This study investigated the effect of bactocease, as a natural preservative, on the microbial growth and quality of fried fish paste during storage. To select the optimal concentration of bactocease, the inhibition effect of its different treatment concentrations (0.2, 0.4, and 0.8%) on total aerobic bacteria in fish paste dough during 5 days of storage was examined. The sample treated with 0.4% bactocease showed a 1.21 log reduction in microorganisms compared with that of the control. This result was higher than that with 0.2% bactocease and potassium sorbate and similar to that with 0.8% bactocease. Consequently, 0.4% bactocease was chosen as the best concentration for preparing the fried fish paste. Microbial growth on fried samples treated with preservatives was more inhibited by adding preservatives regardless of their type than that of the control after 15 days of storage. In addition, there were no significant differences in the quality between the samples treated with 0.4% bactocease and 0.2% potassium sorbate, such as volatile basic nitrogen contents, TBARS values, pH, and acidity. Therefore, these results indicate that food preservatives should be added into fried fish paste for controlling microbial growth, and bactocease can have a high potential to replace potassium sorbate in processed marine foods, including fried fish paste.

본 연구는 ‘스마트꿀’ 참외를 수확 후 ascorbic acid (AA) 및 salicylic acid (SA) 침지 처리와 PE film 처리가 저온저장(10℃) 중 과골 갈변 발생과 과실품질 변화에 미치는 영향을 조사하였다. 참외 과실의 저장기간 동안 과골 갈변 발생 정도는 무처리 과실의 경우 저장기간 동안 꾸준히 증가하여 저장 15일후 3.8 수준으로 증가하였으나, PE film 처리 과실은 저장 15일후 2.7 수준으로 낮은 과골 갈변 증상을 보였다. 참외 과실의 고유색을 나타내는 황색 과피의 황색도(b*)의 경우, 무처리 과실은 저장 15일 후 38.1로 감소하였으나, PE film 처리 과실은 저장 15일 후에도 39.8로 높은 황색도를 보였다. 흰색 과골 명도(L*)는 무처리 과실은 저장 15일 후 67.9로 감소하였으나, PE film 처리 과실은 72.9로 높게 유지되었다. 그리고 흰색 과골 적색도(a*)의 변화는 무처리 과실의 경우 저장 15일 후 1.0으로 증가하였나, PE film 처리 과실은 저장 15일 후에도 –1.4 이었으며, AA 처리 과실 역시 –0.5로 적색도 변화를 효율적으로 억제하였다. 가용성 고형물 함량은 무처리 과실은 저장기간 동안 점차 감소하였으나 PE film, AA 및 SA 처리 과실들은 거의 변화가 없었다. 그리고 과실 중량감소율은 무처리 과실은 저장 15일 후 1.98%이었으나, PE film 처리 과실은 1.33%로 가장 낮은 중량감소율을 나타내었다. 따라서 ‘스마트꿀’ 참외를 저장 및 유통할 때 과골 갈변 발생과 과색 및 품질의 변화를 억제하는데 PE film 처리가 효과를 보여 처리방법에 대한 효율적인 적용 방안을 모색할 필요가 있다고 판단되었다.

Post-slaughtering storage of pork meat is important to improve the flavor and texture profile. Although irradiation of meat improves the keeping qualities of red meat, less work was done on the effect of quality in irradiated pork leg meat during post-slaughtering storage. Therefore, this study was done to compare low dosages of single beam irradiation treated pork leg meat on eating quality parameters over the nontreated meat stored at different storage temperatures. Freshly slaughter pig carcasses were brought to the irradiation unit for treatment. Pork leg meat was treated at 2 kGy with single beam. Treated (2 kGy) and non-treated pork leg meat were kept in three different temperatures as 2, 10 and 25°C for 1, 3 and 5 days and analyzed for cooking loss, shear force, color and nitrogenous flavor compounds. Cooking loss in day 5 in irradiated pork leg (30.29) was significantly lower than the control (33.27) (p<0.05). Shear force of treated (1.93) and non-treated (1.29) pork leg meat after day 5 had significant difference (p<0.05). “L*” and “b*” values of pork leg meat had significant difference at day 5 compared non treated leg meat (p<0.05) whereas the “a*” value was increased with storage time and temperature. Hypoxanthine level was significantly lower in pork leg meat at day 5 in treated (16.07) and non-treated (24.59) meats at 25°C (p<0.05) whereas the changes in AMP, IMP and Inosine was not significantly difference (p>0.05). As conclusion, post-slaughtering storage and irradiation with single beam of 2 kGy could ensure the meat quality of leg pork at even higher storage temperatures, with cooking loss, tenderness, flavor and the color which will be benefited in the processing industry.

