• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.7
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• pp.994-1001
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• 2012

Quality changes of pre-processed garlic, peeled and chopped, were analyzed during storage at $-18^{\circ}C$ or $2^{\circ}C$ for 30 days and at $20^{\circ}C$ for 3 days only for chopped garlic. As storage time increased, Hunter L values decreased and a, b values increased, indicating browning regardless of the pre-process type and storage temperature. Decay and sprouting rates of peeled garlic during storage at $2^{\circ}C$ significantly increased while those of peeled garlic were maintained during storage at $-18^{\circ}C$. Weight loss of peeled garlic during storage was greater at $-18^{\circ}C$ than at $2^{\circ}C$. Hardness of peeled garlic rapidly decreased by half from 1.04 kg to 0.58 kg by freezing, and it did not significantly change during the storage period. Viable numbers of total aerobic bacteria of peeled and chopped garlic did not significantly change during the storage period at $2^{\circ}C$ but were reduced at $-18^{\circ}C$. Total aerobic bacterial count of chopped garlic stored at $20^{\circ}C$ slightly increased during the storage period. Pyruvic acid content of chopped garlic was almost 2.5 times higher than that of peeled garlic at the initial stage (463.87 ${\mu}mol/g$ and 190.52 ${\mu}mol/g$, respectively). As storage time increased, pyruvic acid content of peeled garlic increased while that of chopped garlic decreased. These results indicate that pre-process type and storage temperature affected the quality changes of garlic during storage.

• Horticultural Science & Technology
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• v.32 no.6
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• pp.819-826
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• 2014

This study was carried out to investigate the effects of night-time far-infrared irradiance quality of red pepper dried in greenhouses. This study involved 4 treatments: sunlight alone (control), or sunlight plus nightly far-infrared irradiation at $250W{\cdot}6.6m^{-2}$ ($250W{\cdot}6.6m^{-2}$), far-infrared irradiation at $250W{\cdot}3.3m^{-2}$ ($250W{\cdot}3.3m^{-2}$), or far-infrared irradiation $500W{\cdot}3.3m^{-2}$ ($500W{\cdot}3.3m^{-2}$). The drying periods were 12 days in $500W{\cdot}3.3m^{-2}$ and $250W{\cdot}3.3m^{-2}$, and 14 days in $250W{\cdot}6.6m^{-2}$, and 15 days in the control. The daytime temperature was same among the treatments. The lowest temperature was at $23.8^{\circ}C$ in control, and $29.5-37.2^{\circ}C$ in far-infrared irradiation treatments. The marketable yield was 7-14% higher in far-infrared irradiation treatments compared to the control. The rate of marketability was higher in far-infrared irradiation treatments (93.6-96.3%) than in the control (87.0-87.5%). The American Spice Trade Association (ASTA) value was greatest in the $250W{\cdot}3.3m^{-2}$ treatment, followed by $250W{\cdot}6.6m^{-2}$, then $500W{\cdot}3.3m^{-2}$, and finally the control. Capsaicinoid content showed no regular trend among the treatments. Our results provide an optimized method for reducing drying time of red pepper under sunlight, and improving the quality of dried red pepper.

• Korean Journal of Food Science and Technology
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• v.35 no.6
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• pp.1079-1085
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• 2003

Modified atmosphere packaging was applied to oyster mushrooms (Pleurotus ostreatus) to study the effect of storage temperatures and packaging materialso. Whole mushrooms (200g) were package with polyethylene film $(PE,\;60{\mu}m\;thickness)$, ethylene vinyl acetate (EVA), or ceramic film (containing 5% zeolite) and stored at 0, 5, 10 and $20^{\circ}C$. Weight loss, color, firmness, gas composition $(O_2,\;CO_2)$ inside the film package and ethanol content in the tissue of MA packaged mushrooms were examined. Mushroom that were packed unwrapped in a conventional hardboard box (2 kg) lost marketability at a very early stage of storage due to weight loss, shrinkage, browning, and spore formation. During storage, film packaging prevented or retarded the deterioration of the mushrooms in the aspects of appearance, texture, and discoloration. Firmness slightly decreased with storage time. Total color difference was much higher in the control than in the film-packaged mushroom and rapidly increased at the early of storage. Correlation analysis showed a high correlation between total color difference and b values. These results were characterized by the reduced respiration rate resulting from elevated carbon dioxide and reduced oxygen levels in the package. At all storage temperatures, ethanol content in the tissue increased slightly at the early part of storage and rose considerably towards the end of the storage period. Ethanol content in the oyster mushrooms was higher in the stipe than in pileus tissues. The shelf life of the oyster mushrooms was about $8{\sim}11$ days at $0^{\circ}C$, about $4{\sim}6$ day at $5^{\circ}C$, about $2{\sim}3$ days at $10^{\circ}C$, and about $1{\sim}2$ days at $20^{\circ}C$.

