• Preventive Nutrition and Food Science
• /
• 제13권4호
• /
• pp.348-353
• /
• 2008

Aerobic bacterial growth on Korean pan.fried meat patties as a primary quality deterioration factor was modeled as a function of temperature to estimate microbial spoilage on a real.time basis under dynamic storage conditions. Bacteria counts in the stretch.wrapped foods held at constant temperatures of 0, 5, 10 and $15^{\circ}C$ were measured throughout storage. The bootstrapping method was applied to generate many resampled data sets of mean microbial counts, which were then used to estimate the parameters of the microbial growth model of Baranyi & Roberts in the form of differential equations. The temperature functions of the primary model parameters were set up with confidence limits. Incorporating the temperature dependent parameters into the differential equations of bacterial growth could produce predictions closely representing the experimental data under constant and fluctuating temperature conditions.

• Fisheries and Aquatic Sciences
• /
• 제23권9호
• /
• pp.21.1-21.10
• /
• 2020

Background: This study aimed to provide a basic standard for assessing freshness and acceptability of whiteleg shrimp (Litopenaeus vannamei). Methods: It was divided into whole body and meat and stored at 25 ℃ to evaluate both quality and freshness changes that occur over time. The shelf life of shrimp was estimated as 17 and 20 h for whole body and meat, respectively. Results: In chemical analysis, K-value increased from 9.96 to 12.32% to a maximum of 75.14%, and TVB-N increased from 1.86 mg/100 g to 34.71 mg/100 g. For volatile sulfur compounds, methyl mercaptan and dimethyl disulfide increased from 0.00 mg/100 g to 1.10 mg/100 g and 1.26 mg/100 g, respectively, rapidly increasing with decreasing freshness. Conclusion: Changes in all biochemical indicators significantly correlated with the sensory evaluation results. This study contributes to the knowledge about whiteleg shrimp spoilage and freshness, providing a basis for developing methods to improve shrimp quality control and management.

• 대한가정학회지
• /
• 제23권2호
• /
• pp.37-43
• /
• 1985

The effect of irradiation at dose of 3~10 kGy on the extension of the shelf-life of sliced dried squid and dried file and on its quality were investigated during nine months of storage at room temperature. The number of microorganisms, TBA value and TMA-N content were used as objective indices concerned to the sensory evaluation. In the number of initial microbial loading, total bacterial count of sliced dried squid and dried file fish were $2.7{\times}10^{8}\;and\;2.0{\times}10^{5}$, yeast and mold were $5.7{\times}10^{5}\;and\;6.2{\times}10^{5}$ and coliform group were $2.1{\times}10^{5}$ and above 10 per gram of the samples, respectively. The number of total bacteria was sterilized by 99% with irradiation of 3~10 kGy and irradiation of above 7 kGy was shown to be effective for the radurization of yeast, mold and coliform group. TBA value of irradiated groups were higher than storage time. The TMA-N content of nonirradiated group was markedly increased by microbial spoilage during storage, however above 8 kGy irradiated group were indicated about 10 mg% after nine months storage. In the sensory evaluation, the nonirradiated group was off favor after three months storage and was changed in color of dried fishes but 7~10 kGy irradiated group were maintained good qualit compared with those of fresh samples after nine months storage at room temperature.

• 한국미생물·생명공학회지
• /
• 제48권2호
• /
• pp.138-147
• /
• 2020

Various microorganisms play important roles in food fermentation, food spoilage, and agriculture. In this study, the biotype of 54 yeast and bacterial strains having high potential for utilization in food and agriculture, including Candida spp., Lactobacillus spp., and Acetobacter spp., were characterized by matrix-assisted laser desorption/ionization time-of flight mass spectrometry (MALDI-TOF MS). This characterization using a fast and robust method provides much-needed information on the selected microorganisms and will facilitate effective usage of these strains in various applications. Importantly, the unique protein profile of each microbial species obtained from this study was used to create a database of fingerprints from these species. The database was validated using microbial strains of the same species by comparing the mass spectra with the created database through pattern matching. The created reference database provides crucial information and is useful for further utilization of a large number of valuable microorganisms relevant to food and agriculture.

