Food & Nutrition

Arab Journal of Food & Nutrition
40. Effect of Packaging in Three Types of Plastic Films on the Quality of Some
Selected Vegetables and Meats Stored Frozen for Six Months (2000)
Ismail Ali Al-Wahsh\ University of Jordan
Supervisor: Dr. Salma K. Tukan
Co-Supervisor: Dr. Mohammad A. Humeid
This study was conducted to investigate the effect of plastic film used in food
packaging on quality of frozen foods. Three types of plastic films were used, low
density polyethylene (LDPE), plasticized polyvinyl chloride (PVC), and laminated
polyethylene terephthalate (PET laminate). Also the effect of nitrogen gas flushing
was studied.
Two vegetables (green beans and cauliflower) and two types of meat (Iamb and
chicken) were used as models. Changes in ascorbic acid content in vegetables and lipid
oxidation in meats were used as indicators of quality, in addition to sensory evaluation
using nine-point hedonic scale test.
The results showed that nitrogen gas flushing, in general, had a Positive effect on
ascorbic acid retention in vegetables and retardation of lipid oxidation in meats.
Regarding the effect of the plastic films, packaging in bags made of PET laminate
gave the best results of ascorbic acid retention in vegetables, followed by LDPE,
whereas plasticized PVC gave the lowest retention results.
Relatively high amounts of ascorbic acid were lost from the studied vegetables
during blanching (25% in green beans and 36% in cauliflower). The losses during six
months of frozen storage ranged from 18-30% in green beans and 21-34% in
cauliflower. The vitamin losses during cooking of the vegetables after six months of
storage were also measured, and were 28% in green beans and 29% in cauliflower.
The results of lipid oxidation in meats as measured by the thiobarbituric acid
(TBA) method gave close TBA values for all packaging treatments.
The sensory evaluation showed that the type of packaging treatment did not
largely affect the sensory attributes of the studied food items.
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