• Korean Journal of Food Science and Technology
• /
• v.32 no.1
• /
• pp.82-89
• /
• 2000

Relationship among the properties of rice, such as amylose contents of endosperm starch, sugar content and amylogram characteristics, and processing properties for rice bread was studied. The amylose content of the rice cultivars decreased in order of Nampungbyeo, Whachungbyeo>Punchilmi(fl)>Nampung CB243> Whachung du-I, Nampung EM90>Whachung-chalbyeo>shr. Protein contents of rice tested in this study were almost same level, however, shr, the high sugar rice, showed the highest protein content scored as 8.2%. The study showed that the amylose contents of rice cultivars were negatively correlated with their protein contents. The starting temperatures for gelatinization of the flour of Punchilmi(fl) and Shurunken(shr) were low, however, in case of Whachungbyeo and Nampungbyeo plus their mutants derived from the both, the stickiness and the hardness of the flours were shown to be positively correlated with the amylose contents. In addition, loaf volume tested using sensory evaluation and overall quality showed the same tendency. Among the rice cultivars tested in this study, breads made from white rice had good qualities in bread making process than those made from brown rice. The bread made from Nampungbyeo was demonstrated to have highest score e in overall quality, as well as the lowest retrogradation index during storage at $4^{\circ}C$

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.36 no.9
• /
• pp.1205-1210
• /
• 2007

Texture properties of a Korean rice cake (Karedduk) added with carbohydrate materials after 0, 2, 6, 24 and 30 hrs of storage at $5^{\circ}C$ were investigated using textural characteristics and sensory descriptive analysis. Carbohydrate materials such as powdered sugar, trehalose, fructooligosaccharide (95%), isomalto, healtholigo, and galactooligosaccharide (50%) were added in 0, 1, 5 and 10% levels to dry rice flour. The texture profile analysis by Texture Analyzer revealed that adhesiveness and cohesiveness of the Korean rice cake (Karedduk) added with carbohydrate materials were similar to those of the control in trends, while hardness was low compared to the control except for fructooligosaccharide (95%) 5% and healtholigo 1% addition. The hardness and sweetness by sensory characteristics were significantly different compared to the control. Instrumental hardness was correlated with sensory hardness. Lastly, the Korean rice cake (Karedduk) added with carbohydrate materials except fructooligosaccharide (95%) 5% and healtholigo 1% addition was effective in delaying retrogradation.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.47
• /
• pp.15-32
• /
• 2002

The endeavors enhancing the grain quality of high-yielding japonica rice were steadily continued during 1980s-1990s along with the self-sufficiency of rice production and the increasing demands of high-quality rices. During this time, considerably great progress and success was obtained in development of high-quality japonica cultivars and quality evaluation techniques including the elucidation of interrelationship between the physicochemical properties of rice grain and the physical or palatability components of cooked rice. In 1990s, some high-quality japonica rice cultivars and special rices adaptable for food processing such as large kernel, chalky endosperm, aromatic and colored rices were developed and its objective preference and utility was also examined by a palatability meter, rapid-visco analyzer and texture analyzer, Recently, new special rices such as extremely low-amylose dull or opaque non-glutinous endosperm mutants were developed. Also, a high-lysine rice variety was developed for higher nutritional utility. The water uptake rate and the maximum water absorption ratio showed significantly negative correlations with the K/Mg ratio and alkali digestion value(ADV) of milled rice. The rice materials showing the higher amount of hot water absorption exhibited the larger volume expansion of cooked rice. The harder rices with lower moisture content revealed the higher rate of water uptake at twenty minutes after soaking and the higher ratio of maximum water uptake under the room temperature condition. These water uptake characteristics were not associated with the protein and amylose contents of milled rice and the palatability of cooked rice. The water/rice ratio (in w/w basis) for optimum cooking was averaged to 1.52 in dry milled rices (12% wet basis) with varietal range from 1.45 to 1.61 and the expansion ratio of milled rice after proper boiling was average to 2.63(in v/v basis). The major physicochemical components of rice grain associated with the palatability of cooked rice were examined using japonica rice materials showing narrow varietal variation in grain size and shape, alkali digestibility, gel consistency, amylose and protein contents, but considerable difference in appearance and texture of cooked rice. The glossiness or gross palatability score of cooked rice were closely associated with the peak, hot paste and consistency viscosities of viscosities with year difference. The high-quality rice variety "IIpumbyeo" showed less portion of amylose on the outer layer of milled rice grain and less and slower change in iodine blue value of extracted paste during twenty minutes of boiling. This highly palatable rice also exhibited very fine net structure in outer layer and fine-spongy and well-swollen shape of gelatinized starch granules in inner layer and core of cooked rice kernel compared with the poor palatable rice through image of scanning electronic microscope. Gross sensory score of cooked rice could be estimated by multiple linear regression formula, deduced from relationship between rice quality components mentioned above and eating quality of cooked rice, with high probability of determination. The $\alpha$-amylose-iodine method was adopted for checking the varietal difference in retrogradation of cooked rice. The rice cultivars revealing the relatively slow retrogradation in aged cooked rice were IIpumbyeo, Chucheongyeo, Sasanishiki, Jinbubyeo and Koshihikari. A Tonsil-type rice, Taebaegbyeo, and a japonica cultivar, Seomjinbyeo, showed the relatively fast deterioration of cooked rice. Generally, the better rice cultivars in eating quality of cooked rice showed less retrogradation and much sponginess in cooled cooked rice. Also, the rice varieties exhibiting less retrogradation in cooled cooked rice revealed higher hot viscosity and lower cool viscosity of rice flour in amylogram. The sponginess of cooled cooked rice was closely associated with magnesium content and volume expansion of cooked rice. The hardness-changed ratio of cooked rice by cooling was negatively correlated with solids amount extracted during boiling and volume expansion of cooked rice. The major physicochemical properties of rice grain closely related to the palatability of cooked rice may be directly or indirectly associated with the retrogradation characteristics of cooked rice. The softer gel consistency and lower amylose content in milled rice revealed the higher ratio of popped rice and larger bulk density of popping. The stronger hardness of rice grain showed relatively higher ratio of popping and the more chalky or less translucent rice exhibited the lower ratio of intact popped brown rice. The potassium and magnesium contents of milled rice were negatively associated with gross score of noodle making mixed with wheat flour in half and the better rice for noodle making revealed relatively less amount of solid extraction during boiling. The more volume expansion of batters for making brown rice bread resulted the better loaf formation and more springiness in rice breed. The higher protein rices produced relatively the more moist white rice bread. The springiness of rice bread was also significantly correlated with high amylose content and hard gel consistency. The completely chalky and large grain rices showed better suitability far fermentation and brewing. The glutinous rice were classified into nine different varietal groups based on various physicochemical and structural characteristics of endosperm. There was some close associations among these grain properties and large varietal difference in suitability to various traditional food processing. Our breeding efforts on improvement of rice quality for high palatability and processing utility or value-adding products in the future should focus on not only continuous enhancement of marketing and eating qualities but also the diversification in morphological, physicochemical and nutritional characteristics of rice grain suitable for processing various value-added rice foods.ice foods.

