University of California

For Abstracts

Browning inhibition and microbial control in fresh-cut persimmon (Diospyros kaki Thunb. cv. Rojo Brillante) by apple pectin-based edible coating and modified atmosphere packaging

Elena Sanchí¬s (Instituto Valenciano de Investigaciones Agrarias (IVIA), Spain), Christian Ghidelli (IVIA), Chirag C. Sheth (Universidad CEU-Cardenal Herrera, Spain), Milagros Mateos (Universidad CEU-Cardenal Herrera), Lluí¬s Palou (IVIA), María B. Pérez-Gago (IVIA- Fundación AGROALIMED)

The aim of this work was to study the ability of a pectin-based edible coating and modified atmosphere packaging (MAP) to control enzymatic browning and microbial growth of fresh-cut ‘Rojo Brillante’ persimmon. The pectin-based coating was amended with 1% (w/v) citric acid and 1% (w/v) calcium chloride as antioxidants and Nisin (NI) at 500 IU/mL as antimicrobial. Persimmon slices were dipped in the coating or in water (control), packed under MAP (5 kPa O2, balance N2) or ambient atmosphere and stored at 5 degrees C for up to 9 days. Microbial growth, package gas composition, color, firmness, polyphenol oxidase (PPO) activity, visual quality and overall sensory flavor were measured during storage. The coating significantly reduced the CO2 emission and O2 consumption in the headspace of MAP-samples and PPO activity of persimmon slices. MAP reduced firmness loss of control samples. The coated-MAP samples presented the lowest a* and the highest hue values, and maintained a good visual quality up to day 9 of storage. At the end of the storage period, the overall fruit flavor was ranked above the limit of acceptability. The coating inhibited the growth of mesophilic aerobic bacteria. No growth of molds, yeasts and psychrophilic aerobic bacteria was observed during storage. Overall, the combination coating-MAP was the best treatment to maintain a good visual quality and control microbial growth of fresh-cut persimmons.

Design of the proper modified atmosphere packaging for fresh-cut broccoli raab (cv. Novantina)

Maria Cefola (Institute of Sciences of Food Production, CNR - National Research Council of Italy Via G. Amendola, 122/O – 70126 Bari, Italy) Maria Luisa Amodio and Giancarlo Colelli (Dept. SAFE, University of Foggia, Via Napoli 25, 71122 Foggia, Italy)

Low oxygen controlled atmosphere was reported to be useful for fresh-cut broccoli raab cold storage in maintaining freshness and qualitative traits. Starting from these finding the aim of this work was to evaluate the proper modified atmosphere packaging (MAP) for fresh-cut broccoli raab in order to achieve and maintain low oxygen atmosphere composition during cold storage. Broccoli raabs harvested from a commercial farm, were selected for defects and were cut from the stalks, obtaining the ready-to-use product. After washing the product was packaged in plastic trays sealed in bags of different plastic materials. Two commercially available polymeric coupled films (polypropylene/polyethylene terephthalate, PP/PET, and polypropylene/polyamide, PP/PA microperforated (MF), were used as packaging materials with or without the inclusion of a CO2 absorbers (used in 5-g sachets). For each packaging condition a passive (P-MAP) and an active atmosphere with 5% O2 in nitrogen (A-MAP) were used. Unpackaged samples were used as control and stored with all packages at 5 degree C. Initially, and after 3 and 8 days samples were taken and quality attributes (overall appearance, odour and flavour, colour analysis and weight loss) were evaluated. Gas concentration were also monitored. Among the packaging treatments tested the combination using PP/PA in A-MAP with and the use of CO2 absorbing sachets reached equilibrium condition very close to optimal for broccoli raab. Fresh-cut broccoli raab stored in this condition for 8 days showed the best appearance, odour, and flavour scores, compared to all other packaging combinations.

