Double-bottom antimicrobial packaging for apple shelf-life extension

Food Chemistry 279 (2019) 379–388

Contents lists available at ScienceDirect

Food Chemistry journal homepage: www.elsevier.com/locate/foodchem

Research Article

Double-bottom antimicrobial packaging for apple shelf-life extension a,b,e

c

d

Argus Cezar da Rocha Neto , Randolph Beaudry , Marcelo Maraschin , ⁎ Robson Marcelo Di Pierob, Eva Almenara,

T

a

School of Packaging, Michigan State University, East Lansing, MI 48824-1223, USA Laboratory of Plant Pathology, Crop Science Department, Federal University of Santa Catarina, Florianópolis, Santa Catarina 88040-900, Brazil Department of Horticulture, Michigan State University, East Lansing, MI 48824, USA d Laboratory of Morphogenesis and Plant Biochemistry, Federal University of Santa Catarina, Florianópolis, Santa Catarina 88040-900, Brazil e School of Agricultural Engineering, Adventist University Center of São Paulo, Engenheiro Coelho, São Paulo 13165-000, Brazil b c

ARTICLE INFO

ABSTRACT

Keywords: Antimicrobial packaging Apple Shelf-life extension ß-Cyclodextrin Essential oils Fungal growth

A package was created that extends apple shelf-life by slowing Penicillium expansum growth. The package consisted of a peelable lid and a tray with a double bottom with inclusion complexes (ICs) of ß-cyclodextrin (ßCD) containing the essential oils of palmarosa (ICp) or of star anise (ICsa). Oil amounts required for antimicrobial activity were obtained from in vitro assays. After 12 days at 23 °C, P. expansum-inoculated apples in both of the double-bottom antimicrobial packages (DBAP) had 1/3 less fungal growth, less than 50% weight loss and ethylene and CO2 production, and less than 25% firmness loss, TA and SSC increase, and pH decrease compared to controls. The DBAP with ICsa performed better than with ICp in reducing ethylene production, respiration rate, firmness loss, TA increase, and pH decrease. This demonstrates DBAP containing ICp or ICsa can maximize the shelf-life of apples injured by P. expansum, validating a novel type of antimicrobial packaging.

Chemical compounds studied in this article: ß-cyclodextrin (PubChem CID: 444041) trans-anethole (PubChem CID: 637563) estragole (PubChem CID: 8815) geraniol (PubChem CID: 637566) geranyl-acetate (PubChem CID: 1549026) polyethylene terephthalate (PubChem CID: 223961227)

1. Introduction Apple (Malus domestica Borkh.) is one of the most economically important fruit crops in the world (FAO, 2017). As the major commercialized temperate fruit, apples are commonly stored for long periods in cold rooms in order to extend their shelf life and facilitate their availability all year round (Morales, Marín, Ramos, & Sanchis, 2010). However, a fraction of these apples are lost as cold storage can retard but not prevent apple spoilage caused by blue mold (Penicillium expansum) to occur (Baert et al., 2007). Furthermore, the cold room capacity in developing countries such as Brazil is insufficient to store the apples harvested over the course of a year (MAPA, 2017). Consequently, fungicides containing imidazole and dicarboximide are recommended by the Brazilian Ministry of Agriculture, Livestock and Food Supply against decay caused by P. expansum. Nevertheless, blue mold continues to be a major problem for stored apples worldwide, causing up to 80% of the decay found in stored fruits (Sánchez-Torres et al., 2018). Moreover, the chemical preservatives present in these

⁎

fungicides not only differ from current consumer expectation and desire for healthy and ecological food, but they have increased the risk of resistant isolates. These drawbacks have led to the need for alternative strategies to eradicate the presence of blue mold in apples (da Rocha Neto, Luiz, Maraschin, & Di Piero, 2016). Plant metabolites have long been used as preservatives in traditional medicine. Hence, they could be a viable alternative to conventional fungicides. Essential oils (EOs) are one of the most promising plant metabolites as they not only exhibit antimicrobial capacity against a wide range of fungi and bacteria (Hu, Zhang, Kong, Zhao, & Yang, 2017), but possess biological safety, biodegradable nature, and a low risk to cause resistance in pathogens (Calo, Crandall, O’Bryan, & Ricke, 2015). Furthermore, they are classified as Generally Recognized As Safe (GRAS) by the U.S. Food and Drug Administration and allowed in organic agriculture (Hu et al., 2017). However, the strong aroma, volatility, and oxidation of EOs can modify food organoleptic and physicochemical characteristics, which limits their direct addition into the food product and challenges their commercial usage (Ribeiro-Santos,

Corresponding author at: 448 Wilson Road, Room 130, Packaging Building, Michigan State University, East Lansing, Michigan 48824-1223, USA. E-mail addresses: [email protected] (R. Beaudry), [email protected] (M. Maraschin), [email protected] (R.M. Di Piero), [email protected] (E. Almenar).

https://doi.org/10.1016/j.foodchem.2018.12.021 Received 19 June 2018; Received in revised form 30 November 2018; Accepted 4 December 2018 Available online 13 December 2018 0308-8146/ © 2018 Elsevier Ltd. All rights reserved.

Food Chemistry 279 (2019) 379–388

A.C. da Rocha Neto et al.

Andrade, de Melo, and Sanches-Silva, 2017). Strategies to overcome such drawbacks include the use of matrixes with the capability of trapping highly volatile compounds that are posteriorly released at a controlled rate. Examples of such matrixes are cyclodextrins (Almenar, Auras, Wharton, Rubino, and Harte, 2007; Almenar, Auras, Rubino, and Harte, 2007; da Rocha Neto, de Oliveira da Rocha, Maraschin, Di Piero, & Almenar, 2018), coatings (Perdones, Escriche, Chiralt, & Vargas, 2016), films (Wen et al., 2016), and nanofibers (Kayaci, Sen, Durgun, & Uyar, 2014). In a previous study, this research group showed that the EOs of palmarosa (Cymbopogon martinii) and star anise (Illicium verum) can be entrapped into cyclodextrins and posteriorly released from the formed inclusion complexes at specific levels by manipulating temperature and RH (da Rocha Neto et al., 2018). These two EOs have a strong antimicrobial capacity (De, De, Sen, & Banerjee, 2002; Huang et al., 2010; Wilson, Solar, El Ghaouth, & Wisniewski, 1997). Therefore, they can be used for the development of antimicrobial packaging to control blue mold and to extend apple shelf life. Antimicrobial packaging is commonly obtained using antimicrobial films. However, the extrusion of inclusion complexes (ICs) along with a polymer resin for antimicrobial film development results in a significant loss (> 70%) of the antimicrobial volatile (Joo, Merkel, Auras, & Almenar, 2012). Other possibilities for antimicrobial packaging development like the use of a sachet with ICs may not be the best option because consumers would likely shy away from sachets in contact with food (Wilson, Harte, & Almenar, 2018). Therefore, a novel approach is needed for the development of antimicrobial packaging using ICs. The authors hypothesize that packaging with a double-bottom containing ICs with trapped antimicrobial volatile can be created and used to slow fungal growth. The goal of this study was to develop an antimicrobial package with a double-bottom containing ICs with trapped palmarosa and star anise EOs capable of reducing blue mold growth, thereby extending apple shelf life. Our findings could help to develop a new strategy to reduce postharvest losses caused by P. expansum in countries with a lack of suitable cold storage.

