Isomaltooligosaccharides were prepared from puffed rice flour by a One-step processing method under different conditions, and their physicochemical properties were evaluated. Sample was prepared by allowing puffed rice flour to pass through a 50 mesh standard sieve and segregated into experimental groups (PR15-60, PR20-60, PR15-65, and PR20-65) according to the substrate concentrations (15%, 20% w/v) and reaction temperatures (60℃, 65℃). Enzyme reaction of puffed rice flour and water mixture was performed for 0, 1, 6, 24, and 48 h using commercial enzymes (Maltogenic amylase, Promozyme D2 and Transglucosidase; amount: 0.5% (w/v) to obtain the corresponding isomaltooligosaccharides. The reducing sugar content, dextrose equivalent, and total soluble solids of the reactants increased with increasing reaction time. The carbohydrate composition and amount of isomaltooligosaccharides with degree of polymerization (DP) 2 to DP 7 in the rice flour were examined by HPLC with an evaporative light scattering detector. Because of the high carbohydrate composition, the PR20-65 group showed the highest isomaltooligosaccharide content after 6 h of reation (138.47 mg/mL). After 24 h of reaction, the amount of isomaltooligosaccharides (DP2-DP7) and the isomaltooligosaccharides/total carbohydrate ratio in this group were 135.00 mg/mL and 68.04%, respectively.
For the production of Yakhobak (Cucurbita maxima subsp. maxima) paste under various heating conditions, we steamed Yakhobak for roughly 20 min, followed by heating under high pressure treatment for 0 min (HHP0), 20 min (HHP20), 40 min (HHP40), and 60 min (HHP60). The physicochemical and sensory characteristics were subsequently investigated. Generally, no significant difference was observed in organic acid content and sensory characteristics score between Yakhobak paste treated with and without high-pressure heating. However, there was a significant difference in color value, soluble solids, and free sugar content. The L value for color of the group HHP0, untreated control Yakhobak paste (no high-pressure heating), decreased as time increased from 20 min to 60 min, with L values of 44.33, 44.25, and 42.86, respectively. The b value for the color of Yakhobak paste also decreased, showing a significant difference. Soluble solids and free sugar (fructose, glucose, sucrose) contents of the high-pressure heat-treated groups HHP20, HHP40, and HHP60 decreased compared with untreated group HHP0. Organic acid composition of Yakhobak paste included citric acid, malic acid, and fumaric acid, and the major organic acid was malic acid. Sensory score of HHP40 was the highest among all experimental groups in terms of overall preference, but there was no significant difference.
The present study investigated the sensory characteristics of 31 types of gochujang, a Korean fermented chili paste, produced in various regions of Korea. Generic descriptive analysis was conducted to analyze the sensory properties of the samples. Among these, four samples were selected for consumer taste test based on their distinct sensory profiles. The drivers of liking for gochujang were identified when the samples were applied to four different food systems. Consumers (age range: 20’s–60’s) rated the acceptance of the samples. ANOVA and multivariate analyses were conducted on the data. The types of carbohydrate sources or usage of additional seasoning showed stronger influence on the sensory characteristics of gochujang than the production location. Samples with strong fermented soy and fish sauce characteristics were fairly unacceptable to the consumers. The positive drivers of gochujang were appropriate levels of spiciness and sweet odors/flavors, whereas the negative drivers were off-note and fermentation-related flavors.
Food freezing preservation is an important process due to its high quality and long shelf-life. In order to improve the quality of frozen sweet potato stem, the freezing rate, thawing, and packaging method was optimized by the determination of physical properties. There was no significant difference among the treatment of freezing rate. Further, the drip loss of sweet potato stem was higher at a relatively fast freezing rate (immersion freezing) than at slow freezing rate (natural convection freezing at -20 or -40°C). For the comparison of packaging methods, the aircontaining packaged sweet potato stem had the lowest significant differences from the result of color, pH, and hardness. From the result of the drip loss, the high frequency and microwave using thawing samples were more effective than room temperature and water thawing. Therefore, fast freezing and thawing rate with air-containing package were recommended to obtain the better quality of sweet potato stem.
