• KSBB Journal
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• v.19 no.6 s.89
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• pp.484-488
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• 2004

Fermentation studies were conducted in batch and continuous flow cell-recycle reactors with food by-products as substrates. The genus Propionibacterium acidipropionici ATCC 4965 was utilized in the production of organic acids. Good performance was achieved in the batch fermentation using hydrol as a carbon source and corn steep liquor (CSL) as nitrogen and vitamin sources. Product yields and productivity based on maximum values were 0.80 g total acids/g glucose and 0.26 g total acids/L/h, respectively, when $3\%$, (w/v) of hydrol and $2.5\%$, (w/v) of CSL were utilized. Continuous fermentation with cell-recycling system using the optimum amounts of substrates resulted in dramatic increase in cell concentration (X) and maximum productivity (P). Compared to the batch fermentation, X and P were increased by as much as 21 and 13 times, respectively, at the dilution ratio of $0.2\;hr^{-1}$, indicating that cell recycling fermentation of food by-products provides valuable means for the mass production of organic acids as well as utilizing cell mass as good nutrient resources.

• Journal of the Korean Society of Food Culture
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• v.5 no.4
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• pp.431-436
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• 1990

The functional properties of novel sugar derivative sweeteners, fructo-oligosaccharide, maltitol, sorbitol and high maltose syrup(HMS) were examined for their humactant effect, lactic acid bacterial growth, Streptococcus mutants growth and relative sweetness compared to sucrose. Sorbitol exhibited remarkably high water activity reducing capacity, whereas fructo-oligosaccharide and maltitol showed the same level as sucrose. Maltitol showed distinct anti-bacterial(bacteriocidic) effect against Stc. mutants and most of lactic acid bacteria tested except for L. plantarum. The molar basis relative sweetness of sugar derivatives in comparison with 1%(w/w) level of sucrose were 0.69 for Neosugar(fructo-oligosaccharide), 0.21 for sorbitol, 0.50 for maltitol and 0.27 for HMS.

• Microbiology and Biotechnology Letters
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• v.33 no.4
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• pp.288-294
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• 2005

Flavonoid compounds show several biological activities and generally exist in the forms of glycones linking sugar moiety to main structure. Flavonoid glycones such as naringin and hesperidin in korean citrus peel are slower absorbed and consequently less active than their aglycone, naringenin and hesperetin, respectively. Therefare to increase the content of flavonoid aglycone in korean citrus peel, we used commercial carbohydrate-hydrolysing enzymes, AMG 300 L, Pectinex 100 L, and Viscozyme for transforming flavonoid glycones to aglycones. Optimal conditions of enzyme reaction were pH 5.0-7.0, $5\%$ enzyme, and 24-48 hrs. The content of naringenin and hesperetin as flavonoid aglycones in untreated citrus peel is $100\~200\;ng/g$ of dried citrus peel. In case of enzyme-treated citrus peel the content of naringenin and hesperetin increased to $1,539\∼6,674\;ng/g\;and\;1,974\∼8,906\;ng/g$ of dried citrus peel, respectively. Finally the content of flavonoid aglycones could be extracted to 10-80 times. Now enzyme-treated citrus peel may be applied to use for functional food because of its higher flavonoid aglycones as more active compounds.