• Food Science of Animal Resources
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• v.22 no.1
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• pp.59-65
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• 2002

This study was carried out to evaluate the effect of whey protein concentrate-80%(WPC-80) and whey protein isolate(WPI) on the growth of B. bifidum Bb-11. Whey proteins($\alpha$-lactalbumin, $\beta$-lactoglobulin) were digested with trypsin, then their hydrolyzates were separated into three fractions (>10,000Da, 3,000∼10,000Da, <3,000Da) by two-step ultrafiltration process with Centriprep 10 and Centricon-30. These three fractions by molecular weight were evaluate growth-promoting effects for the B. bifidum Bb-11. The results obtained were summarized as follows; The growth rate of B. bifidum Bb-11 tended to increase by supplementation of WPC-80 to basal medium, but decreased by supplementation of WPI. Two whey proteins were hydrolyzed by trypsin at 40$\^{C}$ for 6 hrs, and three fractions were collected by UF treatment and concentrated by Centricon-30. Collected concentrations of protein of F-I and F-II and F-III from $\alpha$-lactalbumin were 11.53mg, 7.79mg, and 5.21 mg and those of protein from $\beta$-lactoglobulin were 4.13mg, 5.30mg, and 9.351mg, respectively. Three fractions of $\alpha$-lactalbumin hydrolyzates promoted the growth rate of B. dbifidum Bb-11. Growth promoting activities of hydrolyzates(F-I and F-II) with molecular weight below 10,000Da were stronger than that of hydrolyzate(F-III) above 10,000Da. However, there was no significant difference between the hydrolyzate F-I and F-II. Three fractions of $\beta$-lactoglobulin hydrolyzates improves the growth rate of B.bifidum Bb-ll. The growth of B.bifidum Bb-ll was decreased after 24 hr incubation by supplementation of either F-II or F-III fraction compared to basal Whey medium, but maintained the enhancement by supplementation of F-I.

• Korean Journal of Food Science and Technology
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• v.54 no.4
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• pp.445-454
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• 2022

This study aimed to improve the physiological activity of onion juice via lactic acid bacterial fermentation. Seven types of lactic acid bacteria were used for the fermentation of onion juice. The pH and sugar content of the onion juice decreased, while its titratable acidity increased after lactic acid bacteria fermentation, and the cell count of lactic acid bacteria was 7.31-10.40 log CFU/mL. The total free sugar content decreased, while the total organic acid content increased in the fermented onion juice. Quercetin content of the fermented juice was 0.13-0.53 mg/kg. The total polyphenol and flavonoid contents increased after fermentation. Additionally, the 2,2-diphenyl-1-picryl-hydrazyl-hydrate free radical and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonate) radical cation scavenging activities were increased by fermentation. Overall, lactic acid bacteria fermentation of onion juice enhanced its physiological activity. Based on these findings, Bifidobacterium breve KCTC 3441 was selected as the onion juice fermentation strain.