• Food Science and Preservation
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• v.20 no.6
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• pp.784-790
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• 2013

The quality characteristics of Campbell grape juice with different extraction processes (AE; autoclave extraction, HWE: hot water extraction, and EE: enzyme extraction) were investigated. The juice yields of the AE, HWE, and EE juices were 79.8%, 82.3% and 92.6%, respectively. The titratable acidity and soluble solids of the EE juice were significantly higher than those of the other extracts. There was no significant difference in the $L^*$ values of the juices, but the $a^*$ and $b^*$ values of the EE juice were higher than those of the other extracts. The viscosity of the HWE and EE juices was higher than that of the AE juice. The major free sugars in the grape juice were identified as glucose and fructose, and the highest organic acid content was found in the EE juice. The total polyphenol content of the EE juice was 55.7 mg% and was higher than those of the AE and HWE juices, which were 31.3 mg% and 39.5 mg%, respectively. Especially, the anthocyanin content of the EE juice was 22.1 mg%, which was two to four times higher than those of the AE and HWE juices, which were 4.5 mg% and 10.5 mg%, respectively. The EE juice showed the highest antioxidant effect, measured from the DPPH free radical scavenging activity and reducing power. In conclusion, we suggest that the enzyme treatment in the grape extraction was more effective than the autoclave and hot water methods.

• Food Science and Preservation
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• v.13 no.2
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• pp.204-210
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• 2006

To accept basic data of utilizing of citron (Citrus junos) as a raw material of industrial produce, major chemical components of citron were investigated. Weight ration of poet flesh md seed of citron were 44.7, 42.9 and 12.4%, respectively. Comparing proximate composition of peel and flesh of citron, peel showed higher in crude protein crude fat and crude ash than flesh but lower in moisture, carbohydrate and soluble solid. The major free sugars of citron were fructose, glucose and sucrose. Peel contained higher in sucrose than flesh, but lower in fructose and glucose. The content of K md P were 309 and 15.9 mg% in peel and 175 and 22.4 mg% in fresh, respectively. The main organic acids of citron were citrate, malate and oxalate. Total organic acid content of flesh (6.6%) was higher than that of peel (4.6%). Total amino acid content of peel and flesh were 671.9 and 315.7 mg%, respectively. Free amino acid content of peel and flesh were 324.3 and 280.7 mg%, respectively, and the major ones were proline, serine, glutamic acid, aspartic acid, and histidine. Total 49 volatile compounds were detected and 26 of these ones were identified in cion. The major volatile component of citron was limonene, which consists of 80% among the total volatiles in peel by all extract methods.

• Food Science and Preservation
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• v.19 no.2
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• pp.243-248
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• 2012

The physicochemical properties and nutritional components of fermented black jujube (FBJ) were compared with those of dried jujube (DJ) to improve their utilization as food materials. The moisture contents and brix of the DJ and FBJ were 22.6% and 6.07 brix, and 10.36% and 7.23 brix, respectively. Their L values were 34.78 and 31.82, and the a and b values of DJ were higher than those of FBJ. DJ had a lower water activity level (0.75) than FBJ (0.45), but FBJ had a higher amount of reducing sugar and soluble protein than DJ. The major free sugars in the two types of jujube were fructose and glucose, and their potassium content was highest (about 90%) among minerals. Their unsaturated fatty acid contents were 51.0% and 59.83%, respectively, and the major fatty acids myristoleic acid, palmitic acid, and palmitoleic aid were detected in them.

• Food Science and Preservation
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• v.17 no.6
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• pp.853-860
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• 2010

We quantitated the major chemical components of ramie leaves (Boehmeria nivea L.) powder. The proximate compositions (all w/w) was 5.42% moisture, 28.15% crude protein, 6.95% crude fat, 15.27% crude ash, and 54.79% carbohydrate, respectively. The total, insoluble, and soluble dietary fiber contents were $39.66{\pm}1.84g/100g$, $20.32{\pm}2.02g/100g$, and $19.34{\pm}2.84g/100g$, respectively. The major free sugars were glucose, galactose and lactose. Seventeen amino acids were isolated. Essential amino acids constituted 44.65% of the total. When free amino acid levels were evaluated, 25 kinds of components were detected, of which 18.15% were essential. Only caproic acid methyl ester and pentadecanoic acid were detected when fatty acid examined. The contents of vitamin A, vitamin E and vitamin C were 0.0194 mg%, 0.0184 mg%, and 0.1833 mg%, respectively. The mineral contents of were in order of Cu

• Korean Journal of Food Science and Technology
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• v.41 no.3
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• pp.296-301
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• 2009

In order to investigate the effect of different yeasts (La Parisienne (LP), Y18-2, Y54-3, Y90-2, Y90-9 and Y272-7) from nuruks on the quality of Glutinous rice wines, physicochemical properties and volatile flavor components were evaluated. Glutinous rice wines prepared with different yeasts were analyzed for ethanol, pH, total acid, amino acid, soluble solid, coloring degree, UV absorbance, reducing sugar, organic acid, free sugar and volatile compounds. After fermentation for 17 days, the ethanol contents ranged from 13.40 to 14.50%, while the total acid levels were from 0.33 to 0.44%. The amino acid contents in six samples ranged from 0.13 to 0.18%, while soluble solid contents ranged from 12.1 to $14.7^{\circ}Bx$. The glutinous rice wine prepared with LP showed the highest level of coloring degree, soluble solid and reducing sugar among six samples. Organic acid contents of the glutinous rice wine prepared with LP had the highest levels of lactic acid and acetic acid, while the glutinous rice wine prepared with Y90-9 had the highest level of succinic acid. In all glutinous rice wines tested, the most abundant free sugars were glucose followed by maltose. Volatile flavor components in the glutinous rice wines were identified by using GC-MSD. Nineteen esters, ten alcohols, eight acids, one aldehyde and one miscellaneous compound were identified in the glutinous rice wines. Using relative peak area, it was found that other than ethyl alcohol, hexadecanoic acid ethyl ester was the major component, predominantly found in the range of 2.73-10.41%. Phenylethyl alcohol, isoamyl alcohol, ethyl oleate, ethyl linoleate and tetradecanoic acid ethyl ester were some of the major volatile components present through the fermentation, respectively. Overall, it was shown that different yeast strains from nuruks greatly affected chemical and volatile characteristics of the glutinous rice wines.

