• Korean Journal of Food Science and Technology
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• v.41 no.1
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• pp.16-20
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• 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
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• v.28 no.4
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• pp.219-225
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• 1985

The viscometric properties of six kinds of waxy starches of Olchal and Hankang(waxy rice), Chalborie (waxy barley), Yullmoo (waxy Job's tears), Chajoe (waxy foxtail millet), Chalsusu (waxy great millet) and Chalocsusu (waxy corn) were investigated. The increase in optical transmittance of 0.1% starch suspensions occurred at $55^{\circ}C$ for Hankang, $60^{\circ}C$ for Olchal, Chalborie, Chajoe and Yullmoo and $65^{\circ}C$ for Chalsusu and Chalocsusu, and further inrreased $70^{\circ}C$ for Hankang and Olchal, $75^{\circ}C$ for Chajoe, Chalsusu, Chalocsusu and Yullmoo and above $85^{\circ}C$ for chalborie. Amylogram on 5%, starch suspensions showed that gelatinization temperature and maximum peak height were 850 B.U. at $62^{\circ}C$ for Hankang, $65^{\circ}C$ and 980 B.U. for Olchae, $64^{\circ}C$ and 1,080 B.U. for Chalborie, and 1,410 B.U. at $69^{\circ}C$ for Yullmoo, and 1,280 B.U. at $71^{\circ}C$ for Chajoe, and 1,260 B.U. at $71^{\circ}C$for Chalsusu and 1,420 B.U. at $70^{\circ}C$ for Chalocsusu. Swelling power of starches was $38{\sim}55$, and Hankang, Olchal, Chajoe, Chalocsusu and Yullmoo starches had higher swelling power than Chalsusu and Chalborie starches. Intrinsic viscosity of them was $1.43{\sim}1.75$ and hardness of them highly relevant to the gelatinization properties.

• Korean journal of food and cookery science
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• v.13 no.4
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• pp.478-483
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• 1997

The effects of defatting by ether or 85% methanol on the properties of nonwaxy rice flours (Odaebyeo and Mankeumbyeo) were investigated. Starch granules in the rice flour were all polygonal and showed all A-type crystalline patterns regardless of defatting. Amylose content of the rice flour extracted by ether (crude lipid-defatted rice flour, CLDRF) was similar to the untreated (untreated rice flour, URF), however, that of 85% methanol (total lipid-defatted rice flour, TLDRF) was increased. Defatting decreased the water binding capacities of rice flour in all samples. The swelling power of rice flour was higher in Odaebyeo than Mankeumbyeo, and that of CLDRF showed a similar pattern to the untreated. Swelling power was the highest in TLDRF up to 85$^{\circ}C$, but decreased in the following order CLDRF > URF > TLDRF at above 95$^{\circ}C$. A similar pattern was observed in the leached soluble fraction, and its apparent amyloae content was increased rapidly at above 85$^{\circ}C$.

• Korean journal of food and cookery science
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• v.27 no.2
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• pp.19-29
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• 2011

Sweet potato powders made from eight Korean varieties, including purple-fleshed, orange-fleshed, and commercial dry type sweet potatoes, were investigated for physicochemical and pasting properties to develop processed food. Crude protein and lipid contents of Shinjami and Borami were higher than those of other varieties. The lightness value of raw sweet potato flesh was the highest value in Shinchunmi, and the lowest in Shinjami. Using the color difference (${\Delta}E$), color similarities compared to the white plate occurred in the following order; purple-fleshed > orange-fleshed > commercial dry type sweet potatoes. Total and damaged starch contents were significantly different (p<0.05). Total starch content of sweet potatoes was higher in commercial dry sweet potatoes (61.89-70.46%), particularly Shinchunmi (70.46%) but lower in orange-fleshed sweet potato (48.87 and 49.53%, respectively). Water binding capacity of Yeonwhangmi, swelling power and solubility of Shinyulmi were the highest values (174.70, 25.54 and 87.49%, respectively) among them (p<0.05). But oil absorptions of Shinyulmi and Shinchunmi showed lower values (97.08 and 97.54%, respectively). All sweet potato powders had an A type x-ray diffraction pattern. The initial pasting temperatures of sweet potato powders ranged from 69.50 to $75.95^{\circ}C$ and the amylolytic enzyme in sweet potato powder lowered pasting viscosity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.3
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• pp.270-278
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• 1992

Two of the Hard White Winter (HWW) wheats had higher farina yield than mixed Hard Red Winter (HRW) wheat. Optimum steaming time for HRW farina spaghetti was 3min under 86-98$^{\circ}C$. Optimum cooking time decreased after steam treatment. Steam treated spaghetti showed much higher strength of dried spaghetti, lower cooking loss, and cooked weight, less stickiness, and total organic matters (TOM) value than in treated spaghetti after cooking. The rooking qualities except stickiness were significantly different between treated and untreated steam. The quality of hard wheat farina spaghetti was more affected than that of durum spaghetti after steam treatment. HWW farina spaghetti im-roved all the qualities of steam treated and untreated spaghetti than those of HRW farina spaghetti except stickiness. From the observations of scanning electron microscope (SEM), maybe two general principles of steaming can be explained by : i) forming hydrophobic protein film on surface of pasta, ii) higher retrogradation of starch, which cause less swelling of starch.