본 연구는 저장 온도를 달리하여 높은 상대습도의 환경에서 건조 감자를 저장하였을 때 발생하는 품질변화를 관찰하였다. 저장기간 및 건조온도가 증가함에 따라 L* value 는 감소하였고, a* 및 b* value는 증가하는 경향을 나타내었다. 수분활성도는 높은 습도 조건으로 인해 10일차부터 급격히 증가하였으며, 환원형 비타민 C 함량은 급격히 감소하는 경향을 나타내었다. pH 값은 저장기간 동안 완만하게 감소하였으며 40oC에서 저장했을 때 큰 폭으로 감소하였다. 저장기간 동안 대장균군은 검출되지 않았으며, 일반 세균 수는 저장 온도가 증가함에 따라 많이 검출되었다. 전체적으로 20oC와 30oC에서 저장한 시료 간의 차이는 크지 않았으나, 40oC에서 저장한 시료의 경우 큰 품질변화를 나타내었고, 밀봉된 상태로 저장한 대조구의 경우 품질변화가 적게 나타나는 것을 확인할 수 있었다. 따라서 본 연구결과를 종합해 볼 때, 밀봉하여 산소와 수분을 차단한 상태로 저장하는 것이 제품 고유의 특성을 유지하는데 가장 효과적이며, 높은 습도의 환경일 경우 낮은 온도로 저장하는 것이 품질 변화를 지연시키는데 도움이 될 것으로 판단된다.

This research aimed to investigate the effects of the inoculation method and diverse ingredients on the quality properties and probiotics viability of pudding with milk and/or soymilk. The probiotic strain (Lactobacillus acidophilus, LA-5) was inoculated into the yogurt base and fermented until the pH is 5.10 ± 0.05. The fermented yogurt was added into pudding base (yogurt inoculation), or LA-5 was directly inoculated (direct inoculation). During the storage of the puddings at 4±1oC for 4 wks, the quality characteristics (pH, acidity, texture) and the probiotics viability of pudding were measured and compared. As a result, the puddings with yogurt inoculation showed significantly lower pH and higher acidity than those with direct inoculation. In texture properties, including hardness, chewiness, and gumminess, the addition of rice powder increased those in milk pudding more but the addition of inulin in the milk-soymilk pudding more. The addition of rice powder increased probiotics viability more than inulin in milk and milk-soymilk puddings. Therefore, adding rice and/or inulin can potentially improve the probiotics viability and quality characteristics of pudding.

This study sought to investigate the effects of heat-moisture treatment (HMT) and ethanol treatment (EOH) for improving the quality and storage stability of Tteokbokki Tteok. The quality characteristics were evaluated by moisture, pH, color, texture profile analysis, and observing the microbial properties after the heat-moisture treatment or ethanol treatment. As the storage period increased, the moisture content of Tteokbokki Tteok tended to decrease except for the HMT group (p<0.05) while the pH did not show significant variation except for the EOH group (p<0.05). While measuring the color, the L-value tended to increase in all groups during the storage period. The a-value and the b-value showed the highest values in the HMT group and the control (CON) group, respectively. In the texture profile analysis, all groups showed a significant tendency to increase levels of hardness and chewiness as the storage period increased (p<0.05). The HMT group showed an increase in hardness and adhesiveness, which are characteristics of the HMT treatment. The results of examining the microbial properties of Tteokbokki Tteok showed that the total microbial count in the HMT group was 4.52 on the 8th day of storage, which was lower than the level in the CON group and the EOH group on the 4th day of storage. Yeast and mold were not measured during the storage period. Thus the results of this study showed that when manufacturing Tteokbokki Tteok, the heat-moisture treatment of rice powder increased the storage stability by delaying microbial growth and also had positive effects on quality.