• Journal of Animal Science and Technology
• /
• 제61권1호
• /
• pp.47-53
• /
• 2019

This study was performed to evaluate the microbial and temperature changes of boxed beef during transport and distribution under vacuum and modified atmosphere packaging (MAP), and to compare between excision and swab sampling for 15 days. The top round and striploin (quality grade 1) from Hanwoo steers at 2 days post-slaughter were obtained from a local meat processing plants and chilled at $4{\pm}2^{\circ}C$ in a cold room. The boxes were transported under refrigeration ($4{\pm}2^{\circ}C$) to the laboratory within half an hour. Vacuum and MAP packs were subsequently taken out from cool boxes, and microbiological examinations were carried out at 0, 6, 12, and 24 h of storage time. MAP was more effective than vacuum packaging for the inhibition of total aerobic, lactic acid bacteria and Pseudomonas (p < 0.05). Microbial loads of swab methods were slightly lower than those of excision ones (p < 0.05). The results of this study could be utilized by meat consumers in future studies as well as by manufacturers to determine the ideal storage conditions for cool boxed meat, thus ensuring reduced economic losses due to spoilage.

• 식품보건융합연구
• /
• 제10권2호
• /
• pp.13-17
• /
• 2024

Oxygen is necessary to sustain life, but reactive oxygen species (ROS) produced by oxygen metabolism can cause mutations and toxicity. ROS can damage cellular macromolecules, leading to oxidative stress, which can accelerate cell death and aging. ROS generated in food affect the taste, color, and aroma of food, and high levels of ROS in meat can cause spoilage. Superoxide dismutase (SOD) plays an important role in scavenging ROS in food and reducing their toxicity to organisms. SOD exerts its antioxidant effect by catalyzing the breakdown of O₂-• to H₂O₂. As a natural antioxidant, SOD has the ability to regenerate and maintain its activity over a long period of time without depletion, unlike chemical antioxidants that may have side effects or stability issues. This antioxidant effect of SOD has great potential in a variety of industries, and in the food industry it can be utilized to improve product quality and provide safe and healthy products to consumers. By disrupting the SOD2 and SOD3 genes in Candida albicans, we studied the effects of SOD2 and SOD3 genes on the antioxidant system, suggesting its potential as a natural antioxidant.

• 한국식품과학회지
• /
• 제17권3호
• /
• pp.186-191
• /
• 1985

방사선(放射線) 조사(照射)가 닭고기의 저장성과 품질에 미치는 영향을 검토하기 위해 시료에 5-8kGy의 감마선(線)을 조사(照射)하고 $3{\sim}4^{\circ}C$에서 41일간 저장하면서 이화학적 특성변화 및 냄새와 외관변화의 관능실험을 수행 결과는 다음과 같다. 보수력은 조사직후(照射直後) 선량(線量)의 증가와 더불어 다소 감소하였으나 저장기간이 경과함에 따라 조사구(照射區)가 우수하였고, TBA가(價)는, 조사선량(照射線量)의 증가와 저장기간의 경과에 따라 증가하였으며, 휘발성 염기 질소량에 있어서는 비조사구(非照射區)는 저장 10일경부터 미생물적 부패로 급증하였으나 8kGy 이상 조사구(照射區)에서는 저장 40일까지도 16${\sim}$18mg% 정도였다. 냄새 및 외관에 있어서는 조사구(照射區)에서는 약간의 조사취(照射臭)가 발생되었으나 저장 3일정도에서 사라졌으며 육색(肉色) 선량(線量)의 증가와 더불어 다소 진한 pink색을 보였고, 비조사구(比照射區)는 저장 후 약 5${\sim}$7일 정도에서 부패로 인한 off-odour와 육색(肉色)이 변화되기 시작한데 반해 5kGy 이상 조사구(照射區)는 저장 25${\sim}$30일 동안 신선도를 유지할 수 있었다.