Neubauer chamber (Labovert FS, Leitz, Oberkochen, Germany). All experiments, both in vitro and in situ, were set up inside the previously mentioned biohazard safety cabinet in order to avoid contaminations. 2.2. Methods 2.2.1. Preparation of the ß-CD/EO inclusion complexes Two different inclusion complexes (ICs) were prepared using the procedures described in da Rocha Neto et al. (2018). An amount of 360 mg of vacuum-oven-dried ß-CDs (30 min., 92,000 Pascal, 100 °C, VWR, Pennsylvania, U.S.A.) was added to 20 mL of distilled water (70 °C) and the solution was stirred for 300 s at 200 rpm using a hot plate stirrer (MS-H-pro Circular top LCD Digital, SCILOGEX LLC, Connecticut, U.S.A.). After the solution was cooled down to room temperature, either palmarosa EO or star anise EO at a concentration of 3% (v/v) was added to the solution. Each of the two ß-CD/EO solutions was first stirred for 2 h at 200 rpm, and subsequently centrifuged (1 h, 250 g, 23 °C) for IC accumulation. After the supernatants were discarded, the resulting ICs containing either palmarosa EO (ICp) or star anise EO (ICsa) were dried in the aforementioned oven at 60 °C for 24 h, placed inside airtight glass containers sealed with parafilm, and kept inside a freezer until their use. The entrapment efficiency of the ICs was 63.7% and 70.7% for ICp and ICsa, respectively (da Rocha Neto et al., 2018). The same protocol, excluding the use of the EO, was repeated to obtain a control (ß-CDs). All experiments were carried out in triplicate. 2.2.2. Bioassays 2.2.2.1. In vitro antimicrobial assay. The inhibitory effects of ICp and ICsa against P. expansum were determined by correlating the growth of the fungus with the level of released EO, palmarosa or star anise, over time. Additionally, the respiratory activity of the fungus was monitored daily. The bioassay systems were obtained by adding 10 mL of PDA to 250-mL glass jars. After media solidification, 25 µL of P. expansum conidial suspension (105 conidia per mL) was centrally placed on the PDA in the form of a drop. In addition, a sterilized small aluminum pan containing 350 mg of ICs (ICp or ICsa) was placed next to the jar wall to avoid the contact between the ICs and either the PDA or the drop. The jars were then tightly closed with their screw lids, sealed with highvacuum grease, covered with parafilm, and incubated for 5 days at 23 °C (PTC-1, portable temperature-controlled cabinet, Sable Systems, Nevada, U.S.A.). Glass jars containing only PDA, PDA and P. expansum, and PDA, P. expansum and ß-CDs were used as controls and blanks. The amount of 350 mg of ICp or ICsa used in the experiment was previously determined by correlating the amounts of EO released from ICp and ICsa with the effect of the pure EOs (not entrapped into ß-CDs) on P. expansum growth (data not shown). All procedures were performed inside a biohazard safety cabinet (Class II BSC, ESCO, Tampines, Singapore). The diameter of P. expansum colonies was measured daily using a ruler without opening the jars. All experiments were carried out in triplicate. The results are presented in cm. The viability of P. expansum was confirmed through its respiration activity as previously done for Penicillium species (Chitarra, Abee, Rombouts, & Dijksterhuis, 2005). Respiration activity was obtained from the headspace O2/CO2 ratio of the jars after measuring the levels of both gases using a gas chromatograph (Trace GC Ultra) coupled to a thermal conductivity detector (Thermo-Scientific, Florida, U.S.A.) and equipped with a Zebron ZB-1 column (30 m × 0.32 mm, 0.25 µm; Phenomenex, California, U.S.A.) following the method described by Koutsimanis, Harte, and Almenar (2014), with modifications. A 50-µL sample of headspace gas was withdrawn daily from each jar using an SGE gastight syringe (Supelco Analytical, California, U.S.A.) through a 20-mm rubber stopper previously attached to the jar lid and sealed with high-vacuum grease. The gas was injected into the GC. The injector temperature was 125 °C and the split flow and split ratio were 150 mL min−1 and 30, respectively. The oven temperature was set to and held at 45 °C for 4 min, and then increased first to 190 °C at a rate of

2. Materials and methods 2.1. Materials 2.1.1. Essential oils Palmarosa and star anise essential oils (EOs), containing geraniol and trans-anethole as a major volatile component, respectively (da Rocha Neto et al., 2018), were purchased from By Samia (São Paulo, Brazil). Types and relative amounts of the volatile components forming these two EOs can be found in da Rocha Neto et al. (2018). 2.1.2. ß-Cyclodextrin and other reagents ß-Cyclodextrin (ß-CD) was purchased from Wacker Chemical Corporation (Michigan, U.S.A.). All other reagents used were of analytical grade and purchased from Sigma-Aldrich (Missouri, U.S.A.). 2.1.3. Fruit and fungus Commercially grown and packed 'Red Delicious' apples were purchased in a local supermarket (Walmart, Fowlerville, Michigan, U.S.A.) in August and were then stored a few hours in a refrigerator (6 °C ± 2 °C) until use. Apples were removed from cold storage, disinfected with 0.5% (v/v) hypochlorite solution for 120 s, rinsed with tap water, and finally air-dried inside of a biohazard safety cabinet (Class II BSC, ESCO, Tampines, Singapore). Penicillium expansum was isolated from an infected apple exhibiting typical symptoms of blue mold. The isolate was grown and maintained in potato dextrose agar (PDA) medium at 23 °C. After 14 d, conidia were collected and added to sterile distilled water. The conidial suspension was adjusted to the desired concentration, 105 conidia per mL and 104 conidia per mL for in vitro and in situ assays, respectively, using a 380

Food Chemistry 279 (2019) 379–388

A.C. da Rocha Neto et al.

60 °C min−1 and next to 230 °C at a rate of 120 °C min−1. The thermal conductivity detector block was set at a temperature of 200 °C, while the transfer temperature was set at 190 °C. The GC was previously calibrated using known amounts of pure and mixed gases (Airgas USA Great Lakes, Ohio, U.S.A.). All experiments were carried out in triplicate. The results are presented as percentages of O2 and CO2. The amounts of EO released from ICp and ICsa into the jar headspace were also quantified daily using a 50/30 µm DVB/CAR/PDMS SPME fiber (Supelco, Bellefonte, California, U.S.A.) and an HP 6890 series GC (Agilent Technology, Palo Alto, California, U.S.A.) equipped with a flame ionization detector and an HP-5 column (30 m × 0.32 mm × 0.25 µm). The oven temperature was initially set at 100 °C for 3 min and increase at a rate of 5 °C min−1 until 165 °C was achieved. The injector and detector temperatures were set at 220 and 250 °C, respectively. The fiber was exposed to the jar headspace through the rubber stopper mentioned above. After 600 s, the fiber was moved to the split injection port of the GC where the trapped compounds were desorbed for 180 s. The amount of each EO in the jar headspace was determined using previously prepared calibration curves (da Rocha Neto et al., 2018).

then immersed into a P. expansum conidial suspension (104 conidia/mL sterile distilled water) for 2 min. The apples were immediately placed inside the packages and these were heat sealed with the aforementioned PET film using a T200 semi-automatic tray sealer (MultiVac, Wolfertschwenden, Germany). The resulting packages are described below:

• Packages with empty double bottoms and containing apples not inoculated with the fungus. • Packages with empty double bottoms and containing apples inoculated with the fungus. • Packages with ß-CDs in double bottoms and containing apples inoculated with the fungus. • Packages with ICp in double bottoms and containing apples inoculated with the fungus. • Packages with ICsa in double bottoms and containing apples inoculated with the fungus.