In this study, we investigated the effects of cooling rate during storage on spring kimchi cabbage from an economic perspective. For long-term storage, kimchi cabbage (KC) should be maintained at a low temperature immediately after harvest; however, a sudden change in temperature during storage may lead to chilling injury in KC. The optimal cooling rate is important for the long-term storage of KC. To identify the optimal cooling rate, KC was cooled at different cooling rates (1oC, 2oC, 4oC, 6oC, 8oC, and 24 oC/day), and then stored at 1oC for 90 days. Thereafter, weight, trimming, total loss, pH, free sugar content, and total bacterial count changes were measured. Spring KC stored at the cooling rate of 6 oC/day presented a lower total loss and better sensory properties than KC stored at other cooling rates; thus, 6 oC/day is an appropriate cooling rate for long-term storage of KC.

본 연구는 정수압 처리와 초음파 처리가 20일 숙성기간 동안 돈육의 삼겹살과 목살 부위의 품질특성에 미치는 영향에 대해 조사하였다. 다양한 품질특성을 관찰한 결과 정수압에서 숙성하고 초음파 처리한 돈육은 부위별로 효과의 차이는 있지만, 품질향상에 효과적인 것으로 나타났으며 또한, 초음파 처리했을 때 특히 고기의 연도와 관계가 있는 pH, 보수력, 경도 품질을 높이는 것으로 관찰되었다. 본 연구에서 이용한 저온 정수압 숙성 및 초음파 처리공정은 낮은 온도에서 돈육을 빠른 시간안에 숙성하는데 적용 가능할 것으로 판단된다.

This study investigated the effect of the addition of various levels of pig head meat (HM) as a substitute for rear leg meat (RLM) on the physico-chemical quality characteristics of non-emulsified, smoked, and cooked sausage during refrigerated storage. Sausages were prepared in four variations according to the proportion (0%, 10%, 20%, or 30%) of HM added and maintained at 4°C. Quality measurements were taken for 28 days. The sausages added with the addition of 20% and 30% HM had significantly (p<0.05) higher moisture and lower protein content compared to those without the addition of HM. The pH value during the storage period was higher (p<0.05) in the sausages to which the HM had been added than in those without HM. The sausages with 30% HM showed the lowest (p<0.05) L* and b* values and the highest (p<0.05) a* value during the storage period. The 2-thiobarbituric acid reactive substances (TBARS) content, hardness, cohesiveness, springiness, gumminess, and chewiness of the sausages showed no significant variations with the addition of various levels of HM. These data suggest that RLM could be substituted with 30% HM because it does not negatively affect the quality of the non-emulsified sausage. However, a further study on sausages made with 100% HM instead of RLM may be needed to improve its utilization.

In this study, we investigated the effects of the ripening level (50% and 100%), storage temperature (1°C and 10°C), and storage period (0, 7, and 14 days) on the fruit quality of the strawberry (Fragaria × ananassa Duch) cultivars “Arihyang” and “Kuemsil”, which are commonly grown for export in South Korea. Strawberry plants of each cultivar were grown in a plastic greenhouse, and fruit samples were harvested in January 2019 to evaluate the fruit hardness, gray mold rot, anthocyanin content, sugar content, and antioxidant activity. We found that “Arihyang” had a greater fruit hardness than “Kuemsil” across all storage periods excluding the day of harvest, and that fruit stored at 1°C had a greater hardness than fruit stored at room temperature (10 ± 2°C) for both cultivars. In incidence of gray mold rat, “Kuemsil” had a higher than “Arihyang”. The soluble solid content was highest at 7 days after harvest for both cultivars, with the exception of “Kuemsil” following storage at 1°C. The anthocyanin content was higher in “Arihyang” than in “Kuemsil” and was also greater in fruit that had been stored at room temperature due to the faster ripening time. Finally, the DPPH activity of fully ripened fruit tended to decrease as the storage period increased, while the ABTS activity was the same across all treatments. These findings demonstrate that “Arihyang” are more advantageous for long-term distribution as well as export than “Kuemsil”, and recommend that the two new cultivars of strawberry be cool stored at 100% ripening state and eaten within 7 days.

