• Korean Journal of Food Science and Technology
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• v.21 no.4
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• pp.536-541
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• 1989

In present paper, we investigated the quality stability of frozen seasoned anchovy meat products during storage at $-25\;{\pm}\;2^{\circ}C$. The pH and VBN contents of the products revealed a tendency to increase slightly during frozen storage 150 days. Viable cell counts and histamine contents of products are $0.8-2.6\;{\times}\;10^5/g,\;70.6-76.7 mg/100g$, respectively. In changes of fatty acid composition, percentage of polyenes such as eicosapentaenoic docosahexaenoic acid slightly decreased, while that of saturates and monoenes increased during frozen storage, The results of changes in POV, TBA values, color values, drips and salt extractable nitrogen contents during frozen storage showed that lipid oxidation and freeze denaturation of products could be retarded, and flavor could be enhanced by adding 0.2% sodium erythorbate and 12.8% emulsion curd.

• Journal of Food Hygiene and Safety
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• v.14 no.4
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• pp.327-332
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• 1999

The prevalence and serotype of food-borne pathogens was investigated from 888 samples of chilled meat, 222 samples of packed frozen meat and 117 samples of imported frozen meat during the period from March 1996 to October 1998. Isolation rates of pathogens associated with food poisoning were revealed in order of Staphyloccus aureus, Campylobacter jejuni /coli, Listeria monocytogenes and Salmonella spp, but Escherichia coli O157:H7 was not isolated in all of the meat samples. Amusingly, Campylobacter jejuni /coli were isolated highly in refrigerated meat, but was not isolated in packed frozen meat. L. monocytogenes was encounted higher isolation frequency in packed frozen chicken meat than in refrigerated chicken meat. In the distribution of serotypes of isolates, most isolates of Sta. aureus classified as enterotoxin type C and D. All of the Salmonella spp. isolated from pork were diagnosed group A and most of isolates from chicken meat were grouped B and D. Most of L. monocytogenes isolated from chicken meat were grouped type 1 and a few number of isolates classified as type 4.

• Journal of Biosystems Engineering
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• v.41 no.2
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• pp.108-115
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• 2016

Purpose: Radio frequency (RF) heating is a promising thawing method, but it frequently causes undesirable problems such as non-uniform heating. This can occur because of the food shape, component distribution, and initial temperature differences between food parts. In this study, RF heating was applied to the thawing of cylindrically shaped pork sirloin by changing the shape of electrodes and the surrounding temperature. Methods: Curved electrodes were utilized to increase the thawing uniformity of cylindrically shaped frozen meat. Pork sirloin in the shape of a half-circle column was frozen in a deep freezer at $-70^{\circ}C$ and then thawed by RF heating with flat and curved electrodes. In order to prevent fast defrosting of the food surface by heat transfer from air to the food, the temperature of the thawing chamber was varied by -5, -10, and $-20^{\circ}C$. The temperature values of the frozen pork sirloin during RF thawing were measured using fiber-optic thermo sensors. Results: After multiple applications of curved electrodes resembling the food shape, and a cooled chamber at $-20^{\circ}C$ the half-cylindrically shaped meat was thawed without surface burning, and the temperature values of each point were similarly increased. However, with the parallel electrode, the frozen meat was partially burned by RF heating and the temperature values of center were overheated. The uniform heating rate and heat transfer prevention from air to the food were crucial factors for RF thawing. In this study, these crucial factors were accomplished by using a curved electrode and lowering the chamber temperature. Conclusions: The curved shape of the electrode and the equipotential surface calculated from the modeling of the parallel capacitor showed the effect of uniform heating of cylindrically shaped frozen food. Moreover, the low chamber temperature was effective on the prevention of the surface burning during RF thawing.

