• Korean journal of food and cookery science
• /
• v.22 no.2 s.92
• /
• pp.147-157
• /
• 2006

To improve the properties of non-waxy rice flours for baking, soaked-wet milled rice flour (SWRF) was adjusted moisture content (MC) to 30 and 50 % and heated at 50 and $70^{\circ}C$ in a shaking water bath for 6 and 18 hrs, respectively. Moisture-heat treated rice flours were investigated with regard to particle size distribution, and morphological, physicochemical and pasting properties for comparing dry and wet milled flours. The particle size of rice flour treated with 30% MC was distributed between $4-20{\mu}m\;and\;100-200{\mu}m$, like SWRF. The particles above $200{\mu}m$ in the flour were produced at higher heating temperature. By SEM, starch granules were found in the rice flours treated with 30% MC, who whereas aggregated starch granules were shown in the flours treated with 50% MC. Moisture-heat treatment using higher MC and heating temperature decreased the lightness and increased the yellowness of non-waxy rice flours. Water binding capacity of 30% moisture treated rice flour was similar to that of SWRF. In the same moisture treated rice flour, swelling power was higher, but solubility was lower at $50^{\circ}C$ than at $70^{\circ}C$. The initial pasting temperature by RVA increased after moisture-heat treatment. The peak viscosity of moisture-heat treated rice flour was higher for 30% moisture than that of the others. The rice flour treated with 30% MC and heated at $50^{\circ}C$ showed low setback and increased stability for retrogradation.

• Applied Biological Chemistry
• /
• v.44 no.1
• /
• pp.30-34
• /
• 2001

Physicochemical properties of milled rice, brown rice, pearled barley, wheat, sorghum, foxtail millet, soybean, and adzuki bean were evaluated for the production of extrusion formed multi-grain. Grain flours showed large differences in chemical composition including starch, protein, fat, ash, and total dietary fiber contents. Grain flours were brighter in the following order of milled rice>pearled barley>soybean>brown rice>wheat>sorghum>adzuki bean>foxtail millet, and most of the grain flours showed red-yellowish color. Mean particle sizes of grain flours were different among various grains, and whole grain flours tended to have coarser particle size than milled grain flours. The amounts of damaged starch in cereal flours were varied from 5.4 to 10.9%, and limited amount of damaged starch was present in legume flours. Water absorption index of grain flours was, in decreasing order, adzuki>bean>milled rice>brown rice>sorghum>wheat>foxtail millet>pearled barley>soybean. Water solubility index was higher in legume flours containing high protein content.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.37 no.7
• /
• pp.900-907
• /
• 2008

The physicochemical properties of black rice flours produced from dry and wet milling were carried out to investigate their applications in food processing industry. The dry milled black rice flours showed lower fat, protein, ash, and anthocyanin contents than those of wet milled black rice flours with no effect due to number of millings. Average particle sizes ($379{\sim}288\;{\mu}m$) of dry milled flours were bigger than those ($336{\sim}253\;{\mu}m$) of wet milled flours. Particles with 60 mesh or more increased with increasing milling times. Wet milled flours had higher damaged starch, water solubility index (WSI), and water absorption index (WAI) compared to dry milled flours. Pasting properties measured by rapid visco analyzer (RVA) resulted in higher pasting temperatures in dry milled flours ($62.5{\sim}69.4^{\circ}C$) than wet milled flours ($46.1{\sim}46.4^{\circ}C$). As the number of milling times increased, pasting temperature of wet milled flours were not effected. Dry and wet milling resulted in reduced trough, final viscosity, and consistency with increasing milling times.

• Korean journal of food and cookery science
• /
• v.23 no.6
• /
• pp.908-918
• /
• 2007

To prepare ready-to-use rice flour as de novo material for processed rice foods, glutinous(W) and normal rice grains (N) were soaked for 1, 8, and 12 hours prior to processing. One half (DG) was air-dried and milled, and the other (WG) was milled and air-dried. General, morphological and pasting properties of the flours (NDG, NWG, WDG, WWG) were compared to those of a control (raw milled rice without soaking). The general compositions of the rice flours varied with soaking. Crude ash was considerably decreased at the beginning of soaking (1 hour). With the soaking, the rice flour, having polygonal shaped particles and a layered surface, acquired particles with smooth edges, which were then uniformly distributed. Additionally, the WG flour was lighter and had a lower ${\Delta}E$ value than the DG flour, due to a higher L and less +b as a result of soaking. Compared to the control, the WBC of the normal rice flour was decreased significantly with soaking, and the WG flour had significantly lower WBCs than the DG flour. Stirring number (SN), an indicator of ${\alpha}-amylase$ activity, was highly and significantly correlated with WBC (r=-0.85, p=0.0001) in the normal rice flour. At $80^{\circ}C$, the SP and solubility of all the soaked rice flours were much higher than those of the control. Positive (r=+0.85, p=0.0001) and negative (r=-0.61, p=0.02) correlations between the SP and solubility of the normal and glutinous rice flours were found, respectively. Using RVA, the pasting temperature of NDG was lower than that of NWG (p<0.0001). The peak viscosities of all the soaked flours were significantly decreased with soaking (p<0.0l), with the highest viscosity in the normal rice flour soaked for 8 hrs. Total setback, indicative of retrogradation, was lower in NDG than in NWG, with the lowest setback at 8 hrs of' soaking. Based on these finding, the NDG flour with 8 hrs of soaking was less damaged, and had a lower total setback and lower pasting temperature, which would make it an appropriate rice flour for commercial mass production.

