• Reproductive and Developmental Biology
• /
• v.28 no.4
• /
• pp.261-265
• /
• 2004

The present study was conducted to assess sperm characteristics in miniature-pig. The semen samples were transported to the laboratory at 17℃ within 3 hours after collection. The extended semen was stored at 17℃, and sperm quality was evaluated at 0, 1, 3, 5 and 7 days after storage. The semen volume of miniature-pig (62±22㎖) was significantly (p<0.05) lower than that of Duroc (155±25㎖) and Yorkshire (154±23㎖). Significant differences were also observed in sperm concentrations. During 3 days of storage, sperm viability did not differ among miniature-pig, Duroc and Yorkshire. However, the viability was significantly (p<0.05) lower in miniature-pig than in Duroc and Yorkshire semen after Day 3 of storage. In abnormality, acrosome intactness and intensity, there were no differences among miniature-pig, Duroc and Yorkshire semen. On the other hand, the viability of frozen-thawed sperm in miniature-pig was significantly (p<0.05) lower than in that of Duroc and Yorkshire. This study also examined CTC patterns in frozen-thawed spermatozoa. The rates of AR pattern were higher in miniature-pig than in Duroc and Yorkshire. However, no difference was found in F, B and AR patterns. The results of present study suggest that further research is necessary to develop of semen extender and freezing methods to improve sperm quality in miniature-pig.

• Food Science of Animal Resources
• /
• v.34 no.6
• /
• pp.777-783
• /
• 2014

This study investigated the effect of various freezing and thawing techniques on the quality of beef. Meat samples were frozen using natural convection freezing (NF), individual quick freezing (IQF), or cryogenic freezing (CF) techniques, followed by natural convection thawing (NCT) or running water thawing (RT). The meat was frozen until the core temperature reached $-12^{\circ}C$ and then stored at $-24^{\circ}C$, followed by thawing until the temperature reached $5^{\circ}C$. Quality parameters, such as the pH, water binding properties, CIE color, shear force, and microstructure of the beef were elucidated. Although the freezing and thawing combinations did not cause remarkable changes in the quality parameters, rapid freezing, in the order of CF, IQF, and NF, was found to minimize the quality deterioration. In the case of thawing methods, NCT was better than RT and the meat quality was influence on the thawing temperature rather than the thawing rate. Although the microstructure of the frozen beef exhibited an excessive loss of integrity after the freezing and thawing, it did not cause any remarkable change in the beef quality. Taken together, these results demonstrate that CF and NCT form the best combination for beef processing; however, IQF and NCT may have practical applications in the frozen food industry.

• Korean Journal of Agricultural Science
• /
• v.48 no.4
• /
• pp.753-760
• /
• 2021

This study was carried out to discover suitable packaging methods during the cold or frozen storage of sawtooth oak and Japanese larch seedlings, which are major afforestation tree species in Korea. The weight loss rate of sawtooth oak was lower under frozen storage at -2℃ (maximum, 33.7%) than under cold storage at 2℃ (maximum, 61.0%). A film liner treatment inside the packaging box effectively suppressed the increase in the weight loss rate. For the sawtooth oak containerized seedlings, when stored at -2℃, the rate of weight loss was 17.9 to 25.4% in the untreated group and less than 1% in the film liner treatment group. Similar results were observed with Japanese larch. After two months of freezing at -2℃, both species maintained a low index of 1.0 - 1.1 with regard to the degree of shoot desiccation of containerized seedlings, and there was no significant difference between the treatments. On the other hand, the chlorine dioxide treatment could more effectively reduce the occurrence of mold and shoot desiccation than a PE single treatment in bare-root seedlings. According to these results, it was concluded that frozen storage is generally suitable as a means of long-term storage compared to cold storage of sawtooth oak and Japanese larch. A chlorine dioxide treatment at 20 ppm was effective for maintaining seedling quality levels during storage, demonstrating the good effect of suppressing the occurrence of shoot desiccation and the occurrence of mold.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.56 no.6
• /
• pp.818-825
• /
• 2023