Finally, the packages were stored at 23 °C in the dark for 12 d. At each sampling day, three replicates per treatment were randomly selected for analysis. Each replicate consisted of a single package containing one apple with two injuries. The lesion growth rate (LGR) of P. expansum was determined according to da Rocha Neto, Maraschin, and Di Piero (2015) by measuring the diameter of the lesion (cm) of the two injuries made to each fruit with a ruler every 4 days. The LGR was calculated using the equation LGR = Σ(θt − θt-1)/t. Where “θ” indicates the average diameter of the lesions and “t” indicates time. The results are presented as cm/day. The incidence of P. expansum was calculated at the end of experiment (day 12), by dividing the total number of injuries showing blue mold symptoms by the total number of injuries made to the fruits. The results are expressed in percent. The amount of EO released from the ICp and ICsa into the package headspace was measured every 4 days following the methodology proposed by Almenar, Auras, Wharton, et al. (2007) but using a modified desorption system. This consisted of the package itself with an adhesive septum (3 M, Maplewood, Minnesota, U.S.A.) placed on its lid instead of the glass jar with a screw cap modified with a snapped septum used by Almenar, Auras, Wharton, et al. (2007). The adhesive septum was placed on the PET film to allow exposure of the fiber described in Section 2.2.2.1 to the package headspace for 600 s without any gas leaking. The EO compounds trapped into the fiber were then desorbed for 180 s into the split injection port of the HP 6890 series GC described previously. The same oven temperature profile and injector and detector temperatures were used. The calibration curves showed in da Rocha Neto et al. (2018) were used for quantification purposes. 2.2.2.2.3. Physiological evaluations. The ethylene, O2, and CO2 levels inside the packages described in Section 2.2.2.2.2 were assessed on days 0, 4, 8, and 12. Ethylene levels were measured by withdrawing an amount of 100 µL from the package headspace using the gastight syringe and septum described above. The gas was injected into the splitless port of the HP 6890 series GC described previously but equipped with a Carboxen™ 1010 Plot fused silica capillary column (30 m × 0.53 mm × 30 µm) (Supelco, Bellefonte, California, U.S.A.). The oven and injector temperatures were set to 150 °C and 220 °C, respectively. The splitless flow was 2.0. Ethylene levels were quantified using a previously prepared standard curve with the following regression equation: Y = -2.17E − 14x2 + 7.01E − 08x (R2 = 0.991). The results are expressed as parts per million (ppm). O2 and CO2 levels in package headspace were determined as described in Section 2.2.2.1. Three packages per treatment were randomly selected to measure the ethylene, O2, and CO2 levels at each sampling day. 2.2.2.2.4. Physico-chemical evaluations. The weight loss (WL) of the apples was quantified by weighing each individual fruit on day 4, and on the following sampling days, using an analytical balance (Discovery

2.2.2.2. In situ assays 2.2.2.2.1. Double-bottom package design. Cylindrical stainless-steel permeation cells (10.8-cm diameter × 1.0-cm deep) were used to compare the barrier to palmarosa EO and star anise EO of several packaging materials in order to select a material capable of minimizing EO escape through the package (data not shown). Polyethylene terephthalate (PET) was selected. The package design consisted of a rigid tray with dimensions 7-cm width × 10-cm height with a shaped PET piece containing 90 microperforations (0.06 mm of diameter) fitted to its bottom to form a double-bottom of ∼2-cm height (Fig. 1). 1 g of ß-CD, 1 g of ICp, 0.5 g of ICsa, or nothing was placed on the tray bottom prior to the fitting of the microperforated piece. The amount of either ICp or ICsa was selected to achieve a target amount of EO in the package headspace using the in vitro results. The top of the package consisted of a peelable lid made of a 50-µm thick PET film. 2.2.2.2.2. In situ antimicrobial assay. This assay was performed using the package described in Section 2.2.2.2.1 and apples contaminated with P. expansum or not as follows. The apples described in Section 2.1.3 were injured twice in their equatorial zones with a standard needle (1 mm wide × 5 mm deep) and were

Fig. 1. Developed antimicrobial package consisting of a perforated double bottom (A-B), a tray (C), and a peelable lid (D), all of them made of PET. 381

Food Chemistry 279 (2019) 379–388

A.C. da Rocha Neto et al.

DV314C, Ohaus, New Jersey, U.S.A.). The values are reported as percentage (%) of weight loss with respect to the initial individual fruit weight (day 4). Firmness of each individual fruit (FF) was measured approximately 5 cm from one of its injuries using a Wagner FT Series fruit tester (Connecticut, U.S.A.). The results are presented as N/mm2. Each apple was sliced into 4 pieces and was then blended for 30 s in a household blender (KitchenAid, Benton Harbor, Michigan, U.S.A.). The part of the blender containing the apple juice was placed inside a plastic container full of ice in order to slow down enzymatic reactions and oxidation. The pH of the juices was measured using a SevenCompact S220 pH/Ion meter (Mettler Toledo, Schwerzenbach, Switzerland). Results are presented as pH units. The aforementioned juices were also used to determine the titratable acidity (TA) of the packaged apples. Titration was performed with 0.1 mol/L NaOH solution to an end point of pH 8.2 using the pH/Ion meter described above. Results are expressed as %. The solid soluble content (SSC) of the aforementioned juices was determined using an Atago PAL-1 portable refractometer (Washington, U.S.A.). The results are expressed in °Brix. Weight loss and FF evaluations were performed after 4, 8, and 12 d of storage, whereas pH, TA and SSC were performed at day 0 and after 4, 8 and 12 d of storage. Three packages (three apples) per treatment were randomly selected for physico-chemical analyses each sampling day.

listed fungi. This could be attributed to the higher affinity of P. expansum structures like cell wall and plasma membrane for the EO compounds compared to other fungi. These results also show that ß-CDs by their own cannot reduce P. expansum growth in vitro since the fungus grew at the same rate in the jars containing ß-CDs as in the empty jars (controls). The antimicrobial capacity of palmarosa and star anise EOs could be attributed to their main components, geraniol and trans-anethole, respectively, since both of these have shown antimicrobial activity (Cavoski & Wieczyńska, 2018; Sacchetti et al., 2005). No toxic effects are expected for palmarosa EO or star anise EO at the assessed concentrations due to their classification as Generally Recognized As Safe (GRAS) compounds within the meaning of section 409 of the Federal Food, Drug, and Cosmetic Act by the U.S. Food and Drug Administration (FDA, 2018). The levels of O2 and CO2 monitored inside the jars (Fig. 2C and D), indicative of colony respiration, show a reduction of P. expansum growth due to the EOs released from either ICp or ICsa. The O2 and CO2 levels in the jars containing either ICp or ICsa changed by less than 2% at the end of storage, while that same day, the jars containing ß-CDs showed a decrease in O2 of approximately 16% and an increase in CO2 of approximately 15%. The reduction of the growth of P. expansum by the EOs released from either ICp or ICsa was also confirmed visually. The color of the colonies in the jars containing either ICp or ICsa remained white throughout storage while those exposed to either ß-CDs or nothing (controls) had a green color. Similarly, Li et al. (2017) observed that the reduction of P. expansum growth caused by the volatile 1-methylcyclopropene resulted in a whitish mycelia whereas the mycelia of the control colony was green. The amount of either ICp or ICsa was selected to achieve a target amount of EO in the package headspace using the above results. Since the ICsa was twice as effective the ICp in controlling P. expansum, the amount of ICsa was half the amount of ICp.

