• Journal of the East Asian Society of Dietary Life
• /
• v.23 no.2
• /
• pp.218-226
• /
• 2013

This study examined the optimal mixture ratio of rice gruel supplemented with puffed rice by mixture design. The quality characteristics of rice gruel samples were examined according to mixture ratios at eleven experimental points. The high soluble solid content and viscosity of gruel samples were significantly dependent on rice (short grain) content instead of glutinous rice. The viscosity ranged from $2,891{\sim}9,153\;cP{\cdot}s$ and soluble solid content ranged from $8.23{\sim}10.13^{\circ}Brix$ at the eleven experimental points. The mixture with the highest solid content and viscosity, 12% rice gruel sample was $10.10{\sim}10.13^{\circ}Brix$ and $9,150{\sim}9,153\;cP{\cdot}s$. The L color of sample decreased with decreasing rice content, while "a" (redness) and "b" (yellowness) values slightly increased. In the sensory evaluation, samples with higher amount of puffed rice and glutinous rice scored higher for brown color, flavor and sweetness than high-content rice samples. The response surface and trace plot results showed that increasing of puffed rice increased the brown color, sweet taste and sticky aftertaste. From the results of the F-test, viscosity, "a" (redness) and "b" (yellowness) values fit a quadratic model with significant probabilities within 0.05%. The optimum predicted formulations of rice gruel containing puffed rice were 1.69% of puffed rice, 0.47% of glutinous rice and 9.84% of rice, respectively.

• Korean Journal of Food Science and Technology
• /
• v.22 no.3
• /
• pp.266-271
• /
• 1990

Yukwa(Korean traditional puffed rice snack) puffed by vegetable oil was evaluated its shelf-life and monitored its physicochemical changes during long term storage. And air puffing instead of oil was tested for substitution of puffing medium. The shelf-life of oil puffed Yukwa was less than 4 weeks at $30^{\circ}C$ by peroxide value and negligible changes in physical texture was detected after 9 weeks storge. There was a possibility to apply air puffing method for Yukwa making and its optimum temperature was around $250^{\circ}C$. Air puffed Yukwa was a little less expansion rate, same level of hardness and high brittleness compared with oil puffed . Sensory evaluation of air puffed Yukwa was as same as air puffed in odour, firmness and texture but overall taste was less score probably causing by oil used which need a impovement for air puffed Yukwa. No differences in structure of both Yukwa observed by SEM was showed.

• The Korean Journal of Food And Nutrition
• /
• v.7 no.2
• /
• pp.137-143
• /
• 1994

To optimize extrusion cooking condition of single screw extuder for production of puffed rice extrudate using response surface methodology (RSM), moisture content, barrel temperature and screw speed were determined from contour maps, showing relationship between dependent (hardness, expansion ratio, water absorption index, water solubility Index, degree of gelatinization) and independent variables. Optimum operational conditions for production of puffed rice extrudate with suitable quality properties were moisture content 17%, barrel temperature 1$25^{\circ}C$ and screw speed 210 rpm, respectively.

• Journal of the East Asian Society of Dietary Life
• /
• v.10 no.1
• /
• pp.55-61
• /
• 2000

Physicochemical and sensory characteristics of Yukwa(fried rice cookie) made by different processing condition were investigated to estabilish the optimum expansion of Yukwa. The expansion rate and crispness of Yukwa prepared by soaking waxy rice for 24 hours was satisfactory . Addition of 15% soy slurry gave better effect on increasing the expantion rate, crispiness and sensory preference than no addition of soy slurry . Yeast, Soju(distilled liquor) , Mackeali(rice wine, turbid) and Chunju(rice wine, clear) as expansion reagent were added to Yukwa prepration . Yeast and Mackeali among tested expansion reagent showed better expansion rate and lower hardness meausred by texturometer than Chunju. Yukwa added chungju showed more fine structure and lower expantion rate than others. Microwave puffed Yukwa was less expansion rate, but same level of crispiness and hardness compared with oil puffed. And no difference in sensory characteristics such as degree of crispiness and stickiness of microwave puffed and oil puffed.

• Food Engineering Progress
• /
• v.13 no.2
• /
• pp.159-163
• /
• 2009

The pH, moisture, solid, total sugar, amylose, viscosity, line spread and color of Tarakjuk containing puffed rice powder were investigated. The pH of rice Tarakjuk was higher than that of puffed rice powder. Also, samples with whole milk powder were higher than fresh milk (p<0.05). The highest moisture contents, 84.56% was observed in rice Tarakjuk prepared with whole milk powder, while lowest 81.04% in puffed rice powder sample with fresh milk (p<0.05). Samples with lower moisture contents resulted in greater solid contents (p<0.05). Higher total sugar contents were noticed in cooked samples than uncooked ones, however no differences were found among cooked ones (p<0.05). Amylose contents of puffed rice powder Tarakjuk were higher than rice sample (p<0.05). The rice Tarakjuk showed higher viscosity and lower spreadability (p<0.05). Higher "L" value was observed in rice. Highest "a" values were shown in puffed rice powder and lowest value in rice with fresh milk (p<0.05). The "b" value tended to be similar to "a" value.

