which could reduce the free volume space of protein polymer, leading to the formation of a compact film network. As a result, the WVP of the developed films decreased. Polyphenol, which contained aromatic rings, reacted with hydrophobic sites of protein by hydrophobic interactions. Hydroxyl group of polyphenol combined with H-acceptor sites of proteins by hydrogen bond (Bourvellec & Renard, 2012; Ozdal et al., 2013; Propran et al., 2012). Moreover, Nie et al. (2017) reported that sulfhydryl groups in myofibrillar protein interacted with tannins by covalent bonds (mainly CeS bond) led to a lower of WVP of tannins contained silver carp myofibrillar protein film. The lower amount of moisture content in the CK incorporated films also led to lower WVP values. Similar trends have been presented for myofibrillar protein film containing grape seed procyanidins or green tea polyphenol (Nie et al., 2015) and longan seed extract contained gelatin film (Vichasilp, Sai-Ut, Benjakul, & Rawdkuen, 2014). From this result, the developed films had greater WVP values than LDPE film (0.04 × 10−9 g m−1 s−1 Pa−1). A high WVP of a protein based film is not able applied as food packaging. However, the characteristics of the film depend on the specific requirements for food preservation. For instance, dry food needs a film that has low WVP to prevent moisture uptake from the environmental. Films with moderate WVP are suitable for fruit and vegetables that need

0.02a 0.08b 0.08bc 0.14cd 0.05d 0.02e

Different superscripts in each column are significantly difference (P < 0.05). Values are mean ± SD of 3 independent determinations. CK: catechin-Kradone extract, LDPE: low density polyethylene, ND: not detected.

the soluble substances that contain in the film. So, the soluble substances could escape from the film during immersion in distilled water. CK could be released into distilled water due to their hydrophilic nature. Other soluble substances like a plasticizer, hydrophilic molecules, could be eluted into water easily, so the film solubility increased. Emam-Djomeh et al. (2015) concluded that increases in film solubility were presumably due to the disruption of film structure by peel extract added. Sai-Ut et al. (2015) reported that increasing the concentrations of longan seed extract in gelatin film led to an increase in solubility (41.83–53.77%). Wang et al. (2017) observed that the solubility of chitosan film increased from 23.52% to 31.37% when increasing the concentrations of honeysuckle flower extract. In general, high film solubility may indicate the poor water resistance (Sai-Ut et al., 2015). High solubility of film may have the possibility for developing active food packaging, which can be easily soluble and can release active agents contained in the active film (Ahmad, Benjakul, Prodpran, & Agustini, 2012). Furthermore, the film with high solubility can be degraded rapidly when compared with commercial wrap film (LDPE film), which is good for the environment. However, the ultimate 62

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Fig. 3. Antioxidant and antimicrobial activities of FMP films incorporated with a combination of catechin-Kradon extract at different concentrations. (A). DPPH scavenging activity, (B). Ferric reducing antioxidant power (FRAP), and (C) developed FMP films against L. monocytogenes, S. aureus, S. Typhimurium, and V. parahaemolyticus. Antibiotic: Ampicillin (10 μg/disc) and tetracycline (30 μg/disc). Values are given as mean ± SD. Different letters indicate significantly different (P < 0.05).

study, the control film possessed very low DPPH and FRAPS radical scavenging activity, which is mainly attributable to the peptide fraction of FMP (P < 0.05). Furthermore, the FMP films containing CK exhibited greater antioxidant capacities over the control film by about 54–90 times, which is consistent with findings reported by Sriket (2014). Furthermore, catechin has been reported to be an effective scavenger of free radicals, inhibitor of oxidative enzymes and redox active metal chelation (Almajano et al., 2008). It can be concluded that CK contained FMP film could promote more antioxidant properties, which is beneficial for application in food products, especially in high lipid-based food.

