본 연구에서는 전처리 방법별 건조 단호박의 이화학적 특성을 비교 분석하고 반응표면분석법을 이용하여 단호박 말랭이의 최적 건조 조건을 설정하였다. 단호박의 이취 제거와 가공적성을 위한 건열(굽기), 습열(증자), 마이크로웨 이브 처리의 전처리 방법을 비교하고자 호화 점도를 측정 하여 전처리 시간을 설정하였다. 각 전처리 방법별 열풍 건조 전후의 단호박 품질특성을 비교한 결과, 마이크로웨이브 처리에서 가용성 고형분, 과당, 포도당, 자당 함량이 건열과 습열 처리보다 높았고, 수분 함량, 강도 및 경도가 낮게 나타나 마이크로웨이브 처리를 단호박 열풍 건조를 위한 최적의 전처리 방법으로 설정하였고 반응표면분석법을 이용하여 최적의 열풍 건조 조건을 확인하였다. 반응표면분석은 중심합성 계획법으로 실험을 디자인하여 독립변수로서 건조 온도(30, 40, 50oC, X1)와 건조 시간(4, 6, 8 h, X2)을 설정하고, 종속변수로는 건조 단호박의 수분 함량, 수분활성도, 가용성 고형분, 강도, 경도, 과당, 포도당, 자당 함량, 색도(L*, a*, b*)를 측정하여 건조 조건을 최적화하였다. 최적화 변수로는 적합성 결여 검증에서 Pr> F 값이 0.05 이상인 수분 함량, 수분활성도, 가용성 고형분을 최적화 변수로 설정하였으며, 최적화 결과 43oC의 온도와 7.2시간이 최적 건조 조건으로 확인되었고, 예측값과 실험 값을 비교한 결과 90% 이상의 최적 비율을 보였으며, 해당하는 값이 95% 신뢰구간과 예측구간 범위에 들어 실험 디자인과 모델의 적합성 또한 검증되었다.
이상의 결과를 종합하면, 혼합유산균 2종(Bifidobacterium animalis ssp. Lactis Bf141와 Lactobacillus rhamnosus Lb102)의 섭취는 고지방식이 유도 비만 마우스에서 체중, 체지방, 제지방, 골밀도 등 주요 체성분에 영향을 주지 않았다. 혼합유산균은 식욕 조절 효과를 위해 측정한 사료 섭취량에도 영향을 주지 않았으며, 간 조직 무게에도 영향을 미치지 않았다. 인슐린저항성과 포도당신생합성의 주요 지표인 공복혈당량 또한 혼합유산균 급여에 의해 변화 하지 않았다. 또한 혼합유산균은 심혈관질환의 지표로 사용되는 혈중 중성지방 및 총 콜레스테롤에 영향을 주지 않았으며, 체내 지방의 소화 및 흡수율에서도 영향을 미치지 않았다. 결론적으로, 고지방식이유도 비만 마우스를 이용하여 혼합유산균(Bf141 + Lb102)의 항비만 생리활성 을 검증한 결과, 유의미한 물리적, 대사적 표현형 개선은 검증되지 않았다. 따라서, 추후 개별 보다 다양한 혼합 조건 및 농도로 연구를 설계하여 혼합유산균의 항비만 효과를 검증할 필요성이 있다.
A total of 87 kinds of dried sweet potato products from Korea, China, and Japan were collected to compare dried sweet potatoes' quality characteristics for preparing CODEX. The characteristics of Aw, moisture, and reliable soluble content, color, and hardness were analyzed using Principal Component Analysis. The moisture content varied from country to country in order of Korea (21%), China (20%), and Japan (25%). In terms of color, Chinese products were dark and red compare to Korean and Japanese. Chinese products had a wide distribution of quality characteristics in common, so the product quality was not uniform. As a result of the PCA analysis, 67.2% of the total variance was explained. The first component evaluated the degree of the drying progress and the second component evaluated the appearance of the product, how it was bright and yellow. Based on the first component, Japanese, Korean and Chinese products were placed from the left, so the drying degree varied from country to country. Japanese products were the softest, Chinese products were hard, and Korean products were moderately hard. In conclusion, the moisture and reliable soluble content, color, and hardness of the dried sweet potato are essential quality factors, and they are expected to help identify the primary quality elements of sweet potato in neighboring countries.
