• 한국식생활문화학회지
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• 제31권5호
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• pp.489-497
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• 2016

Kunrak, a type of Korea traditional cheese, is made using Tarak, a yogurt produced with makgeolli as the fermentation source. Kunrak is produced by removing whey from Tarak, followed by drying process for safe storage and consumption over a longer period. In this study, we produced kunrak based on the method described in "Imwonsibyukji". Prepared Kunrak was ripening for 96 hours at 20, 30, and $40^{\circ}C$. In order to study characteristics of Kunrak, physiochemical properties (pH, acidity, water contents) and contents of metabolites (organic acids, sugars, amino acids, and fatty acids) were analyzed. During ripening, water contents decreased. The main organic acids in Kunrak were citric acid and lactic acid, and the main free sugar was lactose. Main amino acids were glutamate and phenylalanine, and main fatty acid was saturated capric acid. At later ripening, all metabolites increased immediately after preparation. The sensory evaluation score of overall preference was highest for Kunrak, which was ripening at $40^{\circ}C$ for 96 hours. This study was aimed to assay metabolites of Kunrak under various ripening conditions. The results provide basic data to produce conditions for standardized manufacturing of Kunrak.

• 현장농수산연구지
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• 제20권2호
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• pp.89-97
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• 2018

대목용 박은 개화 후 50~70일 정도 지난 종과를 수확하여 10~15일 간 후숙한 후 채종하고 있는데, 본 연구에서는 수정 후 종과의 수확시기와 후숙기간에 따른 발아율(발현율)을 비교하였다. 실험재료로는 2010년 한국농수산대학에서 정식하여 채종한 대목용 박 5품종을 이용하였다. 채종과의 수확은 수분 후 각각 24, 31, 50, 70일에 하였으며 후숙 기간은 수확 후 5일과 수확일과 후숙일을 더하여 85일이 되도록 각각 62, 55, 35, 15일 후에 채종하였다. 수분 후 24일 후에 채종한 종자는 전혀 발아하지 않았으며, 31일과 50일째 수확한 것이 경제적인 발현율을 보였다. 24일째에 수확한 종과도 62일간 후숙하면 78% 이상의 발현율을 보여 미숙과실도 효과적인 후숙을 통해 채종이 가능함을 보였고, 50일 이상 성숙한 종과의 경우 10-15일 정도의 후숙 처리를 하여도 발아율이 높은 종자를 채종할 수 있을 것으로 추찰되었다. 종자에 대한 배의 비율과 유묘의 하배축 길이와 굵기로 본 종자의 성숙도에 있어서도 후숙의 효과가 뚜렷하였으며, 24일째 수확하여 62일 후숙한 종자는 성숙한 종과에서 채종한 종자에 버금가는 성능을 보였다.

• 미생물학회지
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• 제7권1호
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• pp.10-21
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• 1969

The effect of glucose and 2-thiobarbituric acid on the biosynthesis of cell constituents such as protein, carbohydrate, DNA, RNA, phospholipid and PCA-soluble phosphate compounds in Chlorella duing the life cycle was measured, and the changes in the content of these main cellular components of the algal cell were analyzed in connection with the nuclear and cytoplasmic divison. In the normal autotrophic synchronous culture the contents of protein, RNA, and DNA in the cell showed a chracteristic changes according to the progress of cell development, increasing more or less throughout all the life cycle. The synthesis of protein is more prominent in the division period nad that of DNA is more active in the ripening period, while the synthesis of RNA is more rapid in the growing and ripening periods than other developmental stages. The period of division cycle was little affected by glucose in the medium, although the synchrony of the growth and cellular division was disturbed and the n value increased. The cotents of protein, carbohydrate, RNA nad DNA of the cell were increased by the glucose treatment throughout all the life cycle. On the other hand, both of cellular growth and division were retarded severely and the n value was decreased by the 2-thiobarbituric acid treatment throughout all the life cycle. On the other hand, both of cellular growth and division were retarded severely and the n value was decreased by the 2-thiobarbituric acid treatment. The synthesis of protein, carbohydrate, DNA, RNA and phospholipid of the cell was also retarded by 2-thiobarbituric acid. In the autotrophic, mixotrophic and 2-thiobarbituric acid-treated cultures, each having different mode cytoplasmic division, a common general schema occurring in the cell during the life cycle may be drawn as follows. The ratio of RNA to protein attains maximum value in the $L_1$-cell stage prior to the nuclear division and thereafter decreases during the periods of ripening and division. The ratio of PCA-soluble phosphate compounds to protein increased from the begining of the culture to $L_4$-cell stage successively and thereafter decreased gradually during the division period, while the ratio of protein to DNA kept almost constant up to the division period and thereafter increased during the division period. Therefore, it is presumed that the increase in the ratio of RNA to protein is to be an inducer of nuclear division and that the cytoplasmic division is induced by the increase in the ratio of protein to DNA.

