76C-6 |
The quality change of aseptic and hot-packed orange juice in can and PET bottles during processing and storage |
K. HASHIMOTO, Central Research Laboratories, Daiwa Can Co. LTD, 5-5-1 Nishihashimoto Sagamihara, Kanagawa, 229-1183, Japan and T. Suzuki, Department of Food Science and Technology, Tokyo University of Fisheries, 5-7 Konan-4 Minato-ku, Tokyo, 108-8477, Japan. Justification: Orange juices are now sold in brick pack containers, PET bottles, glasses and cans. However, it is difficult to maintain its fresh flavor and the initial ascorbic acid level, even if fresh squeezed single strength juice was used. Objective: We used cans, which have light- and gas-barrier, and PET bottles. Quality change of orange juice in cans and PET bottles was measured during processing and storage, and the quality of aseptic and hot-pack fillings was compared. Method: In aseptic filling, fresh squeezed single strength Valencia orange juice was sterilized with high temperature short time (HTST) processing on condition when it was deoxygenated or not. Cans and lids were sterilized with retort in advance, and orange juice was filled in containers in a clean room. In hot-packing, orange juice was sterilized with HTST processing and filled at 90ßC. Samples were stored at 10ßC, 23ßC and 38ßC. L-ascorbic acid, color differences, and flavor compounds were measured. Results: The remainders of ascorbic acid were related to the amount of oxygen, and the more contents of oxygen increases, the less ascorbic acid decreases. The decreasing speed of ascorbic acid was fast until oxygen was consumed. The amount of ascorbic acid in PET bottles decreased faster than those of cans. The color differences of aseptic cans and bottles were less than those of hot-packed ones. The quantity of color differences was not related to contents of oxygen. The differences in PET bottle were more than those in cans, and flavor was more stable in cans than in PET bottles. Significance: Exclusion of dissolved oxygen from orange juice before heat processing and filling in cans aseptically was very effective to keep the orange flavor fresh and the initial ascorbic acid level.
Session 76C, Citrus: General
|