• Korean Journal of Food Science and Technology
• /
• v.30 no.6
• /
• pp.1267-1272
• /
• 1998

The changes in physicochemical properties of gamma irradiated porks were investigated during storage at different temperature and periods. TBA values increased according to the increment of irradiation dose levels. TBA values of nonirradiated and irradiated samples drastically increased with storage period and temperatures at both $5^{\circ}C\;and\;-20^{\circ}C$. The acid value of porks stored at $5^{\circ}C$ was increased rapidly with the elapse of storage period in both nonirradiated and irradiated samples. However, the value decreased with increasing irradiation dose levels. VBN values increased more rapidly in nonirradiated samples than in irradiated samples with the storage period. Especially, VBN value of nonirradiated pork was four times higher than that of 3 kGy-irradiated one. No significant differences in the composition of fatty acids were observed in gamma irradiated samples. Free amino acids were changed with storage periods, but were not significantly affected by gamma irradiation.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.2
• /
• pp.517-522
• /
• 2013

Small size ice-cream maker has two evaporators having different evaporating temperatures of $4^{\circ}C$ and $-8^{\circ}C$. In such case, ice-cream maker system design becomes complicated because multiple capillary tubes affects one another. In this study, performance analysis was conducted for the soft ice-cream maker having two evaporators operating at different temperatures. The compressor was analyzed using efficiency models, the capillary tube was modeled assuming one-dimensional flow, the condenser and the evaporators were modeld based on UA-LMTD method. The refrigeration cycle simulation program was developed applying the enthalpy, pressure and mass balance on each component. Comparison of the test data with the simulated results for R404A revealed that evaporator temperatures of refrigerator and freezer agreed within $3^{\circ}C$.

• Korean Journal of Food Science and Technology
• /
• v.45 no.4
• /
• pp.416-421
• /
• 2013

The purpose of this study was to investigate the effects of pH, temperature, light, sugars, and organic acids on the stability of anthocyanin pigments extracted from aronia (Aroniamelanocarpa). Pigments from aronia were most stable at pH 3.0, with maximal absorbance at 514 nm. High temperatures and prolonged heating substantially reduced anthocyanin contents. Anthocyanin levels were as low as approximately 21.70 and 79.63% of normal levels after 300 min of heating at 30 and $100^{\circ}C$, respectively. All of the sugars tested decreased the abundance of aronia pigments, with the levels highest in the presence of maltose, and decreasing progressively in the presence of galactose, sucrose, glucose, and fructose. Among the organic acids tested, citric acid was the most effective in stabilizing the aronia pigment, followed by tartaric acid, malic acid, formic acid, and ascorbic acid. These results provide useful reference data for efforts to use pigments from aronia in processed foods or for developing natural food colorants.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.32 no.2
• /
• pp.175-180
• /
• 2003

Effect of the addition of maltitol to Korean rice cake (Karedduk) on its retrogradation was examined. Degree of retrogradation was also examined in terms of recrystallinity of starch and color change with a differential scanning calorimeter. As a result, retrogradation was suppressed by the increasing addition of maltitol. In particular, enthalpy showed a tendency to decrease at $25^{\circ}C$ rather than at 4$^{\circ}C$ during 4 days. In the gelatinization properties using DSC, onset temperature (To) was shown to increase slightly according to storage time. Maximum peak temperature (Tp) was shown to decrease by the addition of maltitol during 4 days. Melting enthalpy was decreased at $25^{\circ}C$ and 4$^{\circ}C$ by the addition of maltitol. The analysis X-ray diffraction also revealed that retrogradation of the Korean rice cake was suppressed by the addition of maltitol because crystalline region did not appear. The addition of maltitol into the Korean rice cake was found to result in an increase of its qualify or color stability.

• Proceedings of the Korea Society of Poultry Science Conference
• /
• 2003.11a
• /
• pp.107-108
• /
• 2003

This study was conducted to investigate the effects of dilution rate and stored temperature of semen at 5, 25 and 35$^{\circ}C$ on fertility in liquid rooster semen. At 5$^{\circ}C$ cold temperature, no significant difference were found in sperm mobilities on dilution rate(1:1, 1:3, 1.6) among treatments. Sperm mobility for the conservation of 3 hours at 25∼35$^{\circ}C$ were significantly higher for 1:3 and 1:6 dilution rate(semen：diluent) groups than for 1:1 dilution rate group(P<0.05). In Fertility results after artificial insemination with the conservation of 3 hours at 5∼25$^{\circ}C$ temperature, no significant difference were found in fertility on dilution rate among treatments. Fertilities after artificial insemination with the conservation of 3 hours at 35$^{\circ}C$ were significantly higher for 1.3 and 1:6 dilution rate(semen：diluent) groups than for 1：1 dilution rate group(P<0.05).

