• Applied Biological Chemistry
• /
• v.32 no.3
• /
• pp.278-285
• /
• 1989

Effects of cooking and drying methods on the taste component and microstructure of shrimp, Metapenaeus joyneri, were investigated. The nucleotides and their related compounds of fresh shirmp such as ATP, ADP, AMP, IMP, inosine and hypoxanthine were detected. AMP was detected as a trace amount in fresh shrimp, however, it increased up to $23.5{\sim}45.7{\mu}$ moles with cooking and drying due to the decomposition of ATP and ADP to AMP during cooking and drying. The major component of the free amino acids of fresh shrimp was arginine followed by glycine, lysine, proline and alanine. These free amino acids contents were 70% of the total free amino acids. One hundred grams of fresh shrimp contained 1,198mg (dry basis) of the total free amino acids. However, for hot air and freeze dried cooked shrimps it was decreased down to 342mg (dry basis) and 503mg (dry basis), respectively. It might be due to the dissolution of soluble amino acids during cooking. Hot air-and freeze-dried fresh shrimps was higher in hardness and brittleness but lower in cohesiveness and gumminess than hot air-and freeze-dried ones with boiling and microwave heating. Freeze dried shrimp had softer myofibril texture than hot air dried one. At the same time, more dense and multiporous structure in the tissue could be obtained from the hot air and freeze drying, respectively, after microwave heating of shrimps.

• Food Science and Preservation
• /
• v.30 no.5
• /
• pp.868-874
• /
• 2023

This study aimed to investigate the drying characteristics of Caragana sinica Rehder flowers, which are basic data necessary for increasing utilization. The flowers were harvested in mid-April and dried at different hot-air temperatures (50-90℃), and the physicochemical properties of the dried flowers were analyzed. It was found that the drying rate was proportional to the air temperature. The visual color of dried flowers was relatively strong in green when dried at 50℃, while browning was relatively severe when dried at 90℃. The greenness (-a^* value) of the mechanical color of the powder decreased with increasing temperature, and the yellowness (b^* value) decreased with increasing temperature above 70℃. The soluble solids of the hot water extract were maintained at a certain level after increasing up to 70℃, and the pH decreased with increasing temperature. The total polyphenol contents tended to increase with increasing temperature, and DPPH radical scavenging activity did not show a significant change after increasing up to 70℃. These results suggest that the hot-air drying temperature had a significant effect on the physicochemical characteristics of the C. sinica flower. The appropriate hot-air drying temperature was judged to be less than 50℃ for maintaining the unique color, and approximately 70℃ considering the high hot-water extraction yield and antioxidant capacity.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.44 no.2
• /
• pp.106-112
• /
• 2024

The objective of this study was to compare the feeding effects of imported timothy hay, domestic Italian ryegrass silage (IRGS) and IRG dried by hot-air dry system (IRGHDS) under basic total mixed ration (bTMR) on rumination activity, milk production, and milk composition in lactating dairy cows. Eighteen Holstein dairy cows were divided into three groups: control (bTMR + imported timothy hay), treatment 1 (bTMR + IRGS) and treatment 2 (TMR + IRGHDS) groups. The study was conducted over a total period of 24 days, including a 10 days adaptation period and a 14 days main experimental period. The results indicate body weight was not significantly different between the three groups (p>0.05), and rumination time was significantly higher in the treatment 1 group compared with the control group (p<0.001). Milk fat, protein, and lactose were not significantly different between the three groups (p>0.05), however, somatic cell counts were significantly lower in the treatment 1 group compared with the control group (p<0.001). As a result of the economic feasibility analysis, it is expected that feeding TMR using IRGS and IRGHDS will increase profit by 402.8 won/day and 331.4 won/day per cow compared to imported timothy hay. Therefore, IRGS and IRGHDS can be used as substitutes for imported timothy hay in feeding lactating dairy cows.

• Current Research on Agriculture and Life Sciences
• /
• v.1
• /
• pp.151-158
• /
• 1983

This study was performed to obtain a basic materials for improvement of garlic storage ability. The "Namhae jaerae" of southern strain and the "Dalsung jaerae" of northern strain were harvested by period, their stems were cut at 7cm and 25cm from disk and then placed them in blast drying system 12 hours per day at $40^{\circ}C$ for 4 days, or in natural state. The decrease rate of bulb weight was compared and rooting, sprouting, the rate of decay was investigated between natural dry(conventional method) and hot-air dry (blast drying system). The results obtained were as follows. In the case of the decrease rate of bulb weight after hot-air dry; 7cm plot" "Namhae jaerae" was similiar to one of 13th day of natural dry and 25cm plot 14th day. In "Dalsung jaerae" 7cm plot of early, common and late harvest was respectively similiar to one of 22nd, 18th and 16th day of natural dry, 25cm plot of early, common and late harvest showed the same decrease rate of bulb weight as that of 18th, 16th and 14th day of natural dry respectively. In the case of rooting and sprouting in sand culture at the early period of storage, hot-air dry showed more prolonged tendency than conventional drying method. In the case of clove state in the latter period of storage, number of eatable cloves was more numerous and number of decayed cloves were less in blast drying system than in conventional method.

