• Applied Biological Chemistry
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• v.36 no.4
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• pp.277-283
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• 1993

In order to brew foxtail millet wine, a folk wine of Cheju, properties of raw materials, optimum brewing conditions were inveatigated. Carbohydrate and crude fat content of glutinuous foxtail millet are 71.27% and 3.47%, respectively. Since the ratio of water to steamed millet and ethanol concentration of wine showed negative correlation, less than 250% water had to added to steamed millet to maintain ethanol concentration in wine above 13%, Sugar consumption and ethanol production increased rapidly for the first 2 days, and main fermentation was done in 4 days. Ethanol concentrations were $13.0{\sim}13.4%$ when foxtail millet was used, and they were $14.0{\sim}14.3%$ for the mixture substrates of 90% millet and 10% rice or barley. Organic acids in millet wine were lactic acid, malic acid and succinic acid. The residual carbohydrates after fermentation were mainly xylose and oligosaccharides. A trace of methanol was detected in millet wine. The content of fusel oil was low, while the concnetration of organic acids was high. Optimum conditions for millet wine-making were as follows. Glutinuous foxtail millet with 10% rice as fermentation source need to be soaked in water and steamed for enough time. Water was added to steamed millet with the ratio of 2 : 1. The resulting mixture was stmnultaneously saccharified and fermented by Aspergillus orzae and Saccharomyces cerevisiae IAM 4274 at $20^{\circ}C$ for a week. Millet wine was prepared after filtering fermented broth while pressing for a week.

• Korean Journal of Food Science and Technology
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• v.16 no.4
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• pp.463-471
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• 1984

For the eventual alcohol production from uncooked starch, an efficient saccharification process was examined by using the combined action of steeping, pectin depolymerase, ${\alpha}-amylase$ and glucoamylase. The total sugar content of rice, sweet potato and tapioka used were 4.53, 4.26, and 3.92 mmole/g sample. $70\;{\pm}\;10%$ of the total sugar was hydrolyzed when cooked starch was saccharified under the condition which is currently used in industry. The smaller starch particle was used, the more saccharification was obtained. Efficient saccharification was obtained by treatment with 5% $H_2SO_4$ (sample: working volume = 1:2) at $60^{\circ}C$ for 12 hr. Optimization was carried out for the saccharification of uncooked starch by the combined action of pectin depolymerase, ${\alpha}-amylase$, and glucoamylase. The conditions are: pectin depolymerase; pH 4.5, $45^{\circ}C$, 2 hr, ${\alpha}-amylase$; pH 6.0, $60^{\circ}C$, 1 hr, and glucoamylase; pH 3.5, $60^{\circ}C$, 1 hr. Simultaneous treatment of the combined action of macerating, liquifying and saccharifying enzymes yielded better result than stepwise treatment of 3 enzymes. Degrees of saccharification of uncooked tapioka, rice and sweet potato were 82, 90.5, and 84.5%, respectively on the basis of total sugar, under the optimized conditions.

• Food Science of Animal Resources
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• v.33 no.5
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• pp.646-654
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• 2013

In this study, quantitative analysis of major volatile flavor compounds from yogurt was conducted using headspace-solid phase microextraction (HS-SPME) GC-FID analysis technique, and the changes of volatile aroma compounds during the storage period were evaluated. The yogurt was prepared with the addition of 2% cereals, such as, white rice (WR), brown rice (BR), germinated brown rice (GBR) and saccharified germinated brown rice (SGBR). After fermentation, the products were stored at $5^{\circ}C$for 15 d. The major volatile aroma compounds in yogurt, such as acetaldehyde, acetone, diacetyl and acetoin were able to be extracted using HS-SPME technique efficiently. The regression ($r^2$) value of standard curve prepared with various concentrations of individual flavor chemicals was analyzed over 0.9975, and reproducibility was acceptable to apply quantitative analysis. The analysis of volatile components of control sample during storage showed that the acetaldehyde on 0 d was 10.83 ppm, and that contents were increased to 15.67 ppm after 15 d of storage. However, addition of BR, GBR and SGBR decreased the acetaldehyde contents during storage periods. The acetone content of all treatments during storage was not significantly different. The diacetyl content of all treatments were increased during storage and the addition of SGBR showed the highest amount of diacetyl (0.84 ppm) among treatments on 15 d of storage. The acetoin content of yogurt added with grains was higher than that of control during storage. As a result, the content of volatile aroma compounds in yoghurt during storage period could be analyzed HS-SPME extraction technique effectively, and HS-SPME/GC analysis can be considered for quality control of fermented milk products.