• Korean journal of food and cookery science
• /
• v.6 no.2
• /
• pp.7-14
• /
• 1990

This study has been carried out in order to investigate the physicochemical properties of two small red bean starches. Some of rheological properties of the starch gels were also studied by experiments of various starch concentrations. Water binding capacity of black bean starch was 172.3% and that of red bean starch was 199.0%. Black bean starch had lower swelling power than red bean starch, but the solubility of the black bean starch was higher. When the temperature increased from 60$^{\circ}C$ to 70$^{\circ}C$, the transmittance of two starches rapidly increased. The gelatinized temperature in DSC for black bean was 66.2$^{\circ}C$ and that for red bean was 66.0$^{\circ}C$. Black bean and red bean starches had the blue vlaues of 0.55 and 0.56 and the alkali numbers of 4.40 and 4.13. The molecular weight of amylose was 40,000 and 33,611. The amylose contents of two starches were same at 52%. Brabender Amylographs of two small red bean starch pastes showed C pattern, which is stable. The results of compression test pointed out that TPA parameters varied with the change of storage time, and black bean starch gels had the higher TPA value. The retrogradation study by glucoamylase digestion method revealed that red bean starch gels were more easily retrogradated than black bean. X-ray diffraction patterns of two small red bean starches were A pattern, and diffraction peaks disappeared with gelatinization of starches.

• Korean Journal of Food Science and Technology
• /
• v.27 no.5
• /
• pp.690-696
• /
• 1995

Properties of dry milled rice flours made of paddy with different moisture content (12.6, 18.4 and 24.4%) were compared with those of wet milled rice flour. Among dry milled rice flour, the higher moisture content of paddy the finer particle size and the more distinct shape of starch were observed. As the moisture content of paddy increased, L (lightness) value and water absorption index of rice flour were increased, while setback in amylogram and water soluble index were decreased. Lower gel consistency and gel strength were found in dry milled rice flours than in wet milled rice flour, while no significant difference was found among dry milled rice flours. Enthalpy for melting crystalline of retrograded gels was higher in dry milled rice flours made of paddy with 24.4% moisture content than in other dry milled rice flours. Wet milled rice flour had lower retrogradation enthalphy than dry milled rice flours.

