• Preventive Nutrition and Food Science
• /
• 제17권1호
• /
• pp.46-52
• /
• 2012

This study was performed to investigate the effects of pre-treatment and storage temperature and periods on the quality characteristics of ginger paste. The pH of the ginger paste remained constant during room temperature storage but increased with prolonged refrigerated storage periods. During five months of frozen storage, regardless of pre-treatment, the pH of most of the samples decreased slightly and then remained constant. In the color value of ginger paste stored at room temperature, the samples with and without chemical additives changed in color more prominently than fermented or pasteurized samples. Intriguingly, the color value for samples containing chemical additives changed more dramatically when stored under refrigerated conditions. However, the L, a, and b values of samples stored under frozen storage conditions did not change even after ten months. Most of the samples contained glucose and fructose, except for the fermented samples. The free sugar content of samples slowly decreased with increasing storage periods, while the organic acid content generally decreased also, regardless of sample type. Depending on pre-treatment and storage temperature, the gingerol content of the samples was either retained or decreased with prolonged storage time.

• Archives of Pharmacal Research
• /
• 제25권4호
• /
• pp.546-549
• /
• 2002

The impact of storage conditions on the permeability of porcine buccal mucosa to [$^3H$]water and [$^{14}C$]mannitol was assessed. The fresh pocine buccal tissue (fresh tissue) was obtained by utilizing pig heads within 24 hours of slaughter. The stored and frozen porcine buccal tissues (stored tissue and frozen tissue) were obtained after the storage of the tissue intact in the pig heads at $4^{\circ}C$ or -$20^{\circ}C$, respectively, for 24 h. The results demonstrated that the barrier properties of the porcine buccal mucosa were maintained with regard to [$^3H$]water permeability when stored at $4^{\circ}C$ for 24 h. However, freezing the tissue resulted in tissue damage illustrated by a significant increase in [$^3$H]water permeability. [$^{14}C$]Mannitol does not appear to be a suitable model solute to assess the ex vivo permeability of porcine buccal mucosa due to its extremely low permeability.

• 한국수산과학회지
• /
• 제19권4호
• /
• pp.356-362
• /
• 1986

This experiment was designed to evaluate effects of freezing and frozen storage on survival of sanitary indicative bacteria in seafoods. Culture of bacteria such as Escherichia coli type I, Citrobacter freundii type I, Klebsiella aerogenes type I and Streptococcus faecalis was inoculated into homogenates of pollack, shrimp, and sardine frozen in a contact plate freezer at $-40^{\circ}C$ and chest freezer at $-20^{\circ}C$, stored at $-20^{\circ}C$, and then survival of the inoculated bacteria was determined over a period of 95 days. Coliform group was highly sensitive to freezing and frozen storage showing survival of about $2\%$ after 95 days of frozen storage at $-20^{\circ}C$, whereas Streptococcus faecalis was relatively resistant with $20\%$ survival rate. The sanitary indicative bacteria count was rapidly decreased in the early stage of frozen storage revealing 90 to $95\%$ loss of coliform group and 40 to $70\%$ loss in case of Streptococcus faecalis after 10 days storage. In determining recovery rate, most probable number (MPN) method gave more reproducible recovery of the tested strain than did the selected agar plate method.

