• Korean Journal of Food Science and Technology
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• v.28 no.6
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• pp.1026-1032
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• 1996

The effects of steeping temperature $(7^{\circ},\;15^{\circ},\;20^{\circ}\;and\;30^{\circ}C)$ and steeping time $(2{\sim}14\;hr)$ on the physicochemical properties of milled rice (variety; Chucheongbyeo) were investigated. The pH of the steep water decreased as the steeping time increased, which was more pronounced at higher steeping temperature. The solid loss was about 4.0% during steeping. The contents of protein, fat and ash decreased during steeping, which was greater at elevated temperature. The lightness of rice was slightly increased, and the yellowness was decreased upon steeping. The water-binding capacity of rice was increased during steeping at above $15^{\circ}C$. The slight increase of the swelling power of rice at $80^{\circ}C$ was observed upon steeping. The maximum wavelengh for the rice flour-iodine complex was moved to a higher wavelengh, but X-ray diffraction patterns remained constant regardless the steeping conditions. The pasting properties of rice flour (10%) by amylograph indicated that the peak viscosity increased as the steeping time was increased at all steeping temperatures. The steeping resulted in the greater breakdown and the 1ower setback. The log peak viscosity showed a linear relationship with the steeping time. The activation energy and $Q_{10}$ value for the visciosity increase rate was 2, 320 cal/mole and 1.14, respectively.

• Korean Journal of Food Science and Technology
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• v.41 no.6
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• pp.644-651
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• 2009

This study was conducted to investigate the effects of steeping periods and temperatures of waxy rice on the microflora and enzyme activities of steeping water and waxy rice, as well as on the microscopic structures of waxy rice during the preparation of gangjung. When the steeping water was 15 and $35^{\circ}C$, yeast and lactic acid bacteria were the major microflora after 1 day. After 11 days, Lactobacillus spp. were the major bacteria, while Bacillus spp. were the primary microflora after 21 days. At $25^{\circ}C$ the primary species were Bacillus spp., Leuconostoc spp., and Bacillus spp. after 1, 11 and 21 days, respectively. The $\alpha$-amylase activity of steeping water increased proportionally with the increase of temperature and period, while the protease activity tended to increase for 11 days, but decreased at 21 days. The enzyme activities of the steeped waxy rice, especially the $\alpha$-amylase activity, decreased with higher steeping temperature, while the $\beta$-amylase and glucoamylase activity remained constant for up to 21 days. Observation using scanning electron microscopy indicated that intracellular cleavage of steeped waxy rice endosperm resulted in a rough surface morphology due to the exposure of polygonal starch granules. Tiny pinholes on the surface of waxy rice starch granules were also observed after steeping for 11 days.

• Korean Journal of Food Science and Technology
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• v.34 no.4
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• pp.597-603
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• 2002

The analysis of traditional process for a Korean puffed rice snack (Yukwa) is needed to develop an advanced process for Yukwa-making. Steeping and punching (Koarichigi) processes, consume time and labor in Yukwa-making, were analyzed on this study. Steeping of waxy rice at $15^{\circ}C$ for 3 days was required to equilibrate moisture absorption in waxy rice kernel. However, steeping for more than 6 days was required soft texture and small air cell distribution of Yukwa. Protein content at pericarp on endosperm of waxy rice kernel was decreased and starch granule was damaged during steeping. RVA paste viscosity was the highest at 6 day steeping after than decreased. Expansion ratio of Yukwa was increased with the increase in steeping time. Air bubbles in dough after punching were uniformly distributed and kneading energy input was decreased with the increase in steeping time. Soft texture, unique texture of Yukwa could be controlled by controlling steeping time and kneading energy input during punching process.

• The Korean Journal of Food And Nutrition
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• v.13 no.3
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• pp.213-220
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• 2000

본 연구는 찹쌀가루액에 효소처리 및 미생물 접종을 시킴으로써 유과의 제조시 수침과정을 거치지 않고도 유과를 만들수 있는 새로운 방법을 개발하기 위하여 시도되었다. 찹쌀 수침액에 분포된 미샐울은 Bacillus sp와 Lastobacillus spp.로 나타났다. 찹쌀 수침액에 인위적으로 상기 미생물을 배양하였을 대 유과를 제조하기 위한 최적 조건은 3$0^{\circ}C$에서 18시간 이었다. 이때 찹쌀수침액의 PH는 배양시간이 증가함에 따라 증가하였다. 이 찹쌀 수침액에서는 수침시간이 증가함에 따라 $\alpha$-amylase 활성이 증가하여 효소처리된 시료액의 효소 활성화 유사한 경향을 나타내었다. 유과의 팽화도는 효소처리시킨 혼합 접종처리 군을 제외한 모든 처리군에서 28일간 수침한것과 유사하게 나타났다. 경도와 peak수는 모든 처리순에서 28일간 수침시킨 대조군에 비해 유의적으로 더 낮게 나타났다.(P<0.05). 미세구조에서 기공수는 효소처리시킨 단독 접종군이 다른 모든 처리군에 비해 더 많은 기공수를 지니고 있었고 기공의 둘레 및 면적도 유의 적으로 낮은 수치를 나타내었다. .(P<0.05). 따라서, 수침공정을 대폭 단축할 수 있었으며, 향후 미생물 접종을 고려한 효소처리 조건을 정밀 분석한다면 수침공정이 없어도 유과의 품질특성을 나타내는것이 가능할 것으로 보인다.

