• Food Science and Preservation
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• v.17 no.2
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• pp.230-235
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• 2010

We investigated the physicochemical quality characteristics of apple juice upon sterilization using hot water, and under various storage conditions. None of sugar content, acidity, or pH differed significantly among various sterilization conditions but chromaticity was considerably reduced in sterilized juice compared with control material. The chromaticity of non-sterilized juice decreased significantly after sterilization compared with material supplemented with vitamin C (0.1%, w/v). Fungi, yeast, and aerobic bacteria were detected in juice sterilized at $65^{\circ}C$ for 10 or 20 min, but no microorganisms were observed in juice sterilized by other procedures. Vitamin C content affected sterilization temperature to a greater extent than sterilization time. When juice was stored at $4^{\circ}C$ or $37^{\circ}C$ for 3 weeks after application of different sterilization conditions, almost no change in acidity, sugar content, or pH was observed, regardless of sterilization mode or storage period. However, chromaticity decreased with longer storage. Vitamin C levels were reduced by higher sterilization temperatures. However, longer storage periods had the greatest effect on reduction of vitamin C levels, which tended toward lower values regardless of differences in sterilization and storage conditions. In sensory evaluation tests, all of taste, color, and overall preference were highest for juice sterilized at $75^{\circ}C$ for 20 min. The ASC value was low at a storage temperature of $4^{\circ}C$ and at high sterilization temperatures, and a long storage period was associated with a greater ASC value. Thus, the quality of apple juice was excellent when juice was hot water-sterilized, with additional vitamin C, at $75^{\circ}C$ for 20 min, followed by storage at $4^{\circ}C$.

• Korean journal of food and cookery science
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• v.9 no.2
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• pp.94-98
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• 1993

The purpose of this study was to investigate the effects of garlic or lemon juice on the lipid oxidation of fish oil as antioxidants and color difference of fish muscle. The samples was treated with garlic or lemon juice by the amount 5%(w/w) or 10%(w/w) of fish muscle were stored at $4\pm$1^{\circ}C$$ and $-18\pm$2^{\circ}C$$ for 10 and 40 days, respectively. The results of this study were as follows; 1. pH of fish muscle had little change during all the storage time at $-18\pm$2^{\circ}C$$. pH of the fish muscle was decreased within 5 days and then was increased untreated or treated with garlic juice at $4\pm$1^{\circ}C$$. 2. Lipid oxidation of fish was measured by POV and TBA value. Both POV and TBA value of the sample treated with garlic juice were generally lower than those of the sample treated with lemon juice and the sample treated with 5f% garlice or lemon juice was lower than the sample treated with 10% garlice or lemon juice. 3. Lightness of the sample treated with loft lemon juice was the highest and that of untreated sample was the lowest during all the storage time at $4\pm$1^{\circ}C$$. As the storaging periods at $4\pm$1^{\circ}C$$, redness of the samples treated with 5% garlic or lemon juice were higher than that of the samples treated with lO%) garlic or lemon juice. Yellowness of the samples treated with 10% garlic or lemon juice showed the highest. Yellowness of the samples treated with lemon juice was higher than that of samples treated with garlic juice.

• Korean journal of food and cookery science
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• v.32 no.4
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• pp.458-465
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• 2016

