Factors Affecting The Quality of Fresh-cut Lettuce.
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Abstract
A study on factors affecting the quality of fresh-cut lettuce was conducted. The head lettuce was longitudinal cut into 1.5-2.5 centimeter wide using a sharp knife. Fresh-cut lettuces that were dipped in 1.0% citric acid solution for 5 seconds, were packed in 40 and 50 micron polypropylene bags. These vegetables were stored at 2, 5 and 10 °C. It was found that fresh-cut lettuce packed in 40 and 50 micron polypropylene bags and stored at 2, 5 and 10° had the storage life of 13, 10 and 5 days respectively. 40 and 50 micron polypropylene bags were not affected storage life. Polyphenol oxidase activity of fresh-cut lettuce that was dipped in 1.0% citric acid solution for 5 seconds, packed in 50 micron polypropylene bags and stored at 2 °C was determined. It was found that brown colour development of cutting surface and leaf rib related to increasing of the polyphenol oxidase activity. 1.0% citric acid solutions reduced the total pre-and post-storage microbial count for 3.10-4.76% in the fresh-cut lettuce. The respiration rate of the fresh cut lettuce was higher than the head lettuce for 52% and dipping in 1.0% citric acid solution increased the respiration rate of the fresh-cut lettuce for 64%.
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References
Albrecht, J.A. 1993. Ascorbic acid and retention in lettuce. J. Food Quality 16: 311-316.
Brackett, R.E. 1994. Microbiological spoilage and pathogens in minimally processed refrigerated fruits and vegetables. pp. 269-312. In R.C. Wiley (Ed.). Minimally Processed Refrigerated Fruit & Vegetables. Chapman & Hall Inc. New York
Bolin, H.R., A.E. Stafford, J.R. King and C.C. Huxsoll. 1977. Factors affecting the storage stability of shredded lettuce. J. Food Sci. 42(5) : 1319 1321.
Fujita, S., T. Tono, and H. Kawahara. 1991. Purification and properties of polyphenol oxidase in head lettuce (Lactuca sativa). J. Sci. Food Agric 55 : 643-651.
King, A.D. and H.R. Bolin. 1989. Physiological and microbiological storage stability of minimally of processed fruits and vegetables. Food Technol. 43(2): 132-139.
Kiss, I. 1984. Testing Method in Food Microbiology. Amsterdam, Elsevier Science. 447 p.
Lipton, W.J. 1987. Senescence of leafy vegetables. HortScience. 22 : 854-859.
Lopez-Galvez, G., M. Saltveit and M. Cantwell. 1996. The visual quality of minimally processed lettuces stored in air or controlled atmosphere with emphasis on romaine and iceberg types. Postharvest Biol. Technol. 8 : 179-190.
Selvarai, Y. and R. Kumar. 1989. Studies on fruit softening enzymes and polyphenol oxidase activity in ripening mango (Mangifera indica. L.) fruit. J. Ed. Sci Technol. 26(4): 218-22.
Siriphanich, J. and A.A. Kader. 1986. Effects of Co2 on total phenolics, phenylalanine ammonialyase, polyphenol oxidase in lettuce tissue. J. Amer. Soc. Hort Sci. 110: 249-253.
Vamos-Vigyazo, L. 1981. Polyphenol oxidase and peroxidase in fruits and vegetables. Critical Reviews in Food Science and Nutrition. 15: 49 127.
Whitham, F.H., D.H. Blaydes, R.M. Devin and D. Van. 1971. Experiments in Plant Physiology. Nostrand company, New York., 245 p.
Wills, R.B.H., W.B. McGlasson, D. Graham and D. Joyce. 1998. Postharvest : An Introduction to the Physiology and Handling of Fruits, Vegetables and Ornamentals. 4th ed. New South Wales University Press, New South Wales, 262 p.