• 한국식품과학회지
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• 제31권6호
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• pp.1503-1510
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• 1999

영귤을 이용한 다양한 가공제품의 개발을 위한 기초자료로 영귤의 과피와 과즙을 분리하여 수확시기별 (9월 3일부터 11월 8일까지 약 20일 간격) 및 산지별(서귀포, 제주시)에 따른 물리화학적 성분특성을 조사하였다. 영귤의 평균중량은 서귀포산이 제주시산보다 2배 이상이었으며, 평균직경도 10mm 이상 큰 것으로 나타났다. 과피의 수분함량은 $74.0{\sim}78.7%$로 성숙함에 따라 높아지는 경향을 보였으나 과즙에서는 $90.1{\sim}91.9%$ 수준으로 차이를 보이지 않았다. 환원당은 과피와 과즙에서 모두 9월 3일에서 11월 8일 사이에 약 2배 가량 증가하였고, 조섬유는 과피와 과즙에서 모두 감소하는 경향을 나타냈으며 조단백질과 회분의 경우, 과피에서는 감소하는 경향을 나타냈으나 과즙에서는 뚜렷한 차이를 나타내지 않았다. pH와 비타민C는 성숙이 진행됨에 따라 과피 및 과즙에서 다소 감소하는 경향을 나타내었다. 또한 과즙의 경우 중요한 품질인자가 되는 transmittance는 9월 20일에서 10월 13일 사이에 급격히 증가하였다. 그리고 유리당의 함량은 과피의 경우 9월 3일에서 11월 8일까지 2배 가량 증가한 반면에 과즙은 4배까지 증가하였다. 무기질의 경우 과피에는 Ca과 K이 다량 함유되어 있었고 과즙에는 K이 가장 큰 비율로 함유되어 있었으며 각 무기질의 함량은 과실이 성숙함에 따라 감소하는 것으로 나타났다.

• 한국작물학회지
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• 제27권3호
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• pp.229-234
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• 1982

이앙기에 따른 등숙기상조건의 차이가 수도의 탈립성에 미치는 영향을 구명하기 위하여 탈립성이 큰 태백벼와 비탈립성인 진흥을 재료로 40일 묘를 5월 11일부터 15일 간격으로 4회 이앙하고 출수 후 40일 및 55일의 시기에 각각 벼알의 인장강도를 측정하였으며 작기 및 수확시기의 영향, 그리고 기상요인들과 탈립성과의 관계를 분석하였다. 1. 벼알의 인장강도는 각 처리를 통틀어 진흥의 경우 214-251g의 변이폭을 보였고 이 범위의 인장강도는 벼의 포장손실에 무관하나 태백벼의 경우 인장강도는 127.5-204g의 변이폭을 보였고 이앙기 및 수확시기가 탈립성 및 벼의 포장손실에 미치는 영향은 매우 컸다. 2. 벼알의 인장강도에 미치는 영향은 태백벼의 경우 수확시기, 이앙기 및 이앙기와 수확시기와의 상호작용이 모두 컸으며, 특히 이앙기가 6월 25일 경우 현저히 탈립성이 커졌다. 진흥의 경우에는 이앙기의 영향은 유의하지 않았고 수확시기가 늦을수록, 즉 벼알이 건조될수록 인장강도가 다소간 커지는 경향이었다. 3. 기상요인들의 탈립성에 미치는 영향은 일평균, 최저, 최고기온 및 일기온교차가 컸고, 특히 수확전 30일간의 이들의 영향이 컸으며, 태백벼의 경우 일사량과 대기온도가 영향하지 않았지만 진흥의 경우에는 수확전 10일간의 일사량과 수확전 30일간의 대기온도가 영향하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제18권2호
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• pp.267-276
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• 2005

This study was carried out to investigate the effect of phytosterol ester addition on lowering blood cholesterol in cholesterol-reduced Cheddar cheese. For cholesterol removal, separated cream was treated with 10% ${\beta}$-cyclodextrin at 800 rpm, then blended with remaining skim milk and homogenized with 1,000 psi at $70^{\circ}C$. Experimental cheeses were manufactured by five different levels of phytosterol addition. After the cholesterol reduction process by ;${\beta}$-cyclodextrin, the cholesterol removal rate was in the range of 91.0 to 92.1%. Amount of short-chain free fatty acid and free amino acids increased with an increase of phytosterol ester, and those were significantly different from that of control in all ripening periods. All rheological properties also increased with an increase of phytosterol ester during ripening period. In sensory analysis, the scores of rancid, bitterness Cheddar flavor and off-flavor intensities increased significantly, while texture was decreased during ripening in phytosterol ester-added groups. Total blood cholesterol was reduced by 18% when rats were fed Cheddar cheese treated with 8% phytosterol. The present study indicated that phytosterol ester addition resulted in a profound lowering effect of blood with cholesterol-reduced Cheddar cheese.

