Quality and Safety of Fresh-Cut Vegetables and Fruits

Non-Technical Summary:<br/>
Relevant information will be available to fresh-cut processors to assist them in making decisions on harvest maturity, processing procedures, handling and packaging conditions to best maintain fresh-cut product quality and safety. The fresh-cut industry will achieve considerable savings (potentially millions of dollars a year) from reductions of product losses and recalls. Consumers will benefit from increased availability of fresh-cut products with improved sensory quality and higher nutritional value through improvements in cultivars and more effective preparation and handling practices. Incidence of fresh-cut products at retail with insufficient shelf life for consumer satisfaction will decrease. Human health will be improved as a result of increased consumption of vegetables and fruits. Availability of best-practice guidance and standardized methods for food safety risk assessments of fresh-cut product treatments will reduce the likelihood of food safety events by replacing ineffective food safety practices with science-based procedures. Food safety risk will be reduced through availability of new, more efficacious, strategies for controlling human pathogens. Researchers will have standard protocols for quantifying flavor-based shelf life and standard microbiological methods. Longer-term scientific benefits will be derived from obtaining a better understanding of ethylene and stress physiology of wounded plant tissues.
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Approach:<br/>
All produce will be appropriately prepared and cut under highly sanitary conditions at refrigerated temperatures where the processing area, tools, and gloved hands are appropriately sanitized and personnel wear proper clothing to protect the cut produce from contamination. Standard sanitation procedures to be used in conducting experiments will be determined by consensus of the participants. Any post-cutting treatments and packaging will also be performed using good manufacturing practices. After treatment, the fresh-cut products, along with intact control samples, will be stored using appropriate refrigerated temperatures and durations depending on the commodity, its stage of maturity at harvest or upon treatment, and the storage temperature of the intact produce prior to processing.Standard sensory and instrumental measures of flavor quality to be used in work encompassing the first three objectives will be developed by project members in CA, FL, ARS-FL, and ARS-LA. Visual quality of fresh-cut products will be evaluated by applying standard hedonic scoring systems. Since apparent responses to temperature, ethylene, etc. can be strongly affected by different fresh-cut preparation procedures, certain basic preparation procedures such as slicing procedures, slice or chunk sizes, and sanitation methods will need to be agreed upon.Flavor-related factors will be measured upon sampling or removal from packages or storage containers after a standard, specified period of time at a specified temperature. Objective 2 Procedures: 1) We will work with public and private entities to identify germplasm with outstanding sensory quality. 2) We will identify optimum initial (whole product) quality factors relating to improved flavor-based shelf life. 3) We will investigate improved processing and packaging strategies to better maintain fresh-cut product quality as compared to standard commercial practices. Objective 5 Procedures: 1) test novel intervention strategies and compare to standard commercial practices Commodity tolerance at different maturity stages to hot water immersion over a range of temperatures and effects on pathogen populations will be determined (FL, ARS-PA).Whole produce (tomatoes, pineapples, mango) will be inoculated with the appropriate pathogen of interest or its surrogate to give an initial microbial load of 106 CFU/g. The potential for reducing the transfer of microorganisms of interest from the peel to the flesh of produce during fresh-cut preparation will be evaluated by testing of fresh-cut pieces for pathogen contamination. The potential for injured cells of interest to grow following storage will be also evaluated after 1 to 21 days in storage by plating to selective and nonselective media. Subtracting populations enumerated on selective media from those on nonselective media gives an estimate of the number of injured cells present. The impact of hot water immersion on the produce quality will be evaluated using sensory evaluation and chemical and flavor analyses in conjunction with physiologists and food scientists working on Objectives 1-3 (CA, FL, ARS-FL, ARS-LA).
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Progress:<br/>
2012/01 TO 2012/12<br/>
OUTPUTS: Activities: Teaching: (1) development of slides (text and images) for two PowerPoint presentations, and (2) addition of these new educational materials to the curriculum. Research: (1) processing of whole celery into 4 inch sticks, (2) fresh-cut celery sanitation (chlorine (50 and 100 ppm) and sanitizer based on citric acid at the recommended concentration and at half of this), (3) fresh-cut celery packaging (nitrogen (100%), oxygen (100%), helium (100%), air (21% oxygen/0.03 carbon dioxide), and a blend of 15 % carbon dioxide and 5 % oxygen), (4) packaged produce storage (treatments and controls) in controlled-temperature chambers at 3 C for two weeks, (5) produce quality assessment (respiration rate, color, texture, off-flavor, density (pithiness) and spoilage microorganisms growth (bacteria and fungi)), (7) development of a new method to evaluate celery bending, (8) development of a color scale for stored fresh-cut celery, (9) discriminatory sensory tests, (10) establishment of correlations between instrumental and sensory results.
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Products: Curricula products: two new presentations (classes) offered through Adobe Connect for an on-line course focused on shelf life of perishables (PKG 491). Research products: (1) establishment of a panel of trained panelists, (2) new method to measure bending in celery and related fresh produce during sensory evaluations, (3) knowledge of the effect of the gas composition on the respiration rate, microbial growth, and color of fresh-cut celery, (4) knowledge of interactions between gas compositions/sanitizer, (5) identification of the best performing packaging gas compositions to be used in future experiment. Events: Ryser, E.; Mark, B.; Almenar, E.; Dolan, K.; Vorst, K.; Wojtala, G.; Schaffner, D.; Scharff, R.; Beaudry, R.; Rubino, M.; Jeong, S.; Siddiq, M.; Harte, J. Minimizing Microbial Food Safety Hazards of Fresh and Fresh-cut Fruits and Vegetable. United Fresh 2012 Convention. May, 1. Dallas, Texas, USA.
<br/>PARTICIPANTS: INDIVIDUALS (1) Projector director: Dr. Eva Almenar, School of Packaging-MSU, (2) Collaborators: Dr. Randy Beaudry, Horticulture-MSU, Dr. Janice Harte, Food Science and Human Nutrition-MSU, Dr. Elliot Ryser, Food Science and Human Nutrition-MSU, PARTNER ORGANIZATIONS: USDA NIFA NIFSI, TRAINING OR PROFESSIONAL DEVELOPMENT: (1) Graduate students: Natalie Page, Hunter Gartner, Maruscha Pranata, Georgios Koutsimanis, (2) Undergraduate students: Shelby Curlew (2) Visiting scholars: Dr. Kojo Afrifah. TARGET AUDIENCES: (1) growers (2) package end users (3) produce industry PROJECT MODIFICATIONS: Not relevant to this project.
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IMPACT: (1) The effect of gas compositions on the physico-chemical quality and sensory quality of fresh-cut celery has been characterized. (2) A new method to measure bending in celery and related fresh produce during sensory evaluations has been developed. (3) Interactions between sanitizer and gas composition have been identified.