Development and characterization of an antimicrobial packaging film coating containing AITC or carvacrol for preservation of fresh-cut vegetable

Haiyan Gao*, Yongjun Zhou, Xiangjun Fang, Honglei Mu, Qiang Han , Hangjun ChenKey Laboratory of Fruits and Vegetabl es Postharvest and Processing Technology Research of Zhejiang Province, Food Science Institute, Zhejiang Academy of Agricultural Science, Hangzhou, Zhejiang, 310021, China

Antimicrobial packaging film (APF) is a feature film which can inhibit or kill microorganisms on the surface after adding an antibacterial agent. The APF packaging technology have a positive impact on improving food safety and extending shelf life. However, the majority of studies about antimicrobial packaging were focused on the traditional packaging materials, and mainly by contact inhibition. In this study, the APF prepared with polylactic acid and essential oils stretch film preparated with polylactic acid was applied to the fresh cut fruits and vegetables, such as cherry tomatoes, greens. The minimum inhibitory effect (MIC), antibacterial effects and preservation effect of APF on Escherichia coli ATCC 8739 (EC), Fusarium oxysporum (FO), Geotrichum candidum (GC), Phytophthora spp. (PP) in vitro were studied in this research. The different MIC of carvacrol and allyl isothiocyanate(AITC) for various microorganism were found. Generally speaking, MIC for various microorganisms of AITC was slightly higher than carvacrol. The AITC and carvacrol were used as additives to made APF, low MIC value and good antibacterial effects were found. Although the MIC value of carvacrol without was lower than AITC, the antibacterial effect APF contained AITC better than carvacrol. This could be interpreted as the different release laws of AITC and cavacrol in APF. The probably reasons may diffuse speed of carvacrol was fast, the inhibitory time became shorter, it caused the microorganisms re-growth at later period. However, AITC released more slower throughout the process, resulting the period of inhibition was longer.

Humidity-regulating trays: Moisture absorption kinetics and applications for fresh produce packaging

Guido Rux, Pramod Mahajan, Manfred Linke, Oluwafemi Caleb, Martin Geyer(Department of Horticultural Engineering, Leibniz Institute for Agricultural Engineering, Potsdam Bornim, Germany)Astrid Pant, Sven Saengerlaub(Fraunhofer Institute of Process Engineering and Packaging, Freising, Germany)

Most polymeric materials used in fresh produce packaging have lower water vapour transmission rate relative to the transpiration rate of fresh produce. The consequences are high humidity levels and condensation of water vapour inside the package. The humidity-regulating trays were developed and tested in this study. They were made from a thermoformed multilayer structure: polyethylene (outside)/foamed hygroscopic ionomer (active layer) with 0 or 12 wt.-% NaCl/hygroscopic ionomer (sealing layer, inside). These trays were used to study moisture absorption kinetics at 76, 86, 96 and 100% RH for 16 days. Furthermore, the trays containing 7 g of water were closed with the high barrier lidding film and headspace relative humidity was continuously monitored over time. Finally, strawberries and tomatoes were used to test the effectiveness of trays on humidity regulation and weight loss of product. The amount of moisture absorbed by the tray was directly proportional to the amount of salt embedded into the tray matrix e.g. 0 and 12 wt % salt trays absorbed 7.6 and 13.2 g of moisture, respectively. The headspace RH of trays covered with a lidding film was found to be 89.8, 99.6 and 100 % in the tray with 12 and 0 wt% salt and control-PP trays, respectively. The trays containing fresh produce were able to regulate humidity below 97% but at the expense of higher product weight loss (2-3% for strawberry, 1% for tomatoes) compared to control polypropylene tray (0.6%).

Incorporating Bacteriophages into Edible Dip Coatings to Control Food Pathogens on Fresh Produce

Erica Vonasek (Dept. of Biological and Agricultural Engineering, UC Davis), Angela Choi (Dept. of Food Science & Technology, UC Davis), Juan Sanchez (Dept. of Biological and Agricultural Engineering, UC Davis), and Dr. Nitin Nitin (Depts of Biological and Agricultural Engineering and Food Science & Technology, UC Davis)

