17D-7 |
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T. FURUTA1, E. Miyawaki1, H. Yoshii1, M. Ohishi2, and K. Ogawa2. (1) Dept. of Biotechnology, Tottori University, 4-101, Koyamacho-minami, Tottori, 680-8552, Japan, (2) Research Institute, Nihon Shokuhin Kako Co., Ltd., 30, Tajima, Fuji, Shizuoka, 417-8530, Japan To control the coloring of the seasoning liquid of pickles is very important problem for the preservation. The eggplant pickles are common food in Japan, which is made by pickling the sliced eggplants into a special seasoning liquid. During storage, the color of the seasoning liquid often changes into an unappetizing purple. The coloring is considered to be the result of the chemical binding of nasunine of the eggplant with the alum in the seasoning liquid. We tried to minimize the coloring by the addition of several poly-saccharides to the seasoning liquid. The objective was to study the effect of the addition of poly-saccharides on minimizing the coloring of the seasoning liquid in the eggplant pickles. Nasunine was extracted by immersing the sliced eggplant into 50 mM KH2PO4 buffer at pH 6 for 5 days. b-Cyclodextrin, glucose and four types of maltodextrins of different DE (dextrose equivalent) were chosen as poly-saccharides. Titration experiments were used to evaluate the decolorization effect of each of the poly-saccharides. The absorbance of nasunine at 580 nm was decreased with the addition of each of the poly-saccharides. The differential absorbance at 580 nm increased in directly proportion to the amount of each poly-saccharide. b-Cyclodextrin and maltodextrin showed to be effective in removing the purple coloring of nasunine. This implies that the higher the molecular mass, the better the decolorization effect. High molecular mass sugars such as b-cyclodextrin and maltodextrin were found to be effective for minimizing the purple coloring of the seasoning liquid of eggplant pickles. This implies that the poly-saccharides may inhibit the stacking formation by entering between the co-pigment structures of nasunine. b-Cyclodextrin was also effective at lower concentrations due to its ability to include the aromatic part of nasunine molecule in its molecular cavity.
Session 17D, Food Chemistry: Chemical effects of food processing and preservation
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