• 대한영양사협회학술지
• /
• 제13권4호
• /
• pp.345-356
• /
• 2007

The purpose of this study was to investigate utilization and storage management practice of the frozen and refrigerated foods in school foodservice. 222 dietitians employed in school foodservice were surveyed. In school foodservice, the refrigerated stock farm products and seafoods (78.3%) were more used rather than frozen products (47.5%). According to school foodservice characteristics, the refrigerated meats including dairy products were more frequently used in elementary and middle schools than high school foodservice. On the other hand, the foodservice in high school used more frozen seafoods and processed foods than elementary school did. The data also showed a tendency for the contracted foodservice using more frozen meats and seafoods rather than refrigerated products when comparing with the self-operated foodservice. In terms of receiving conditions, storage methods and storage time, the result indicated that frozen or refrigerated products were often delivered at inappropriate temperature. Especially some products which were needed to be shipped and stored at refrigerated temperature such as mollusks, were delivered and kept at room temperature. The most frequently used thawing method were running water (56.9%), however, the frozen products were often sitted at room temperature for the purpose of thawing. According to the results, several inappropriate handling processes for frozen and refrigerated products were found in school foodservice. In order to improve handling process for frozen and refrigerated products, recognition of food handlers' weakness about storage and distribution, development of radical standards for receiving conditions, storage and thawing methods should be debated.

• 한국식품영양과학회지
• /
• 제22권6호
• /
• pp.763-770
• /
• 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.

• 한국축산식품학회지
• /
• 제21권4호
• /
• pp.292-299
• /
• 2001

기계발골 노계육을 수세하여 제조한 surimi의 저장중 oleoresin 향신료 첨가효과를 구명하기 위해 실험을 실시하였다. 계육 surimi에 rosemary, thyme, sage, mace, marjoram, bay를 각각 0.2% 첨가한 후 -18$^{\circ}C$에 14주간 저장하였다. Surimi의 pH는 냉동저장중 감소하였고, 대조구에 비해 향신료 첨가구가 더 많이 감소하였다. 향신료 첨가와 상관없이 냉동저장중 명도(L*)가 감소되고 적색도(a*)와 황색도(b*)가 증가하여 저장중 색깔이 어둡고 농후해졌다. Oleoresin 향신료를 첨가하면 대조구에 비해 L*과 a*가 낮고 b*가 높았으며 첨가구별 차이도 심하였다. 이것은 향신료의 자체 색깔에 더 많음 영향을 받았을 뿐 저장중 색깔 개선에 기여하지 못하였다. 향신료 첨가구는 대조구에 비해 gel 강도가 낮았다. 냉동저장중 모든 surimi에서 지방산화가 촉진되었으며 냉동 14주에 있어서 oleoresin sage가 대조구를 기준으로 TBARS가 42%를 나타내어 가장 산화가 억제 되었다. 결론적으로 본 연구에 이용된 6종류의 oleoresin 향신료는 surimi의 냉동저장중 지방산화를 억제시켰지만, 색깔과 조직감에는 개선 효과가 없는 것으로 나타났다.

• 대한수의학회지
• /
• 제15권2호
• /
• pp.207-213
• /
• 1975

Skimmed goat milk heated at $92^{\circ}C$ for 10 minutes was used as a basal extender for bull semen. The extenders for liquid semen were prepared by adding simultaneously at various ratio of 5% dextrose solution and egg yolk to skimmed goat milk. After bull seven was diluted with the extenders at the rate of 20 million spermatozoa per ml of the extenders. The extenders were stored at $5^{\circ}C$ and the survival rates of spermatozoa were examined at 4 and 24 hours, and 3, 5 and 7 days after dilution. The extenders for frozen semen were prepared by adding various ratlo of glycerol to skimmed goat milk containing 20 parts of 5% dextrose solution and 3 parts of egg folk to 77 parts of skimmed goat milk. After bull semen was diluted with the extenders at the rate of 40 million spermatozoa per ml of the extenders, the extenders were frozen in liquid nitrogen tank. The frozen extenders were thawed at $40^{\circ}C$ for 2 minutes, and the revival rates of the spermatozoa in the extenders were examined. These thawed extenders were stored at $5^{\circ}C$ and the survival rates of the spermatozoa were examined at 10 minutes and 24 hours and 3 and 5 days after thawing. The results obtained were as follows: 1. Among the extenders stored at $5^{\circ}C$, the survival rate of the sperm was the highest in the extender including 20 parts of 5% dextrose solution and 3 parts of egg yolk to 77 parts of skimmed goat milk, and the survival rate was significantly higher that of the spermatozoa in egg folk-2.9% sodium citrate (1 : 4) extender. (P<0.05) 2.Among the extenders frozen in liquid nitrogen tank, the revival rate of the spermatozoa was the highest in the extender containing 7ml of glycerol per 100ml of the extender with consisted of 77 parts of skimmed goat milk, 20hparts of 5% dextrose solution and 3 parts of egg yolk, and the revival rate was significantly higher than that of the spermatozoa in egg yolk-2.9% sodium citrate (1 : 4) extender containing 8ml of glycerol per 100ml of the extender (p<0.01). 3. Among the extenders stored at $5^{\circ}C$ after thawing, the survival rate of the spermatozoa was the highest in the extender containing 7ml of glycerol per 100ml of extender which consisted of 77 parts of skimmed goat milk, 20 parts of 5% dextrose solution and 3 parts of egg yolk, and the survival rate was significantly higher than that of the spermatozoa in egg yolk -2.9% sodium citrate (1 : 4) extender containing 8ml of glycerol per 100ml of the extender (p<0.01).

