냉축열 잠열재로 Na2SO4.10H2O를 선정하여 냉축열을 위한 잠열축열 온도 수준을 NH4Cl과 KCI을 잠열온도 조절제로 활용하여 16℃에서 -0.3℃까지 조절하였으며, 상변화 사이클에 의한 열특성 변화 추이와 물성의 안정성을 실험 분석하여 다음과 같은 결과를 얻을 수 있었다. 1. 냉축열재로 선택한 Na2SO4.10H2O는 물성이 불안정한 상변화 잠열 재였으나, 조핵제로 BRX를, 증점제로 CBP를 첨가하여 물성을 안정시켰으며, NH4Cl과 KCl을 상변화 온도조절제로 선택하여 상변화 온도를 조절할 수 있다. 2. SSD＋NH4Cl서 NH4Cl을 g~21wt%로 증가시킴에 따라 상변화 온도는 16~-0.3℃로 조절할 수 있었으며, 잠열축열량은 30kca1/kg에서 23.4kca1/kg으로 감소하였고, 상변화 온도조절제, KCl을 l7wt%에서 25wt%로 증가시킴에 따라 상변화 온도를 14℃에서 4℃까지 조절할 수 있었다.

This study was carried out to investigate the microbiological and chemical properties of natural water during storage. The water samples were taken at the time of purchase and the opened bottles and the unopened bottles stored at the temperature of 4, 18, and 30. The bacterial content normally rose to 2.06 × 10² CFU/ml for the unopened bottles and 2.91 × 10² CFU/ml for the opened bottles after 2 weeks of storage, and 1.21 × 10^7 CFU/×ml and 2.64 × 10^7, respectively, after 24 weeks of storage. The number of viable cells of bacteria peaked more rapidly at the storage temperature of 30℃ than 18℃. But the total samples were found to be negative for coliforms test during the study period. The average range of pH value was from 7.39 to 7.76. The results showed that the nitrates and chlorides satisfied the Korea Drinking Water Quality Standards during the storage period of 24 weeks. However, the undesirable changes of the taste and odor were detected within 2 weeks and 3 weeks, respectively.

In order to investigate bacterial sanitary condition of fish and shellfish, we examined the normal flora in the 25 species of commercial fish and shellfish, and also proportional change of normal flora by storage period and temperature. Isolated 334 were isolated in the normal fish and shellfish and predominant genera were Pseudomonas (25.2%), Staphylococcus (10%), Acinetobacter (7.2%), Vibrio (6.9%), Micrococcus (5.4%), Aeromonas (5.2%), and Enterobacter (5.2%). In accordance with storage period and temperature, Pseudomonas grew on high ratio at 10℃ steadily, but Proteus had increased proportionally at 20℃ and 30℃. Additionally, Citrobacter, Moganella, and Pasteuralla had increasd, while Achromobacter, Acinetobacter, Yeast, and Micrococcus had decreased by period.

