2008 Annual Report
1a.Objectives (from AD-416)
Develop novel or alternative postharvest systems to maintain quality of intact and fresh-cut fruits and vegetables with consideration of cultivar selection, physical and sensory characteristics, physiology, pathology, food safety, and produce responses to non-chemical and GRAS (Generally Regarded As Safe) treatments. Apple, melon, pepper, squash, tomato, and potentially other products will be evaluated.
Develop new or improved instrumental quality measurements after elucidating the relationships between physical and sensory characteristics of intact and fresh-cut products.
1b.Approach (from AD-416)
The approaches used in this project to reach our objectives will be based on developing and integrating different technologies to achieve the desired levels of quality, stability and safety. We will integrate technologies such as cultivar selection, postharvest non-chemical and chemical treatments to prevent or decrease microbial contamination, fresh-cut processing methods, biocontrol methods, modified atmosphere packaging, and different storage regimes. Microbial assays, sensory evaluations, and a variety of instrumental methodologies will be used or developed to measure changes in produce quality and safety after treatment. Specifically, alternative processing and packaging technologies to improve shelf stability and food safety of fresh-cut products will be combined with the selection of optimal cultivars. Methods for maintaining quality of intact produce with GRAS (generally regarded as safe) substances will be optimized. Instrumental methods that better predict overall quality or specific sensory characteristics will be developed following study of the relationships between physical and sensory properties.
Carvacrol, anethole, cinnamaldehyde, cinnamic acid, perillaldehyde, linalool, and p-cymene were evaluated for their effectiveness in reducing decay and increasing antioxidant levels and activities in ‘Duke’ blueberries. Carvacrol, anethole, and perillaldehyde showed the capability to promote total anthocyanins and phenolics and enhance antioxidant activity in fruit tissues. All of the essential oils tested in this study were able to inhibit fruit decay development to some degree compared to controls. The most effective compound for mold retardation was p-cymene, followed by linalool, carvacrol, anethole, and perillaldehyde. Treatment with carvacrol, anethol, or perillaldehyde also significantly increased the levels of fructose, glucose, and citric acid. Individual flavonoids were variably affected by the essential oils. Levels of chlorogenic acid, which was the major phenolic compound in blueberry fruit, were enhanced by all of the essential oils in this study. Increased amounts of quercetin 3-galactoside and quercetin 3-arabinoside were generally found in treated fruit. The levels of individual anthocyanins including malvidin 3-galactoside, petunidin 3-galactoside, delphinidin 3-galactoside, petunidin 3-glucoside, petunidin 3-arabinoside, delphinidin 3-arabinoside, and cyaniding 3-galactoside were generally higher in treated fruit compared to controls. These essential oils have positive effects on enhancing anthocyanins, phenolic compounds and antioxidant activity of fruit, but decreased microbial growth and decay development. This research is under National Program 306, Component I, Problem Areas 1a, 1c and 1d; and ARS Strategic Plan Goal 2, Performance Measure 2.1.2 (Goal 2, PM 2.1.2.).
Fruits of a new apple germplasm collection from the center of origin in Kazakhstan, maintained in Geneva, NY and representing a much broader gene pool than that used by apple breeders, were evaluated for postharvest physiological characteristics and resistance to blue mold caused by Penicillium expansum. Fruits of all accessions were harvested at the preclimacteric to climacteric stage with early-season genotypes generally have higher climacteric respiration and ethylene production rates than late-season genotypes. Among apple accessions, SS ranged from 8.6 to 20.4 % and TA from 0.2 to 2.4 %. For each accession-harvest season, six were classified as immune (no decay when wound-inoculated with spores at 3 or 4 log/mL), 27 as resistant (no decay at 3 log/mL), 34 as moderately resistant (=20 % decay at 3 log/mL) and 108 as susceptible (>20 % decay at log 3/mL). Across accessions, correlation coefficients between decay incidence and physiological characteristics were generally small indicating that factors other than fruit maturity were influencing decay. The results indicate a great diversity among the accessions in the Kazak apple collection not only in physiological characteristics but also in susceptibility to decay. This research is under National Program 306, Component I, Problem Areas 1a, 1c and 1d; and ARS Strategic Plan Goal 2, Performance Measure 2.1.2 (Goal 2, PM 2.1.2.).
