• Korean Journal of Food Science and Technology
• /
• v.31 no.4
• /
• pp.977-983
• /
• 1999

This study was conducted to investigate the effects of emulsifiers on the quality of steamed bread. initial pasting temperature of the flour was decreased from $63.8^{\circ}C$ to $59.40{\sim}62.95^{\circ}C$ by adding 1% of emulsifiers such as monoglyceride, lecithin, sugar ester and diacetyl tartaric acid esters of mono- and diglycerides (DATEM). But other rheological properties of the doughs were varied with different emulsifiers. Flour with 1% sugar ester showed the lowest value of final viscosity and set back, therefore sugar ester might be effective for retard the retrogradation of bread. By alveogram test, flour with 1% DATEM showed the highest value of P (tenacity) but the lowest value of L (extensibility), that means DATEM might be effective for strengthening tenacity of dough but it lowered extensibility. After 72 hours of storage test, the steamed bread based on the flour with 1% monoglyceride showed the best crumb softness and the highest score of sensory test.

• Korean Journal of Food Science and Technology
• /
• v.40 no.6
• /
• pp.643-648
• /
• 2008

The principal objective of this study was to evaluate the effects of the addition of sourdough to bread dough, specifically with regard to the physicochemical characteristics of bread dough, organoleptic evaluation, and bread storage. Marked increases in lactic acid bacterial counts $10^{9-10}CFU/g$ in dough samples with 30, 50, and 100% of added sourdough to the respective bread dough were observed after the first fermentation period of the dough, but decreases were observed in yeast cells. The highest overall acceptance scores were recorded for the 100% sourdough-added bread, and almost no differences in taste and texture were detected between the regular bread (control bread) and sourdough-added bread on the sensory evaluations, with slightly lower evaluation scores (for sour taste) in the sourdough-added bread. The sourdoughadded bread also showed retarded mold growth in the bread on our storage tests. Six days had elapsed prior to the appearance of mold growth in the sourdough-added bread, whereas three days elapsed in the regular bread. The more sourdough was added to the dough, the less was the total count in bread. Increases of 13.1, 20.9, and 36.2% in the retardation of starch retrogradation of the bread were observed as the result of additional increases in sourdough quantity to bread at 30, 50, and 100%, respectively.

• Korean Journal of Food Science and Technology
• /
• v.22 no.6
• /
• pp.651-658
• /
• 1990

Starch phosphates were prepared by dry heating, gelatinizing method and extrusion process using sodium tripolyphosphote (STPP) as a substitution reagent and their physicochemical properities were compared. In the preparation of starch phosphate by dry heating method(DSP), the effect of reaction temperature was the most significant to the DS(Degree of substitution). In the phosphorylation reaction with gelatinized starch(GSP), the substitution ratio was increased with increasing the reaction temperature, but the increase was insignificant above $85^{\circ}C$. By extrusion with the corn starch containing 2.0% STPP at various moisture contents of 20, 25 and 30%, the DS values of extrudate(WESP) were within the range of between 0.0066 and 0.0083. The starch phosphate(DSP) products showed lowering the gelatinization temperature, increasing the clarity of the starch paste. However, WESP showed higher gelatinization temperature than that of raw starch. The starch phosphate prepared by extrusion process showed lower apparent viscosity of paste than that of the DSP at same condition. All of starch phosphates showed reducing the tendency of the paste retrogradation.

• Journal of the East Asian Society of Dietary Life
• /
• v.24 no.6
• /
• pp.883-895
• /
• 2014

This study investigated quality characteristics of pan breads prepared with 0, 10, 20, 30 and 40% purple rice flour and naturally fermented blueberry-rice starters. RVA (Rapid Visco Analyzer) analysis showed that wheat flour retrogradation was not retarded by addition of purple rice flour. Using amylography, gelatinization tem. perature of purple rice flour samples was higher than that of the control, whereas maximum viscosity temperature. and maximum viscosity of purple rice flour samples were lower than those of the control. Weights of pan breads containing purple rice flour were lower than that of the control, whereas volume, specific volume and baking loss rate were higher than those of the control. The anthocyanin contents and antioxidative activites as measured by DPPH radical scavenging activity of breads increased as the concentration of purple rice flour increased. The moisture content of pan breads containing purple rice flour decreased as storage time increased. The pH of breads containing purple rice flour was higher than that of the control. Color L value decreased, whereas a and b values increased significantly, as storage time increased. In texture analyzer measurement, hardness of breads containing purple rice flour significantly increased as storage time increased. Breads containing 10~20% purple rice flour showed acceptable sensory properties, such as mouth feel, appearance, flavor, texture, taste and overall acceptability.

• Korean Journal of Food Science and Technology
• /
• v.28 no.3
• /
• pp.528-537
• /
• 1996

Qualify changes of microwave-reheated cooked rice aseptic-packaged with different lid materials and oxygen absorbers were determined during storage at $20^{\circ}C,\;30^{\circ}C$ and $40^{\circ}C$. Springiness cohesiveness and adhesiveness increased as storage temperature increased, while gumminess and hardness decreased. Lid materials oxygen absorbers, and storage temperatures showed no significant effect on the textural properties of cooked rice after microwave reheating. Degree of gelatinization was increased as storage temperature increased and was restored after microwave reheating. Scanning electron micrograph showed that the surface of cooked rice became rough and hollowed after microwave reheating for 1.5 min, indicating starch was regelatinized, while there was no difference with respect to lid materials. Photomicrographs of the cross-section of aseptic-Packaged cooked rice showed that a compact and solid structure increased and retrogradation occured in starch as storage temperature decreased, while a compact and solid structure was decreased and starch was regelatinized after microwave reheating.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.20 no.4
• /
• pp.354-362
• /
• 1991