This paper intends to investigate commercial fish and shellfish 25 species (fish 8 species, shellfish 7 species, crustacean 3 species, molusc 4 species and echinodermata) for the distribution of sanitary indicator organisms (total viable counts, coliforms, staphylococci, vibrios, and enterococci) and diatributional change of indicator organisms according to storage temperature and period. The logarithmic mean of total viable counts for total commercial fish and shellfish 25 species was 5.41±0.26 CFU/g, and in accordance with fish and shellfishes, crustacean 6.76±0.67 CFU/g, shellfish 5.67±0.56 CFU/g, echinodermata 5.47±0.50 CFU/g, fish 5.021±0.38 CFU/g, and mollusc 5.03±0.65 CFU/g. The logarithmic mean of enterococci was 2.36±0.37 CFU/g, and in accordance with fish and shellfish, crustacean 3.44±0.12 CFU/g, shellfish 3.87±0.45 CFU/g, echinodermata 3.38±0.0 CFU/g, fish 2.16±0.41 CFU/g and mollusc 0.01±0.0 CFUIg. The logarithmic mean of vibrios was 1.60±0.59 CFUIg, and in accordance with fish and shellfish, crustacean 4.23±0.11 CFU/g, shellfish 3.58±0.90 CFUIg, echinodermata 1.64±0.34 CFU/g, fish 1.79±0.67 CFU/g and mollusc 1.07±0.61 CFU/g. The logarithmic mean of staphylococci was 1.60±0.59 CFU/g, and in accordance with fish and shellfish, shellfish 0.01±0.00 CFU/g, echinodermata 3.51±0.60 CFU/g, fish 1.68±0.64 CFU/g, crustacean 0.34±0.33 and mollusc 2.90±0.11 CFU/g. The logarithmic mean of coliforma was 2.2±0.32 CFU/g, and in accordance with fish and shellfish, echinodermata 3.58±0.89 CFU/g was highest, shellfish 3.25±0.30 CFU/g, crustacean 3.23±0.49 CFU/g, fish 2.18±0.63 CFU/g, peeled shellfish 1.80±0.51 CFU/ g and mollusc 1.55±0.95 CFU/g. As the results of research of the change of the contaminated indicator microflora in working with storage period at 10℃, 20℃ and 30℃, total viable counts was increased without storage temperature and enterococci were decreased slowly at 10℃, but increased at 20 and 30℃ Vibrios were decreased slowly at 10℃, decreased at 20℃ and 30℃ in 2 days after increased rapidly. Staphylococci were increased promptly without storage temperature in 2 days, then the total viable counts were maintained. Coliforms were increased at 10℃ by 7 days, then decreased or maintained after 14 days, changed at 20℃ in accordance with fish species in 2 days, then returned to the initial total viable count, and decreased rapidly at 30℃ on 2 days. By the way, there were no difference among the species.

For improved preservation of boiled-dried anchovies, the current preservation method of corrugated-cardboard box packaging and freezing below - 18℃ was compared to the nylon/polyethylene(NY/PE) packaging along with cooling temperature ranging from 5℃ to 10℃ as well as ambient condition for eight months by determining physicochemical quality of stored samples. Lipid oxidation of stored anchovies and their browning increased with storage time. The phenomenon was delayed under the conditions of lower temperature and air-tight packaging. As quality-indicative criteria of stored anchovies, carbonyl value(r=-0.989), browning (r=-0.949) and color a value(r=-0.989), browning(r=-0.965), Hunter's color b value (r=-0.949) and color a value(r=-0.940) showed a highly-negative correlations with organoleptic qualities of the samples. Based on the above results, air-tight packaging in a laminated film and subsequent storage at cooling temperature was found to be a possible alternative to the current freezing-storage of boiled-dried anchovies from the physicochemical point of view.

For improved preservation of boiled-dried anchovies, the current preservation method of corrugated-cardboard box packaging and freezing below - 18℃ was compared to the nylon/polyethylene(NY/PE) packaging along with cooling temperature ranging from 5℃ to 10℃ as well as ambient condition for eight months by determining physicochemical quality of stored samples. Lipid oxidation of stored anchovies and their browning increased with storage time. The phenomenon was delayed under the conditions of lower temperature and air-tight packaging. As quality-indicative criteria of stored anchovies, carbonyl value(r=-0.989), browning (r=-0.949) and color a value(r=-0.989), browning(r=-0.965), Hunter's color b value (r=-0.949) and color a value(r=-0.940) showed a highly-negative correlations with organoleptic qualities of the samples. Based on the above results, air-tight packaging in a laminated film and subsequent storage at cooling temperature was found to be a possible alternative to the current freezing-storage of boiled-dried anchovies from the physicochemical point of view.

담배거세미나방 핵다각체병 바이러스(Spodoptera litura nuclear polyhedroses virus: SINPV) 미생물살충제로 개발하기 위하여 기주식물, 온도 보관조건 및 태양광선에 의한 병원성 및 안정성에 대하여 조사하였다. 콩잎에 살포한 SlNPV의 담배거세미나방 3령과 5령 유충에 대한 은 각각 와 였으며 에 대한 은 3령과 5령에 대하여 각각 7.3일파 8.9일이었다. SINPV는 에서 4시간, 에서 1 10분 처리하였을 때 활성이 저하되었으며 처리시간이 길어질수록 급격한 활성감소현상을 보였다. 또한 SINPV는 동결보관이 나 보관보다 안정적인 활성을 유지하였다. 콩잎표변에 살포한 SINPV는 콩잎표변에 살포한 경우 3일 후에 불활화하였으나 콩잎 이면살포에서는 10일간 활성이 지속되었다.