2.2.3. Statistical analysis Experiments were carried out in a completely randomized design. Experiments were performed in triplicate and data were reported as means ± 1 standard deviation. The data were subjected to Levene’s or Cochran’s tests to verify the homogeneity of the variances of the treatments (factorial analysis or one-way ANOVA). When ANOVA was significant (p < 0.05), means were separated by Tukey’s multiple range test. These statistical analyses were performed using the software STATISTICA 10.0 (StatSoft, Palo Alto, California, U.S.A.) and SAS University Edition (SAS, Cary, North Carolina, U.S.A.). The resulting graphs were created with Prism software for Mac OS Sierra (GraphPad, La Jolla, California, U.S.A.).

3.2. Antimicrobial activity of the double-bottom package containing ICp or ICsa against P. expansum growth on apple fruit Fig. 3A and B compare the developed double-bottom packages in terms of antimicrobial capacity against P. expansum growth. After 12 days of storage at 23 °C the Penicillium-inoculated apples stored in the double-bottom packages containing either ICp or ICsa had a LGR of 0.09 cm d-1 and a lesion diameter of 1.08 cm whereas the Penicilliuminoculated apples stored in the control packages (empty double-bottom) showed a LGR of 0.23 cm d-1 and lesion diameter of 2.88 cm. Therefore, the two antimicrobial packages were able to reduce the growth of P. expansum on apples by a third when held at ambient conditions for two weeks. This demonstrates a meaningful antimicrobial capacity of the double-bottom packages containing either ICp or ICsa. The antimicrobial packages showed about the same effectiveness, thereby confirming the use of twice as much ICsa as ICp based on the proven double effectiveness of ICsa on reducing Penicillium growth compared to ICp in the in vitro studies. The growth of P. expansum in apples stored in the antimicrobial packages can be attributed to the small amount of EO released from the ß-CDs (below GC detection limit) until after day 4 as shown in Fig. 3C. The reason could be a sub-optimal RH during the first days of storage. As previously reported by these authors, the amount of EO released from either ICp or ICsa depends on the RH level surrounding the ICs (da Rocha Neto et al., 2018). Furthermore, some of the released EO could have been lost due to its permeation through the lidding material. We hypothesize that the apple transpiration and respiration created an environment with sufficient RH for a significant release of EO inside the packages as time passed. At the end of storage, the in-package amounts of palmarosa EO and star anise EO were 2.1 and 33.7 ppm, respectively (Fig. 3C). These amounts were lower than those expected based on the in vitro results (Fig. 2B), which could be attributed to the generation of a non-optimal RH for EO release inside the packages, to the permeation of

3. Results and discussion 3.1. In vitro antimicrobial activity of ICp and ICsa against P. expansum The antimicrobial effectiveness of the ICp and ICsa against P. expansum growth on agar plate is presented in Fig. 2A. The release of approximately 57 ppm of palmarosa EO from ICp into the jar headspace (Fig. 2B) was able to completely inhibit the growth of P. expansum during 24 h (Fig. 2A). The amount of the EO increased to approx. 140 ppm after 120 h (Fig. 2B), which resulted in a fungal growth reduction of 90% compared to the control (no ICs or ß-CD) and the blank (ß-CD) (Fig. 2A). Based on these results, palmarosa EO seems to be more effective at inhibiting P. expansum growth in vitro than Cymbopogon citratus EO and its polar fractions, which required 1,000 ppm to inhibit in vitro Penicillium growth (Nguefack et al., 2012). Furthermore, the amount of palmarosa EO shown to inhibit P. expansum growth was less than that reported by Wilson et al. (1997) as necessary to inhibit the growth of Botrytis cinerea spores in vitro (7800 ppm). ICsa was more effective than ICp in reducing P. expansum growth as shown by the complete inhibition of the fungus during 48 h instead of 24 h, and by the equal reduction of the growth of the fungus from 72 h to 120 h (Fig. 2A) when releasing less than half of EO throughout storage (Fig. 2B). Approx. 70 ppm of star anise EO reduced the growth of P. expansum by 90% after 120 h (Fig. 2A). Slightly higher amounts of star anise EO (80–90 ppm) have been reported to be needed to slow the mycelial growth of Alternaria solani, Fusarium graminearum, Rhizoctonia solani (Huang et al., 2010). This may indicate a higher antimicrobial efficacy of star anise EO against P. expansum compared to the above 382

Food Chemistry 279 (2019) 379–388

A.C. da Rocha Neto et al.

Fig. 2. Effects of palmarosa and start anise released from the ICs (B) on P. expansum growth (A) and P. expansum respiration (C-D) during in vitro studies at ambient temperature. Different lowercase letters indicate differences between treatments (p ≤ 0.05) on each sampling day.

Fig. 3. Effects of palmarosa and start anise released from the ICs inside the double-bottom packages (C) on the growth and incidence (A-B) of P. expansum in apples and on apple ethylene production (D) at ambient conditions. Different lowercase letters indicate differences between treatments (p ≤ 0.05) on a specific time of analysis.

383

Food Chemistry 279 (2019) 379–388

A.C. da Rocha Neto et al.