• Food Science of Animal Resources
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• v.39 no.2
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• pp.240-254
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• 2019

This study investigated the effect of storage state (chilled state on sous-vide, CS; frozen state without thawing on sous-vide, FS; and frozen/thawed states on sous-vide, TS) and sous-vide cooking temperature ($65^{\circ}C$ and $72^{\circ}C$) on the longissimus dorsi muscle quality of pork. FS showed a higher moisture content than that of CS and TS (p<0.001), whereas both FS and CS showed higher expressible moisture loss than that of TS (p<0.001). FS showed a lower cooking loss (p<0.001) than that of CS and TS. FS and TS exhibited significantly higher lipid oxidation than that of CS. Carbonyl and sulfhydryl content were not significantly affected by the storage treatment. FS and TS exhibited lower shear force than that of CS (p<0.001). FS and TS showed higher springiness than that of CS (p<0.001), FS exhibited lower gumminess than that of CS and TS (p<0.01). Sous-vide treatment at $65^{\circ}C$ exhibited significantly higher moisture content and lower expressible moisture loss, cooking loss, and total and sarcoplasmic protein than those at $72^{\circ}C$. Shear force and springiness of $65^{\circ}C$-treated groups were lower than those of $72^{\circ}C$-treated groups (p<0.01). Cooking temperature significantly influenced overall acceptability, whereas the storage state did not affect the overall acceptability. These results indicated that meat quality might be improved upon cooking from the frozen or frozen/thawed state using sous-vide when compared with traditional processing.

• Journal of the Korean Society of Food Culture
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• v.19 no.2
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• pp.209-216
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• 2004

To investigate physico-chemical changes of mashed red repper and red pepper powder during frozen storage, we analyzed the quality of samples after mashing, mashing and blanching, mashing and addition of vitamin C, mashing and addition of NaCl. The most important quality factor of red pepper is red color. $\alpha$ value of red pepper powder of Pochungchun was 31.51. These results showed that those processing methods were effective to preserve red color. Capsanthin contents of mashed red pepper treated with vitamin C were decreased 1.8% after 180 days of frozen storage. This decrease was the least, showing that addition of vitamin C helped retaining capsanthin contents. Capsaicin and dihydrocapsaicin contents in Pochungchun powder ore decreased 11.9 and 18.3% during frozen storage respectively. These results showed that capsaicin was more stable than dihycrocapsaicin during frozen storage. Generally capsaicin and dihydrocapsaicin in the Pochungchun red pepper frozen-stored after mashing were less decreased than red pepper powder, and addition of vitamin C to the mashed red pepper was the most effective to retain capsicin and dihydrocapsaicin than others. The content of vitamin C in the red pepper frozen-stored after masking and blanching was 12.0 mg/100g, compared with 44.0 mg/100g in the sample stored after only mashing. This suggested that blanching process destroyed vitamin C in the mashed red pepper. Addition of salt in the mashed red pepper showed the same inclination. But, addition of vitamin C to the mashed red pepper was decreased 32.9% compared with 69.0% in the mashed red repper during frozen storage. Theser results indicated that addition of vitamin C could retain vitamin C in the mashed red lopper.

• Korean Journal of Food Science and Technology
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• v.33 no.6
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• pp.676-681
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• 2001

This study was carried out to evaluate the quality characteristics of frozen soy yogurts prepared with different proteolytic enzymes and starter culture. The viable cell counts of lactic acid bacteria in frozen soy yogurts were measured $10^8$ CFU/g by the single culture method, while $10^9$ CFU/g by the mixed culture method except ${\alpha}-chymotrypsin$ treatment. The viable cell counts of lactic acid bacteria did not decrease after freezing for 30 min in ice cream maker. The lactic acid bacteria from the mixed culture showed better bile acid tolerance than those from the single culture. The lactic acid bacteria from the frozen soy yogurt prepared with ${\alpha}-chymotrypsin$ and mixed culture of Bifidobacterium bifidum and Lactobacillus bulgaricus showed better acid tolerance and bile acid tolerance. The highest(73.45%) overrun was observed in the frozen soy yogurt treated with ${\alpha}-chymotrypsin$ and mixed culture of B. bifidum and L. bulgaricus. The melt-down percent was higher in the single culture than the mixed culture. In sensory test, the frozen soy yogurt prepared with ${\alpha}-chymotrypsin$ and mixed culture of B. bifidum and L. bulgaricus was the most desirable, the highest scores in sourness, bitterness and mouthfeel.