• 한국수산과학회지
• /
• 제51권2호
• /
• pp.121-126
• /
• 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.

• Preventive Nutrition and Food Science
• /
• 제6권4호
• /
• pp.211-215
• /
• 2001

The packaging effect on physicochemical changes in irradiated sausage stored at -2$0^{\circ}C$ was studied. Emulsion-type cooked pork sausage was made with (156 ppm) or without NaNO$_2$ (0 ppm), and packaged in three different conditions such as aerobic, vacuum and $CO_2$ (100%). The samples irradiated at 0, 5 and 10 kGy absorbed dose, and the total number of microorganisms, lipid oxidation, color and texture were analyzed during frozen storage at-2$0^{\circ}C$. Irradiation of the sausage at 10 kGy completely controlled microbial growth during storage. An NaNO$_2$ addition to the sausage significantly reduced lipid oxidation, and the TBARS value of the sausage with aerobic packaging was higher than that with the vacuum and $CO_2$ packaging. The NaNO$_2$ addition increased Hunter color a-value dramatically, but no packaging effect was found (p > 0.05). Irradiation influenced shear values resulting in lower shear values in 10 kGy-irradiated sausages with aerobic packaging, and $CO_2$ packaged sausage showed comparatively lower shear value than other packaging methods. From the results, vacuum or $CO_2$ (100%) packaging were better than aerobic packaging for frozen stored pork sausage, especially far microbial quality and lipid oxidation.

• 한국식품과학회지
• /
• 제20권4호
• /
• pp.536-540
• /
• 1988

Blanching시간, chemical dipping, 냉동방법 및 저장기간이 냉동양송이의 texture, 색깔 및 수율에 미치는 영향을 연구한 결과는 다음과 같다. Whole mushroom의 경우 5분간 blanching한 것은 1-2분간 blanching한 것 보다 shear press값이 현저히 높았으며, 저장기간이 연장됨에 따라 shear press값이 매우 유의성 있게 증가했다. 그러나 냉동방법은 texture에 유의성 있는 영향을 주지 않았다. Sliced mushroom의 경우 blanching시간이 길어짐에 따라 shear press 값이 증가하기는 하나 유의성은 없었으며, 저장기간이 연장됨에 따라 texture가 현저히 tough 해짐을 알 수 있었다. 그리고 시료의 texture를 관능적으로 측정한 결과는 대체적으로 shear press 결과와 유사한 경향을 보였다. Chemical dipping 방법은 blanching 시간을 짧게하여 냉동양송이의 수율을 높히면서 저장중 색깔의 변화를 방지하는데 효과적이었으며, 특히 whole mushroom의 수율은 상당히 증진시킬 수 있었다. Sliced mushroom의 경우는 blanching time을 2분이하로 단축시키면 rotary slicer로 절단작업을 할 때 조직이 부스러져 생기는 중량손실이 증가하므로 2분 또는 그 이상의 blanching time이 필요했다.