약식의 유통기간을 결정하는 중요한 품질요소인 조직감의 경화현상을 측정하는 방법을 수집하고 제조방법과 저장조건에 의한 경화속도의 변화를 조사하였다. 전통적으로 사용되는 표준 제조방법으로 만든 약식은 실온 (20˚C)에서 3일간 저장할 수 있었으며 유통 상한점에서의 경도는 multipuncture시험의 700g 하중 수준이었다. 냉장저장(5℃)에 의하여 약식의 굳는 속도는 급격히 증가하였으며 Avrami식으로 산출한 속도상수비는 1.3~3.3배 증가하였으며 수분함량이 높은 압력솥 처리구가 가장 큰 차이를 나타내었다. 물엿첨가는 약식의 경화속도를 다소 낮추는 효과를 나타내었다. 압력솥 처리에 의하여 약식은 너무 무르게 되어 기호도가 다소 떨어지나 냉장보관시에는 저장기간을 연장할 수 있는 방법으로 사료된다. 전자렌지로 조리한 약식은 대단히 높은 경도를 나타내었다. 약식의 종합적인 기호도는 조직감 기호도와 높은 정의 상관관계를 나타내며, 조직감 기호도는 multipuncture 시험의 최대 하중과 높은 부의 상관관계를 나타내어 multipuncture 시험이 약식의 품질평가 방법으로 사용될 수 있음을 확인하였다.

양송이 유통에 적합한 필름 포장방법 연구를 위해 저장온도 및 필름 산소투과도에 따른 양송이 품질변화를 분석하였다. 실험에 이용된 필름은 PVC와 OPP(OTR 1,000, 6,000, 10,000, 20,000 mL/m2/day/atm)이고 저장 온도는 4, 8, 12, 20℃로 설정하였다. 분석 결과, 중량감소율은 대조구, PVC, OPP 순으로 높았다. 갓 개열은 온도 별로 결과가 다르게 나타나 8℃ 이상에서 필름 처리구의 갓 개열 억제 효과가 나타났고 12℃에서는 필름 내부의 산소 농도가 낮을수록 억제 효과가 높은 경향이었다. 필름 중 OPP20000은 20℃에서 갓 개열 억제 효과가 나타나지 않았다. 대 신장은 모든 온도에서 전반적으로 필름 처리구가 대조구에 비해 억제되었으나 예외적으로 OPP20000은 대 신장이 대조구보다 오히려 촉진되는 결과였다. 조직의 경도는 필름 중 OPP1000이 다른 처리구에 비해 유의하게 높았다. 버섯의 내외부 색도는 모두 OPP 필름의 버섯이 대조구와 PVC에 비해 색 변화가 큰 경향이었다. 전반적으로 OPP는 중량감소, 갓 개열, 대 신장, 조직 경도에서 대조구에 비해 품질이 유지되는 효과가 있었으나 온도 및 산소투과도에 따라 효과의 차이가 있었고 OPP20000은 조직 생장 억제와 관련된 효과가 나타나지 않았다. OPP1000과 OPP6000은 OPP 중 조직 생장 억제에 가장 효과적이었으나 내부 단면에서 조직손상 및 수침 현상과 같은 장해가 나타났다. 한편 PVC 필름은 중량감소, 갓 개열, 대 신장이 대조구에 비해 변화가 적었고 내외부 갈변은 OPP보다 변화가 적어 전반적인 품질변화가 적은 것으로 분석되었다.