• Journal of the East Asian Society of Dietary Life
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• v.17 no.2
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• pp.234-241
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• 2007

The aim of this study was to investigate the effects of the addition of red wine of pork patties during frozen storage on their water holding capacity, thawing loss, cooking loss, diameter change, thickness change, surface color, pH, VBN (volatile basic nitrogen) and TBARS (2-thiobarbituric acid reactive substances). Four types of pork patty were prepared; pork patty without red wine (control), and with the addition of 1%, 3% and 5% red wine (RWP-1, 3 -and t respectively). The pork patties were stored for 5 months at $-20^{\circ}C$. The water holding capacity was significantly decreased during frozen storage, which was not influenced by the addition of red wine (p<0.05). The thawing loss and cooking loss were significantly increased during frozen storage, which also was not influenced by the addition of red wine (p<0.05). There were no significant differences in the diameter and thickness changes during frozen storage, which was not influenced by the addition of red wine (p<0.05). There were no significant differences in the $L^*\;and\;b^*$ values, but the a value was significantly decreased during frozen storage. The $L^*,\;a^*\;and\;b^*$ values of the pork patties containing red wine were lower than those of the control patties (p<0.05). There were no significant differences in the pH and VBN content during the frozen storage period or on the addition of red wine to the patties. The TBARS value of the pork patties tended to increased with increasing in frozen storage period, but were decreased with increasing amount of red wine addition (p<0.05).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.4
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• pp.463-470
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• 1998

To improve muscle quality and prolong freshness of sashimi, the effects of freezing-thawing condition on physicochemical and rheological properties of plaice muscle were investigated. Muscle tested were frozen with quick freezing (liquid nitrogen gas) or slow freezing ($-15^{\circ}C$ air). Transition time of zone of ice crystal formation was within 10 minute for quick freezing and 110 minute for slow freezing. Time required for thawing to $0^{\circ}C$ in muscle temperature by various thawing methods was shortest with $25^{\circ}C$ tap water, followed by $15^{\circ}C$ tap water, $10^{\circ}C$ tap water, $25^{\circ}C$ air, $5^{\circ}C$ tap water and $0^{\circ}C$ cold water. Breaking strength of muscle was higher in quickly frozen sample than in slowly frozen sample. According to sashimi term, changes in breaking strength of muscle did not show any difference in quickly frozen sample, while showed significant difference in slowly frozen sample. The remaining content of ATP was not effected by freezing speed, and ATP content was apt to higher in quickly thawed sample than in slowly thawed sample. IMP was the majority of ATP and it's related compounds of sample after freezing and thawing. Collagen matrix was weakened markedly in slowly frozen sample than in quickly frozen sample.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.3
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• pp.290-296
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• 2020

We investigated the effect of the modified starch [physical treatment, acetate (SA-1, SA-2, and SA-3), hydroxypropyl (HS), and acetylated distarch adipate] content on the physicochemical properties of fish cakes, called Eomuk in Korea, during storage at -20℃. When wheat flour (native starch, NS) was used, the moisture content decreased during frozen storage, resulting in a lower water-holding capacity and higher expressible drip. Compared with NS, adding modified starch had a lower effect on the moisture content during frozen storage. The water-holding capacity and expressible drip differed with the type of modified starch added. The expressible drip was lowest with HS; the SA-3 and HS modified starch were whiter than NS. Therefore, HS and SA-1 are suitable additives to improve the quality of frozen fish cakes.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.2
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• pp.121-126
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• 2018

The purpose of this study was to assess bacteriological hazards in the following 7 kinds of minimally processed shellfish products purchased from Korean seafood retail outlets: raw oysters stored with seawater in polyethylene bags, frozen oysters, raw mussels, frozen mussels, boiled mussels, raw short-necked clam, and frozen short-necked clams, obtained from Korean seafood retail outlets. The total coliform and Escherichia coli counts determined in all samples were detected below regulation limit of the Korean government guidelines (Food Code). In addition, the high-risk bacterial pathogens, Listeria monocytogenes, Salmonella spp., and E. coli O157:H7 were not detected in any samples. Low-risk pathogens such as Staphylococcus aureus and Vibrio parahaemolyticus were detected at levels above $1.0{\times}10^2$ colony forming unit (CFU)/g in some minimally processed shellfish products. Notably, S. aureus was detected in all samples. Raw oysters stored with seawater in polyethylene bags, frozen oysters, and boiled blue mussels are commonly ingested without heating, and therefore these minimally processed shellfish products pose bacteriological hazards. The detection of S. aureus in all shellfish products, an organism indicative of poor personal hygiene, which can grow and multiply during distribution, indicates the necessity of improving the food safety of minimally processed shellfish products.