The surge in online seafood consumption has increased parcel delivery, leading to a need to implement effective preservation methods. As the cold chain system is not fully established in Korea, styrofoam boxes and cold packs are commonly used for low-temperature seafood distribution. The impact of cold packs on product preservation depends on the number utilized. Herein, the freshness of vacuum-packed frozen fish fillets (Paralichthys olivaceus and Scomber japonicus) stored at 25±0.5℃ for up to 84 h was measured. Chemical (pH and volatile base nitrogen), microbiological (viable cell count), and physical (odor intensity) properties were assessed using 2 or 4 cold packs in a styrofoam box. Four cold packs yielded lower values, indicating superior freshness, and extended fish freshness by approximately 12 h compared with two cold packs. Therefore, it is recommended to use a minimum of 4 cold packs (-350 g/cold pack) in a styrofoam box for distributing approximately 300 g of frozen fish fillets at room temperature during the summer, considering an average delivery period of 2 days in Korea.

• Korean Journal of Food Science and Technology
• /
• v.12 no.1
• /
• pp.34-40
• /
• 1980

In order to establish the frozen storage method of pork and contribute to the stabilization of pork price physicochemical changes and sensory evaluation of pork, stored at $-20^{\circ}C$ up to the period of 12 months, were analyzed every three months. The drip loss of frozen meat cuts was below 1% regardless of storage months. In the course of storage, pH of frozen half carcass rose a little, while that of meat cuts remained almost the same. WHC(water holding capacity) of frozen half carcass and meat cuts was in the range of $50{\sim}60\;and\;55{\sim}62%,$ respectively and VBN (volatile basic nitrogen) was about $11{\sim}18mg%,$ all of which did considerably change during the storage. TBA(thiobarbituric acid) value was not increased up to the 6th month of storage, but represented a considerable increase after the 9th month of storage, Both tenderness and juiciness of frozen pork were decreased after the 12th month of storage but the axxrptability of frozen pork to the consumers turned out fairly good.

• Applied Biological Chemistry
• /
• v.46 no.1
• /
• pp.39-45
• /
• 2003

This study was conducted to investigate the effect of ash contents of bread flour on the rheology of frozen dough In making frozen dough by measuring amylograph, flrinograph and extensograph. The quality of frozen-stored dough under freezing condition ($-20^{\circ}C$, 12 weeks) was evaluated by measuring final proof time, moisture content, baking loss, loaf volume and hardness of bread with storage time. In bread flour with high ash content farinogram showed that water absorption, degree of softening increased but valorimeter value decreased. In bread flour with low ash content amylogram showed that gelatinization temperature and maximum viscosity increased and extensogram showed that the area and resistance of the bread flour increased. As the proof time increased the extensibility decreased. Final proof time of frozen dough was shortened at the bread flour with low ash content with storage time. In bread using the flour with high ash content, moisture content, increased but baking loss rate decreased while the hardness of product increased slowly with time. But in bread using the flour with low ash content, the loaf volume of baking increased but the hardness of product decreased. As the frozen storage time was shortened, the product was more stable and better in quality.

• Korean Journal of Food Science and Technology
• /
• v.23 no.5
• /
• pp.527-531
• /
• 1991

Frozen mandu, which is one of the main frozen prepared foods, purchased from a local manufacturer, were stored at five constant temperatures ($0,\;-5,\;-10,\;-20\;and\;-30^{\circ}C$) for six months. Effects of the storage temperature and the storage period on the changes in pH, acid value, peroxide value, volatile basic nitrogen, color, sensory score and microbial counts of frozen mandu were studied. The changes in microbiological and physicochemical characteristics were significantly increased in comparison with the initial value after 1 month at $0^{\circ}C$, after 3 months at $-5^{\circ}C$ and after 5 months at $-10^{\circ}C$, but nearly constant in spite of storage periods when the temperature dropped below $-10^{\circ}C$Out of five chemical components, AV and POV were the most reliable components in the quality judgement of frozen mandu and its upper limiting content were 2.56 and 19.35 meq/kg each. Regression equation for shelf life prediction of frozen mandu with sensory scores and POV was determined.