to avoid dehydration (Cazón, Velazquez, Ramírez, & Vázquez, 2016). Thus, the incorporation of CK can be beneficial for improving the protein based films’ water barrier properties by decreasing moisture transfer between the environmental surrounding and the food. As a result, the quality could be maintained, and the shelf life of a food product could be prolonged. 3.9. Antioxidant properties of the films Antioxidant packaging is a primary system for active packaging. It controls the oxidation of pigments and fatty components; as a result, it can prolong the shelf life of packaged foods. Antioxidant activity of FMP films containing different concentrations of CK is shown in Fig. 3A and B. These activities are expressed in term of DPPH radical scavenging activity and ferric reducing antioxidant power (FRAP). The lowest antioxidant activity was observed in the control FMP film, while the maximum antioxidant capacity was found in the FMP film enriched with the highest level of CK. Changes in DPPH and FRAPS radical scavenging activity of the developed films when increasing the level of CK concentration (P < 0.05). Furthermore, the DPPH radical scavenging activity of the developed FMP films in this study was higher than values reported by Sai-Ut et al. (2015). They reported that the DPPH radical scavenging activity of gelatin films containing longan seed extract (50–500 ppm) and synthetic antioxidant (butylated hydroxytoluene; BHT) (50 and 100 ppm) to be in the range of 1.5–41.9% and 2–5%, respectively. Kadam et al. (2015) reported that the addition of brown seaweed extract (0, 25, and 50% based on protein) to gelatin films enhanced the films’ antioxidant properties (3.86–77.68%). In this

3.10. Antimicrobial properties of the films The antimicrobial properties of FMP films contained different concentrations of CK against selected microorganisms, including V. parahaemolyticus, S. aureus, S. Typhimurium and L. monocytogenes, are presented in Fig. 3C. The antimicrobial films’ inhibitory activity was determined the clear zone that appeared around a film disc. If there is no inhibition, it is no observable clear zone. In the present study, the control film did not show any antimicrobial effect against all of the microorganisms tested. The FMP film containing CK exhibited antimicrobial activity against only V. parahaemolyticus (6.67–8.97 mm). An increase in the clear zone was noted when the level of CK concentration increased. However, no observable clear zone was found at the CK concentration of 3 mg/ml. It may be inferred that CK was not released out of the film matrix, probably due to the interactions between it and FMP. Protein-polyphenol interactions may decrease the antimicrobial 63