Background: In Korea, seeds of Panax ginseng C. A. Meyer need to be stored under cold temperature and high humidity condition for months to break physiological dormancy, making storage difficult until spring-sowing. This study was conducted to test the effects of seed storage conditions and seed treatment on the emergence of seedling after spring-sowing in a nursery greenhouse. Methods and Results: After dehiscence, endocarp dried seeds in mild or completely, and wet seeds were stored in 2℃ and −3.5℃ during winter. Storage at −3.5℃ resulted in a lower emergence rate (ER) than that at 2℃, and additional cold (2℃) treatment before or after storage at −3.5℃ increased the ER. Endocarp dehydration prevented pre-germination at 2℃ storage and increased the ER of seeds stored at −3.5℃. ER was also dependent on the batch of seeds. However, seed treatments before sowing had only limited effects on ER. Root loss was the main reason for damping-off; prolonged cold storage of seeds increased damping-off, as the detection of pathogens was not high. Conclusions: This study showed that storage conditions such as temperature and moisture content of seeds, affect the ER after spring-sowing and vitality of seedlings, suggesting further attention on seed control for secure seedling stands after spring-sowing.

Background : Platycodon grandiflorum has been used as famous medicinal vegetable and traditional medicine in Korea. Platycodon grandiflorum is used more for vegetable than it is used as a medicine. Proper storage conditons are required for distribution of Platycodon grandiflorum as vegetables. The purpose of this study was to find the appropriate storage temperature. Methods and Results : 2-years old Platycodon grandiflorum cultivated in Herbal Crop Research, RDA Eumseong was used. They were packed with plastic container box of 45 × 70 × 30 ㎝ and then stored at –2℃, 2℃, 5℃, 25℃, humidity 80 - 82%. During the storage, hardness, L a b values, weight loss, decay rate were measured every 30 days as quality indices. During the storage period, L value decreased but a and b values increased and same pattern was observed at all storage temperatures. Hardness decreased and same pattern was also observed at all storage temperature. Under constant humidity conditions, weight loss was larger at higher temperature. The higher the temperature, the larger the deviation at weight loss. There were little decay but 25℃ temperature stored showed that dacay rate was higher with time over. Conclusion : The favorable temperature for storage is –2℃ - 2℃ while maintaining constant humidity.

We investigated the effect of PE film thickness on the modified atmosphere packaging (MAP) deastringency of ‘Sanggamdungsi’ (Diospyros kaki cv.) astringent persimmon at room temperature (25°C) and low temperature (-1°C). The fruits were individually packaged with PE film of which the thickness is 60, 80, 100, 115 or 130 μm and stored at room or low (-1°C) temperature. At room temperature, firmness shows the highest value (23.3-26.5) at 100 μm thickness. Top flesh browning and decay was monitored at 20 days after storage, and peel blackening and style-end softening was negligible at optimal thickness. Therefore, optimal film thickness of deastringency at room temperature is 80-100 μm. At this thickness, the astringency was removed after 5 days and the fruits can be distributed until 10 days after the MAP. At low (-1°C) temperature, firmness was maintained regardless of film thickness. However, the firmness is higher as the film is thicker. Top flesh browning and decay was not occurred even after 90 days after storage. Peel blackening and style-end softening was monitored at 90 days after storage. Off-flavor was monitored at 115 and 130 μm thickness. Therefore, optimal film thickness of deastringency at low (-1°C) temperature is 80-100 μm. At this thickness, the astringency was removed after 50 days and the fruits can be distributed until 80 days after the MAP.

Background : The practice of keeping the medicinal herbs at room temperature causes many problems, but due to lack of sufficient field research and study, it is difficult to improve related regulations and safety management. Methods and Results : The Cnidium Rhizome and Angelica gigas Root were inoculated with Lasioderma serricorne F. and incubated at 28℃ for 2.5 months and 5 months. After five months, the number of Lasioderma serricorne F. in Cnidium Rhizome increased from 30 to 1,429 (about 47 times). In the same period, the number of insects in Angelica gigas Root increased from 30 to 663 (about 22 times). Due to the rapid increase in pest population, hygiene deteriorated, changes in the active ingredient and appearance quality of the herbal medicines, which greatly damaged the value of the herbal medicine. Conclusions : These results show that current regulation requiring only sealing and not specifying the storage temperature do not guarantee quality safety. Therefore, it is necessary to establish appropriate preservation standards and improve management regulations in order to preserve safety.

