• Food Science of Animal Resources
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• v.38 no.5
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• pp.970-980
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• 2018

We evaluated the effects of pre-cooking methods on the quality of reheated marinated pork loin. Frozen marinated pork loins cooked using various methods (boiling, grilling, pan frying, infrared cooking, and superheated steam cooking) were reheated in a microwave, and their pH, color, cooking loss, re-heating loss, total loss, thiobarbituric acid reactive substance (TBARS) value, sensory properties, and shear force were determined. Although all parameters varied with different cooking methods, lightness values and TBARS values showed the tendency to decrease and increase, respectively, after reheating. Superheated steam-cooked samples showed the lowest values of cooking loss, total loss, TBARS value, and shear force (p<0.05) and the highest lightness, redness, and yellowssness values and juiciness, chewiness, and overall acceptability scores (p<0.05). These results show that pre-cooking with superheated steam maintains the quality characteristics of marinated pork loin upon reheating. Therefore, pre-cooking with superheated steam may be beneficial for the commercial distribution of frozen cooked marinated pork loin.

• Applied Biological Chemistry
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• v.35 no.4
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• pp.260-264
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• 1992

In present paper, we investigated the quality stability of sardine burgers during storage at $-20{\pm}2^{\circ}C$. During frozen storage of sardine burger, the PH were decreased, while volatile basic nitrogen contents were increased. The results of changes in peroxide values, thiobarbituric acid values, fatty acid compositions and color values during frozen storage showed that lipid oxidation and discolorization of antioxidant treated sardine burger and vacuum packed sardine burger could be effectively retarded. The changes in the taste compounds such as free amino acid, nucleotide and their related compounds, total creatinine, betaine and trimethylamine oxide, total amino acids and texture profile analysis of vacuum packed sardine burger were negligible during frozen storage. From the results of sensory evaluation and chemical experiments, the vacuum packed sardine burger could be preserved in good quality during frozen storage of 90 days.

• Korean Journal of Food Science and Technology
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• v.32 no.2
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• pp.335-340
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• 2000

The objectives of this research were to investigate changes in characteristics of whole frozen soft persimmon during storage, and to evaluate effects of blanching and addition of ascorbic acid on the quality of frozen soft persimmon puree. Reducing sugar, soluble solids and carotenoids contents in frozen soft persimmon did not change significantly during storage, while ascorbic acid of whole frozen soft persimmon and puree was continuously decreased during 8 months of storage. Whole frozen soft persimmon thawed at low temperature or by microwave oven did not show remarkable quality differences, whereas thawing puree resulted in a drastic decrease in consistency. Addition of ascorbic acid to puree reduced browning discoloration, but blanching puree caused significant loss of color and increase of consistency.

• Food Science and Preservation
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• v.22 no.1
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• pp.44-50
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• 2015

This study was performed to optimize the preparation of frozen lotus roots. Prior to freezing, an optimal blanching condition at $100^{\circ}C$ for 5 min was established, based on the microbial growth, texture, total phenolic content (TPC), and sensory evaluation results. The blanched samples were then frozen under various freezing conditions ($-20^{\circ}C$ in a freezer for 2 hr, $-70^{\circ}C$ in a gas nitrogen convection chamber for 7 min, and $-196^{\circ}C$ in liquid nitrogen for 20 sec), and their qualities after thawing were determined. The scanning electron microscopic analysis indicated that the microstructure of the sample frozen at $-70^{\circ}C$ was similar to that of the control sample, compared with the other freezing conditions (-20 and $-196^{\circ}C$). The antioxidant activities of the frozen samples decreased compared to those of the control, but there was no significant (p<0.05) difference among the treatments. In terms of TPC, the samples frozen at -70 and $-196^{\circ}C$ had significantly (p<0.05) higher values than the sample frozen at $-20^{\circ}C$. In addition, the drip loss of the sample frozen at $-20^{\circ}C$ was higher than those of the other frozen samples. These results suggest that freezing at $-70^{\circ}C$ in a gas nitrogen convection chamber can be an optimal freezing method of producing high-quality frozen lotus roots.