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Cerqueira, M. A., Costa, M. J., Fuciños, C., Pastrana, L. M., & Vicente, A. A. (2014). Development of active and nanotechnology-based smart edible packaging systems: Physical–chemical characterization. Food and Bioprocess Technology, 7, 1472–1482. Daduang, J., Vichitphan, S., Daduang, S., Hongsprabhas, P., & Boonsiri, P. (2011). High phenolics and antioxidants of some tropical vegetables related to antibacterial and anticancer activities. African Journal of Pharmacy and Pharmacology, 5, 608–615. Dahmoune, F., Nayak, B., Moussi, K., Remini, H., & Madani, K. (2015). Optimization of microwave-assisted extraction of polyphenols from Myrtus communis L. leaves. Food Chemistry, 166, 585–595. Emam-Djomeh, Z., Moghaddam, A., & Ardakani, S. A. Y. (2015). Antimicrobial activity of pomegranate (Punica granatum L.) peel extract, physical, mechanical, barrier and antimicrobial properties of pomegranate peel extract-incorporated sodium caseinate film and application in packaging for ground beef. Packaging Technology and Science, 28, 869–881. Hafsa, J., Smach, M. A., Ben Khedher, M. R., Charfeddine, B., Limem, K., Majdoub, H., & Rouatbi, S. (2016). Physical, antioxidant and antimicrobial properties of chitosan films containing Eucalyptus globulus essential oil. LWT Food Science and Technology, 68, 356–364. Han, J., & Floros, J. (1997). Casting antimicrobial packaging films and measuring their physical properties and antimicrobial activity. Journal of Plastic Film & Sheeting, 13, 287–298. Hirose, M., Yada, H., Hakoi, K., Takahashi, S., & Ito, N. (1993). Modification of carcinogenesis by α-tocopherol, t-butylhydroquinone, propyl gallate and butylated hydroxytoluene in a rat multi-organ carcinogenesis model. Carcinogenesis, 14, 2359–2364. Hoque, M. S., Benjakul, S., & Prodpran, T. (2011). Properties of film from cuttlefish (Sepia pharaonis) skin gelatin incorporated with cinnamon, clove and star anise extracts. Food Hydrocolloids, 25, 1085–1097. Jaramillo, C. M., Seligra, P. G., Goyanes, S., Bernal, C., & Fama, L. (2015). Biofilms based on cassava starch containing extract of yerba mate as antioxidant and plasticizer. Starch, 67, 780–789. Kadam, S. U., Pankaj, S. K., Tiwari, B. K., Cullen, P. J., & O’Donnell, C. P. (2015). Development of biopolymer-based gelatin and casein films incorporating brown seaweed Ascophyllum nodosum extract. Food Packaging and Shelf Life, 6, 68–74. Kaewprachu, P., & Rawdkuen, S. (2016). Application of active edible film as food packaging for food preservation and extending shelf life. In N. Garg, S. M. Abdel-Aziz, & A. Aeron (Eds.), Microbes in food and health (pp. 185–205). Cham: Springer International Publishing. Kaewprachu, P., Osako, K., Benjakul, S., & Rawdkuen, S. (2016a). Effect of protein concentrations on the properties of fish myofibrillar protein based film compared with PVC film. Journal of Food Science and Technology, 53, 2083–2091. Kaewprachu, P., Osako, K., Benjakul, S., Tongdeesoontorn, W., & Rawdkuen, S. (2016b). Biodegradable protein-based films and their properties: A comparative study. Packaging Technology and Science, 29, 77–90. Kim, H., Yang, H.-J., Lee, K.-Y., Beak, S.-E., & Song, K. B. (2017). Characterization of red ginseng residue protein films incorporated with hibiscus extract. Food Science and Biotechnology, 26, 369–374. Kowalczyk, D., & Biendl, M. (2016). Physicochemical and antioxidant properties of biopolymer/candelilla wax emulsion films containing hop extract—A comparative study. Food Hydrocolloids, 60, 384–392. Li, J.-H., Miao, J., Wu, J.-L., Chen, S.-F., & Zhang, Q.-Q. (2014). Preparation and characterization of active gelatin-based films incorporated with natural antioxidants. Food Hydrocolloids, 37, 166–173. Limpan, N., Prodpran, T., Benjakul, S., & Prasarpran, S. (2010). Properties of biodegradable blend films based on fish myofibrillar protein and polyvinyl alcohol as influenced by blend composition and pH level. Journal of Food Engineering, 100, 85–92. Liu, F., Ma, C., McClements, D. J., & Gao, Y. (2017). A comparative study of covalent and non-covalent interactions between zein and polyphenols in ethanol-water solution. Food Hydrocolloids, 63, 625–634. Loranty, A., Rembiałkowska, E., Rosa, E. A. S., & Bennett, R. N. (2010). Identification, quantification and availability of carotenoids and chlorophylls in fruit, herb and medicinal teas. Journal of Food Composition and Analysis, 23, 432–441. Maisuthisakul, P., & Pongsawatmanit, R. (2005). Effect of sample preparation methods and extraction methods and extraction time on yield and antioxidant activity from Kradonbok (Careya sphaerica Roxb.) leaves. Kasetsart Journal: Natural Science, 38, 8–14. Maisuthisakul, P. (2012). Phenolic constituents and antioxidant properties of some Thai plants. In V. Rao (Ed.), Phytochemicals—A global perspective of their role in nutrition and health (pp. 187–212). InTech. Marsh, K., & Bugusu, B. (2007). Food packaging—Roles, materials, and environmental issues. Journal of Food Science, 72, R39–R55. Mayachiew, P., Devahastin, S., Mackey, B. M., & Niranjan, K. (2010). Effects of drying methods and conditions on antimicrobial activity of edible chitosan films enriched with galangal extract. Food Research International, 43, 125–132. Mekoue Nguela, J., Poncet-Legrand, C., Sieczkowski, N., & Vernhet, A. (2016). Interactions of grape tannins and wine polyphenols with a yeast protein extract, mannoproteins and β-glucan. Food Chemistry, 210, 671–682. Nagarajan, M., Benjakul, S., Prodpran, T., & Songtipya, P. (2015). Properties and characteristics of nanocomposite films from tilapia skin gelatin incorporated with ethanolic extract from coconut husk. Journal of Food Science and Technology, 52, 7669–7682. Negar, G., Susan, H., & Ayman, O. S. E.-K. (2007). Chemoprotective and carcinogenic effects of tert-butylhydroquinone and its metabolites. Current Drug Metabolism, 8, 1–7. Nie, X., Gong, Y., Wang, N., & Meng, X. (2015). Preparation and characterization of edible myofibrillar protein-based film incorporated with grape seed procyanidins and green tea polyphenol. LWT Food Science and Technology, 64, 1042–1046.