the EOs through the lidding material, or to the absorption of the EOs by either the plant tissue or the fungus. All of these processes have previously been linked to lower antimicrobial concentrations in the headspace of a package. Balaguer et al. (2014) reported the capability of the fungus Colletotrichum acutatum to absorb and metabolize cinnamaldehyde, thereby reducing its amount and consequently its antimicrobial activity. Almenar, Catala, Hernandez-Muñoz, and Gavara (2009) showed an increased amount of 2-nonanone in strawberries due to the sorption of the antimicrobial by the fruit. The growth of the fungus on the Penicillium-inoculated apples stored in the double-bottom packages containing ß-CDs was also reduced compared to the controls (packages with empty double-bottoms) (Fig. 3C). This can be explained in terms of water activity (aw) of the package headspace since aw is one of the main factors affecting the growth of microorganisms. An aw lower than 0.848 has been reported as non-optimal for the growth of P. expansum (Nguyen Van Long et al., 2017). An aw in this range could have been generated inside the doublebottom packages since ß-CDs have the capability of absorbing water from both environment and fruits (Winkler, Fioravanti, Ciccotti, Margheritis, & Villa, 2000). 3.3. Effect of the double-bottom package containing ICp or ICsa on apple shelf life 3.3.1. Physiological changes Fig. 3D shows the levels of ethylene inside the different doublebottom packages throughout storage. Comparing the packages with empty double-bottoms containing Penicillium-inoculated apples or noninoculated apples shows that the stress produced in the plant tissue by the inoculation process and the subsequent growth of the fungus resulted in increased ethylene production. Alternatively, P. expansum could have contributed producing some ethylene by itself (Chou & Yang, 1973). However, less ethylene was accumulated when the Penicillium-inoculated apples were stored in double-bottom packages containing ß-CDs, ICp, or ICsa compared to packages with empty bottoms (p < 0.05). After 12 d holding at 23 °C, the ethylene levels in the double-bottom packages with ICsa containing Penicillium-inoculated apples were the same as those in the packages with empty bottoms containing non-inoculated apples (0.01 ppm) (p > 0.05). In contrast, the ethylene contents in the double-bottom packages with ICp and ßCDs were 2- and 4-fold higher than in the double-bottom packages with ICsa containing Penicillium-inoculated apples and in the packages with empty bottoms containing non-inoculated apples, respectively. This variation in ethylene production (Fig. 3D) correlates to the different lesion diameters presented by the apples in the different double-bottom packages (Fig. 3B) except for the apples stored in the double-bottom packages with ICsa. Between these three packages, the amounts of both P. expansum and ethylene were the highest (p < 0.05) for the empty double-bottoms, lower (p < 0.05) for the ones with ß-CDs, and the lowest (p < 0.05) for the ones with ICp. The reason for the lower ethylene production of the Penicillium-inoculated apples when stored in the double-bottom packages with ICsa instead of ICp (Fig. 3D) could be the capability of one of the compounds forming the star anise oil of competing with ethylene for either ethylene receptor binding sites or ethylene precursors like 1-methylcyclopropene and polyamides (Bregoli et al., 2002; Li et al., 2017) since the same amount of Penicillium (Fig. 3A) grew inside both packages. Further studies would be needed to confirm or reject the above hypotheses. Fig. 4A compares the levels of O2 inside the different double-bottom packages after 12 days of storage at 23 °C. These levels ranged between 0.8 and 2.9% with no statistical differences (p > 0.05). It is worth to note that they are close to the O2 levels used in standard controlled atmosphere storage of ‘Red Delicious’ apples (0.7–2%) (Watkins, Kupferman, & Rosenberger, 2016). These levels are used because low O2 slows the ripening of apple fruit (Mir & Beaudry, 2016). Regarding the CO2 levels inside the double-bottom packages at the end of storage

Fig. 4. O2 and CO2 contents inside the different double-bottom packages containing non-inoculated or inoculated apples after 12 days of storage at ambient conditions. Different lowercase letters indicate differences between treatments (p ≤ 0.05).

(Fig. 4B), the packages with ß-CDs and empty bottoms containing Penicillium-inoculated apples had the highest CO2 levels (14% CO2; p < 0.05). This is almost twice the amount of CO2 inside the antimicrobial packages with ICsa containing Penicillium-inoculated apples, which had the same CO2 levels (p > 0.05) as the packages with empty double-bottoms containing non-inoculated apples (8% CO2). These differences in CO2 among the double-bottom packages can be explained by their different ethylene contents (Fig. 3D) and amounts of Penicillium growth (Fig. 3B). It is well known that ethylene enhances respiration rate in apples (Yang et al., 2016), which likely led to the higher CO2 levels inside the double-bottom packages. Furthermore, the respiration of Penicillium expansum (Fig. 2D) likely contributed to increasing the CO2 levels inside the packages having greater lesion diameter. CO2 injury in 'Red Delicious’ apples caused by exposure to levels of CO2 levels higher than 2% has been reported under standard controlled atmosphere storage (Watkins et al., 2016). However, the symptoms that the authors associate to CO2 injury such as a wrinkled, depressed, and 384

Food Chemistry 279 (2019) 379–388

A.C. da Rocha Neto et al.

Fig. 5. Effects of palmarosa and start anise released from the ICs inside the double-bottom packages on apple weight loss (A), texture (B), titratable acidity (C) and pH (D) during 12 days of storage at ambient conditions. Different lowercase letters indicate differences between treatments (p ≤ 0.05) on a specific day of analysis.

colorless skin, cavities in the flesh, and/or brown heart were not observed. This could be attributed to either the shorter storage period or the higher temperature compared to standard controlled atmosphere storage. Studies reporting CO2 injury in 'Red Delicious’ apples at high temperature are lacking in the literature. CO2 has been reported to be fungistatic (de Vries-Paterson & Jones, 1991). However, the levels of CO2 inside the packages had no discernable effect on Penicillium growth since the inoculated apples stored in the double-bottom packages with the highest amount of CO2 (14%) (Fig. 4B) had the highest lesion diameter (2.88 cm) (Fig. 3B).

antimicrobial packages. These findings are supported by the lesion diameter results, which did not differ in the apples stored in the doublebottom packages with either ICp or ICsa (1.08 cm) and were higher in the apples stored in the packages with ß-CDs (1.52 cm) and empty bottoms (2.88 cm) (Fig. 3B). It seems reasonable that the higher fungal growth caused greater stress and consequently, the apple transpiration process was enhanced. Similarly, Almenar et al. (2009) reported a reduction of weight loss in wild strawberries stored in antimicrobial packages compared to the controls. The weight loss of the apples in the active packages was less than the maximum reported as permissible for commercial apples (Thompson, Mitchell, Rumsey, Kasmire, & Crisosto, 2002) while it exceeded that maximum for the apples in the control packages. The effect of the developed double-bottom packages on the SSC of the apples during 12 days of holding at ambient conditions is presented in Table 1. The SSC of the P. expansum-inoculated apples stored in packages with either ß-CDs or empty double-bottoms increased starting on day 4 (p < 0.05) while no SSC increase was observed in the apples stored in the double-bottom packages with ICp until day 12 (p < 0.05). The SSC of the P. expansum-inoculated apples stored in the double-bottom packages with ICsa and of the non-inoculated apples stored in packages with empty double-bottoms did not change throughout storage (p > 0.05). Comparing the different packaging systems at each sampling day, the highest SSC increase (p > 0.05) was observed for the P. expansum-inoculated apples stored in the packages with either ß-CDs or empty bottoms. Furthermore, no significant differences (p > 0.05) were found between the SSC of the P. expansuminoculated apples stored in the double-bottom packages with either ICp

3.3.2. Physico-chemical changes Fig. 5A compares the effect of the developed double-bottom packages on apple weight loss. The injury resulting from P. expansum inoculation and the subsequent growth of the fungus increased apple weight loss by 12% and 15% after 8 and 12 days of storage, respectively. These values resulted from the differences in weight losses between the inoculated (13 and 18%) and the non-inoculated (1 and 3%) apples stored in the controls (packages with empty double-bottom) (Fig. 5A). This high weight loss caused by P. expansum-inoculation was significantly reduced (p < 0.05) when the apples were stored in the double-bottom packages with either ICp, ICsa, or ß-CDs. Significant differences (p < 0.05) in weight loss between the three packaging systems were observed only at the end of storage. The apples stored in the double-bottom packages with either ICp or ICsa had a weight loss of 7–9% compared to the 16% weight loss of the apples stored in the double-bottom packages with ß-CDs. There were no significant differences in weight loss between the apples stored in the two types of 385

Food Chemistry 279 (2019) 379–388

A.C. da Rocha Neto et al.

