• Journal of Microbiology and Biotechnology
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• v.3 no.2
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• pp.129-133
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• 1993

The effect of different compositions of organic acids on the flavor profile of 10% sugar solution was investigated by the response surface methodology, and the results were used to evaluate the flavor characteristics of lactic acid fermented cereal beverages. A mixture of extruded rice flour (10%) and soymilk (7.8% dry matter) was fermented with Leuconostoc mesenteroides (Sikhae). Depending on the substrate pretreatments, for example, the malt or amylase digestion and the proteolytic enzyme hydrolysis, the sugar and organic acid composition of the product varied. The organic acid composition of the fermented beverages was in the ranges of 0.44-0.55% lactic acid, 0.05-0.09% acetic acid and 0.07-0.09% citric acid, while that of commercial apple juice was 1.59% malic acid and 0.49% acetic acid. The flavor profiles of fermented beverages added with 10% sucrose were compared to those of apple juice and a model mixture containing 0.48% citric acid, 0.39% lactic acid and 0.12% acetic acid in 10% sugar solution. The QDA diagram of fermented beverages approached to that of apple juice, when the substrate was digested by amylase but not by protease.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.6
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• pp.912-920
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• 2015

The study was designed to investigate the effects of die temperature and $CO_2$ injection on the physical and antioxidant properties of extruded rice with tomato flour. Moisture content and screw speed were fixed at 25% and 150 rpm, respectively. Die temperatures and $CO_2$ injection were adjusted to 80, 110, and $140^{\circ}C$ and 0, and 300 mL/min, respectively. Specific mechanical energy input decreased as die temperature increased from 80 to $140^{\circ}C$. The expansion index increased, while bulk density decreased with $CO_2$ injection. All extrudates showed increased water soluble index (WSI) and water absorption index through the extrusion process. WSI increased as die temperature increased. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and total phenolic compounds increased as die temperature increased from 80 to $140^{\circ}C$. Total carotenoid and lycopene contents decreased through the extrusion process. Total carotenoid and lycopene contents upon 0 mL/min $CO_2$ injection and $140^{\circ}C$ die temperature were highest at $6.65{\mu}g/g$ and 2.69 mg/kg, respectively. In conclusion, $CO_2$ injection affects expansion properties while an increased die temperature leads to increased DPPH radical scavenging activity and total phenols.

• Korean journal of food and cookery science
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• v.32 no.4
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• pp.449-457
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• 2016

Purpose: The study was conducted to analyze the change in quality characteristics of Ddukguk Garaedduk and Ddukgukdduk by the frequency of extruding rice dough. Methods: Ddukguk Garaedduk samples were made by extruding and shaping rice flour dough 2, 3, and 4 times; while Ddukgukdduk samples were made by drying the Ddukguk Garaedduk at room temperature for 48 hours and slicing them in slices of 0.3 cm thickness. Results: Significant differences were not found in water content by the extrusion frequency for Ddukguk Garaedduk and Ddukgukdduk. The adhesiveness and springiness of Ddukguk Garaedduk with a 4 times extrusion were significantly higher than those of Ddukguk Garaedduk with a 2 times extrusion. Ddukgukdduk with a 4 times extrusion generated finer cells and a more even distribution of cells than the other samples, as observed by scanning electron microscopy. Upon boiling, significantly more water was absorbed in Ddukgukdduk of a 2 times extrusion than in that of a 4 times extrusion. Hardness and adhesiveness scores of the cooked Ddukgukdduk were the highest, and springiness was the lowest in the sample with the 4 times extrusion. Conclusion: The extrusion of rice dough makes the structure of Ddukguk Garaedduk finer and more even, which results in the increased adhesiveness of Ddukguk Garaedduk. When cooking Ddukguk, Ddukgukdduk that has been extruded more absorbs less water and dissolves less solids, which maintains the chewiness and structure of cooked Ddukgukdduk.

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.502-508
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• 1997

Rice bran dietary fiber extract, which was obtained after termamyl treatment of defatted rice bran contained $27.3{\sim}30.5%$ protein, $49.7{\sim}54.1%$ insoluble dietary fiber, and $1.9{\sim}2.7%$ soluble dietary fiber. Extrusion decreased the insoluble dietary fiber content but increased the soluble dietary fiber content, while roasting did not. Influence those content. Each mineral element content was depended upon heat processing method. Extrusion increased the water binding capacity and L value, while roasting reduced the water binding capacity and L value. Scanning electron microscopy showed damaged cell walls for extruded sample compared to roasted one which had fully collapsed cell walls. The increase of water absorption, developing time, and stability and the of MTI of wheat flour-dietary fiber extract composites with addition of dietary fiber extract were observed by Farinograph. Rice bran dietary fiber extract had an effect on the bread making resulting in increase of bread weight and color of crumb and crust, and decrease of bread volume and texture. As a result of sensory evaluation, appearance, texture, overall acceptability were significantly different from control but flavor and taste were not different significantly up to 6% level. Heat treated samples had differences in mean values, but not significant differences statistically.