• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.44 no.1
• /
• pp.64-69
• /
• 1999

Gelatinization characteristics of 111 glutinous rice varieties were evaluated by Rapid Visco Analyzer. Gelatinization viscosity of glutinous rice tested varied with ecotypes or varietal groups: indica, japonica, and Tongil type. Indica rice showed the highest average value of initial pasting temperature. The average values for peak, hot, and cool viscosities were highest in Tongil-type rice, and lowest in japonica rice. Japonica showed the lowest breakdown and consistency, but the highest setback value. Indica was lower in alkali digestion value (ADV), and shorter in gel length after gelatinization thanjaponica and Tongil-type. Glutinous rices tested could be divided into six groups by cluster analysis based on their gelatinization characteristics. Group I-A was mostly early maturing japonica varieties while I-B was mostly indica and Tongil-type rices. Groups II-A and II-B were consisted of very early maturingjaponica, and III-A and III-B included medium or medium late maturingjaponica varieties. Group III-A showed the lowest average values of peak, hot, cool, and consistency viscosities, and also in breakdown and setback ratios. Group I-B revealed the highest values in peak, hot, cool, breakdown, and consistency viscosities. ADV was low in groups I-A, I-B, and II-B, and gel consistency was not different among the six varietal groups. Principal component analysis using seven traits related with gelatinization produced four effective components, and the first and second components were highly correlated with all the gelatinization characters evaluated.

• Food Science and Biotechnology
• /
• v.18 no.5
• /
• pp.1145-1149
• /
• 2009

Physicochemical properties of native and acid-modified Job's tears (Coix lachryma-jobi L.) starches were investigated. Starch extracted from Job's tears was treated with 2.2 N hydrochloric acid for different length of time (3, 6, 12, and 18 hr). The hydrolysis pattern of starches with the acid proceeded rapidly up to 12 hr and then the approached constant values. The swelling power of acid-modified starches measured at all temperatures was lower than that of its native counterparts and the water solubility index increased as temperature and hydrolysis time increased. Rapid visco analyzer viscograms of acid-modified starches demonstrated a very low viscosity as compared with that of native starch. However, Xray diffraction did not show any significant alteration in the crystallinity after acid-modification.

• Journal of the East Asian Society of Dietary Life
• /
• v.24 no.3
• /
• pp.368-374
• /
• 2014

We investigated the physical and cooking properties of commercial noodles supplemented with functional ingredients. RVA (rapid visco analyzer), color, water activity, texture and cooking properties were tested. Noodles containing kudzu showed the highest initial gelatinization temperatures, whereas noodle containing kelp displayed the highest peak viscosity and set back. Holding strength and final viscosity were highest in noodles containing mugwort. The L value ($94.89{\pm}0.02$) of wheat flour noodle was the highest. Among functional noodles, L value ($88.65{\pm}0.01$) and a value ($7.42{\pm}0.02$) of cactus noodle were the highest, whereas b value of pumpkin noodle was $40.81{\pm}0.03$, which was higher value than in other noodles. Water activity of cactus noodle was highest (0.455), but the difference was not significant. Cooking properties (including weight, volume, and water absorption) and turbidity of pumpkin noodles showed the highest growth rate. In terms of texture, hardness was highest ($12836.8{\pm}7.1g/cm^2$) in green tea noodles, and cohesiveness and gumminess were highest in kelp and mugwort noodles. Considerig the quality characteristics of noodles supplemented with mulberry leaves, cactus, mugwort, green tea, pumpkin, kelp or kudzu, pumpkin noodles were most stable in terms of gelatinization and cooking properties.

• 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 and cookery science
• /
• v.29 no.4
• /
• pp.353-359
• /
• 2013

The effect of the addition of dough ripe stage rice (DRSR) and yellow ripe stage rice (YRSR) on the quality characteristics of Backsulgi was investigated. The DRSR and YRSR addition ratio of 30% was selected by preliminary sensory evaluation study for which backsulgi was prepared with DRSR added to full ripe stage rice (FRSR, control) as the weight ratio of 0, 20, 30 and 50%. The pasting properties of 30% added DRSR and YRSR flours, analyzed with rapid viscosity analyzer (RVA), were compared with FRSR flour. The RVA values of holding, breakdown, final viscosities were higher in 30% DRSR and YRSR flours than in control. Backsulgi prepared with 30% DRSR and YRSR showed lower moisture content along with higher greenness and yellowness than control. As a result of analysis with texture analyzer, adhesiveness, springiness, cohesiveness, chewiness and resilience were lower in backsulgis with 30% DRSR and YRSR than in control. In the sensory evaluation, backsulgis with 30% DRSR and YRSR were assessed as having more intensive green color, and more greenish and delicious taste than control. Furthermore, backsulgi with 30% DRSR showed higher score of overall acceptability than 30% YRSR (p<0.05), and not significantly different score with control (p>0.05). Therefore, the addition of 30% DRSR could give favorable color and flavor to backsulgi.