Table 1 Effects of palmarosa and start anise released from the ICs inside the double-bottom packages on apple soluble solid content during 12 days of storage at ambient conditions. Different lowercase letters indicate differences (p ≤ 0.05) in a specific treatment throughout storage, whereas uppercase letters indicate differences (p ≤ 0.05) between treatments on a specific day of analysis. Treatments

SSC (°Brix) Day 0

Non-inoculated fruits Inoculated fruits ß-CD ICp ICsa

12.8 + 0.2 12.8 + 0.2 12.8 + 0.2 12.8 + 0.2 12.8 + 0.2

A A A A A

a a a a a

Day 4

Day 8

Day 12

12.9 + 0.2 A a 14.0 + 0.3C b 13.3 + 0.2B b 12.9 + 0.1 A a 12.3 + 0.5 A a

13.1 + 0.1 A a 14.1 + 0.3B b 13.8 + 0.1B c 13.0 + 0.2 A ab 12.8 + 0.3 A a

13.2 + 0.2 A a 14.3 + 0.2B b 14.2 + 0.3B c 13.4 + 0.2 A b 13.0 + 0.2 A a

or ICsa and the SSC of the non-inoculated apples stored in packages with double-bottoms. These differences in SSC can be explained by the variation in weight loss (Fig. 5A) and fungal growth (Fig. 3B) among the different packaging systems. A higher water loss results in more concentrated soluble solids, and thereby a higher SSC. As reported above, the active packages reduced weight loss and P. expansum growth on P. expansum-inoculated apples compared to the control packages (ßCDs or nothing). Additionally, less fungal growth reduces the catabolism of sugars in a fruit through the action of fungal enzymes like αamylases and pectinases, which contributes to the maintenance of the fruit SSC (da Rocha Neto et al., 2016). Almenar et al. (2009) also reported a better maintenance of the SSC of wild strawberries in antimicrobial packaging compared to the controls. Fig. 5B compares the firmness of the apples in the different doublebottom packages throughout storage. The initial firmness of the apples was 0.53 N/mm2 and this was maintained until the end of storage only in the case of the non-inoculated apples stored in the packages with empty double-bottoms (0.53 N/mm2 on days 4 to 12) (p ≥ 0.05). In contrast, all inoculated apples softened, albeit, to different degrees, depending on the type of double-bottom package (p ≤ 0.05). The firmness of the inoculated apples in the double-bottom packages with either ß-CD or nothing decreased from 0.35 or 0.30 N/mm2 (day 4) to 0 N/mm2 (day 12) while a firmness change from 0.53 N/mm2 (day 4) to 0.19 and 0.23 N/mm2 (day 12) occurred for double bottoms containing ICp and ICsa, respectively. These results can be explained by the different amounts of Penicillium that grew in each type of double-bottom package (Fig. 3B). The apples with a larger lesion diameters were softer than those with smaller lesion diameters. These results are supported by Barad, Horowitz, Kobiler, Sherman, and Prusky (2014) who demonstrated that apple colonization by Penicillium expansum results in the degradation of the apple tissue due to the secretion of acids and enzymes by the fungus. Turgor has been reported to play a central role in softening during storage of apples and water loss is considered to be the reason for loss of turgor in apple fruit (Hatfield & Knee, 1988). Therefore, the differences in weight loss presented by the apples in the different double-bottom packages most likely affected apple firmness as well. Similarly, González-Buesa et al. (2014) reported a loss of turgor in packaged celery sticks due to water loss. Alternatively, water redistribution could have been the reason for a firmness change. Although CO2 injury has been related to wrinkled apple skin and cavities in the apple flesh, the different CO2 levels inside the double-bottom packages did not affect the firmness of the apples. This was due to CO2 having no effect on weight loss or fungal growth. The TA and pH of the apples were assessed (Fig. 5C-D) in order to determine the effect of the developed double-bottom packages on the maturity stage and flavor of the apples. The initial TA of the apples was 0.33%, this value that falls within the range of 0.2 to 0.4% reported for ‘Red Delicious’ in the literature (Watkins et al., 2016) and places ‘Red Delicious’ into the group of low-acid apples. As a function of storage time, this value decreased to 0.28% in the non-inoculated apples and increased in all the P. expansum-inoculated apples except for those stored in the double-bottom packages with ICsa where it was

maintained (0.34% on day 12) (Fig. 5C). Using TA decline as a measure of ripening (Oms-Oliu et al., 2010), the data suggest ripening of noninoculated apples progressed during holding, but the P. expansum-inoculated apples packaged with ICsa did not. Therefore, star anise OE seems to have retarded apple ripening. This could be explained by its capability to impair the use of acids during the respiration process (Meigh, Jones, & Hulme, 1967) since the CO2 content in the packages with ICsa was the same as that in the packages with empty doublebottoms containing non-inoculated apples (Fig. 4B) whereas one would have expected it to be higher due to the presence of P. expansum (Fig. 3B). As for the other P. expansum-inoculated apples, the ones stored in the packages with empty double bottoms had the highest TA increase (0.48% on day 12) while the lowest increase in TA occurred when the fruit was stored in the double-bottom packages with ICp (0.39% on day 12). Therefore, the double-bottom package with ICp was the second-best package at impairing the TA increase in the P. expansum-inoculated apples. This could be attributed to the smaller amount of fungus in the packages with ICp since it has been reported that P. expansum acidifies its host during infection by the secretion of citric and gluconic acids, which allow its growth and reproduction (Prusky & Lichter, 2008). Water loss could have also contributed to the TA increase, which would be supported by the greater increase in TA occurring in the apples of the double-bottom packages with either ß-CD or nothing. Based on the above results, only the apples in the packages with ICsa maintained their acidity. The pH of the apples (Fig. 5D) was maintained throughout storage in the case of the non-inoculated apples stored in the packages with empty double bottoms and the P. expansum-inoculated apples stored in the double-bottom packages with ICsa (3.73–3.83). The pH of the other P. expansum-inoculated apples decreased throughout storage. The largest and smallest pH changes occurred in the packages with empty double-bottoms (3.23 on day 12) and the packages with ICp (3.57 on day 12), respectively. 4. Conclusions Packages with double-bottoms containing either ICp or ICsa can reduce the growth of P. expansum on apples stored at 23 °C, which demonstrates the efficacy of a novel type of antimicrobial packaging. These packages could completely inhibit the growth of P. expansum if higher amounts of either ICp or ICsa are used as supported by the presented in vitro results. Alternatively, EOs also effective in reducing P. expansum growth on apples could be used to form the inclusion complexes. Even a different volatile encapsulating matrix could be used in order to improve EO release at the beginning of storage. All of the above indicates the possibility of using a double-bottom antimicrobial package against microbial growth on produce. The system described here is quite flexible: the IC amount, EO type, and encapsulating matrix type are production variables that can be readily changed. Comparing the two developed antimicrobial packages, the double-bottom package with ICsa performs better than with ICp in reducing ethylene production, respiration rate, softening, TA increase, and pH decrease. In 386

Food Chemistry 279 (2019) 379–388

A.C. da Rocha Neto et al.

principle, PET double-bottom packages with ICsa are a viable alternative for the commercialization of apples during the postharvest period since they can extend apple shelf life. However, a sensorial evaluation is needed to determine whether star anise EO affects apple flavor or not.