capacities of catechin and Kradon extract. Mayachiew, Devahastin, Mackey, and Niranjan (2010) reported that 0.3% (w/w) galangal extract contained chitosan film has no inhibitory effect against S. aureus. Emam-Djomeh et al. (2015) found that sodium casinate films incorporated with 1-time of minimum inhibitory concentration (MIC) of pomegranate peel extract showed no inhibitory effect against Escherichia coli O157:H7. Nevertheless, all of the CK incorporated films in this study showed microbial inhibitory effects on the contact surface against all of the microorganisms tested. From the visual observation, the contact area of the film discs showed that all of the microorganisms did not grow. The film incorporated with CK possessed the microbial inhibitory effect on the contact surface between the film and the culture medium. When comparing the film with and without the addition of CK, the results showed that CK could enhance the FMP films’ antimicrobial activity, especially against V. parahaemolyticus. From these results, it could be concluded that FMP film incorporated with CK provided some antimicrobial activity against pathogens, particularly against V. parahaemolyticus, which is usually found in seafood products. 4. Conclusion Active films based on FMP incorporated with CK were manufactured. The developed FMP films exhibited improved TS, WVP, and thermal property when compared to the control FMP film. Moreover, the incorporation of CK enhanced the films’ antioxidant properties. However, antimicrobial activity was observed only against Vibrio parahaemolyticus. According to these findings, FMP films incorporated with 9 mg/ml of CK have a potential for being used for active food packaging. Acknowledgements The author would like to thank Mae Fah Luang University and the Thailand Research Fund, Thailand, for the financial support through the Royal Golden Jubilee Ph.D. Program (Grant No. PHD/0029/2555) to Ms. Pimonpan Kaewprachu. Tokyo University of Marine Science and Technology, Japan, was also acknowledged for materials, reagents, and equipment during research work. Thank you to Matthew Robert Ferguson of Mahidol University International College for language and editing support. References Aewsiri, T., Benjakul, S., & Visessanguan, W. (2009). Functional properties of gelatin from cuttlefish (Sepia pharaonis) skin as affected by bleaching using hydrogen peroxide. Food Chemistry, 115, 243–249. Ahmad, M., Benjakul, S., Prodpran, T., & Agustini, T. (2012). Physico-mechanical and antimicrobial properties of gelatin film from the skin of unicorn leatherjacket incorporated with essential oils. Food Hydrocolloids, 28, 189–199. Almajano, M. P., Carbó, R., Jiménez, J. A. L., & Gordon, M. H. (2008). Antioxidant and antimicrobial activities of tea infusions. Food Chemistry, 108, 55–63. Association of Official Analytical Chemists AOAC (2011). Official methods of AOAC international (18th ed.). Arlington, VA, USA: AOAC. Arfat, Y. A., Benjakul, S., Prodpran, T., Sumpavapol, P., & Songtipya, P. (2014). Properties and antimicrobial activity of fish protein isolate/fish skin gelatin film containing basil leaf essential oil and zinc oxide nanoparticles. Food Hydrocolloids, 41, 265–273. ASTM (1989). Standard test methods for water vapor transmission of materials. Standarad designation E96-E80. Annual book of ASTM standards, . Philadelphia: American Society for Testing and Materials, 761–770. ASTM (1999). Standard test methods for tensile properties of thin plastic sheeting. Standarad designation D 882-97. Annual book of ASTM standards, . Philadelphia: American Society for Testing and Materials, 163–171. Bergo, P., & Sobral, P. J. A. (2007). Effects of plasticizer on physical properties of pigskin gelatin films. Food Hydrocolloids, 21, 1285–1289. Bitencourt, C. M., Fávaro-Trindade, C. S., Sobral, P. J. A., & Carvalho, R. A. (2014). Gelatin-based films additivated with curcuma ethanol extract: Antioxidant activity and physical properties of films. Food Hydrocolloids, 40, 145–152. Bourvellec, C., & Renard, C. M. G. C. (2012). Interactions between polyphenols and macromolecules: Quantification methods and mechanisms. Critical Reviews in Food Science and Nutrition, 52, 213–248. Cazón, P., Velazquez, G., Ramírez, J. A., & Vázquez, M. (2016). Polysaccharide-based films and coatings for food packaging: A review. Food Hydrocolloids, 68, 136–148.