• Korean Journal of Food Science and Technology
• /
• v.39 no.4
• /
• pp.412-418
• /
• 2007

The physicochemical properties and mixograph characteristics of soft white winter (SWW) and club wheat, as well as their product potentiality, were investigated. There were no significant differences between the SWW wheat and club wheat regarding their Single Kernel Characterization System (SKCS) properties. The straight-grade flour yield, break flour yield, ash content, and milling score of the SWW wheat were similar to those of the club wheat, and the straight-grade flour yield had a significant positive correlation to the break flour yield (r = 0.805**). The Rapid Visco-Analyzer (RVA) peak viscosity and swelling volume of the SWW wheat flour were very similar to those of the club wheat flour, and there was a significant positive correlation between the RVA peak viscosity and the swelling volume (r = 0.662**). The average mixograph absorption of the SWW wheat was higher than that of the club wheat. The club wheat resulted in a higher cookie diameter than the SWW wheat, but the difference was not significant. The sponge cake volume using the SWW wheat flour was higher than that with the club wheat flour. In addition, there was a significant correlation between the cookie diameter and the sponge cake volume (r = 0.745**).

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.46 no.5
• /
• pp.616-621
• /
• 2017

The objective of this study was to investigate the physicochemical properties of domestic strong wheat flour (DSWF). Three commercial DSWFs (D1, D2, and D3) were compared with imported strong wheat flour (ISWF). DSWFs had higher moisture content, crude protein content, lightness, and whiteness than ISWF. DSWFs showed lower solvent retention capacity and water absorption index than ISWF. DSWFs also showed significantly higher water solubility index than ISWF (P<0.05). Setback values by rapid visco analysis were significantly higher in D1 and D2 than in ISWF and D3, which means ISWF and D3 were better in retarding retrogradation. Differential scanning calorimetry results showed that ISWF required 6.2 J/g of energy for phase transition, whereas DSWFs needed 6.67~7.13 J/g. The farinograph results showed that ISWF had higher water absorption, longer dough stability time, and significantly higher softening of dough at 20 min than DSWF (P<0.05). Dough resistance and extensibility were higher in ISWF than in DSWFs.

• Korean Journal of Food Science and Technology
• /
• v.35 no.4
• /
• pp.545-550
• /
• 2003

The effect of ${\beta}-glucan$ on gelatinization of barley starch was studied. By the rapid visco-analyzer measurement, gelatinization of starch became rapid and viscosity increased largely on the RVA pattern by addition of ${\beta}-glucan$ to starch. The results of differential scanning calorimeter showed that molecular structure of starch was getting stabilized through shifting up of gelatinization temperature and increase in enthalpy by addition of ${\beta}$-glucan. X-ray diffraction pattern also showed the same results as differential scanning calorimeter. But it was revealed that addition of ${\beta}$-glucan to starch didn't affect characteristics such as microscopic observation, solubility, swelling power, and iodine binding properties during gelatinization of starch.

• Food Science and Biotechnology
• /
• v.17 no.1
• /
• pp.52-57
• /
• 2008

The effects of transglutaminase (TG) on the pasting and rheological properties of different wheat cultivars ('Sharpshooter', 'Russ', and 'AcAriss') blended with barley (40%) or soy (20%) flour were investigated. In the rapid visco-analyzer (RVA) pasting profile, the addition of barley or soy flour to wheat flour samples induced a decrease in peak, trough, final viscosity, breakdown and setback values. However, TG treatment of these blends significantly increased peak viscosity and breakdown (p<0.05). In particular, TG treatment greatly increased the breakdown of wheat flour blended with soy flour, indicating that the cross-linking of proteins through TG may somehow be related to an increase in starch granule rupturing in pastes. Storage (G') and loss (G") moduli of the sample pastes increased with an increase in frequency ($\omega$), while complex viscosity (${\eta}*$) decreased. In all wheat cultivars, G', G", and $\eta$ were decreased by the addition of barley or soy flour, or TG treatment. Results suggest that protein cross-linking by TG can produce unique and improved properties in wheat flours blended with barley or soy flour.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.39 no.7
• /
• pp.992-998
• /
• 2010

This study investigated changes of quality during storage period with 6 types of Backsulgie manufactured by adding enzyme (BS-300 0.3%) and trehalose (3%, 6%) to minimize the changes of quality and tried to determine their optimal combination ratio. When Rapid Visco Analyzer (RVA) gelatinization properties of rice powder were examined, adding both of enzyme and trehalose to the powder increased stability of process and reduced retrogradation. In comparison of the degree of retrogradation of Backsulgie by using Differential Scanning Calorimetry (DSC), the sample with enzymes and trehalose suppressed retrogradation. Moreover, the retrogradation effect became larger by using both of enzyme and trehalose and it was the largest in the sample with 0.3% enzyme and 6% trehalose. Enzyme and trehalose added to Backsulgie were found to improve water retention, to minimize changes of texture and color during storage of Backsulgie. Therefore, optimal combination ratio of Backsulgie is 0.3% enzyme with 6% trehalose added Backsulgie.