De, M., De, A. K., Sen, P., & Banerjee, A. B. (2002). Antimicrobial properties of star anise (Illicium verum Hook f). Phytotherapy Research, 16, 94–95. https://doi.org/10.1002/ ptr.989. de Vries-Paterson, R. M., & Jones, A. L. (1991). Fungistatic effects of carbon dioxide in a package environment on the decay of Michigan sweet cherries by Monilinia fructicola. Plant Disease, 75(9), 943–949. FAO (2017). Total estimated apple production for 2014 year. Retrieved May 15, 2017, from http://www.fao.org/faostat/en/#compare. FDA (2018). 21CFR182.20. Retrieved October 24, 2018, from https://www.accessdata. fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=182.20R. González-Buesa, J., Page, N., Kaminski, C., Ryser, E., Beaudry, R., & Almenar, E. (2014). Effect of non-conventional atmospheres and bio-based packaging on the quality and safety of Listeria monocytogenes-inoculated fresh-cut celery (Apium graveolens L.) during storage. Postharvest Biology and Technology, 93, 29–37. https://doi.org/10. 1016/j.postharvbio.2014.02.005. Hatfield, S. G. S., & Knee, M. (1988). Effects of water loss on apples in storage. International Journal of Food Science and Technology, 23, 575–582. Hu, Y., Zhang, J., Kong, W., Zhao, G., & Yang, M. (2017). Mechanisms of antifungal and anti-aflatoxigenic properties of essential oil derived from turmeric (Curcuma longa L.) on Aspergillus flavus. Food Chemistry, 220, 1–8. https://doi.org/10.1016/j.foodchem. 2016.09.179. Huang, Y., Zhao, J., Zhou, L., Wang, J., Gong, Y., Chen, X., ... Jiang, W. (2010). Antifungal activity of the essential oil of Illicium verum fruit and its main component trans-anethole. Molecules, 15(11), 7558–7569. https://doi.org/10.3390/molecules15117558. Joo, M., Merkel, C., Auras, R., & Almenar, E. (2012). Development and characterization of antimicrobial poly(l-lactic acid) containing trans-2-hexenal trapped in cyclodextrins. International Journal of Food Microbiology, 153, 297–305. https://doi.org/10.1016/j. ijfoodmicro.2011.11.015. Kayaci, F., Sen, H. S., Durgun, E., & Uyar, T. (2014). Functional electrospun polymeric nanofibers incorporating geraniol-cyclodextrin inclusion complexes: High thermal stability and enhanced durability of geraniol. Food Research International, 62, 424–431. https://doi.org/10.1016/j.foodres.2014.03.033. Koutsimanis, G., Harte, J., & Almenar, E. (2014). Freshness maintenance of cherries ready for consumption using convenient, microperforated, bio-based packaging. Journal of the Science of Food and Agriculture, 95(5), 972–982. https://doi.org/10.1002/jsfa. 6771. Li, J., Lei, H., Song, H., Lai, T., Xu, X., & Shi, X. (2017). 1-methylcyclopropene (1-MCP) suppressed postharvest blue mold of apple fruit by inhibiting the growth of Penicillium expansum. Postharvest Biology and Technology, 125, 59–64. https://doi.org/ 10.1016/j.postharvbio.2016.11.005. MAPA (2017). Ministry of Agriculture, Livestock and Supply – Apple. URL: http://www. agricultura.gov.br/assuntos/politica-agricola/arquivos-de-estatisticas/informativo_-_ maca_2013_-2-1.pdf/view. (Accessed 16 October 2018). Meigh, D. F., Jones, J. D., & Hulme, A. C. (1967). The respiration climateric in the apple. : Production of ethylene and fatty acids in fruit attached to and detached from the tree. Phytochemistry, 6(11), 1507–1515. https://doi.org/10.1016/S0031-9422(00) 82943-X. Mir, N., & Beaudry, R. M. (2016). Modified atmosphere packaging. In K. C. Gross, C. Y. Wang, & M. Saltveit (Eds.). Agriculture handbook number 66 (HB-66): the commercial storage of fruits, vegetables, and florist and nursery stocks. Washington: United States Department of Agriculture (USDA) Agricultural Research Service (ARS). Morales, H., Marín, S., Ramos, A. J., & Sanchis, V. (2010). Influence of post-harvest technologies applied during cold storage of apples in Penicillium expansum growth and patulin accumulation: A review. Food Control, 21(7), 953–962. https://doi.org/10. 1016/j.foodcont.2009.12.016. Nguefack, J., Tamgue, O., Dongmo, J. B. L., Dakole, C. D., Leth, V., Vismer, H. F., ... Nkengfack, A. E. (2012). Synergistic action between fractions of essential oils from Cymbopogon citratus, Ocimum gratissimum and Thymus vulgaris against Penicillium expansum. Food Control, 23(2), 377–383. https://doi.org/10.1016/j.foodcont.2011.08. 002. Nguyen Van Long, N., Vasseur, V., Coroller, L., Dantigny, P., Le Panse, S., Weill, A., ... Rigalma, K. (2017). Temperature, water activity and pH during conidia production affect the physiological state and germination time of Penicillium species. International Journal of Food Microbiology, 241, 151–160. https://doi.org/10.1016/j.ijfoodmicro. 2016.10.022. Oms-Oliu, G., Rojas-Graü, M. A., González, L. A., Varela, P., Soliva-Fortuny, R., Hernando, M. I. H., ... Martín-Belloso, O. (2010). Recent approaches using chemical treatments to preserve quality of fresh-cut fruit: A review. Postharvest Biology and Technology, 57(3), 139–148. https://doi.org/10.1016/j.postharvbio.2010.04.001. Perdones, A., Escriche, I., Chiralt, A., & Vargas, M. (2016). Effect of chitosan-lemon essential oil coatings on volatile profile of strawberries during storage. Food Chemistry, 197, 979–986. https://doi.org/10.1016/j.foodchem.2015.11.054. Prusky, D., & Lichter, A. (2008). Mechanisms modulating fungal attack in post-harvest pathogen interactions and their control. European Journal of Plant Pathology, 121(3), 281–289. https://doi.org/10.1007/s10658-007-9257-y. Ribeiro-Santos, R., Andrade, M., de Melo, N. R., & Sanches-Silva, A. (2017). Use of essential oils in active food packaging: Recent advances and future trends. Trends in Food Science & Technology, 61, 132–140. https://doi.org/10.1016/j.tifs.2016.11.021. Sacchetti, G., Maietti, S., Muzzoli, M. V., Scaglianti, M., Manfredini, S., Radice, M., & Bruni, R. (2005). Comparative evaluation of 11 essential oils of different origin as functional antioxidants, antiradicals and antimicrobials in foods. Food Chemistry, 91(4), 621–632. https://doi.org/10.1016/j.foodchem.2004.06.031. Sánchez-Torres, P., Vilanova, L., Ballester, A. R., López-Pérez, M., Teixidó, N., Viñas, I., ... Torres, R. (2018). Unravelling the contribution of the Penicillium expansum PeSte12 transcription factor to virulence during apple fruit infection. Food Microbiology, 69, 123–135. https://doi.org/10.1016/j.fm.2017.08.005.

