Changes in free amino acid and vitamin C contents and viable bacterial count of half-dried cabbage during preservation
2008
Yaghi, S.(Nippon Veterinary and Life Science Univ., Musashino, Tokyo (Japan). Faculty of Applied Life Science) | Egawa, M. | Otoguro, C. | Hara, H. | Kaneko, K.
We propose that half-dried cabbage is a very useful processed form of cabbage, because the appearance of its rehydrated form is almost the same as those of fresh cabbage; moreover, its microbial count showed no increase over a 3-week preservation, its gamma-amino butyric acid content tended to increase, and its vitamin C was held constant. To produce half-dried cabbage, shredded cabbage was dehydrated up to 70% its original weight by vacuum drying at 50 hpa at 50degC. The dried cabbage was stored at -2 and 5degC. During 3 weeks of preservation, we analyzed the free amino acid and vitamin C contents of the cabbage once a week. We also measured the total bacterial and coliform counts, as well as the rehydration ratio of the sample immersed in water. The rehydration ratios of the dried cabbage samples preserved at 5 and -2degC decreased by 12.7% and 14.9%, respectively, after 3 weeks. The dried sample stored at -2degC did not freeze even with more than 2 weeks of preservation, and the rehydrated form of this sample hardly differed from fresh cabbage in appearance. Throughout the storage at both 5 and -2degC, the content ratio of glutamic acid to total amino acid decreased and that of gamma-amino butyric acid content to total amino acid increased even though total amino acid content showed no change. Total vitamin C content seemed to remain unchanged, and the content ratios of both ascorbic acid and dehydroascorbic acid to vitamin C hardly varied throughout the preservation. The total bacterial and coliform counts of the dried sample hardly changed during preservation at both 5 and -2degC.
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