• Korean journal of food and cookery science
• /
• v.8 no.4
• /
• pp.371-378
• /
• 1992

This experiment was carried out in order to investigate effect of rice varieties, milling methods and particle sizes of rice flours on characters of songe cake. The expansion height of batters peaked from in 14 to 18 minutes during baking for 34 minutes at $150^{\circ}C$, and then was gradually decreased. The decrease in the height ranged from 6 to 50% compared to the expansion peak of batters at one day after baking. The inner temperature of the batters showed a tendency to increase slowly and was greatly increased for 8 to 10 minutes. The highest temperature was 94 to $96^{\circ}C$ in 24 to 26 minutes during baking. The volume of the rice cake was not affected by the particle sizes of the rice flours and milling treatment, and ranged from 89 to 95% compared the volume of wheat cake. Therefore, this result indicated the great possibility baking sponge cake used with rice flours. The baked sponge cake by the hydrated flours showed lower stregth than that by the non-hydrated rice flours without correlation with kinds and particle sizes of rice flours, and there were not significant differences in the cohesiveneness of the cakes. The sponge cake of the hydrated rice flour of Taebaek variety was generally superior in texture and taste to the cake of wheat flour as the result of sensory evaluation.

• Food Science and Biotechnology
• /
• v.17 no.1
• /
• pp.180-183
• /
• 2008

Digestion properties of 3 types of cereals, white rice, brown rice, and barley, were measured after cooking or grinding. Regardless of the processing methods, white rice showed the highest rate and the greatest extent of digestion, whereas barley showed the lowest values. During the early digestion period, cooked white rice kernels had a larger k (kinetic constant) value than uncooked white rice flour, indicating that cooking induced faster digestion than grinding. In the case of brown rice and barley, the cell wall in cooked kernels remained intact and resulted in a lower k values than those of uncooked flour. However, after 3 hr of digestion, the total digestion extent was greater for the cooked brown rice and barley than that for uncooked flours. The high content of slowly digestible starch (SDS) in cooked brown rice and barley might be due to the starch fraction which was protected by the cell wall. The resistant starch (RS) content, however, was greater for the uncooked flours than that for cooked kernels. The cooked kernels of 3 cereal samples tested showed higher glycemic index (GI) values than the uncooked flours.

• The Korean Journal of Community Living Science
• /
• v.11 no.1
• /
• pp.1-8
• /
• 2000

The characteristics of rice-breads with wet-milling and dry-milling rice-flours were investigated. Rice-breads by wet-milling had a good fermentation than the breads by dry-milling. Also, the fermentation of mugwort rice-breads was lower than those. Rice-breads by dry-milling indicated the higher value in hardness and the lower value in springiness, cohesiveness and chewiness than rice-breads by wet-milling. Also, mugwort rice-breads was the higher value in hardness, springiness, chewiness and the lower value in cohesiveness than rice breads. The test of the sensory characteristics for rice-breads showed that moistness, springiness, chewiness was higher for rice-breads by wet-milling. The sensory characteristics of mugwort rice-breads were lower than those, of rice-breads except the chewiness. Overall quality of rice-breads by wet-milling was higher than that of rice-breads by dry-milling. The overall quality of mugwort rice breads was higher than that of rice-breads by wet-milling, but lower than that of rice-breads by dry-milling.

• Korean Journal of Food Science and Technology
• /
• v.41 no.1
• /
• pp.16-20
• /
• 2009

To develop health functional foods using high amylose rice flours, the properties of flours prepared from domestic high amylose rice varieties, Goamy2 and Goamy, and imported rice from Thailand were investigated. After soaking the rice grains and drying, the dry-milled rice flours were passed through a 120-mesh sieve. The protein and total starch contents of the Goamy2 rice flour were lowest, but its crude lipid and ash contents were highest among the flours. In addition, apparent amylose content, water binding capacity, and total dietary fiber were highest in the Goamy2 flour (36.2, 255.0, and 9.2%, respectively). The Thai rice flour had the highest swelling power, whereas the Goamy2 flour had the lowest swelling power and solubility. By Rapid visco-analysis, the Thai flour showed the highest peak and total setback viscosities and lowest breakdown viscosity. The pasting pattern of the Goamy2 flour was different from that of the other flour, where low viscosity was maintained during heating and cooling. Goamy and Thai rice flours showed an A type crystallinity, but Goamy2 flour showed a B type crystallinity similar to high amylose maize starch. The Goamy2 flour presented a dull and yellowish color, and the lowest lightness (L) value and the highest yellowness (+b) value.

• Applied Biological Chemistry
• /
• v.28 no.2
• /
• pp.106-109
• /
• 1985

Gelatinization of Japonica(30 varieties) and J/Indica(22 varieties) rice flours in 0.2N NaOH was examined. J/Indica rice flours were easily gelatinized and showed higher viscosities at all reference points than Japonica counterparts. Viscosity development rate was not correlated with protein or amylose content. Only J/Indica rice varieties showed positive correlation between hydration rate and viscosity development rate.

• Korean Journal of Food Science and Technology
• /
• v.34 no.2
• /
• pp.343-345
• /
• 2002

The study was investigated hot-water soluble on waxy black and waxy rice flours according to gelatinization temperatures and heating time. The hot-water soluble contents of both samples were increased during heating time at $90^{\circ}C$. The waxy black and waxy rice flours solutions according to gelatinization temperatures ($80^{\circ}C,\;90^{\circ}C,\;95^{\circ}C\;and\;98^{\circ}C$) were heated for 10, 20 and 30 min. Determination of elution patterns of rice flours was used by Sepharose CL-2B column. As a result, the elution patterns were eluted the most in void volume ($V_0$) and the elution patterns of the hot-water solubles were increased according to heating time and gelatinization temperatures.