• Korean Journal of Food Science and Technology
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• v.36 no.5
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• pp.761-764
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• 2004

Effects of pretreatment conditions on ${\gamma}-aminobutyric$ acid (GABA) contents of brown rice and germinated brown rice were investigated. As steeping time increased, GABA contents of brown rices increased gradually. The highest GABA content, 3.33mg/100g, was found in brown rice steeped at $40^{\circ}C$ for 8 hr. GABA content of brown rice decreased significantly at pH 8 (p<0.05), but changed slightly at pH of steeping solution ranging 4-7. Steeping of brown rices in glutamate solution increased GABA contents. Brown rice steeped in glutamate solution at 200-300 ppm showed GABA content between $4.09{\pm}0.48-4.11{\pm}0,47mg/100g$, which was much higher than that of untreated brown rice. Anaerobic treatment of brown rices using $N_2$ gas increased GABA contents, ranging from $4,70{\pm}0.49\;to\;4.92{\pm}0.83mg/100g$. Germinated brown rice steeped in glutamate solution under anaerobic condition had GABA content of $5.92{\pm}0.72mg/100g$, two-fold higher than that of untreated brown rice, $3.05{\pm}0.67mg/100g$. Optimum pretreatment condition established in this study could significantly increase GABA content in germinated brown rice.

• Korean journal of food and cookery science
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• v.14 no.3
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• pp.225-231
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• 1998

Enzyme-treated glutinous rice flour, which was developed to shorten or skip a steeping process during the preparation of Yukwa, was analyzed for its physicochemical characteristics and compared with glutinous rice flour made by 28-day-steeping method. Total sugar content of the 28-day-steeped flour was the highest among all groups, on the other hand, the reducing sugar content was higher in enzyme-treated glutinous rice flour. The viscosity of enzyme-treated flours was significantly lower than that of the 28-day-steeped and particularly showed the lowest value at 65$^{\circ}C$. The contents of Ca$\^$2+/ and Mg$\^$2+/ in enzyme-treated glutinous rice flours were higher than those of the 28-day-steeped group, however, the content of P$\^$+/ was lower. Free sugar detected in glutinous rice flour prepared from 28-day-steeping method was glucose only, but enzyme-treated flours contained maltose and glucose, and the content of total free sugar was much higher than that of the 28-day-steeped group. In microscopic structure, both 28-day-steeped and enzyme-treated flours showed the particle size decreased and porous surface on some part of the flour granule.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.9
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• pp.1300-1306
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• 2011

This study investigated the physicochemical characteristics of wet-milled rice flour treated with pectinase and cellulase in a steeping process. Enzyme treatments were used as follows: pectinase 0.05%, cellulase 0.05%, and mixed enzyme treatments 0.05~0.2%. For particle distribution, rice flour E-treated with mixed enzymes (pectinase 0.05% and cellulase 0.05%) was the finest at 48.3% particle distribution less than $53\;{\mu}m$. Protein contents and damaged starch were reduced by enzyme treatments. Damaged starch was the lowest (12.1%) in rice flour E compared with non-enzyme treatment (18.1%). Amylose content, water binding capacity, solubility, and swelling power all increased upon enzyme treatments, and their effects increased upon mixed enzyme treatment. For gelatinization characteristics of RVA, peak viscosity, final viscosity, breakdown, and total setback viscosity increased in rice flours treated with mixed enzymes. Especially, in steeping method with mixed enzyme treatment, pectinase 0.05% and cellulase 0.05% treatment was suitable for minimizing damaged starch and high fine particle distribution of rice flours compared with single enzyme treatment.

• Journal of the East Asian Society of Dietary Life
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• v.11 no.2
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• pp.131-139
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• 2001

The physicochemical and sensory characteristics of brown rice flakes by different processing conditions such as flaking Process and their heat treatments were investigated to establish the brown rice flake processing procedure. To successfully make the compressed rice grain type flakes, the most appropriate water steeping conditions were 5 hours at 60'C. The brown rice flakes by compressed flaking procedure and heat treatment with microwave toasting showed the best crispiness-texture that tested from textrometer or sensory evaluation, and there was no significant difference between the source of rice varieties. The water absorption index(WAI) of tested flakes were negatively correlated with the water soluble index( WSI) and positively correlated with bowl life. The flakes made by compressed flaking procedure and heat treatment with microwave toasting showed longer bowl life, which is the length of the time that the cereal can retain its crispness after being soaked in milk.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.6
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• pp.1094-1099
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• 1998

Newly introduced aseptic process for cooked rice was optimized by evaluating the process parameters. The optimal conditions were as follows: ratio of washing water to rice, 3:1 by weight; steeping at 20oC for 20min; heat shock at 140oC for 7sec with 8 repetitions; addition of 0.2% glucono lactone solution; cooking at 103oC for 30min. The final products were incubated at 37oC and 50oC for 8 weeks and no spoilage was occurred at both temperatures. Furthermore, any significant losses of sensory and physicochemical qualities were not observed.