• Journal of Applied Tourism Food and Beverage Management and Research
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• v.15 no.2
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• pp.57-72
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• 2004

This study is carried out to investigate the effect of any periods in the freezer and the product of value, moisture content, baking loss, specific volume loaf in manufncturing process thereof. The moisture content of the croissant slightly decreased as the periods passed in the freezer. And as passed periods frozen croissant dough dried naturally by the freezer fan. 1. As frozen periods passed croissant dough decreased moisture content and loaf volume. The volume is relation to the molsture content and croissant dough' gluten. Yeast is active but croissant dough is dried so pastry margarine's moisture vaporized little by little. 2. 1 day frozen bench time provided maximum specific loaf volume while croissant shape was unsettled, moisture content was highest. At the same dough croissant hardness had very sofi crust. 3. 1week and 2weets frozen dough had specific loaf volume and hardness with proper crust color. As the proper bench time provided best shape of croissant, color. 4. 4weeks and 8weeks frozen dough had over-al] value of croissant accelerating older product. As the same result, over Sweets frozen periods product were not available for sale and serving to customers. 5. By the sensory evaluation tests, over-all croissant as 1 week, 2weeks were significantly higher quality those than 6. 1day, 4weeks and 8weeks. Textural properties of croissant over 4weeks frozen periods so hard for every panel. According to the study, not croissant dough but also any other frozen dough(ex.Danish, brioche etc.)have to need proper bench time and 1week or 2weeks circulation making method have to given encouragement to practical pastry industry. Add to this study using only for frozen dough yeast instead of using fresh and instant

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.6
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• pp.763-770
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• 1993

To investigate the quality changes during frozen storage, top shell, Omphalius pfeifferi capenteri, was stored at -18$^{\circ}C$, -$25^{\circ}C$ and -3$0^{\circ}C$ immediately after shelling and water holding capacity, protein composition and histological features were examined with the lapsed period of the storage. During the storage period, amount of free drip was increased with higher frozen temperature and longer frozen period, but with the longer storage period, the lower water holding capacity was observed. The extractability and composition of muscle protein, sarcoplasmic protein and stroma protein were rather stable regardless of frozen temperature and frozen storage period. However, the extractability of myofibrillar protein was decreased with higher frozen temperature and longer frozen storage period. On the changes of muscle tissue structure, following points were observed. 1) In the muscle tissue structure of fresh sample, fine muscle fiber was closely distributed all over the tissue regardless of cross and longitudinal section. 2) In tissue structure under frozen state, it was observed that ice crystals apparently grew with the higher storage temperature. Empty spaces between muscle bundles which wee formed by aggregations of muscle fiber were observed after 3 months storage at -18$^{\circ}C$ . 3) Tissue structure in thawed state was restored satisfactorily after 1 month storage regardless of storage temperature. After 3 months storage at -3$0^{\circ}C$, muscle tissue was well restored, but at -18$^{\circ}C$, empty spaces were apparent due to incomplete restoration.

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

• Korean Journal of Food Science and Technology
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• v.23 no.5
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• pp.527-531
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• 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
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• v.16 no.2
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• pp.133-138
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• 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
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• v.31 no.5
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• pp.1324-1329
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• 1999

This study was carried out to investigate the distribution and characteristics of Listeria monocytogenes isolated from frozen Mandoo and pizza in 1998. A total 72 samples were examined and USDA, FDA and modified cold enrichment methods were used for the detection of Listeria spp. Overall prevalence of L. monocytogenes in frozen foods was 9.7% and L. monocytogenes was isolated from 11.1% of frozen Mandoo and 5.6% of frozen pizza. The highest detection rate of Listeria spp. in frozen Mandoo was found at USDA method and the serotype of L. monocytogenes isolates was 4. Isolated L. monocytogenes was confirmed by PCR method with Hly 1 and 2 as primers. It would be necessary to develop more rapid and specific method to isolate and confirm L. monocytogenes from foods because USDA and PCR methods used in this study took 3-4 days. D value of L. monocytogenes isolate in tryptic soy broth was 49.2 sec at $60^{\circ}C$ and 8.8 sec $at\;65^{\circ}C$, and D value of L. monocytogenes in foods with high distribution rate of Listeria spp. would be necessary to evaluate for the safe use of frozen foods.