Purpose: Bokbunja (Rub coreanus Miquel), mulberry and blueberry have been reported to have powerful anti-antioxidant and anti-aging activities. The purpose of this study was to compare the quality characteristics and antioxidant activities of gravy sauce added with Bokbunja, mulberry and blueberry. Methods: Quality characteristics pH, brix, color and sensory characteristics of samples were evaluated. Antioxidant activities of samples were compared using total phenol, 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cation radical scavenging and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities. Results: Mulberry juice showed significantly (p<0.05) higher values of pH and $^{\circ}Bx$ compared to Bokbunja and blueberry juice. Bokbunja juice also had significantly (p<0.05) higher value of Color-L value than mulberry and blueberry juice. The total phenol contents and ABTS cation radical scavenging activity of Bokbunja juice were 236.50 mgGAE/100 g and 61.66%, respectively, which were significantly (p<0.05) higher than those of blueberry and mulberry juice. pH value of gravy sauce added with mulberry (MBS) was 4.67, which was significantly higher than that of the control gravy sauce (GS) and gravy sauce added with Bokbunja (BJS) which had the lowest (p<0.05) pH value 4.33. $^{\circ}Bx$ of GS (13.50) was not significantly different from that of MBS and BBS. However, BJS showed the lowest (p<0.05) value $12.33^{\circ}Bx$. Total phenol contents and ABTS cation radical scavenging activity of BJS were 78.09 mgGAE/100 g and 14.47%, respectively, which were significantly (p<0.05) higher than those of MBS or BBS. Values of sensory characteristics color, sour aroma and sour flavor of BJS were significantly (p<0.05) higher value than those of other samples. Conclusion: Bokbunja juice and gravy sauce showed higher antioxidant activities and higher acceptance test compared to blueberry and mulberry. Thus, Bokbunja has the potential to be added to as high value products in the food industry.

• Korean journal of food and cookery science
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• v.13 no.5
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• pp.578-584
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• 1997

Fermentation temperature and salt concentration of Dongchimi were studied for the development of low salt Dongchimi juice. The juice was prepared by soaking the radish in brine solution of 0.3∼3.0% and fermented at the temperature range of 10∼30$^{\circ}C$. The fermentation proceeded faster at higher temperature. However, the salt concentration effect was dependent on the temperature. Fermentation in 3.0% NaCl solution resulted the fastest reach to pH 3.8 followed by 0.5% NaCl at 10 and 20$^{\circ}C$, while higher NaCl concentration caused a decrease in the fermentation rate at 30$^{\circ}C$. Comparison of flavor of the juice of pH 3.9 showed that fresh sourness was high in the juice prepared at 20$^{\circ}C$ and in 0.5% NaCl. The preference test also showed the juice of pH 3.8∼4.0 fermented in 0.5% NaCl at 20$^{\circ}C$ to be the most preferable one. The salt concentration lower than 0.5% at 20$^{\circ}C$ resulted in faster fermentation and high values in turbidity. However 0.5% NaCl was scored high in flavor acceptability.

• The Korean Journal of Food And Nutrition
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• v.10 no.2
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• pp.254-262
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• 1997

new wild grape(NWG) cultivated in north Kyungki province in Korea, was tested by analyzing the proximate and physicochemical components of fresh fruit, the chemical components and sensory evaluation of wines made from the grape. NWG contained about 10% seed, and about 70% of juice. Total sugar content, total acidity and pH of the fruit juice were 17.50, 1.14 and 3.48%, respectively. Tartaric acid and malic acid contents of the NWG juice were 0.396 and 0.509%, respectively. Ethanol fermentation of the NWG by Saccharomyces cerevisiae Montrachet was rapid. The ethanol content, total acidity and pH of pink wine made from the NWG juice showed 11.88, 0.85 and 3.55%, respectively. Tartaric acid and malic acid contents of pink wine were 0.208 and 0.421%, respectively. Total anthocyanin content(A520) and color intensity(A520+A420) of pink wine were 5.46 and 9.39, showing greatly higher total anthocyanin content and color intensity than those of European red wines. Total phenol contents of NWG wine were 2, 300~3, 800mg/$\ell$. The pink wine made from the fruit juice was better than the red wine in their quality parameters and sensory scores.

• Archives of Pharmacal Research
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• v.17 no.4
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• pp.231-235
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• 1994

Fluorenecarboxaldehyde hydrazone 9FCH)was synthesized as a new fluorescent reagent for the determination of acidity. FCH had no fluorescence in itself, however, it strongly fluoresced under acidic conditions at excitation maximum of 392 nm and emission maximum of 447 nm, respectively. It showed good correlation with pH in the range from pH 0.60 to pH 3.60 in strong acids. As an application, the acidity of gastric juice in rats and humans was determined. In comparision with pH-metry, the acidity measured by the developed method showed generally increased values of about 0.7-1.3 unit and 0.8-1.2 unit in rats and humans, respectively. However, these results had statistically close correlation with those of pH-metry and the correlation coefficients were 0.887 in rats and humans between two methods.