• The Korean Journal of Food And Nutrition
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• v.26 no.1
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• pp.15-21
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• 2013

This study investigated the oxidative stability of oils when dough was fried under a lower pressure than the ambient atmosphere. The pressure during the frying process was controlled at measures of 760, 560, 360 or 160 mmHg. The oil containing the dough was heated at $180^{\circ}C$ for 48 hours. Rancidity values, including acid value, peroxide value, fatty acid analysis, color changes, and browning of oil samples, were measured every 8 hours. As the frying process continued at all 4 pressure levels, the acid values (AV) increased. However, compared to the other pressure levels, the increase in AV was the least at 160 mmHg. In addition, the peroxide value at 160 mmHg was only 0.81 meq/kg compared to 1.52 meq/kg at 760 mmHg. For all pressure levels, stearic acid, oleic acid, ${\omega}$-6 linolenic acid were increased, while linoleic acid and ${\omega}$-3 linolenic acid were decreased. In terms of color, a-values representing redness were decreased, whereas b-values were increased as the frying proceeded. These results revealed that the oxidation of frying oil was decreased under reduced pressure condition. Thus, the usage of frying oil may be extended, owing to less oxidative concerns. This leads to a lower cost to the manufacturer, and furthermore, helps the environment by reducing industrial wastes.

• Applied Biological Chemistry
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• v.24 no.1
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• pp.50-58
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• 1981

The influence of high temperature storage on the chemical composition and color intensity of the concentrated red ginseng extract(RGE) was investigated. The concentrated RGE was prepared by extraction of red ginseng tails with water and concentrated under reduced pressure. Changes in free sugars, saponin patterns and brown color intensity were measured during 96 hours of heat treatment at various temperature. A decrease in the contents of glucose, fructose and sucrose was resulted as the brown color intensity increased during the storage. The sugar contents and color intensity showed rapid initial change followed by slowing down at higher temperature. A significant relationship was found between sugar content and browning rate. The saponin pattern measured by high performance liquid chromatography, particularly in the region of protopanaxtriol, was also affected significantly. The peak heights of ginsenoside -Re and $-Rg_1$ were decreased while those of ginsenoside $-Rg_2$ and -Rh group were increased.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.3
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• pp.220-225
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• 2010

Soybean sprouts produced at optimal temperature are placed or displayed for several days in market shelf of relatively cool temperature (ca. $13^{\circ}C$). During this period a number of changes occur including changes in color, smell, taste, nutritional quality, etc. In order to investigate the changes of these factors, soybean sprouts packed in plastic film bag (OPP+PE) were stored at the two different temperature ($3^{\circ}C$ and $13^{\circ}C$). Morphological characters, physicochemical changes and enzymes activity related to visible quality (color) of soybean sprouts were examined. The numbers of fine roots were greater and hypocotyls were longer in soybean sprouts stored at $13^{\circ}C$, although there was no significant difference in diameter, fresh weight and dry weight of hypocotyls between the two storage temperatures. Browning of hypocotyl, as an indicator of a typical deterioration in sprout quality, was highly dependent on the activity of polyphenol oxidase (PPO). Considering the low level of soluble protein in hypocotyls, the relatively higher activity of PPO suggested a critical role of PPO in stored soybean sprouts. PPO activity of sprouts stored at $13^{\circ}C$ was 2-fold higher than that of sprouts stored at $3^{\circ}C$ after 4 days. In sprouts stored at $13^{\circ}C$, the PPO activity was increased from day 0 until 6 days and since then, it was not detected. Crude protein content was increased to 30.9~35.4% based on dry weight with extended storage period. The change in crude protein was greater in sprouts stored at high temperature ($13^{\circ}C$). Total free amino acid content was increased in both temperatures. However, the changing rate of free amino acid was greater in sprouts stored at $13^{\circ}C$.

• Korean Journal of Food Science and Technology
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• v.43 no.4
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• pp.495-503
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• 2011

We evaluated the quality characteristics of fresh-cut produce (potato, sweet potato, carrot, radish, zucchini, cucumber, and green bell pepper) washed with sodium hypochlorite, which were vacuum packaged, and stored at 4 and 10$^{\circ}C$. The L-values of the fresh-cut potato and sweet potato decreased during storage. Lower PPO activities of potato and sweet potato were observed at 4$^{\circ}C$ than those at 10$^{\circ}C$ and development of potato and sweet potato browning was delayed at 4$^{\circ}C$. Total aerobic count and coliform increased continuously at 10$^{\circ}C$ during storage. Diced zucchini and shredded sweet potato had the greatest reduction in hardness among the fresh-cut produce during storage. Differences in the rate of quality change were observed according to the kinds and cut types of produce. Thus, a quality maintenance period for each type of fresh-cut produce must be determined, which will lead to the safe use of fresh cut produce in foodservice establishments.

