99D-14 |
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F.-M. LIN, H.-H. Chiu, H.-Y. Chan, and C.-C. Liao. Bioresources Collection & Research Center, Food Industry Research & Development Institute, PO Box 246, HSINCHU, 300, Taiwan Pickled mustard is a traditional food in Taiwan. Local people make soups or dishes with it for its pleasing and tasty sour flavor. Lactic acid bacteria (LAB) were found to play an important role during the pickling period. Kinds of organic acids contributed by LAB not only brought the taste but also inhibited the growth of some spoilage microorganisms. Acidity of pickled mustard is the major index for commercial products either on the acceptance of consumer or the preservation. The purpose of this study focuses on the isolation of LAB from pickled mustard and brine samples and the capability of acid production of the screened isolates. 13 LAB isolates LA, LB, LC, LD, LE, LF, LG, LH, SA, SB, SC, SD, and SE were obtained from pickled mustard and brine that collected in Taiwan by two selective media: Lactobacilli MRS agar and BCP Plate Count Agar. In addition, eight BCRC LAB strains, which were isolated from fermented vegetables, were chose in this study for reference in the acid production. After culturing all the isolates and strains in MRS broth at 37°C for 24 h, LC, SA and BCRC 10069 were chose for further fermentation for more acids were produced (the titratable acidity were 1.61%, 1.54% and 1.60%, respectively) than others. Interestingly, LC, SA and BCRC 10069 showed no growth when inoculated back to the original brine. However, if we adjusted the pH from 3.76 to 6.5 and supplemented the brine with suitable carbon and nitrogen source, the growth rate and acid-production of SA was significantly improved after fermented for three days. The viable counts were up to 108 CFU/mL and showed no reduction to seven days. The titratable acidity reached to 1.29% at the 7th day, which was increased 1/3 than the original.
Session 99D, Food Microbiology: General
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