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
• /
• v.26 no.3
• /
• pp.165-171
• /
• 2020

Maintaining steady and low temperature during distribution process is a key technique to inhibit microbial growth, one of the most important factors in determining the shelf life. It is possible to provide high-quality fresh products to consumers only when precise and adequate temperature control is guaranteed throughout the entire distribution process for fresh seafood. This study investigated the shelf-life of packaged fresh flounder (Paralichthys Olivaceus) in order to learn the feasibility of super-chilled distribution of fresh seafood. To estimate the shelf life, weight, number of bacteria such as E. coli, pH, sensory test and volatile basic nitrogen were investigated. As a result of the study, the difference in shelf life of 6 days at the super-chilling temperature (0±1℃) and 1 day at the general refrigeration temperature (8±2℃) (based on volatile base nitrogen) showed the market possibility of super-chilling distribution. Through additional empirical studies such as packaging methods and economic feasibility, it is expected to promote commercialization of super-chilling containers and packaging system developed in the future and secure customer reliability.

• Korean journal of applied entomology
• /
• v.44 no.4 s.141
• /
• pp.257-264
• /
• 2005

In order to establish the successive rearing system brush-footed butterflies (Lepidoptera : Nymphalidae) were reared in a room. Artificial diets were developed for a year-round rearing. Bu-diet was best to rear these butterflies among 3 kinds of diet used. The freeze-dried host plant leaf powder in diet was better than heat-dried one $(60^{\circ}C)$ in the growth of larvae. The rearing results were best in the diet C/N ratio was 1:1. The 24-hrs old eggs could be stored for 5 days at $15^{\circ}C$ or for 3 days at $5^{\circ}C$ and showed 75% of hatchability. On the other hand, pupae could be stored for maximum 15 days at $15^{\circ}C$ because the emergence of abnormal adults appeared much more as the cold storage period got longer. And the adult was able to be stored until 60 days at refrigerator without relation of nectar-sucking period before cold-storage and storage temperature. Also a simple artificial ovipositing kit was devised by ${\Phi}9$ cm of petri-dish and a female oviposited $278{\pm}27$ of eggs with adding the ether extract of host plant to this kit. The systematic successive rearing method of brush-footed butterflies in a room was completed.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.34 no.2
• /
• pp.285-290
• /
• 2005

This study was aimed to determine microbiological Quality by adding green tea extracts to cook-chill foods. For this study, Pyeonyuk were blended with green tea extracts to different concentrations of 0, 2 and 3% and prepared in a cook-chill system. Microbiological effects of green tea extracts were assessed during production process by measuring process time, temperature, pH and A wand determining total plate counts and coliforms. Effects of green tea extracts on total plate counts and coliforms were observed during cold storage at 3$^{\circ}C$ for five days. Green tea extracts improved the microbiological Quality and showed antibacterial properties when they are added to Pyeonyuk prepared in a cook-chill production system. The use of green tea extracts can be further explored as a means of enhancing freshness and Quality in cook-chill foods.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.36 no.4
• /
• pp.457-463
• /
• 2012

Current refrigerators are designed to have thin doors and walls to facilitate user convenience and increase inner storage space. However, the thin doors and walls gives rise to the problem of dew generation on the outer surface of a refrigerator due to a large critical temperature difference between the outer wall and the room air; So far, an electric heater is commonly used for making the dew to evaporate; in this case, the heater inevitably requires additional electrical power. We propose a new approach to reduce the dew generation in a refrigerator by redesigning the gasket and varying the thickness of the inner case of the refrigerator. The results of simulations performed in this study indicate that the surface temperature in the region where dew was generated was increased by approximately $0.39{\sim}3.07^{\circ}C$ without the use of a heater.

• Korean Journal of Food Science and Technology
• /
• v.47 no.5
• /
• pp.645-651
• /
• 2015

Sucrose in chiffon cakes was replaced with different levels of sorbitol (0, 30, 50, 70, and 100%), and the effects on the physical properties and storage stability of the cakes were measured. The specific gravity and viscosity of the batter, as well as the volume and moisture content of the cakes, decreased with increasing sorbitol content. The hardness of the cakes slightly decreased as the amount of sorbitol increased, whereas the lowest cohesiveness was observed in the cakes with equal amounts of sucrose and sorbitol. Storage for one day slightly increased the hardness of the cakes and decreased their cohesiveness. Although the amount of mold and total microbial count increased with increasing storage days at room temperature, the replacement of sucrose with 70 or 100% sorbitol was effective in suppressing microbial growth. In sensory tests, the formulation with 70% sorbitol substitution in the chiffon cakes was the most acceptable.