• Food Science and Preservation
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• v.5 no.4
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• pp.368-373
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• 1998

The effects of steeping and washing were investigated in the physicochemical properties of acorn flour. The contents of crude protein, ash and total phenol of acm flour were gradually decreased with the steeping days and washing times. However, the contents of crude fat and dietary fiber were little different. The more steeping days and/or washing times became large, the more the color of acorn flour became light. Swelling power was enhanced by increasing of steeping days and washing times but solubility was some decreased Water binding capacity was decreased and intrinsic viscosity was increased with the increased steeping days and washing times. Washing times were more influential than steeping days to those changes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.8
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• pp.1076-1083
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• 2009

The physicochemical properties of rice flour produced by 3 different grinding methods using various steeping times (3, 6, 9, and 12 hrs) were investigated. Roller mill gave coarse rice flour; the pin mill, intermediate flour; and mixed when both (roller & pin mills) were used. With the increase of steeping times, the rice flours became finer and the contents of crude protein, crude fat and crude ash decreased. Damaged starch was noticeably high in rice flour by roller & pin mills compared to those by roller or pin mills alone. Amylose contents, solubility and swelling power increased as the steeping times increased. Water binding capacity was the highest in roller & pin mills, followed by pin mill. In scanning electron microscope (SEM), pin mill showed distribution of separated fine particles of rice flours. The physicochemical properties of rice flours showed many differences by steeping times of rice and grinding methods. With sufficient steeping times, the rice flours obtained from pin mill were relatively fine having less damaged starch.

• Korean Journal of Food Science and Technology
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• v.17 no.6
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• pp.415-420
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• 1985

In this study, changes in physical and chemical properties of glutinous rice during various soaking periods (0, 0.08, 1, 3, 5, 7, 10 days) were investigated in order to clarify the relations ship between soaking period and expansion volume in the preparation of Gang Jung. The longer the soaking period was, the greater the expansion volume of Gang Jung was. Higher maximum viscosity and breakdown in amylogram of glutinous rice flour were observed as the soaking period was increased, As the length of soaking period increased, hardness of glutinous rice and size of flour particle significantly decreased, while sweeling power and solubility of glutinous rice flour showed no significant difference. Increased length of soaking period was associated with higher fatty acidity, higher acidity of water extract and lower pH of glutinous rice flour. Control of flour particle size distribution resulted in significantly larger expansion volume of Gang Jung. Brabender's amylogram showed that the increase of expansion volume of Gang Jung associated with the increase of soaking period was related to the change of rheological properties of glutinous rice. It seemed that changes in viscometric properties of glutinous rice was attributed to the different flour particle size distribution resulted from changes in hardness of rice during soaking.

• Korean journal of food and cookery science
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• v.17 no.6
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• pp.598-603
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• 2001

Gel characteristics of potato starches which were prepared by steeping potato at 10$\pm$ 1$\^{C}$ and 25$\^{C}$$\pm$1$\^{C}$ incubator for 11days were investigated. Results of the instrumental test of potato starch gels showed significantly different strength, hardness, gumminess, chewiness, cohesiveness by steeping time. The light microscope and scanning electron microscope of starch gels showed three-dimensional network including macroporous structure by steeping. The syneresis of potato starch gel was decreased by steeping potato at 24 for 72 hours.

• Journal of the Korean Society of Food Culture
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• v.7 no.4
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• pp.291-296
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• 1992

The effects of steeping time of glutinous rice and of beating time of the cooked rice on characteristics of Ganjung was examined. and the optimum conditions of traditional Gangjung preparation were determined. Moisture absorption of glutinous rice was the maximum at 2 hours of steeping in water and did not increase much after then. pH of the steep water was the lowest at 7 days of steeping and increased slightly thereafter. Reducing sugar content of the steep water increased as the steepting time was extended. Expansion ratio of Gangiung was the greatest with 5 days of steepting, and tended to decrease with longer beating time. Optimum conditions of Gangjung preparation was 7 days of steeping glutinous rice and 4 minutes of beating (40 times/min) the cooked rice.

• Korean Journal of Food Science and Technology
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• v.25 no.5
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• pp.535-540
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• 1993

Effects of steeping of waxy rice in water at $20^{\circ}C$ for 6 or 30 hr on physicochemical properties of rice flour and molecular structure of starch were examined. pH of the steep water was decreased upon steeping. The lightness of the flour was gradually increased, while redness and yellowness were decreased as steeping time increased. The protein content was linearly decreased during steeping period. The fat content was sharply decreased from 18hr of steeping. The ash content rapidly decreased up to 12hr of steeping. The water-binding capacity was increased up to 12hr of steeping and decreased thereafter. The swelling power at $80^{\circ}C$ was consistently increased during steeping period. The amylograph peak viscosity showed a linear relationship with the steeping time. The molecular structure of starch was not affected by steeping.