Controlling and eliminating common bacterial pathogens like E. coli 0157:H7 and Salmonella enterica in fresh produce is a significant challenge. This study aims to develop food grade formulations for encapsulation and controlled release of bacteriophages (phages) on fresh fruits and vegetables. Phage treatment takes advantage of phages’ extreme host specificity, ability to replicate and generate more phages, and natural ability to mutate to defeat host defense mechanisms. This research is unique as it demonstrates the integration of phages with edible coatings to form a bacterial pathogen specific antimicrobial packaging material. In order to encapsulate and control release rate of phages, a dip coating formulation using the food by-product whey protein was developed and evaluated for loading efficiency, phage stability in cold storage, antimicrobial efficacy, and phage activity post simulated digestion. These dip coatings were evaluated on cut apples, cut cucumbers, whole cherry tomatoes, and 18 cm by 18 cm thin glass squares as a model surface. Phage loading at 5log, 7log, and 9log PFU per cm2 demonstrate high loading efficiencies, with greater than 80% efficiency in cut cucumbers and glass. Phages remain stable over 1 week in cold storage (4 degrees C), with less than 1 log PFU loss in both cucumbers and glass. The dip coatings demonstrate antimicrobial efficacy in glass and whole cherry tomatoes. The current results show that using dip coatings can store and release phage to food surfaces and control pathogen growth.

Influence of Biodegradable Coatings on the Volatiles Profile of Fresh Cut ‘Paluma’ Guava

Rosana Sousa da Silva (CT/UFPB), Silvanda de Melo Silva* (PPGA/CCA/UFPB), Fernanda dos Santos Nunes de Melo (CT/UFPB), George Henrique Camêlo Guimarães (CCA/UFPB), Marta Suely Madruga (PPGCTA/CT/UFPB)

Fresh cut 'Paluma' guava is highly appreciated by the characteristic aroma and taste. However, due to the fresh cut operations the volatiles profile may change. Biodegradable coatings act as a physical barrier on the fruits that interfere with their physiology, affecting the biosynthesis of specific compounds or modifying the profile of volatile. The objective of this study was to evaluate changes in the volatiles profile of slices of fresh cut ‘Paluma’ guava coated with chitosan at 2% (CH), sodium alginate at 1% (SA), calcium chloride at 1% (CC), and calcium chloride at 1% + chitosan at 2% (CC + CH), and control (T - without coating). The evaluation of the volatiles profile was performed by SPME-GC-MS followed 4 days of storage at 3 ± 2 degrees C and 75 ± 4% RH. For slices of fresh cut guava without coating (T) were identified 193 peaks; for slices coated with CH, 211 peaks; for slices coated with SA 157 peaks; for those coated with CC 199 peaks, and, for CC + CH, 239 peaks of volatiles. The 1-hexanol was not identified in slices coated with chitosan and a-humulene was not much expressive in slices coated with alginate, both terpenes with high odor power in guava. The major compound identified in slices of all coatings was the a-caryophyllene, a terpene typical of ripe guava. Coating slices with chitosan resulted in a reduction of the area of the volatile peaks in fresh cut 'Paluma' guava, which may indicate a delay in ripening.

Influence of different MA films on the quality of fresh-cut peach palms

Silvia Regina de Toledo Valentini (Instituto Agronomico de Campinas, State of São Paulo, Brazil), Sylvio Luís Honório (Universidade Estadual de Campinas, State of São Paulo, Brazil), Maria Fernanda Demonte Moretzsohn de Castro(Instituto de Tecnologia de Alimentos,State of São Paulo, Brazil), Claire Isabel Grigoli de Luca Sarantopoulos (Instituto de Tecnologia de Alimentos,State of São Paulo, Brazil),Antonio Carlos de Oliveira Ferraz (Universidade Estadual de Campinas, State of São Paulo, Brazil), Giuseppina Pacce Pereira Lima (Universidade Estadual Paulista Julio de Mesquita Filho, State of São Paulo, Brazil)