• 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.

• Korean Journal of Food Science and Technology
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• v.28 no.6
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• pp.1119-1125
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• 1996

Physically modified rices were prepared by heat/moisture-treatment and its application for sikhe preparation was examined. The modified rice starch showed decreases in swelling, viscosity and enthalpies of gelatinization. But gelatinization temperature was increased by the treatment. The rate of saccharification for sikhe with the heat/moisture-treated rice autoclaved at 15 psi, $121^{\circ}C$ for 1 hr was twice higher than the untreated rice. Brix in sikhe of the untreated rice saccharified for 2 hrs was 8.2, whereas sikhe made with rice autoclaved for 1 hr was 8.7 only after 1 hour of saccharification. However. there was no difference in sugar composition analyzed by HPLC between both of them.

• Journal of the East Asian Society of Dietary Life
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• v.26 no.5
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• pp.457-465
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• 2016

Effects of soaking time on the physicochemical and structural characteristics of waxy rice flours and starches purified from flours using the alkaline steeping method were investigated. Korean cultivar Sinseonchal waxy rice was washed and soaked in tap water (1:2 w/w) and stored at room temperature for 15 days. On each day of soaking for 0, 1,2 3, 5, 10, and 15 days, pH of soaking water was measured and rice grains were dried, ground, and passed through 100 mesh sieve. The pH was reduced to 3.90 by day 5 and increased to 4.60 by day 15. The protein and ash contents, swelling powers and solubilities of flours and starches decreased with increasing soaking time. The water-binding capacities increased while trends were not similar to soaking time. The flour particle size distribution ranged from two to four peaks with increasing soaking times. Starch granule size decreased with increasing soaking time. The peak, trough, and final viscosities of flours and starches showed similar trends until 10 days and 15 days, respectively. The starches presented higher viscosities than the flours. The branch chain length distributions of amylopectin of starches showed an increaseed DP6~12 portion and decreased DP13~24 portion with increasing soaking time of waxy rice grains.

• Journal of the East Asian Society of Dietary Life
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• v.26 no.5
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• pp.450-456
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• 2016

Allulose, a monosaccharide isomer of fructose, was evaluated as a sucrose replacer for healthy cookie production with benefits such as low glycemic impact and low calorie content. Sucrose (as a reference), fructose, glucose, and allulose were used to explore the effects of sugar-replacer type on solvent retention capacity (SRC), differential scanning calorimetry (DSC), rapid visco-analyzer (RVA), and wire-cut cookie baking. SRC results indicated the lowest swelling of solvent-accessible arabinoxylans in allulose compared to that in other sugar solutions. DSC and RVA results showed retardation of starch gelatinization and onset of starch pasting, respectively, in the following order: water < allulose < fructose < glucose < sucrose. Among sugars, wire-cut cookies formulated with glucose showed the least desirable attributes with respect to cookie diameter and thickness. Although the baking response of allulose was slightly inferior to that of the sucrose control, the sugar exhibited a superior baking response to that of fructose, suggesting it could be used successfully as a fructose alternative or sucrose alternative for producing wire-cut cookies with reduced calorie content and low glycemic impact.

• Korean Journal of Food Science and Technology
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• v.50 no.2
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• pp.191-197
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• 2018

This study investigated the influence of starch extraction (ST-EX) solutions on the extraction yield and characteristics of Chinese yam (CY) starches from domestic Dioscorea batatas. Ascorbic acid (VitC), $Na_2S_2O_3$, $NaHCO_3$, and $Na_2CO_3$ were used as ST-EX solutions (0.4%, w/v). The extracted CY starches were examined for ST-EX yield, chemical composition, size distribution, X-ray diffraction, solubility, swelling power, gelatinization, and pasting viscosity. The highest ST-EX yield was obtained from $NaHCO_3$, followed by VitC. Lower protein content, relative crystallinity, and gelatinization enthalpy were found in CY starches from alkaline ST-EX solutions ($NaHCO_3$ and $Na_2CO_3$). Size distribution and gelatinization temperature did not generally differ for CY starches from the different ST-EX solutions. Pasting viscosities increased in the order from $Na_2CO_3$ > $Na_2S_2O_3$ > $NaHCO_3$ > VitC ST-EX solutions. Thus, VitC may be most appropriate to extract CY starch from Dioscorea rhizomes, considering its ST-EX yield, total starch content, and variation in pasting viscosity.