• Culinary science and hospitality research
• /
• v.15 no.1
• /
• pp.149-156
• /
• 2009

This study was carried out to evaluate the effect of whey brew cultured by the mixed Lactobacillus helveticus ATCC 55163 and Propionibacterium acidipropionici 5020 on the rheological properties of flour dough. 10 and 15% of whey brews were added to the dough based on flour. Farinograph, alveograph, Rapid Visco Analyzer, and fermenting power of dough were analyzed. In the farinograph analysis, as the amount of whey brews increased on dough samples, water absorption, dough development time, stability, and breakdown increased. In the alveograph analysis, as the amount of whey brews increased on dough samples, P and W value increased while L and G value decreased. In the Rapid Visco Analyzer analysis, as the amount of whey brews increased on dough samples, initial pasting temperature and peak viscosity increased while final viscosity and setback decreased. Decrease of setback showed the delay of starch retrogradation. As the amount of whey brews increased on dough samples, fermenting power of dough got reduced.

• Preventive Nutrition and Food Science
• /
• v.11 no.2
• /
• pp.146-154
• /
• 2006

Structural modification of corn starch by gamma irradiation was evaluated for under dry conditions at varied intensities from 0 to 40 kGy. Under scanning electron microscopy, the granule shape of corn starch was not significantly affected by the irradiation up to 40 kGy. In addition, X-ray diffraction and melting patterns of the irradiated starches were similar to those of the native starch, indicating that crystalline regions in the starch granules were not changed by irradiation. However, the pattern of gel permeation column chromatography showed a significant increase in partial hydrolysis of gamma irradiated starch samples. The degree of polymerization and the paste viscosity of irradiated starch samples dose-dependently decreased significantly with irradiation, and increased solubility and clarity were observed in the irradiated starch solution. In addition, the degree of retrogradation decreased as irradiation dose increased. Irradiation of corn starch has advantages over the ordinary acid or the enzyme hydrolysis modification methods. It does not affect the granular shape and crystalline phase of starch during hydrolysis, and the process can be carried out in dry state.

• Journal of the East Asian Society of Dietary Life
• /
• v.23 no.2
• /
• pp.227-233
• /
• 2013

The physicochemical, mechanical properties and sensory evaluation of sulgidduk using different ratio of makgeolli lees were investigated. The pH decreased as the amount of makgeolli lees increased, but acidity increased. The soluble solids increased as the amount of makgeolli lees increased but there were no significant difference. The L value decreased and value increased the amount of makgeolli lees. The degree of gelatinization of sulgidduk containing makgeolli lees was high at day then decreased time. As the lees increased, the degree of gelatinization decreased. In all treatments (except control) degree of retrogradation increased 2 days then decreased. As the amount of makgeolli lees, hardness increased but chewiness, adhesiveness, springiness, and cohesiveness significantly decreased. Sensory evaluation results, browness was high while sweetness, moistness, softness low as the amount of makgeolli lees. In overall acceptability, MLS6 was high (4.92). In conclusion, sulgidduk 6% makgeolli lees was found to excellent, when consider dietary fiber content and acceptability.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.27 no.5
• /
• pp.890-896
• /
• 1998

In order to increase the use of waxy barley, cakes were made and the textural and sensory properties were investigated. The moisture content of cakes made out of waxy barley grain and flour were 51.0 and 52.1%, respectively. L values in color of the waxy barley cakes tended to decrease during 3 day storage at 15$^{\circ}C$. Textural analysis showed that there were no differences among two waxy barley and waxy rice cakes in hardness at fresh state. But after 3 day storage at 15$^{\circ}C$, the hardness of the waxy barley cake was lower than that of waxy rice cake. These results implied that the degree of retrogradation of waxy barley cake might be low due to its high dietary fiber content. The hardness and adhesiveness of the waxy barley cake thawed after 15 day freezing were not significantly different from those of the fresh cake. In sensory evaluation, the overall preference of waxy barley cake was lower than that of waxy rice, but the sensory score of the cake made of waxy baley flour was above 4 point in the 5 point scale, showing a patency of waxy barley for the cakes.

• Korean Journal of Food Science and Technology
• /
• v.36 no.6
• /
• pp.879-884
• /
• 2004

Effects of soaking time and particle size on physicochemical properties of nonwaxy rice flour were investigated. Nonwaxy rice grains were soaked at $4^{\circ}C$ for 0, 1, 12, and 24 hr, dried at room temperature, and milled. Resulting flours were passed through 45-mesh ($<355\;{\mu}m$, IL45) and 100-mesh ($<150\;{\mu}m$, IL100) sieves and separated into $<40\;{\mu}m\;and\;40-100\;{\mu}m$ series. IL45 series showed higher amount of large particles ($40-100\;{\mu}m$) than IL100 series. As the soaking time increased, protein and ash contents decreased, and amylose content, water-binding capacity, swelling power, and solubity of nonwaxy rice flours increased. Swelling power and solubility of nonwaxy rice flours also increased between $65-85^{\circ}C$. Water-binding capacity, swelling power, and solubility of IL100 series were higher than those of IL45 series. 12 hr-soaked nonwaxy rice flour pastes showed higher peak viscosity and breakdown but lower setback and viscosity at 95 and $50^{\circ}C$ than 1 hr-soaked ones. X-Ray diffractograms of nonwaxy rice flours were not affected, whereas surface appearance was affected, by soaking time and particle size.