Angelica gigas Nakai (A. gigas) easily changes its color during storage, and appropriate thermal treatment can improve storage stability through inactivation of enzymes such as polyphenol oxidase. Therefore, this study was performed to determine quality characteristics of dried A. gigas in response to high-temperature-short-time (HTST) treatment during storage. Dried A. gigas were treated at 120-180℃ for 10 min, the samples were stored at 4℃ and 50℃ for 10 weeks, and used for the analysis of qualities. Concerning the color values, the sample treated at 120℃ was similar to the control, and the color change was large when treated above 180℃. However, color difference (△E* ab) was lower in treated samples than in control. Browning index was similar for all the samples except for the sample treated at 180℃. Functional qualities (phenolics content, antioxidant activities, and level of major components) showed a slight difference according to storage periods in all samples without control, and nodakenin content was observed in control. The results of this study showed that HTST treatment improved storage stability such as stability of colors and browning index in dried A. gigas during storage, and the appropriate treatment temperature was 120℃ in terms of stability in color and browning index.

This study evaluated the effects of acidulant treatment on the quality and storage period of Topokkidduck. Two samples of Topokkidduck were prepared, one soaked in 10% acidulant (10SAT) and the other without soaking in the acidulant (NSAT). During the storage period, the two samples were tested for presence of microorganisms (aerobic bacteria, E.coli, and mold) and physicochemical properties (color value, texture profile analysis (TPA)). The 10SAT could be stored for 49 days without detection of E.coli and a mold level of 1.0 log CFU/g. NSAT could be stored for only 21 days. NSAT had an aerobic count of 2.27 log CFU/g as early as 7 days, and E.coli was detected at 21 days at a level of 4.15 log CFU/g. The presence of E.coli is not permitted according to the Ministry of Food and Drug Safety (MFDS). The hardness of the 10SAT increased during the storage period but to a much lesser extent compared to the NSAT. Thus the preparation of Topokkidduck by soaking in the acidulant controlled microbial growth for up to 49 days which is a much longer period compared to the control. Also, Topokkidduck soaked in the acidulant had a softer texture than the control during the storage period.

This study was carried out to determine the optimum temperature of the jicama pickle solution by evaluating physicochemical and sensory characteristics at various temperatures. The soaking solution of the jicama pickle was prepared at different temperatures (95, 75, 50, and 25oC). During storage, the titratable acidity, Brix, and the salinity of the jicama pickles increased, and these values increased with increasing temperature of the soaking solution. The higher the temperature of the soaking solution, the lower the L and b values. In all samples, the hardness increased rapidly until the 5th day of storage, and then gradually decreased. During storage, the jicama pickles showed a high tendency to harden at soaking solution temperatures of 75 and 95oC. Sensory evaluation indicated that the taste, flavor, crispness, and overall preference of the jicama pickle were higher at a soaking solution temperature of 75oC and above. The higher the temperature of the soaking solution, the higher the acceptability. Based on these results, we conclude that soaking solution temperature of 75°¦95oC in the manufacture of jicama pickles had a positive effect on the reduction in tissue softening and the sensory properties of the jicama pickle.

This study investigates the physicochemical and sensory properties of the soy-based patties using κ-carrageenan (CG) and methyl-cellulose (MC) as binders. Soy-based patties were prepared using 0%-2% of κ-carrageenan and methyl-cellulose in proportion, and the quality change of soy-based patties was measured by storing them at 4oC for 4 weeks. During the storage periods, the water holding capacity of ‘MC 1.5%+CG 0.5%’ showed high values. As the MC content increased, the weight loss and cooking loss tended to decrease, and both values increased significantly during the storage period. As the MC content increased, the lightness and redness tended to decreased. The hardness and chewiness of soy-based patties tended to increase as the MC content increased. During the storage period, the total aerobic bacteria and the coliforms tended to increase. The VBN content was showed 14.6-17.5 mg%/100g in first week, since then, the VBN content has continued to increase. As a result of sensory evaluation, the springiness, taste and overall acceptability of soy-based patties with ‘MC 1.5%+CG 0.5%’ and ‘MC 2.0%’ showed the highest value.