Postharvests decay resistance in Kazak apple collection.
It is important to find alternatives to chemicals to control postharvest decay in apple fruit. The physiology and postharvest disease resistance of >150 accessions of a new apple germplasm collection from the center of origin in Kazakhstan were evaluated for decay resistance to Penicillium expansum. Several accessions were found to have have enhanced (up to 100 fold higher) disease resistance against Penicillium expansum. Across accessions, correlation coefficients between decay incidence and physiological characteristics were generally small indicating that factors other than fruit maturity were influencing disease resistance. The results indicate a great diversity among accessions in the Kazak collection not only in quality characteristics but also in susceptibility to postharvest decay. The more resistant accessions may serve as a source of resistance in breeding programs.
National Program 306, Component Ia,c,d.
Antimicrobial effects of essential oils.
It is necessary to find alternatives to fungicides to reduce postharvest decay in blueberry. Several natural antimicrobial compounds derived from essential oils of plants were investigated for their efficacies in inhibiting decay and extending shelf-life of blueberries. The severity of decay in postharvest-stored blueberries was significantly reduced by treatment with p-cymene, linalool, carvacrol, anethole, and perillaldehyde. Treated fruit also maintained better quality by enhancing anthocyanins, phenolic compounds and antioxidant activity of the fruit. These compounds could be used by blueberry growers to reduce losses due to decay.
National Program 306, Component Ia,c,d.
5.Significant Activities that Support Special Target Populations
Wang, C.Y., Wang, S.Y., Yin, J., Parry, J., Yu. 2007. Enhancing Antioxidant, Antiproliferation, and Free Radical Scavenging Activities in Strawberries with Essential Oils. Journal of Agricultural Food & Chemistry. 55:6527-6532.
Chua, D., Goh, K., Saftner, R.A., Bhagwat, A.A. 2008. Fresh-cut Lettuce in Modified Atmosphere Packages Stored at Improper Temperatures Support Enterohemorrhagic E. coli Isolates to Survive Gastric Acid Challenge. Journal of Food Science. 73:M148-M153.
Erkan, M., Wang, S.Y., Wang, C.Y. 2007. Effect of UV treatment on antioxidant capacity, antioxidant enzyme activity and decay in strawberry fruit. Postharvest Biology and Technology. 48:163-171.
Lester, G.E., Saftner, R.A. 2008. Marketable quality and phytonutrient concentrations of a novel hybrid muskmelon intended for the fresh-cut industry and its parental lines: Whole-fruit comparisons at harvest and following long-term storage at 1 or 5 deg C. Postharvest Biology and Technology. 48(2):248-253.
Saftner, R.A., Polashock, J.J., Ehlenfeldt, M.K., Vinyard, B.T. 2008. Instrumental and sensory quality characteristics of blueberry fruit from twelve cultivars. Postharvest Biology and Technology. 49:19-26.
Wang, C.Y., Wang, S.Y., Chen, C. 2008. Incresing antioxidant activity and reducing decay of blueberries by essential oils. Journal of Agriculture and Food Chemistry. 56:3587-3592.
Zheng, Y., Fung, R., Wang, S.Y., Wang, C.Y. 2008. Transcript levels of antioxidative genes and oxygen radical scavenging enzyme activities in chilled zucchini squash in response to superatmospheric oxygen. Postharvest Biology and Technology. 47:151-158.
Wang, S.Y., Chen, C., Wang, C.Y., Chen, P. 2007. Resveratrol Content in Strawberry Fruit is Affected by Preharvest Conditions. Journal of Agriculture and Food Chemistry. 55:8269-8274.