• 한국축산식품학회지
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• 제29권5호
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• pp.545-549
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• 2009

The functional properties of cheese, such as texture and melt, are known to be controlled by several important parameters. Recently, the characteristics of Ca in cheeses, especially the form of Ca (insoluble (INSOL) or soluble) and the shift in Ca equilibrium (i.e., from INSOL to soluble Ca), during aging has received a lot of attention. The INSOL form of Ca, which is present as a structural form in casein, plays a critical role in determining the functional properties of cheese during the early period of ripening (~1 mon). It seems that there is always a reduction of INSOL Ca content in cheese during ripening and there are also factors that can affect the shift in Ca equilibrium. These factors may include the composition of cheese milk, cheese manufacturing pH, acid development during aging, adopting curd-washing in various methods, pre-acidification of milk, etc. There have been many studies showing that the rheological and melting properties of cheese during ripening were significantly (p<0.05) affected by the shift in Ca equilibrium. Therefore, for cheese makers, it is now possible to predict/manage the functional properties of cheese by monitoring and controlling Ca equilibrium in cheese during aging.

• Asian-Australasian Journal of Animal Sciences
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• 제31권2호
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• pp.287-292
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• 2018

Objective: The aim of present study was to assess the anti-oxidant potential of water-soluble peptides (WSPs) extract derived from buffalo and cow milk Cheddar cheeses at different stages of ripening. Methods: The antioxidant potential of WSPs extract was assessed through 2,2'-azinobis-3-ethylbenzothiazoline-6sulfonic acid (ABTS)-radical scavenging activity. In addition, impact of WSPs extract on cell viability and production of reactive oxygen species (ROS) in human colon adenocarcinoma Caco-2 (tert-butylhydroperoxide-induced) cell lines was also evaluated. Results: The ABTS-radical scavenging activity increased progressively with ripening period and dose-dependently in both cheeses. However, peptide extract from buffalo milk Cheddar cheese demonstrated relatively higher activity due to higher contents of water-soluble nitrogen. Intracellular ROS production in Caco-2 cells decreased significantly (p<0.05) till 150th day of cheese ripening and remained constant thereafter. Additionally, dose-dependent response of WSPs extract on antioxidant activity was noticed in the Caco-2 cell line. Conclusion: On the basis of current in vitro study, the Cheddar cheese WSPs extract can protect intestinal epithelium against oxidative stress due to their antioxidant activity.

• 한국축산식품학회지
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• 제37권6호
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• pp.833-839
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• 2017

In this study, the physicochemical and sensory properties of Gouda cheese supplemented with microcapsules of chili pepper extract were evaluated. Microcapsules of pepper extract were prepared by coacervation technique using gum acacia-gelatin wall and chili pepper oil core. Changes in pH, lactic acid bacteria (LAB) population, and free amino acid (FAA) content after supplementation of Gouda cheese with chili pepper capsules were monitored during ripening. Texture and sensory characteristics of the Gouda cheese ripened for 6 months were evaluated. The supplementation of pepper extract microcapsules (0.5% or 1%, w/w) did not influence the pH values and LAB content of the Gouda cheese (p<0.05) during the ripening period. While the content of total FAA increased with the ripening process in all the cheese groups (p<0.05), no significant difference (p<0.05) in the content of total FAA was observed among the sample groups at each time point. The addition of pepper extract microcapsules (1%, w/w) to Gouda cheese significantly decreased hardness (p<0.05) and negatively affected sensory attributes in terms of taste and texture (p<0.05). The results demonstrated that supplementation with 0.5% pepper extract microcapsules could provide additional bioactive ingredients, along with maintenance of the quality of Gouda cheese.

• Food Science and Biotechnology
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• 제14권3호
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• pp.358-362
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• 2005

Eudragit E100 microcapsules containing nisin were prepared and employed to control the ripening of kimchi. The recovery yields of microcapsules without/with nisin ranged from 93.53 to 94.61 % and 92.85 to 94.09 %, respectively. The particle size of microcapsules decreased (>200 to $100\;{\mu}m$) as the amount of aluminium tristearate increased from 6.0 to 15 %. The microcapsules were morphologically spherical and possessed rough surface. Nisin was completely released from the microcapsules within a day at pH 3.0 and within two days at pH 4.0, 5.0, and 6.0, respectively, whereas half the amount of nisin was released at pH 7.0 within two days. During fermentation of kimchi with microcapsules containing nisin, the pH decrease was retarded which resulted in a constant pH of approximately 4.2. The pH of 4.2 was optimal for ripening of kimchi for a longer period of time when compared with samples without nisin.