Conflict of interest The authors have declared no conflict of interest. Acknowledgments The authors thank the Hatch project 1007253 from the USDA NIFA (United States Department of Agriculture’s National Institute of Food and Agriculture). A. Rocha Neto acknowledges the financial support (scholarship) from CAPES (Coordination for the Improvement of Higher Education Personnel) and UNASP-EC (Adventist University Center of São Paulo – Campus Engenheiro Coelho). Appendix A. Supplementary data Supplementary data to this article can be found online at https:// doi.org/10.1016/j.foodchem.2018.12.021. References Almenar, E., Auras, R., Wharton, P., Rubino, M., & Harte, B. (2007). Release of acetaldehyde from ß-cyclodextrins inhibits postharvest decay fungi in vitro. Journal of Agricultural and Food Chemistry, 55, 7205–7212. https://doi.org/10.1021/jf071603y. Almenar, E., Auras, R., Rubino, M., & Harte, B. (2007). A new technique to prevent the main post harvest diseases in berries during storage: Inclusion complexes ß-cyclodextrin-hexanal. International Journal of Food Microbiology, 118, 164–172. https:// doi.org/10.1016/j.ijfoodmicro.2007.07.002. Almenar, E., Catala, R., Hernandez-Muñoz, P., & Gavara, R. (2009). Optimization of an active package for wild strawberries based on the release of 2-nonanone. LWT – Food Science and Technology, 42(2), 587–593. https://doi.org/10.1016/j.lwt.2008.09.009. Baert, K., Valero, A., De Meulenaer, B., Samapundo, S., Ahmed, M. M., Bo, L., ... Devlieghere, F. (2007). Modeling the effect of temperature on the growth rate and lag phase of Penicillium expansum in apples. International Journal of Food Microbiology, 118(2), 139–150. https://doi.org/10.1016/j.ijfoodmicro.2007.07.006. Balaguer, M. P., Fajardo, P., Gartner, H., Gomez-Estaca, J., Gavara, R., Almenar, E., & Hernandez-Munoz, P. (2014). Functional properties and antifungal activity of films based on gliadins containing cinnamaldehyde and natamycin. International Journal of Food Microbiology, 173, 62–71. https://doi.org/10.1016/j.ijfoodmicro.2013.12.013. Barad, S., Horowitz, S. B., Kobiler, I., Sherman, A., & Prusky, D. (2014). Accumulation of the mycotoxin patulin in the presence of gluconic acid contributes to pathogenicity of Penicillium expansum. Molecular and Plant-Microbe Interactions, 27(1), 66–77. https:// doi.org/10.1094/mpmi-05-13-0138-r. Bregoli, A. M., Scaramagli, S., Costa, G., Sabatini, E., Ziosi, V., Biondi, S., & Torrigiani, P. (2002). Peach (Prunus persica) fruit ripening: Aminoethoxyvinylglycine (AVG) and exogenous polyamines affect ethylene emission and flesh firmness. Physiologia Plantarum, 114(3), 472–481. https://doi.org/10.1034/j.1399-3054.2002.1140317.x. Calo, J. R., Crandall, P. G., O’Bryan, C. A., & Ricke, S. C. (2015). Essential oils as antimicrobials in food systems – A review. Food Control, 54, 111–119. https://doi.org/10. 1016/j.foodcont.2014.12.040. Cavoski, I., & Wieczyńska, J. (2018). Antimicrobial, antioxidant and sensory features of eugenol, carvacrol and trans-anethole in active packaging for organic ready-to-eat iceberg lettuce. Food Chemistry, 259(1), 251–260. https://doi.org/10.1016/j. foodchem.2018.03.137. Chitarra, G. S., Abee, T., Rombouts, F. M., & Dijksterhuis, J. (2005). 1-Octen-3-ol inhibits conidia germination of Penicillium paneum despite of mild effects on membrane permeability, respiration, intracellular pH, and changes the protein composition. FEMS Microbiology Ecology, 54, 67–75. https://doi.org/10.1016/j.femsec.2005.02.013. Chou, T. W., & Yang, S. F. (1973). The biogenesis of ethylene in Penicillium digitatum. Archives of Biochemistry and Biophysics, 157(1), 73–82. https://doi.org/10.1016/ 0003-9861(73)90391-3. da Rocha Neto, A. C., Maraschin, M., & Di Piero, R. M. (2015). Antifungal activity of salicylic acid against Penicillium expansum and its possible mechanisms of action. International Journal of Food Microbiology, 215, 64–70. https://doi.org/10.1016/j. ijfoodmicro.2015.08.018. da Rocha Neto, A. C., Luiz, C., Maraschin, M., & Di Piero, R. M. (2016). Efficacy of salicylic acid to reduce Penicillium expansum inoculum and preserve apple fruits. International Journal of Food Microbiology, 221, 54–60. https://doi.org/10.1016/j. ijfoodmicro.2016.01.007. da Rocha Neto, A. C., de Oliveira da Rocha, A. B., Maraschin, M., Di Piero, R. M., & Almenar, E. (2018). Factors affecting the entrapment efficiency of β-cyclodextrins and their effects on the formation of inclusion complexes containing essential oils. Food Hydrocolloids, 77, 509–523. https://doi.org/10.1016/j.foodhyd.2017.10.029.

387

Food Chemistry 279 (2019) 379–388

A.C. da Rocha Neto et al. Thompson, J. F., Mitchell, F. G., Rumsey, T. R., Kasmire, R. F., & Crisosto, C. H. (2002). Commercial cooling of fruits, vegetables, and flowers (revised edition). California: University of California. Watkins, C.B.; Kupferman, E.; Rosenberger, D.A. Apple. In: Gross, K. C., Wang, C. Y., & Saltveit, M. (2016). Agriculture handbook number 66 (HB-66): the commercial storage of fruits, vegetables, and florist and nursery stocks. United States Department of Agriculture (USDA) Agricultural Research Service (ARS), Washington. Wen, P., Zhu, D. H., Feng, K., Liu, F. J., Lou, W. Y., Li, N., ... Wu, H. (2016). Fabrication of electrospun polylactic acid nanofilm incorporating cinnamon essential oil/ß-cyclodextrin inclusion complex for antimicrobial packaging. Food Chemistry, 196, 996–1004. https://doi.org/10.1016/j.foodchem.2015.10.043. Wilson, C. T., Harte, J., & Almenar, E. (2018). Effects of sachet presence on consumer product perception and active packaging acceptability – A study of fresh-cut

cantaloupe. LWT – Food Science and Technology, 92, 531–539. https://doi.org/10. 1016/j.lwt.2018.02.060. Wilson, C. L., Solar, J. M., El Ghaouth, A., & Wisniewski, M. E. (1997). Rapid evaluation of plant extracts and essential oils for antifungal activity against Botrytis cinerea. Plant Disease, 81(2), 204–210. Winkler, R. G., Fioravanti, S., Ciccotti, G., Margheritis, C., & Villa, M. (2000). Hydration of beta-cyclodextrin: A molecular dynamics simulation study. Journal of ComputerAided Molecular Design, 14(7), 659–667. https://doi.org/10.1023/A:1008155230143. Yang, X., Song, J., Du, L., Forney, C., Campbell-Palmer, L., Fillmore, S., ... Zhang, Z. (2016). Ethylene and 1-MCP regulate major volatile biosynthetic pathways in apple fruit. Food Chemistry, 194, 325–336. https://doi.org/10.1016/j.foodchem.2015.08. 018.

388