This study aimed to investigate the effect of storage temperature and pressure plate treatment on chemical composition in Prunus mume sugar extracts (PSEs). Green Prunus mume fruit was mixed with an equal amount of commercial sugar and stored at 4 or 25oC for 9 mon with or without a pressure plate. The alcohol contents in PSEs stored at 4oC were lower than those stored at 25oC. The amygdalin contents in PSEs stored at 25oC with pressure plate were significantly low. The sucrose in PSEs was converted into glucose and fructose during storage. The glucose, fructose and total phenol contents in PSEs stored at 25oC were higher compared with those at 4oC. The total soluble solid and polyphenol contents in PSEs were increased at 25oC until 90 d and 4oC until 150 d and then the contents were constant. The total acidity in PSEs stored at 4oC were higher than those at 25oC. These results indicate that storage temperature plays an important role in controlling the alcohol, amygdalin and sucrose contents in Prunus mume sugar extracts (PSEs).
This study was conducted to investigate changes on the quality characteristics of Prunus davidiana sugar extracts (PSEs) by processing conditions. The PSEs were prepared by extraction with commercial sucrose at 4°C or 25°C for 9 months with or without a pressure plate. The quality characteristics of PSEs were analyzed for Bxo, pH, total acidity, Hunter color value, alcohol content, polyphenol content, DPPH radical scaveging activity, and free sugar content. Bxo increased significantly while pH decreased with increased storage period (p<0.05). The PSEs stored at 4oC scored lower than those stored at 25oC for total acidity, alcohol content, and polyphenol contents. The PSEs with pressure plate possessed lower alcohol content and higher polyphenol content and DPPH free radical scavenging activity than those without pressure plate. The sucrose content in PSEs decreased with increased storage period, while glucose and fructose contents increased. These results indicate that by increasing storage period, sucrose in PSEs is decomposed into glucose and fructose, and the quality characteristics of PSEs such as total acidity, alcohol, and polyphenol content depend on processing conditions.
This study was conducted to find out the change in nutritional components and antioxidant activities of salted Chinese cabbage according to storage temperature and duration using supercooling. Salted Chinese cabbage was investigated every 2 weeks while it was stored at -2℃ and 2℃ for 8 weeks. This was followed by an analysis of freeze dried samples. The analyzed contents were free sugar and free amino acid contents, DPPH and ABTS radical scavenging activity, and TPC and TFC. Free sugar content of salted Chinese cabbage decreased with longer storage duration, while free amino acid did not change significantly. DPPH and ABTS radical scavenging activities did not change significantly with storage duration whereas the TPC and TFC of salted Chinese cabbage stored at -2℃ was higher than that stored at 2℃ for 6 weeks. Therefore, the quality of salted Chinese cabbage was maintained in direct refrigerator storage for a long duration, showing economic and industrial values as a new storage technology.
The purpose of this study was to optimize the rice protein extracted using a response surface methodology. The experiment was designed based on a CCD (Central Composite Design), and the independent variables were the high pressure (X1, 0-400 MPa) and processing time (X2, 0-10 minutes). The results of the extraction content (Y1), residue content (Y2), and recovery yield (Y3) were fitted to a response surface methodology model (R2= 0.92, 0.92, and 0.93, respectively). Increasing the pressure and processing time has a positive effect on the extraction content (Y1), residue content (Y2), and recovery yield (Y3). Therefore, these high-pressure conditions (independent variables) can significantly affect the improvement in rice protein extraction efficiency. Thus, the optimal conditions of X1 and X2 were 400 MPa and 10 min., respectively. Under these optimal conditions, the predicted values of Y1, Y2, and Y3 were 62.93, 57.53 mg/g, and 91.76%, respectively.