64

Food Packaging and Shelf Life 13 (2017) 56–65

P. Kaewprachu et al.

starch films incorporated with solid lipid microparticles containing ascorbic acid. Food Hydrocolloids, 55, 210–219. Schmid, M., Sängerlaub, S., Wege, L., & Stäbler, A. (2014). Properties of transglutaminase crosslinked whey protein isolate coatings and cast films. Packaging Technology and Science, 27, 799–817. Siripatrawan, U., & Harte, B. R. (2010). Physical properties and antioxidant activity of an active film from chitosan incorporated with green tea extract. Food Hydrocolloids, 24, 770–775. Sriket, P. (2014). Chemical components and antioxidant activities of Thai local vegetables. KMITL Science and Technology Journal, 14, 18–23. Strauss, G., & Gibson, S. M. (2004). Plant phenolics as cross-linkers of gelatin gels and gelatin-based coacervates for use as food ingredients. Food Hydrocolloids, 18, 81–89. Tongnuanchan, P., Benjakul, S., & Prodpran, T. (2012). Properties and antioxidant activity of fish skin gelatin film incorporated with citrus essential oils. Food Chemistry, 134, 1571–1579. Verbeek, C. J. R., & Bier, J. M. (2011). Synthesis and characterization of thermoplastic agro-polymers. In S. K. Sharma, & A. Mudhoo (Eds.), A handbook of applied biopolymer technology synthesis, degradation and applications. London: Royal Society of Chemistry Publishing. Vichasilp, C., Sai-Ut, S., Benjakul, S., & Rawdkuen, S. (2014). Effect of longan seed extract and BHT on physical and chemical properties of gelatin based film. Food Biophysics, 9(3), 238–248. Wang, L., Wang, Q., Tong, J., & Zhou, J. (2017). Physicochemical properties of chitosan films incorporated with honeysuckle flower extract for active food packaging. Journal of Food Process Engineering, 40, e12305. Wang, H., Hu, D., Ma, Q., & Wang, L. (2016). Physical and antioxidant properties of flexible soy protein isolate films by incorporating chestnut (Castanea mollissima) bur extracts. LWT Food Science and Technology, 71, 33–39. Wu, J., Chen, S., Ge, S., Miao, J., Li, J., & Zhang, Q. (2013). Preparation, properties and antioxidant activity of an active film from silver carp (Hypophthalmichthys molitrix) skin gelatin incorporated with green tea extract. Food Hydrocolloids, 32, 42–51. Yan, M., Li, B., Zhao, X., & Yi, J. (2011). Physicochemical properties of gelatin gels from walleye pollock (Theragra chalcogramma) skin cross-linked by gallic acid and rutin. Food Hydrocolloids, 25, 907–914.

Nie, X., Zhao, L., Wang, N., & Meng, X. (2017). Phenolics-protein interaction involved in silver carp myofibrilliar protein films with hydrolysable and condensed tannins. LWT Food Science and Technology, 81, 258–264. Nouri, L., & Nafchi, A. M. (2014). Antibacterial, mechanical, and barrier properties of sago starch film incorporated with betel leaves extract. International Journal of Biological Macromolecules, 66, 254–259. Oh, J., Jo, H., Cho, A. R., Kim, S.-J., & Han, J. (2013). Antioxidant and antimicrobial activities of various leafy herbal teas. Food Control, 31, 403–409. Ozdal, T., Capanoglu, E., & Altay, F. (2013). A review on protein–phenolic interactions and associated changes. Food Research International, 51, 954–970. Panomket, P., Wanram, S., & Srivoramas, T. (2011). Antimicrobial activity of extracts of Thai plant to Burkholderia pseudomallei. Journal of Medical Technology and Physical Therapy, 23, 151–158. Pavlath, A. E., & Orts, W. (2009). Edible films and coatings: Why, what, and how? In M. E. Embuscado, & K. C. Huber (Eds.), Edible films and coatings for food applications. London: Springer. Prodpran, T., Benjakul, S., & Phatcharat, S. (2012). Effect of phenolic compounds on protein cross-linking and properties of film from fish myofibrillar protein. International Journal of Biological Macromolecules, 51, 774–782. Rawdkuen, S., Sai-Ut, S., & Benjakul, S. (2010). Properties of gelatin films from giant catfish skin and bovine bone: A comparative study. European Food Research and Technology, 231, 907–916. Rawdkuen, S., Suthiluk, P., Kamhangwong, D., & Benjakul, S. (2012). Mechanical, physico-chemical, and antimicrobial properties of gelatin-based film incorporated with catechin-lysozyme. Chemistry Central Journal, 6, 131. Rostamzad, H., Paighambari, S. Y., Shabanpour, B., Ojagh, S. M., & Mousavi, S. M. (2016). Improvement of fish protein film with nanoclay and transglutaminase for food packaging. Food Packaging and Shelf Life, 7, 1–7. Saghir, S., Wagner, K. H., & Elmadfa, I. (2005). Lipid oxidation of beef fillets during braising with different cooking oils. Meat Science, 71, 440–445. Sai-Ut, S., Benjakul, S., & Rawdkuen, S. (2015). Retardation of lipid oxidation using gelatin film incorporated with longan seed extract compared with BHT. Journal of Food Science and Technology, 52, 5842–5849. Sartori, T., & Menegalli, F. C. (2016). Development and characterization of unripe banana

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