This study was carried out to investigate the changes of the microbiological contamination levels, pH, acidity, solid contents, total phenol contents, and color difference of cold-brew coffee products during 4 weeks at room and cold temperatures. The 17 sample coffees were purchased from regional cafes in Jeonju. Each coffee was self-blended by the cafes. Esherichia coli was not detected in all the samples, but bacteria were detected in 1 sample and yeast and molds were detected in 4 samples. Of the samples stored at room temperature (25oC) after 4 weeks, general bacteria were detected in 4 samples (3.0×101 cfu/ml-1.7×103 cfu/ml), and yeast and molds were detected in 11 samples (1.3×101 cfu/ml - 3.1×105 cfu/ml). In the case of the samples stored at cold temperature (4oC), general bacteria were detected in 3 samples, and yeast and molds were detected in 6 samples although the level of contamination was lower than that at room temperature. pH and acidity decreased during the storage period, but the total phenol content did not change. In the case of chromaticity, redness and yellowness tended to decrease.

본 연구의 목적은 레드비트 분말의 첨가가 냉장 저장중 비가열 돈육패티의 품질특성에 미치는 효과를 구명하기 위해 수행하였다. 실험구는 다음과 같이 구분하였다. 대조구: 아질산염 0.01%, T1: 아질산염 0.005%+레드비트 분말 0.1%, T2: 레드비트 분말 0.1%, T3: 레드비트 분말 0.3%, T4: 레드비트 분말 0.5%. 레드비트 분말을 첨가한 비가열 돈육패티의 품질특성에서 모든 처리구들이 수분, 보수력, pH에서 유사한 수준을 나타냈으나 (p>0.05), 가열 후 감량은 레드비트 분말의 첨가가 증가할수록 높아지는 결과를 나타내었다(p<0.05). 레드비트 분말의 첨가는 돈육패티의 조직특성과 관능평가에 큰 영향을 나타내지 않았으며, 레드비트 분말의 첨가가 증가할수록 적색도가 증가하는 결과를 나타내었다. 15일간의 냉장저장 중 레드비트 분말의 첨가는 비가열 돈육패티의 저장특성에 부정적인 영향을 나타내었으나 비가열 돈육패티의 외관을 크게 향상시킬 수 있는 우수한 착색제로서 사용할 수 있을 것으로 판단되었다.

느타리버섯 곤지7호의 수확 후 CO2 처리에 의한 품질 유지 효과 및 적정 처리 농도를 구명하고자 연구를 수행하였다. 수확한 버섯을 3°C에서 1일간 예냉 후에 CO2 농도 0, 30 및 50%에서 3시간 처리한 다음 20 μm 두께 OPP필름 봉지에 밀봉하여 3°C에 21일 저장하였다. 30% CO2 처리에서 대조직의 경도가 저장 21일까지 높게 유지 되었고, 대조직의 색은 명도(CIE L*값)가 30% CO2 처리 한 느타리버섯이 저장 14일, 21일에 높고 황색도(CIE b* 값)가 저장 2일, 7일에 낮게 나타났으며 외관품위가 저장 7일부터 저장기간 내내 대조구와 50% CO2 처리에 비해 높았으며 3°C 저장 중 17일까지 느타리버섯 곤지7호의 상품성을 유지하였다. 30% CO2 농도로 3시간 처리가 느타리버섯 곤지7호의 저온저장 중 품질 유지기간을 연장할 수 있는 수확 후 처리방법으로 판단되었다.

The impact of storage temperature on the changes in acid value(AV), peroxide value(POV), color value, total phenolic content(TPC), and antioxidant activity in perilla seed(PS) was investigated. The PS was stored at 25, 35, and 45℃ for four weeks. An increase in the storage temperature resulted in significantly increased AV, POV, redness, and yellowness of the PS. Conversely, TPC, antioxidant activity, and redness of the PS significantly decreased. The changes in the AV and POV followed a first-order kinetic model, and the kinetic parameters such as k, t1/2, Q10 and Ea were calculated. The k and t1/2 values decreased with increasing storage temperature and the Q10 values for the AV and POV were 1.56, 1.91, 4.61, and 3.43, respectively. The Ea for the changes in of the AV and POV in the PS were 70.40, 102.63 kJ/mol, respectively. The half-life values for the AV and POV of the PS at 25℃ were 169.52 and 373.18 days, respectively, while the values at 45℃ for those, were 28.47 and 27.93 days, respectively.