To investigate nutritional and biochemical values of buckwheat, amino acids and minerals in buckwheat harvested from Kangweon-do were analysed. Mixed flour between buckwheat and wheat were made to be used for buckwheat noodle and were also analysed minerals and major nutrients in composite flours. When three different levels of flour mix were compared, major nutrients were about same among those mixes but minerals were higher by adding more buckwheat flour, especially by adding more imported buckwheat flour. From this mixed flour, 9 minerals and 16 amino acids including 9 essential amino acids were analysed. Contents of selenium, sodium and magnessium were very high in buckwheat flour, Therefore, nutritional value of domestic buckwheat was highly evaluated. BAP method was used to determine the change of gelatinization in the noodles prepared by extruder at 8$0^{\circ}C$, and in the noodles during freeze drying and refrigeration. 70% of gelatinization was done during noolding process and retrogradation was severe during refrigeration.

• Journal of the East Asian Society of Dietary Life
• /
• v.17 no.1
• /
• pp.130-135
• /
• 2007

Ong-keun jook(Korean whole rice porridge)is a traditional Korean porridge made with whole rice. The aim of the present study was to evaluate the effects of gamma-irradiation on the microbial and physicochemical characteristics of rice porridge gamma-irradiation, even at a 1-kGy dose, decreased the total bacteria in cooked rice porridge to lower than the detectable limit($10^2CFU/g$). The viscosity of gamma-irradiated rice porridge was decreased compared to that of control. Upon examination of granule morphology by SEM, cracks were observed on the starch granules in samples irradiated at above 5 kGy. The results of the DSC curve suggest that gamma-irradiation delayed retrogradation of cooked rice porridge. Based on the present results, gamma-irradiation was helpful for developing sterile and tube diets that are needed for ill, old or infant subjects.

• Journal of the Korean Society of Food Culture
• /
• v.29 no.4
• /
• pp.355-363
• /
• 2014

The purpose of this study was to investigate the rheological characteristics of medium wheat flour mixed with bamboo leaf and lotus leaf powders. Rheological properties of the mixed flours were tested based on falling number, color, RVA, farinogram, and rheofermentometer analyses. Falling numbers increased with addition of bamboo leaf and lotus leaf powders. The L values of all mixed flours were less than that of control. The 1% mixed flour sample containing bamboo leaf and lotus leaf powders was not significantly different from 3% mixed flour. The a values of the mixed flour decreased as bamboo and lotus powders increased, whereas b values increased. Addition of bamboo leaf and lotus leaf powders to flour reduced peak viscosity, holding strength, and final viscosity. The set back values of mixed wheat flour containing bamboo leaf powder were lower than those of mixed wheat flour containing lotus leaf powder, suggesting that bamboo leaf powder suppressed retrogradation of flour compared to lotus leaf powder. In the farinogram, the water absorption and consistency of the flours containing bamboo and lotus leaf powders increased, whereas development time and stability decreased. The fermentation time of dough with lotus leaf powder was less than that of dough with bamboo leaf powder.

• Applied Biological Chemistry
• /
• v.25 no.2
• /
• pp.67-74
• /
• 1982

Morphology, physicochemical properties, pasting properties in the presence of various anionic ions and aging of gels of Akibare (Japoica type) and Milyang 23 (Indica type) rice starch were studied, Both starches. were polygonal with length in the range of $3{\sim}6{\mu}m$. Starch granules of Akibare were somewhat smaller than those of Milyang 23. X-ray diffraction study demonstrated that peak shape and intensity were significantly different between the two starches. Akibare and Milyang 23 rice starch had amylose content of 18.5 and 19.5% and water binding capacity of 106 and 100%, respectively. Milyang 23 rice starch had a higher swelling power than Akibare starch. A relationship between percent solubility and swelling power implied that bonding forces within the granules of the both starches were different. The optical transmittance of 0.1% suspension of the two starches increased rapidly from $60^{\circ}C$. In the range of $60{\sim}90^{\circ}C$, the two starches showed a single gelatinization pattern. Amylograms of the two starches in the presence of various anionic ions showed that pasting temperature and peak temperature were progressively increased in the order of SCN-${SO_4}^=$. SCN- and I- ions increased the peak height of Akibare rice starch while only SCN- ion was effective for Milyang 23 rice starch. There were no differences in the rates of retrogradation of 45% gels of the two starches stored at $21^{\circ}C$.

• Food Science and Preservation
• /
• v.19 no.3
• /
• pp.361-367
• /
• 2012

The purpose of this study was to investigate the rheological properties of pound cake cotaining ginger powder. Ginger powder was added to pound cake bases at 1, 3 and 5%. concentrations. The physical properties of the pound cake with ginger powder were tested by rapid viscoanalyzer (RVA), a farinogram, and an alveogram. The falling numbers were increased with the increment of ratio of ginger powder, but they did not show a significant difference. The higher quantity of ginger powder with cake flour made MTI value the higher and these results showed typical cake flour. The farinogram quality number did not show a significant difference between the control and the other samples. The highest initial gelatinization temperature was that of the control, and the increment of ginger powder on the cake flour made initial gelatinization temperature lower. The peak and final viscosities, however, were higher with the quantity increment of ginger powder. The holding strength did not show a significant difference. As the 5% - ginger-powder pound cake showed the highest setback, it was predicted that the addition of ginger powder to the flour would not play the role of anti-retrogradation. The Pmax and L value of the alveogram decreased with the ginger powder increments.