• Korean Journal of Food Science and Technology
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• v.53 no.6
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• pp.749-755
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• 2021

The objective of this study was to investigate the physicochemical properties of rice starch extracted from stale rice using alkaline steeping (AKL) and improved enzymatic digestion (iENZ) methods. The crude protein content (0.5-0.7%) of stale rice starch (SRS) was less than 1% by iENZ, but not so when measured by the existing ENZ methods. SRS is an intermediate amylose rice starch. AKL-SRS and iENZ-SRS exhibited typical A-type crystal packing arrangements with similar relative crystallinities. iENZ-SRS showed higher gelatinization onset and peak temperatures with a narrower gelatinization temperature range, compared to those of AKL-SRS, indicating that iENZ annealed SRS. Thus, iENZ-SRS exhibited lower swelling power and solubility, and higher pasting viscosities with delayed viscosity development. Overall, the use of stale rice as a rice starch source could make economical production of rice starch possible, and iENZ may diversify rice starch characteristics, which expands the utilization of rice starch in food and non-food industries.

• Korean Journal of Food Science and Technology
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• v.53 no.6
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• pp.731-738
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• 2021

This study investigated the physicochemical properties of rice starch isolated from broken rice using alkaline steeping (AKL) and enzymatic digestion (ENZ) methods. Broken rice starch (BRS) by AKL and ENZ possessed crude protein contents (0.6-1.4%) acceptable to commercial products of native starch and belonged to an intermediate amylose rice starch. AKL-BRS and ENZ-BRS showed a typical A-type crystal packing arrangement with small variations in their relative crystallinity. ENZ-BRS exhibited higher gelatinization onset and peak temperatures, and a narrower gelatinization temperature range than AKL-BRS, indicating that annealing occurred in ENZ-BRS. Lower swelling power and solubility were generally observed in the ENZ-BRS. ENZ-BRS also showed slower viscosity development, higher peak and trough viscosities, and lower breakdown, final, and setback viscosities, compared to those in AKL-BRS. These results are ascribed to the annealing phenomenon in ENZ-BRS. Overall, BRS from cheap broken rice using AKL and ENZ could contribute to the expansion of rice starch utilization in food and non-food industries.

• Proceedings of the Korean Society of Crop Science Conference
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• 2007.11a
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• pp.262.2-262.2
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• 2007

• Food Science and Biotechnology
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• v.16 no.3
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• pp.355-360
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• 2007

During the traditional production process of yugwa, a Korean traditional oil-puffed snack, three bacterial isolates, 12, 37, and B1 from waxy rice slurry were characterized by using the molecular techniques, and the quality of the yugwa prepared by using three isolates was examined in relation to physical and sensory properties. Isolates 37 and B1 were identified as Lactobacillus sp. by 16S rDNA sequence analysis, while isolate 12 was as Bacillus amyloliquefaciens by gyrA sequence analysis. Waxy rice inoculated with isolate 12 demonstrated the lowest hardness and the highest peak and [mal viscosity. Yugwa prepared from isolate 12-inoculated waxy rice indicated the lowest hardness and the highest volume expansion, the key characteristics of yugwa. This result presents the possibility for the use of a starter in the commercial production of yugwa and other rice-based snacks.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.7
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• pp.886-890
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• 2006

Rice flours produced by dry, wet, and semi-wet milling methods were used to investigate bread-making properties. Wet milled rice flours were produced by two different steeping temperatures of $25^{\circ}C$ and $55^{\circ}C$, properties of composite flour containing 70% rice flour and 30% wheat flour with the addition of vital wheat gluten were tested. Among rice flours, wet milled rice flour showed increased mixing time and dough stability determined by a mixograph. Wet milled rice flours produced higher loaf volume compared with dry of semi-wet milled rice flours. Wet-milled rice flour steeped at $55^{\circ}C$ appeared to produce good rice breads with relatively high loaf volume. Crumb hardness of bread prepared with wet milled rice flour was lower than the other breads and increased slowly during 3-day storage at $25^{\circ}C$.