Title: TECHNIQUES FOR QUALITY MAINTENANCE AND EVALUATION OF FRUITS AND VEGETABLES
Submitted to: Postharvest International Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: December 15, 2001
Publication Date: N/A
Interpretive Summary: Fresh fruits and vegetables deteriorate rapidly after harvest. Loss of moisture, decrease in firmness, discoloration, and off-flavor contribute to the decline of quality. Mold growth and decay further shorten the postharvest life of fresh produce. It is important to handle fruits and vegetables properly and take precautionary measures using various techniques to reduce deleterious changes, maintain desirable quality, and prolong storage and shelf-life. Quality of fruits and vegetables can be measured subjectively by sensory evaluation or objectively by the use of instruments. These measurements can be destructive or nondestructive. Techniques which can be used for quality maintenance and evaluation are summarized in this manuscript. Information presented in this paper is useful for other postharvest researchers and for the fresh produce industry.
Fresh fruits and vegetables are highly perishable and their quality declines rapidly after harvest, especially if proper postharvest handling procedures are not followed. Changes in color, texture, nutrition, and flavor all affect the market quality of fruits and vegetables. Other factors which contribute to the decline of quality are bruising, mechanical injury, physiological disorders, and pathological diseases. Desirable quality maintenance can be achieved by harvesting fruits and vegetables at optimal maturity and storing them at proper temperature, humidity, and atmosphere. Good sanitation is also important to reduce losses due to contamination and diseases. Quality evaluation includes measurements of color, texture, flavor, and nutritional value. Methods for measuring these quality attributes can be destructive or nondestructive. Color can be measured with a colorimeter. Texture can be assessed by several instruments using puncture, compression, deformation, or shearing methods. Flavor is usually judged by sensory taste panels, and volatile aroma compounds are analyzed by gas chromatography. Nutritional values are determined by chemical analysis, gas chromatography, or high performance liquid chromatography. Internal defects can be detected nondestructively by a light transmittance method or nuclear magnetic resonance imaging technique.