본 연구에서는 토마토를 일정한 기간(15일) 동안 저장하여 토마토의 품질인자인 감모율, 색상과 경도를 분석하고 비 파괴적 방법으로 토마토 경도를 측정한 결과로 경도와 감모율 사이의 상관관계를 분석하고 선형회귀모델을 도출하여 토마토 품질을 예측하고자 하였다. 그린하우스에서 재배된 ‘티와이250’품종을 수확한 후 일반 과실 종이 박스에 포장한 후 설정환경이 10℃, 90%RH인 항온항습챔버에 저장하여 3일 간격으로 경도, 무게와 색상 변화를 조사하였다. 15일간 저장 중 감모율은 저장기간이 증가함에 따라 증가하나 1.1% 정도에 머물러 단순히 감모율 인자로만 판단했을 때 토마토의 신선도 품질에 영향 끼치는 수준은 아니다. 색상변화 중 명도와 색조 각은 저장기간의 증가에 따라 감소하는 경향을, a/b와 ΔE는 증가하는 경향을 나타냈었고 일원분산분석결과를 볼 때 유의한 수준이었다(p<0.001). 경도는 저장기간이 증가함에 따라 감소하는 경향을 나타냈으며 저장 15일차에는 경도감소율이 40% 이상인 것으로 나타났다. 그리고 비 파괴방법으로 측정한 경도 값과 감모율 사이의 상관관계를 분석하여 선형회귀모델 WL=-0.0241×F+1.5213을 하였으며 모델의 추정치 오차는 ±0.231이었다. 이러한 결과에 비추어볼 때 수확 후 일정한 저장환경에서 비파괴적인 경도 측정을 통해 감모율을 추정하고 신선도를 판단하는 지표고 사용하는 것이 가능한 것으로 판단되었다.

Potato greening determines the shelf life and affects the marketability of this tuber. Various stresses during handling and storage interact to affect the tuber’s physiological status and can affect the rate of greening. This study investigated the effects of storage temperature on tuber greening and shelf life in unwashed and washed potatoes of the cultivar Superior. Physiological and biochemical changes were examined during 15 days at room temperature (23±2°C) under cool-white fluorescent light after storage for 1 month at different temperatures (4°C, 20°C). Hunter a values were negative (-) for washed potatoes after 3 days (-0.8) and 15 days (-2.5) at room temperature following 1 month of storage at 4°C while positive (+) values were observed for unwashed potatoes after 15 days at room temperature. The Hunter ΔE values of washed potatoes previously stored at 4°C for 1 month increased after 3 days at room temperature compared with those of unwashed potatoes. The total chlorophyll content of washed potatoes was higher than that of unwashed potatoes. The highest correlation was observed between the Hunter ΔE value and Hunter a value (-0.93506), while a positive correlation coefficient (0.89806) was observed between greening criteria and Hunter ΔE value by using colorimetry. We conclude, therefore, that there is a biosynthetic link between temperature-induced chlorophyll accumulation and tuber greening in storage.

This purpose of this study was to determine the best enrichment medium for rejuvenating and recovering Salmonella placed in cold temperature prior to the employment of the gold biosensor combined with a light microscopic imaging system. A mixture of nalidixic-resistant Salmonella Typhimurium and Enteritidis were inoculated onto chicken (1,000 CFU/chicken). After cold injury at 4℃ for 24 hr, Salmonella on chicken was enriched for 6 hr with six non-selective media including buffered peptone water broth, lactose broth, brain heart infusion broth (BHI), universal pre-enrichment broth, nutrient broth, and tryptic soy broth, and five selective media including brilliant green broth (BG), rappaport-vassiliadis R10 broth, selenite cystine broth, selenite broth, and tetrathionate brilliant green broth (TBG) for the comparison of Salmonella growth. Various concentrations of Salmonella (10, 50, 100, 500, and 1,000 CFU/chicken) were then enriched for 6 hr in both BHI and BG media to select the best media. BHI was selected as the most effective non-selective enrichment medium, while BG was selected as the most effective selective enrichment medium. Finally, BHI medium was selected as the most efficient enrichment medium for Salmonella growth injured from cold temperature during processing or storage.