• Korean journal of food and cookery science
• /
• v.16 no.1
• /
• pp.47-56
• /
• 2000

The purpose of this study was to develop a drying method of Gangjung. a traditional Korean snack, thus to reduce the drying time and to improve the quality of Gangjung. Two drying methods, hot air drying and far infrared ray drying were used by changing conditions such as air velocity(0.4, 1.2, 1.6 m/s), temperature(40, 50, 60$\^{C}$), and aging. Optimal moisture content of dried Gangjung pellet was 17% which was proper for frying. Cracks appeared on the surface of Gangjung pellet at lower levels of moisture content. Far infrared ray drying saved drying time about 20%. Both hot air drying and far infrared ray drying at 0.4 m/s of air velocity tended to show better quality of Gangjung than those dried at higher air velocities. The expansion volume and texture of Gangjung drying at 40$\^{C}$ was better than other temperature conditions, regardless of drying methods. Quality of Gangjung, dried at single stage without aging, was superior to those dried at double stage including aging process. Moreover, single stage drying save the drying time at least 24 hr. Gangjung dried at high temperature became hard and less brittle in sensory evaluation. In image analysis, air cell distribution in inner structure of Gangjung became uniform and fine as drying temperature decreased to 40$\^{C}$. Overall, Gangjung made of Gangjung pellet by the use of far infrared ray drying at 40$\^{C}$ without aging, showed the best quality in terms of physical and sensory properties.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.39 no.12
• /
• pp.1826-1831
• /
• 2010

This study was carried out to examine the changes of the quality feature and antioxidant activity of grape by-products. This experiment was to arrange the basic data for developing a functional material using grape by-products which were useless resources. Hot-air and freeze drying were followed by the gamma irradiation of 1~20 kGy. Hunter's color value, in case of hot-air drying, showed the highest L and a value in the 3 kGy, and it decreased according to the increase of the exposure dose. In the case of fre ze drying it showed the highest L and b value at the highest exposure, 20 kGy. It was considered that the breakdown of the pigment through high temperature processing was launched and the influence according to the gamma irradiation was not shown. The gamma irradiation of 3 kGy appeared to have a good influence on the color of the grape by-products which went through hot-air drying. The contents of the total phenolic compounds, in case of hot-air drying, showed the highest total polyphenol contents in the 3 kGy irradiation and it decreased according to the increase of the exposure dose; in contrast, the higher phenolic contents showed in the irradiated group than in the control. In case of freeze drying, the highest phenolic contents appeared in the control but 3 kGy showed the highest one in the irradiated group. Results of radical scavenging activity using DPPH and ABTS indicated that 3 kGy showed the highest radical scavenging activity in hot-air and freeze drying. Therefore, it was found that gamma irradiation of 3 kGy could improve the color and antioxidant activity of grape by-products, but an antioxidant activity of grape by-product due to the gamma irradiation was a little affected in the aspects of by-product utilization.

• Food Science and Preservation
• /
• v.21 no.4
• /
• pp.451-459
• /
• 2014

The aim of this study was to provide useful information for making guide of quality index of Korean red pepper. The results of physicochemical characteristics analysis showed the moisture content of air-dried and sun-dried red pepper were 10.38~15.60% and 9.46~17.22%, which show that 50% of the 40 samples exceeded the 13% KS moisture standards of red pepper powder. The capsaicinoids content of the air-dried and sun-dried samples were 10.85~126.39 mg% (1,627~18,958 Scoville heat unit) and 0.43~164.09 mg% (64.5~24,613.5 Scoville heat unit). A wide distribution of ASTA values was observed: 49.12~154.69 and 70.08~182.13 for air-dried and sun-dried red pepper, respectively, with 9.29~23.10% free sugar, and 0~1,050 mg% of ascorbic acid. The total viable cells of the air-dried red peppers were 2.01~6.67 log CFU/g and of sun-dried red peppers, 1.74~5.77 log CFU/g. The contamination level of yeast in the samples were 1.03~4.12 log CFU/g of the air-dried samples and 1.05~6.10 log CFU/g of the sun-dried samples. Among the foodborne pathogens, Clostridium perfringens and Bacillus cereus were detected in many red pepper samples regardless drying method. In the principal component analysis, the first (PC1) and second principal components (PC2) accounted for 56.78 % of the total variances (38.47% and 18.31%, respectively). Ascorbic acid, ASTA, color value (L, a, b) were strongly correlated with the PC1, and quality characteristics such as moisture, microorganism, sample (drying method) showed a negative correlation with the PC1.

• Air Cleaning Technology
• /
• v.18 no.4 s.71
• /
• pp.82-84
• /
• 2005

• Proceedings of the Korean Society of Tobacco Science Conference
• /
• 2002.06a
• /
• pp.18-21
• /
• 2002

• Digital Contents
• /
• no.12 s.139
• /
• pp.71-71
• /
• 2004