• Korean Journal of Food Science and Technology
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• v.44 no.4
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• pp.417-421
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• 2012

The optimum conditions for manufacturing pomegranate makgeolli, cloudy Korean rice wine, treated with different levels of pomegranate (Punica granatum L.) juice concentrate were investigated. The pH, titratable acidity, amino acid content, soluble solid content, and alcohol content were measured, and the sensory properties of the makgeolli were evaluated. The pH, titratable acidity, soluble solid content and alcohol content of pomegranate makgeolli increased as the addition level of pomegranate juice concentrate increased. The amino acid content of makgeolli significantly decreased with increasing addition level of pomegranate juice concentrate. In the sensory evaluation, makgeolli with 3% pomegranate juice concentrate added during one-step-brewing had the most preferable flavor, sweetness, bitterness and overall acceptance among all samples. In conclusion, the addition of 3% pomegranate juice concentrate during one-step-brewing for makgeolli would be the best conditions for manufacturing pomegranate makgeolli.

• Journal of Dairy Science and Biotechnology
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• v.35 no.2
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• pp.85-92
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• 2017

Four different types of cheeses were measure detailed changes in the mineral concentrations of cheese-serum during ripening. Concentrations of minerals in cheese juice were measured. The pH value using the low pH method (LPM) cheese was significantly (p<0.05) lower than that of other cheeses. Similarly the total Ca, S, Mg, and P contents of LPM cheese were significantly lower in than those of other cheeses. Ca, S, Mg, and P remained in colloidal form, while other minerals were mostly in soluble forms after 1 day. The minerals associated with the structure of cheese (i.e., casein or colloidal calcium phosphate) remained largely insoluble even after 1 month of ripening.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.1
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• pp.80-91
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• 2014

The aim of this study was to establish the superiority of ohmic heating over conventional heating for the sterilization of mulberry juice. Heat treatment of fresh juice significantly reduced the concentration of soluble solids, lowered the pH, and lowered the reducing sugar content (p<0.01). Color measurements showed decreases in the L and a values and increases in the b, H and C values after heat treatment, although the total color differences were smaller after ohmic heating than after conventional heating of fresh juice. The antioxidant capacities, such as reducing power, FRAP, and DPPH, decreased in the order of fresh juice, ohmically heated juice and conventionally heated juice. Furthermore, the anthocyanin, flovonoid, and total antioxidant capacities of the juices significantly decreased in the same order. Sensory evaluations showed no difference between fresh and ohmically heated mulberry fruit juice excluding off-flavor, whereas conventionally heated juice received significantly lower evaluations. The microbial counts were zero in the juice after either heat treatment. Thus, ohmic heat treatment can be effectively used to sterilize fresh mulberry juice to obtain good shelf life with minimal physicochemical, color, antioxidant and sensory deterioration.

• The Korean Journal of Food And Nutrition
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• v.15 no.2
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• pp.97-103
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• 2002

Five citrus juices were separated into a ascorbate and phenolic portion using rep-pak C$\_$18/ cartridge, respectively, in order to elucidate the nitrite scavenging effect and N-nitrosodimethylamine(NDMA) formation in model system. The nitrite scavenging effect of ascorbate portion from citrus juices, in the different pH, when added with 5ml were 79.9 ∼98.6% under the condition of pH 2.5. 48.5∼86.3% at pH 4.2 and lower than 35.2% at pH 6.0. The nitrite scavenging effect was excellent phenolic portion rather than ascorbate portion. Particularly, the effect was more 2 times than ascorbate portion under the reaction condition of pH 6.0. When added the phenolic portion in the reaction mixture, NDMA formation was inhibited 92.8% or more in kum quat, mandarin orange and sweet orange juices. But the ascorbate portion was a negative response of the inhibition of NDMA formation. The inhibition on NDMA formation in citrus juice may be due to phenolic compounds were reacted.