• Korean Journal of Food Science and Technology
• /
• v.33 no.1
• /
• pp.55-59
• /
• 2001

Pressure-puffing system or extruder has been used to puff rice kernel or rice flour. Most of the study on rice puffing were the effect of process conditions such as moisture content and heating temperature on physical and chemical characteristics of popped rice. The study on mechanism and development of instant puffed rice like popcorn has been limited. Extruded waxy rice pellets were puffed in a microwave oven after drying and conditioning. Extruded pellets were formed with extrusion conditions of $20{\sim}27%$ moisture content, 2.76 MPa $CO_2$ gas injection pressure and 200 rpm screw speed. Under these conditions, puffed waxy rice pellets in microwave oven had low density and soft texture. Density and texture of puffed waxy rice pellet could be optimized by control of moisture content, $CO_2$ gas injection pressure and screw speed that affect significantly when puffing extruded waxy rice pellet.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.41 no.6
• /
• pp.846-852
• /
• 2012

The physical properties of instant puffed rice snacks with non-glutinous, glutinous, and steamed non-glutinous rice were evaluated at different moisture content and puffing temperatures. Raw materials were tempered to 9%, 12%, 15%, and 18% moisture content and puffed at $200^{\circ}C$, $210^{\circ}C$ and $220^{\circ}C$. With the increase in moisture content and puffing temperature, puffed snacks were less bulky. As the moisture content decreased and puffing temperature increased, the whiteness (L) value of puffed snacks decreased, while the redness (a) and yellowness (b) values increased. WSI and WAI were higher with an increase in moisture content and puffing temperature. Instant puffed rice snacks made from non-glutinous, glutinous, and steamed non-glutinous rice showed differences in bulk density, WSI, and WAI, while no difference was found in color values. When the moisture content increased from 9% to 15%, the cells within the products became more uniform and smaller. The instant puffed rice snacks made from glutinous rice showed the smallest and most uniform cell structure.

• Applied Biological Chemistry
• /
• v.37 no.6
• /
• pp.487-491
• /
• 1994

Relative crystallinities, saccharification efficiency, and diazinon(pesticide) residues of rice and rice hull puffed by hot air puffer were investigated. Crystallinities of rice starch in the puffed rice were decreased as compared to those in cooked rice, and those of rice hull were slightly decreased as compared to those in raw hull. By puffing of glutinous rice, the saccharification efficiency treated with malt amylase was higher than in cooked rice, and hydrolysis ratio of rice hull by cellulase was also increased from 14% to 30% by puffing. The residual contents of diazinon of the puffed rice and rice hull were decreased to 42.7% and 47.6%, respectively. In addition, its decreasing rate in nonglutinous rice were higher than that of glutinous rice.

• Food Engineering Progress
• /
• v.15 no.4
• /
• pp.338-345
• /
• 2011

The pH, acidity, protein, color, reducing sugar, total sugar, alcohol and organoleptic characteristics of Takju containing 100% short grain rice (100 S), 100% long grain rice (100 L), 50 S+50% puffed rice powder (50 P) and 50 L+50 P were examined. After a drastic decrease during the initial stage of fermentation, the pH gradually increased except 100 L. Protein peaked at day 1 and decreased. A higher protein was noticed in puffed samples than in rice samples (p < 0.05). The Hunter "L" value decreased after a rise during the beginning of fermentation. Puffed samples showed higher reducing sugar than rice at day 0. Total sugar was similar to reducing sugar. A drastic increase in alcohol concentration was detected at day 2. Higher alcohol was observed in short grain than long grain and also in puffed samples than in rice (p < 0.05). A significant difference between 100 S and 100 L was observed in a sensory evaluation (p < 0.01); while no preference was detected.

• Food Engineering Progress
• /
• v.23 no.4
• /
• pp.290-296
• /
• 2019

Rice in Korea is a highly valuable food resource that serves both as staple food and ingredient in various processed edibles. This study was conducted to explore pre-treatment methods for rice that result in good saccharification upon production of rice beer. When rice was subjected to fine grinding, steeping, roasting, gelatinizing, or puffing prior to saccharification with malt, wort containing puffed rice had the highest soluble solid content (°Bx). Upon production of wort without the addition of any enzymes for liquefaction or saccharification, the addition of 30% rice resulted in the highest soluble solid content (°Bx). Production of beer containing 10, 20, or 30% of either roasted or puffed rice showed that wort containing 30% puffed rice had the highest soluble solid content (15.4 °Bx) with good saccharification. The resulting beer likewise exhibited higher alcohol content (5.0-5.4%) than the beer that had roasted rice added, without the turbidity and with less bitterness. Therefore, rice puffing was considered a beneficial processing method to enhance rice saccharification and to facilitate both the production of fine quality beers and rice beer containing puffed rice.