• Food Science and Preservation
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• v.16 no.1
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• pp.122-127
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• 2009

This study was to separate wild yeast from the Houttuynia Cordata Thunb(HC) extracts fermented in traditional way and investigate the characteristics of fermentation from the HC extracts. As a result, the longer the cultivation time, the more the contents of alcohol in $15^{\circ}Brix$ sugar solutions increased. When it reached to 90 hours since it cultivated, it ranked HCE 12%, HCD 11.2%, and HCA 10.5% in order. As for HCF, HCG, HCB, and HCC), this study has shown that the contents of alcohol were from 7.5% through 8.5%. As a result of selecting germ strains like HCE and HCD with the highest alcohol-genicity in the sugar solutions as separated yeast from HC and of comparing and reviewing the existing Saccharomyces germ strains and fermentation power in the medium of HC(Juice extraction of HC : Distilled water(1:1), this study has found out that 'pH' decreased from $4.09{\sim}4.12$ before fermentation through $3.57{\sim}3.78$ after fermentation. And, the sugar concentration decreased from $15.00{\sim}15.19^{\circ}Brix$ through $7.75{\sim}9.57^{\circ}Brix$ before fermentation. Also, the acid value increased from $0.138{\sim}0.210%$ before fermentation through $0.282{\sim}0.45%$ after fermentation. In addition, as the contents of alcohol became $3.6{\sim}4.6%$ after fermentation, isolates HCD and HCE from HC had higher value rather than ones of DJ97, YJK, R12, and RCY separated from persimmons, apples, and grapes. The result value of color was minimum $4.75{\pm}1.44$ and maximum $6.85{\pm}1.63$, and HCE marked the highest record among the items of sensory evaluation. The overall acceptability was in normal level like minimum $3.95{\pm}1.17$ and maximum $5.00{\pm}1.41$. It is considered as it could lower sensory evaluation because the acceptability of flavor was not satisfied. After all, the significance(p<0.05) among the germ strains was not recognized in aspects of color, flagrance, flavor, and overall acceptability.

• Food Science and Preservation
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• v.15 no.1
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• pp.49-57
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• 2008

This study was conducted to develop an optimal composite recipe for a cookie including yam powder that would be attractive to all age groups. Wheat flour was partially substituted by yam powder to reduce the content of wheat flour. This study has produced the sensory optimal composite recipe by making cookies, respectively with each 5 level of yam powder $(X_1)$, Sugar$(X_2)$, butter$(X_3)$, by C.C.D (Central Composite Design) and conducting sensory evaluation and instrumental analysis by means of RSM (Response Surface Methodology). Sensory items showed very significant values in color, softness, overall quality (p<0.01), flavor (p<0.05) and those of instrumental analysis showed significant values in lightness, redness (p<0.05), spread ratio, hardness (p<0.01). Also sensory optimal ratio of yam cookie was calculated at yam powder 37.35 g, sugar 50.75 g, butter 78.40 g and it was revealed that the factors of influencing yam cookie aptitude were in older of yam powder, butter, sugar.