Influence of different MA films on the quality of fresh-cut peach palms Valentini, S.R.T. 1 *; Honório, S.L. 2; Castro, M.F.P.P.M.3; Sarantopoulos, C.I.G.L.4; Ferraz, A.C.O5; Lima,G.P.P.61 Instituto Agrononômico de Campinas, Campinas,State of São Paulo, 2Universidade Estadual de Campinas,Campinas, State of São Paulo,Brazil, 3Instituto de Tecnologia de Alimentos, Campinas,State of São Paulo, Brazil, 4Instituto de Tecnologia de Alimentos, Campinas,State of São Paulo,Brazil, 5 Universidade Estadual de Campinas,Campinas, State of São Paulo,Brazil, 6 Universidade Estadual Paulista Julio de Mesquista Filho, Botucatu,State of São Paulo, BrazilPeach palm has been cultivated for canned heart of palm due to the extinction of Juçara palms (Euterpe edulis Mart.). Differing from the palms of the genus Euterpe, there is no enzymatic browning in Peach palm tissues, allowing the commercialization of fresh-cut hearts of palm. The objective of this study was to evaluate the effect of modified atmosphere packaging systems and refrigeration for fresh-cut Peach palm conservation. Peach palm hearts were packed with stretchable polyvinyl chloride (PVC) and low density polyethylene (LDPE) films and with a multilayer polyolefin film (CT301) and stored at 5 degrees C for 15 days. The concentration of O2, CO2 and C2H4 inside the packages was determined by gas chromatography, and the fresh-cut hearts of palm analyzed for pH, titratable acidity, soluble solids, color, weight loss, firmness, peroxidase and polyphenoloxidase activity, total polyphenol content, total aerobic psychrotrophic and mesophilic yeasts and molds. The use of PVC resulted in lower concentrations of O2 and C2H4 and higher CO2 inside the packages compared to LDPE and CT 301. The low O2 concentration inside the PVC packages reduced microbial deterioration; while the high concentration of CO2 did not have inhibitory effect on C2H4 and peroxidase specific activities. There was a positive correlation between peroxidase specific activity and the increase in firmness of fresh-cut hearts of palm. Fresh-cut hearts of palm packed in PVC and stored at 5.0oC were microbiologically safe up to the 15th day of storage, and those packed in LDPE and CT301 up to the 6th day.

Packaging Fresh-cut Products

Jeff Brandenburg, President, JSB Group LLC

Modified Atmosphere Packaging in one of the key technologies associated with the shelf life extension of fresh produce. MAP for fresh produce is a complex packaging application as the produce in the bag continues to respire, consuming O2 and giving off CO2. To design and optimize MAP, one first must quantify produce respiration rates (RR). Therefore when designing modified atmosphere packaging (MAP) for fresh produce the convergence of three distinct sciences must take place – produce physiology, polymer engineering and converting technology.

We will discuss the technology, materials, and applications of modified atmosphere packaging, MAP. Discussion will include the symbiotic relationship between the packaging and the produce and the importance of produce physiology when specifying packaging systems. Specific polymers, films, and structures will be reviewed with respect to their individual properties and subsequent impact on MAP. An analysis of packaging types and formats will also be detailed. Additive technologies such as antimists, slip, and antimicrobials, and their impact on the functionality of MAP will be explored. Common reasons why MAP fails will also be reviewed. We will conclude with some of the newest emerging modified atmosphere packaging technologies, such as MAP as a technology platform a marketing and branding tool as well as sustainability.

Postharvest shelf-life extension of pomegranates using Breatheway modified atmosphere packaging technology

Shehbaz Singh (Apio Inc.,California)Angel Reyes (Apio Inc.,California)Mehmet Seckin ADAY (Cal Poly, California)

Pomegranate is known as a non-climacteric fruit and has a shelf-life longer than two months if stored between 0 degrees C and 10 degrees C. Weight loss, discoloration and mold growth are the main problems that limit the storage of fruit. MAP technology maintains the postharvest quality of fruits by lowering respiration rate, enzymatic activity and preventing weight loss and softening. In this work, the effect of different BreatheWay membranes with different permeability and different packaging films (Nylon & LDPE) on 30 lb. pomegranate fruits (var. Wonderful) were investigated during 3 months storage at 4 degrees C. Pomegranates under air conditions were selected as control. Gas compositions inside package, pH and weight loss analysis were performed to monitor quality of pomegranate.Among the nylon group, C and D membrane design treatments maintained the O2 and CO2 levels around 6 % during the storage whereas O2 and CO2 concentrations were around 2% and 12% for E treatment, respectively. Among the LDPE group, CC and DD treatments maintained the O2 and CO2 levels around 5 % during the storage. At the end of the storage, all films delayed the changes in Brix level and weight loss of pomegranates better than the fruits stored under air conditions.

