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1994 - 19992
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Subject: Processing and Food Engineering × End date: 1999 × Start date: 1980 × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Consumer packaging of selected vegetables
    (Department of Processing Technology, College of Horticulture,Vellanikkara, 1994) Sunil Kumar, G; KAU; Raju, V K
    The present study on “Consumer packaging of selected vegetables” was conducted in the Department of Processing Technology, Kerala Agricultural University, Vellanikkara during June 1992 to October 1993. The study on standardization of precooling treatments to improve the postharvest life of the vegetables viz., amaranth, brinjal, chilli, cowpea, okra and tomato revealed that precooling the vegetables immediately after harvest reduced the physiological loss in weight (PLW) and enhanced the marketability both under ambient and refrigerated storage environments. The effect of precooling treatments was more pronounced when precooling was immediately followed by refrigerated storage. Among precooling treatments, contact icing and cold water treatments were found superior to tap water treatment in most of the cases. The study on precooling and packaging treatments on amaranth, brinjal, chilli, cowpea, okra and tomato revealed that precooling followed by immediate packaging of the vegetables in 100 or 200 gauge polyethylene or polypropylene bags reduced the PLW considerably. Moreover, packaged vegetables had better consumer acceptability and has remained marketable for longer periods both under ambient and refrigerated storage conditions. In most of the cases, contact icing and cold water treatments gave better results among precooling treatments. With respect to packaging, under ambient temperature storage, 100 or 200 gauge polyethylene or polypropylene bags with 0.5 per cent ventilation was found to be ideal except in okra where unventilated polybags was the best. In refrigerated storage for brinjal, chilli and tomato, polybags with 0.5 per cent ventilation was found to be ideal. For amaranth, cowpea and okra polybags without ventilation was found to be more efficient. Refrigerated storage enhanced the shelf life of packaged vegetables 3-4 times as compared to packaged vegetables kept under ambient temperature storage. The storage study on precooled portioned vegetables viz., ashgourd, elephant foot yam, oriental pickling melon, pumpkin and snakegourd packaged in polymeric films revealed that portion packaged vegetables had lower PLW and remained marketable for longer periods both under ambient and refrigerated storage environments. Wilting, shrinkage, shriveling, discolouration and microbial rotting were the common types of spoilage in packaged vegetables. Cost- wise, among precooling treatments, tap water treatment was the cheapest followed by cold water and contact icing. Among polybags polypropylene was cheaper compared to polyethylene.
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    ThesisItemOpen Access
    Evaluation of sapota (Manilkara achrar (Mill) Forberg) for postharvest qualities
    (Department of Processing Technology, College of Horticulture,Vellanikkara, 1999) Maya, T; KAU; Jacob John, P
    A study on the screening of post-harvest qualities of five varieties of sapota grown In the college orchard was conducted at the Department of Processing Technology, College of Horticulture, Vellanikkara during 1998-99. On screening varieties like 'Cricket Ball', 'Co-I', 'Co-2', 'PKM l' and 'Oval' for physical, chemical and sensory parameters, 'Co-2', 'PKM l ' and 'Oval' were rated best for table purpose, while 'Co-2' for distant marketing and 'Co-I' for processing qualities. Individually wrapping the fruits with cling film, or packaging fruits with 30 per cent moistened saw dust was evolved as the best storage technique to extend the shelf-life of sapota at ambient temperature. Saw dust being cheap, and less labour intensive can be suggested as an appropriate storage technique at field level without the involvement of any chemical, electricity or civil structure, while cling wrap can be aimed for retail marketing. Osmotic dehydration of sapota slices of thickness 0.5 to 1 cm using dry sugar containing 1500 ppm S02 and 0.3 per cent citric acid in a ratio of 1: 1 for eight hours followed by oven drying took only 16 hours to accomplish the drying unlike the reported 33 hours of osmo-air drying. Thus the technique developed can improve the quality of the product many fold and can reduce the energy consumption considerably.