• 한국식품저장유통학회지
• /
• 제11권1호
• /
• pp.22-27
• /
• 2004

고등어 fillet 제품의 저장 중 항산화와 기능성을 부여하고 고등어 특유의 비린내를 제거하기 위해 식염 외에 녹차, dill weed, 키토산, 올리고당, 생강을 첨가하여 진공포장한 후 5$^{\circ}C$, $0^{\circ}C$, -2$0^{\circ}C$에 80일간 저장하면서 제품 특성을 조사하였다. 5$^{\circ}C$에 저장한 고등어 fillet의 휘발성 염기질소 측정 결과는 이들 첨가물을 단독 또는 복합적으로 첨가한 시제품에서 2주 이내에 초기부패에 도달했고, $0^{\circ}C$에서는 4∼7주, -2$0^{\circ}C$에서는 저장 80일간 모든 시제품에서 신선도를 유지할 수 있었다. 이들 첨가물 가운데서도 키토산과 올리고당을 첨가한 시제품이 가장 신선도가 양호함을 알 수 있었다. 항산화성은 초기 과산화물가가 5.4∼7.8 meq/kg 이었던 것이 5$^{\circ}C$ 저장시 35일째 15.7∼20.4 meq/kg, $0^{\circ}C$ 저장시 49일째 13.9∼18.4 meq/kg, -2$0^{\circ}C$ 저장시 80일째 11.6∼20.2 meq/kg으로 저온 일수록 산화속도가 늦었고 각각의 저장온도에서도 녹차, dill weed, 생강, 키토산, 올리고당을 첨가한 시제품에서 가장 산화속도가 늦었다. 친유성 갈색도는 -2$0^{\circ}C$에서 80일 저장기간 동안 거의 변화가 보이지 않았고 5$^{\circ}C$와 $0^{\circ}C$에서는 저장기간이 연장됨에 따라 갈색도는 증가하는 경향을 나타내었다. 저장 중 생균수 변화는 5$^{\circ}C$와 $0^{\circ}C$에서는 저장 21일째 각각 부패균수에 도달하였고 -2$0^{\circ}C$에서는 저장 80일째까지 생균수 변화는 보이지 않아 신선도 유지가 가능하였다. 관능검사 결과는 5$^{\circ}C$저장시 14∼21일, $0^{\circ}C$저장시 28∼49일 점질물이나 산패취가 발생하여 상품적 가치를 상실하였고, -2$0^{\circ}C$에서는 80일간 저장기간 동안에 이들 변화는 나타나지 않았다.

• Journal of Biosystems Engineering
• /
• 제7권1호
• /
• pp.42-52
• /
• 1982

This study was intended to develop a cost function for the natural air in-bin drying: system which could lead to an optimization of the drying system cost. Based on the cost function developed, a series of simulated drying tests were conducted with 10-year weather data (1970~1979) for 7 different regions by applying an appropriate levels of system factors. System performance factors treated in this study were initial moisture content, airflow rate, bin diameter and grain depth. An optimization procedure to find the least cost system was developed as follows: First, the worst year of the past decade was determined in consideration of the dryiang time and maximum dry matter loss. Second, the minimum airflow rate for a fixed bin diameter and grain depth was determined. Third, the optimum grain depth was found for the minimum airflow rate with different initial moisture contents and bin diameters. The results obtained in this study are summarized as follows: 1. The optimization procedure developed in this study was able to reduce the time and efforts significantly. 2. Optimum values of drying parameters including airflow rate, grain depth, and fan size were determined for different initial moisture contents and bin diameters in each region. The results are shown in Tables 3 to 9. 3. Optimum grain depths decreased as the initial moisture content and airflow rate increased. 4. Drying time for the least cost system should be reduced with higher initial moisture content and lower drying potential to prevent grain spoilage. 5. The fixed cost was 65 to 75 percent of the total system cost and the variable cost was 25 to 35 percent. To reduce the fixed cost it is desirable to use a drying bin 2 or 3 times a year.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제40권2호
• /
• pp.33-40
• /
• 2020

Recently mulberry has been commercialized but it loses its marketability rapidly after harvest. In this study, characteristics of mulberry were examined at different storage temperature after harvest using the typical Korean mulberry cultivars. Postharvest spoilage fungi on the various mulberry cultivars, Cheongilppong, Daeshim, and Gwasang No. 2 was observed 2, 2, and 1 d, respectively, after harvest at 28℃. However, at 4℃, the day was 8, 7, and 4 d, respectively. At 28℃ storage condition, the weight loss behavior of mulberry did not showed significantly different among them. However, at 4℃ storage condition, mulberry Cheongilppong loses its weight rapidly compared to Daeshim and Gwasang No. 2. Sugar content of mulberry stored at 4℃ was nearly constant, but stored at 28℃ decreased with storage time. The acidity of mulberry slightly decreased with storage time and then increased. Juice leakage of frozen mulberry leaked abruptly within 6 h from the fruit body and then flattened at 25℃. The results of our study, the postharvest characteristics of mulberry were affected by mulberry cultivar and need to further study to increase the shelf life.