• Korean Journal of Food Science and Technology
• /
• v.16 no.2
• /
• pp.133-138
• /
• 1984

For the purpose of improving the precooked frozen food, the processing conditions of sardine steaks and the effect of soybean protein and corn starch on quality of the products during frozen storage were investigated. Fresh sardines were purchased from Busan Central Whole Sale Market and filleted. And then sardine meats were separated from fillets by fish meat separator. The meats were mixed with 0.5% sodium bicarbonate, 1.5% of table salt and 0.2% of polyphosphate, monosodium glutamate, white pepper, garlic powder and nutmeg, respectively. The mixture was minced with the stone grinder and filled in polyvinylidene chloride film tube and then stored at $-3^{\circ}C$ for 36 hours prior to frozen storage. Sardine steaks containing 3% of soybean protein were superior to those of containing 3% of corn starch or without soybean protein and corn starch on texture and eating quality of them during the period of frozen storage. It is convinced that addition of 3% of soybean protein to the sardine steak was benefically effective for the control of free drip, oxidative rancidity and the improvement of texture. The quality of frozen sardine steaks, by sensory evaluation, were preserved in good eating quality for 90 days during frozen storage.

• Korean Journal of Food Science and Technology
• /
• v.34 no.3
• /
• pp.413-418
• /
• 2002

The dough was frozen either before or after fermentation at the five different freezing and storage conditions. Although fermentation before freezing was effective for rapid freezing, it reduced bread volume of the dough frozen at both air freezer and liquid immersion freezer. Freezing at the air freezer set to $-70^{\circ}C$ took more time for freezing and resulted in lower bread volume than freezing at the immersion freezer set to $-20^{\circ}C$. Therefore, the freezing in the liquid immersion freezer was more effective to reduce the freezing time and increase the bread volume. At the liquid immersion freezer, the higher temperature was more effective than lower temperature. The doughs frozen in a liquid immersion freezer set to $-10^{\circ}C$ and fermented after de-frosting produced higher bread volume than control unfrozen dough. And also there was no significant difference in bread volume between the control unfrozen dough and the dough frozen in a liquid immersion freezer set to $-10^{\circ}C$, fermented before freezing and re-fermented after defrosting. The longer proof time and greater loaf volume obtained for the dough frozen and stored at the air freezer set to $-70^{\circ}C$. Therefore the optimum process for freezing the dough was freezing immediately after mixing, storing at $-10^{\circ}C$ in a liquid immersion freezer and fermented after defrosting.

• Applied Biological Chemistry
• /
• v.47 no.1
• /
• pp.107-112
• /
• 2004

This study was carried out to investigate properties of the bread prepared by applying emulsifiers to the frozen dough, Doughs made by the sponge and dough method with the sweet dough formula were quickly frozen at $-40^{\circ}C$ and stored for 6 weeks at $-20^{\circ}C$. The effects of emulsifiers on the number of yeast cells, the volume of the bread, the hardness and the quality evaluation were investigated after frozen doughs were thawed, fermented and baked every week. In the effect of the number of yeast cells, SSL 0.3% and DATEM 0,2% produced a more effective result than others during the freezing storage, The highest loaf volume was formed in bread supplemented with SSL 0,3% and DATEM 0,2%, In the moisture content, bread supplemented with SSL 0,5% showed the highest value, Bread supplemented with SSL 0,3% and DATEM 0,2% produced the lowest value of bread hardness and received the highest score in quality evaluation, In this study, the addition of SSL 0,3% and DATEM 0,2% in making frozen dough led to better bread quality as compared to others.