Commercial direct refrigerators have good energy efficiency, but are difficult to use for supercooled storage due to their large temperature deviation. Placing insulators and conductors inside the refrigerator could reduce these temperature deviations to within 0.3 degrees, allowing for the supercooled storage. The supercooled storage of salted Chinese cabbages during ten weeks was progressed to compare the other low temperature storages. The nucleation temperatures of salted Chinese cabbage were around -2.5oC and the freezing points were around -0.4oC, so -2oC was selected for the supercooled storage. The growth rate of lactic acid bacteria and yeast at -2oC storage was lower than that at 2oC storage. The reducing sugar was maintained higher due to the growth rate of lactic acid bacteria. The supercooled storage had an effect of delaying the fermentation of the salted Chinese cabbage, which may have the effect of delaying the fermentation of kimchi. This enhancement method of the direct refrigerator was effective for the supercooled storage and would be promising for commercial use.
The purpose of this study was to optimize the mandarin dry chip manufacturing using a response surface methodology. The experiment was designed based on a CCD (Central Composite Design), and the independent variables were the drying temperature (X1, 50-90oC), drying time (X2, 12-36 hours), and microwave pretreat time (X3, 0-4 minutes). The results of appearance (Y5), color (Y6), taste (Y8) and overall acceptance (Y10) were fitted to the response surface methodology model (R2=0.86, 0.88, 0.89, and 0.84, respectively). Increasing the drying temperature and microwave treatment time were negatively evaluated for consumer acceptance. On the other hand, a high value of consumer acceptance was evaluated when the drying time was more than 24 hr. Therefore, the optimal conditions of X1, X2, and X3 were 52.989oC, 24 hr, and 1 min, respectively. Under these optimal conditions, the predicted values of Y5, Y6, Y8, and Y10 were 5.066, 5.338, 5.063, and 5.339, respectively.
The purpose of this study was to develop a peach spread premix to increase the usability of peaches with low storage stability. We analyzed the effect of adding different ratio of peach powder (0, 5, 10, 15%) on the physicochemical and sensory quality characteristics of peach spread premix. The result showed that the pH of the spread premix significantly decreased with the addition of greater amounts of peach powder (p<0.05). The total titratable acidity (TTA) and sweetness of the peach spread premix were significantly increased as the amount of added peach powder increased (p<0.05). The redness (a-value) and yellowness (b-value) increased with an increase of the peach powder ratio; however, the lightness (Lvalue) decreased (p<0.05). The water activity and viscosity of the spread decreased with an increased amount of added peach powder. The results of the sensory test with spread premix prepared with 10% peach powder had the highest score for color, taste, texture, stickiness, and overall acceptability (p<0.05). We suggested that the peach spread premix made with 10% peach powder may be the most desirable for manufacturing spread premix and for improving sensory preference.
In this study, the effects of different varieties and particle sizes of dry milled rice flour on Jeolpyeon quality were investigated. Classify particle size of dry milled rice flour according to rice variety into 50, 100, and 150 μm. A particle size of 50 μm in the varieties Boramchan and Hanareum resulted in the highest damaged starch contents (p<0.05). Additionally, the Boramchan and Hanareum varieties had the highest water absorption index (WAI) values (p<0.05). Analysis of the gelatinization characteristics of dry milled rice flour according to varieties revealed the peak viscosity of Dasan and Hanareum was high (p<0.05), regardless of particle size, while the breakdown was highest for Hanareum at all particle sizes (p<0.05). The moisture content of Jeolpyeon made with Boramchan varied between 48.83 and 53.64% among particle sizes, with no significant differences relative to the control. The hardness of the control was 3.15 kg, while the hardness of Jeolpyeon made with Boramchan decreased significantly 2.60-2.63 kg (p<0.05).
Aronia has low preference because of astringent and bitter taste. Appropriate processing is essential for eating aronia. For the processing of aronia, the aim of this study is to provide basic information on the cultivar and ripening stages. Three varieties (Viking, Nero and McKenzie) were studied. We divided the stages of maturity into four levels based on color. The physicochemical properties were analyzed. In the case of hardness, the first stage of maturity was the highest, and there was no difference between varieties. As maturation progressed, brightness and yellowness gradually decreased, and redness was highest at the second stage. The sugar content was the lowest in the Viking and significantly increased with the maturity stage. The acidity was highest in the Viking. Nero showed the highest radical scavenging ability. Total polyphenols and flavonoids were the highest in Nero. The highest level was shown at the first stage by the ripening stage.