• Journal of Life Science
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• v.25 no.5
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• pp.557-567
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• 2015

To increase the marketability of Dolsan leaf mustard Kimchi, seasonings were prepared by sea tangle and Lentinus edodes. Gat Kimchi A (GK-A) and Gat Kimchi B (GK-B) were prepared by addition of complex seasoning with Sea tangle (CSS), complex seasoning with Lentinus edodes (CSL), respectively and evaluated the quality characteristics. GK-A contained high minerals and dietary fiber and showed the effect of delaying pH-lowering and acidity-rising. There were no significant differences in salinity test after 70 days. Reducing sugar of test groups was higher than control. During the fermentation, Leuconostoc sp. was grown in GK-A and GK-B than control. Growth of control's Lactobacillus sp. increased 20 days after. Up to 30 days, lightness of control was high. Yellowness were increased browning potential in GK-B, 20 days after. From the initial to 10 days, Hardness of GK-A showed higher than the others. glutamic acid and aspartic acid content of GK-A was higher significantly than the others in the entire fermentation period (p<0.05). At 0, 10, 30 days, sweet-tasty amino acids of GK-A showed a significantly higher level than the others (p<0.05). From 10 days to 40 days of fermentation, the sensory evaluation of GK-A is better than the other groups. Comprehensively reviewed the above results, the conclusion is as follows: CSS made with sea tangle as a main ingredient. GK-A by seasoning the CSS to 90 g GK-A is expected as a new Dolsan leaf mustard products that can provide flavor and nutrition to the consumer at the same time.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.4
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• pp.330-339
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• 1993

To optimize the processing conditions of fermented ascidian, Halocynthia roretzi, fermentation at low temperature with different salt contents, the effect of enzymes added, and the quality changes during fermentation were investigated. As the quality factors, changes in such components as free amino acid, volatile basic nitrogen(VBN), amino nitrogen, total creatinine, total carotenoid, extents of browning, reducing sugar and glycogen were determined. The quality was also evaluated organolatically by pannel test. Fresh deshelled and sliced ascidian were fermented for 50 days at $5{\pm}1^{\circ}C$ with different salt contents of 5, 10, $15\%$ (w/w) with enzyme contents of papain $0.1\%$ and protease-A $0.1\%$ VBN increased gradually during the 50 days of fermentation and showed $30{\sim}40mg/100g$ at 30, 35 and 45 days in case of salt contents 5, 10 and $15\%$ added with $0.1\%$ papain and protease-A, respectively. Amino nitrogen and the total creatinine increased until 20 days, hereafter tended to decrease gradually. Total carotenoid and glycogen also decreased during the fermentation. The results of sensory evaluation of fermented ascidian at $5{\pm}1^{\circ}C$ added $0.1\%$ papain or protease-A showed that the peculiar taste and flavor of ascidian was sustained for $30{\sim}40$ at least 20 days with $5\%$ NaCl and $35{\sim}45$ days of fermentation with 10 and $15\%$ NaCl.

• Korean Journal of Microbiology
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• v.52 no.1
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• pp.98-109
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• 2016

The study was aimed to investigate the mixing ratio of kiwi and persimmon juices for the production of good quality wine by Saccharomyces cerevisiae Y28. Firstly, the optimum condition of rapidase treatment for the kiwi and persimmon juices was established, thereafter various mixing ratio (10:0, 9:1, 8:2, 7:3, 6:4, 5:5) of kiwi and persimmon was investigated regarding physiochemical properties and flavor compounds of wine. As the result, the optimum conditions were obtained as 0.3% rapidase for 1 h in kiwi and 0.3% rapidase for 3 h in persimmon. According to higher ration of persimmon, the pH of wines increased from 3.69 to 3.77, while the acidity of wines decreased from 2.07% to 1.51% at 14 days fermentation. The ranges of brix and reducing sugar in wines were decreased which ranges around 9.6 to 8.8 and 6.07 to 6.90 g/L, respectively, after fermentation. Major organic acid in wines were identified as tartaric acid, malic acid, and citric acid. A small amount of free sugar such as sucrose and glucose were detected in wines, but fructose was completely absent. The soluble phenolic contents were decreased that ranges around 1.00 to 1.25 g/L, in contrast, browning degree were increased ranges around 0.212 to 0.412 after fermentation. The major flavor components were identified as ethyl acetate and hydrazine, and 1,1-dimethyl. Importantly, phenylethyl alcohol was detected from the all wines that have a typical rose like flavor. But sensory test results and preference of kiwi-persimmon (7:3) mixing wine was better than the other wines.