Profile of volatile compounds as a quality marker of MA-packaged fresh-cut melons

Victor Rodov (ARO, The Volcani Center, Israel)Ranjeet Shinde (ARO, The Volcani Center, Israel) Yakov Vinokur (ARO, The Volcani Center, Israel) Batia Horev (ARO, The Volcani Center, Israel) Elazar Fallik (ARO, The Volcani Center, Israel)

Marketing melons as ready-to-eat fresh-cut products is a growing trend in many countries. However, mechanical damage promotes physiological deterioration, biochemical changes and microbial colonization resulting in quality degradation and food safety hazards. Packaging under modified atmosphere (MA) is one of the major approaches to ensure a reasonable shelf-life of fresh-cut produce. The profile of volatile compounds (VOC) is an important quality attribute of climacteric melons of cantalupensis group. The objectives of the study were to investigate the efficacy of different MA packaging types to preserve the quality of fresh-cut melons, and to check the possibility of using VOC profile as a quality marker of fresh-cut melons. The results of the work confirmed the efficacy of MA packaging for preservation of fresh-cut melons. The solution selected for cantalupensis Galia-type melons was based on microperforated passive MA allowing quality preservation for 14 days at 7 degrees C. Microbial spoilage and anaerobic fermentation were the major factors limiting the shelf life of fresh-cut melons. Keeping the products in non-perforated packages resulted in generation of fermented off-flavor indicated by accumulation of ethyl acetate. Statistical hierarchical cluster analysis confirmed that maintaining a genotype-specific VOC profile is a marker of acceptable quality of fresh-cut melons while deviation from this profile indicates product deterioration. The microbial spoilage was associated with degradation of typical melon aroma compounds and/or accumulation of abnormal VOCs. Various types of spoilage microorganisms (lactic acid bacteria, yeast, mold) had their characteristic patterns of VOC change opening a potential for diagnostics of spoilage causes by VOC analysis.

Simulation Studies for Export Minimally Processed Durian by Air Shipment to Hong Kong

Nur Azlin, R. (MARDI), Latifah, M.N. (MARDI), Siti Aisyah, A. (MARDI), Pauziah, M. (MARDI), Zaipun, M.Z. (MARDI), Nurul Adibah, M. (MARDI), Zainab, M.Y. (MARDI), Hairiyah, M. (MARDI), Habsah, M. (MARDI), Razali, M. (MARDI), Zaulia, O. (MARDI), Nur Syafini, G., Joanna, C.L.Y. and Nur Alisha, O (MARDI).

Simulation studies for export minimally processed durian by air shipment to Hong Kong was conducted using newly dropped Mousang King durian. Two packing systems were evaluated by using rectangular polypropylene (PP) container (size; 185X125mm with shrink wrapping/400g/pack (a) and square PP container (size; 110x110mm) with seal packing/200g/pack (b). All samples were stored in -18 degrees C for 5 weeks. Following that, samples were transferred to 2 degrees C for 7 days to simulate retail condition at Hong Kong. Physical changes (colour and visual appearance), chemical changes (total soluble solid), and sensory acceptance were observed daily. Microbial counts (yeast and mould, total coliform, mesophilic aerobes) were also monitored to relate with product safety. Minimally processed durian in both packing systems (a and b) maintained its quality till the end of the 7 days storage as noted by only slight variation of chemical-physical parameter results. However, there are significant difference in the microbial counts as minimally processed durian packed in square PP container with seal packing (b) showed lower microbial aerobes as compared to packing using shrink wrap (a). Total coliform, yeast and mold also showed similar findings. Thus, the results revealed that smaller packing system using seal packing was more suitable for packing minimally processed durian for export by air shipment to Hong Kong.

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