This study was performed to investigate the effect of drying temperature on the quality characteristics and antioxidant activity of blueberry. Blueberries were dried at different times and temperatures, including A (40°C, 72 hr), B (40°C, 48 h and 50°C, 24 hr), C (50°C, 72 hr), and D (60°C, 72 hr). The yield and pH ranges of blueberry were determined to be 17.73~31.17% and 3.20~3.25, respectively. The yield rate of A treatments, soluble solid of D treatments, was the highest. The yield rate and soluble content was the highest in the treatment of A and D, respectively. The moisture content and water activity were significantly decreased with the increase in drying temperature (p<0.05). The L value of A treatment, and a and b values of D treatment were the greatest. In the analysis of texture analyzer, hardness, springiness, cohesiveness, gummiess and chewiness were significantly increased with the increase in drying temperature (p<0.05). In the sensory evaluation of blueberry, the appearance and color were the highest in the A treatment. The moisture, texture and taste was highest in the B treatment. The overall acceptability was in the order of B › A › C ›D. The total polyphenol content and DPPH radical-scavenging activity were 9.21~13.05 mg/GAEg and 61.90~81.42%, respectively, which were significantly decreased with the increase in drying temperature (p<0.05). Therefore, the optimum time and temperature for blueberry drying was founded to be B treatment (40°C, 48 hr and 50°C, 24 hr) among other treatments.
This study tried to develop Siraegi by boiling it down in soy seasoning sauce with excellent sensory attributes and evaluate the quality characteristics in order to enhance the value of traditional agricultural products, dried radish leaves. Sugar content of the seasoning sauce were finally established at 30% (w/v) compared with the starch syrup, which was added to the sauce through sensory evaluation among four groups, 0%, 30%, 60% and 100%. The texture (breaking strength) of Siraegi which was boiled for 30 minutes in water with baking powder was reduced by showing softening effect ranging from 7.6% to 42.1% as the amount of added baking powder was increased. The color of braised Siraegi produced with prepared a seasoning sauce and different content of baking powder, the brightness significantly decreased with an increase of baking powder. The reduction effects of breaking strength ranged from 25.6% to 43.9%, resulting a significant difference. The pH of braised Siraegi with a seasoning sauce significantly increased from 5.71 to 6.04 as the amount of added baking powder was increased, while its acidity was decreased. Sensory evaluation showed significant values for hardness and toughness as the values dropped when compared with the control (p<0.001), and overall acceptability of the group with adding 0.2% baking powder was best (p<0.001). In conclusion, baking powder could be considered as softening agent shorting the cooking time and improvement of the acceptability. Furthermore, it was expected that the newly developed soy sauce barised Siraegi using the dried radish leaves would be successfully utilized by side dishes in the food preparation industry.
This study investigated the effects of thawing conditions on physiological activities and quality of peeled garlic. Peeled frozen garlic was analyzed after thawing at low temperature (4℃), room temperature (20℃), tap water (20℃), radio frequency of 27.12 MHz, and 2.45 GHz in a microwave. As a result, the time required to thaw garlic to 0℃ by various thawing methods was shortest at2.45 GHz in a microwave, followed by 20℃ tap water, radio frequency of 27.12 MHz, 20℃, and 4℃. Microwave thawing was faster than other methods, but it resulted in significant non-uniformity of heating. The hardness of peeled garlic significantly decreased upon freeze-thawing, whereas it showed improved hardness upon radio-frequency thawing. Total color difference in garlic increased upon freeze-thawing, and it was not improved by various thawing methods. Antioxidant activities were determined for DPPH radical scavenging ability, SOD-like activity, and reducing power. Total phenolic compounds and flavonoids in garlic extract were measured as 3.222±0.214 μg GAE/g and 0.149±0.03 μg QE/g, respectively. The content of total phenolic compounds was significantly reduced by 2.45 GHz microwave thawing (1.90±0.02 μg GAE/g); however, flavonoid contents were slightly reduced under freezing and thawing conditions. The DPPH radical scavenging ability of garlic extracts was not affected by thawing methods; however, SOD-like activity and reducing power were slightly reduced by freeze-thawing. These results indicate that physiological activities were not improved by radio-frequency thawing; however, thawing time and maintain hardness were reduced compared with conventional thawing methods.