• Applied Biological Chemistry
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• v.17 no.1
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• pp.63-80
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• 1974

The chemical components of Citrus junos produced in Korea were divided into two parts; common and special components respectively. In the former the relation between the physiological effects of the plant and its ripening process was observed periodically while the latter was analyzed the ripening fruits for their effective utilization as food. The results are summarized as follows: 1. The analytical result of seasonal change showed that the rind ratio was higher than the flesh ratio and on a regional basis, the rind ratio was higher in the islands than on land areas. 2. In the experiment the moisture was increased until the third period, but afterwards it was made constant. While the content of crude fat, cellulose, ash, total acid and soluble non-nitrogen material were decreased until the third period and the cotent of cellulose and total acid were continuousely redused until the last period. In con trast with the above the content of reducing sugars was increased but the content of crude fat, cellulose, ash, crude protein and soluble non-nitrogen material were increased until last period. 3. The content of vitamin C was richer in the rind than in the flesh, in the Korean species than in the Japanese. 4. Free sugars; xylose, fructose, glucose were richer in the rind than in the flesh. 5. The content of volatile organic acids was richer in the rind than in the flesh. Among them, volatile acids, acetic acid, formic and n-valeric acid were found in the rind and formic acid, acetic acid and propionic acid were deteceed in the flesh. 6. The total content of non-volatile acids was richer in the flesh than in the rind. In the kind of non-volatile acids, citric acid,glutaric acid, malic acid, tartaric acid, oxalic acid, malonic acid, succinic acid and an unknown acid were found in the rind and citric acid, malic acid, succinic acid, oxalic acid, glutaric acid and malonic acid in the flesh. 7. Three kinds of aromatic components: D-limonene, ${\alpha}-pinene$, p-cymene and seven other kinds of unknown aromatic components were detected in neutral essential oils. Among them, D-limonene seemed to be main aromatic component in the fruits. 8. From the above results it is confirmed that both rind and flesh of the ripened fruit could be utilized for food effectively, and unripened fruits are suitable for producing citric acid, ripened fruits are also useful for producing juice.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.6
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• pp.904-911
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• 2015

The objective of this study was to investigate the quality characteristics of traditional wine using an radio-frequency identification (RFID) system annexed to a fermenter. In this study, we proposed an RFID-based data transmission scheme for monitoring fermentation of traditional alcoholic beverages. The pH, total acidity, total sugar, soluble sugar, free sugar, alcohol content, and organic acids of were investigated and subjected to fermentation of traditional alcoholic beverages three times. The pH ranged from 7.98, 7.95, and 7.68 at day 0, decreased drastically to 3.31~2.96 at day 2, and then slowly increased to the end point, finally reaching 3.34 at day 20. Acidity tended to increase quickly with time, especially for all samples after day 2. The fermentation environment induced a sudden increase acidity in reactants and indicated a low pH. The total sugars during fermentation quickly decreased to the range of 20.3, 22.43, and 19.2% at day 2, and the slope of reduction steadily decreased to 5.1, 6.1, and 4.8% at day 10. On the other hand, the alcohol content showed the reverse trend as total sugars. The alcohol content also showed the same pattern as total acids, showing the highest alcohol content of 17.3% (v/v) on day 20. In this study on traditional wine fermentation using an RFID system, we showed that pH, soluble sugar, and alcohol content can be adopted as key indicators for quality control and standardization of traditional wine manufacturing.

• Applied Biological Chemistry
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• v.32 no.1
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• pp.14-22
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• 1989

Chemical composition of the oyster mushroom(Pleurotus spp.) at different cropping stage were analyzed. The contents of crude protein, soluble protein, reducing sugar, total sugar and crude fat in Pleurotus ostreatus 201 were a little higher than those of Pleurotus sajorcaju. The Component contents were not different from the first to the second flush, while the contents were slightly decreased from the third flush. A11 component contents were highest in $3{\sim}5cm$ pileus size, the contents were slightly decreased as pileus size increase to over $3{\sim}5cm$, except for reducing sugar. Crude fiber content in Pleurotus sajor-caju were a little more than Pleurotus ostreatus 201, and in course of increasing cropping time, ash contens of two strains were simmilar, and were decreased after the second flush. These component contents mere increased by the growth of the pileus. The sugars were identified as xylose, glucose, mannitol and trehalose in Pleurotus sajor-caju, and xylose, fructose, glucose, mannitol and trehalose in Pleurotus ostreatus 201, respectively. Mannitol and trehalose contents in Pleurotus sajor-caju were a little more than that in Pleurotus ostreatus 201. Glucose content of Pleurotus sajor-caju and Pleurotus ostreatus 201 was highest in $1{\sim}3cm$ pileus size, while other sugars in $3{\sim}5cm$ pileus size, and the sugar contents were decreased at over the above size of the pileus.

• Korean Journal of Food Science and Technology
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• v.38 no.4
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• pp.469-474
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• 2006

This study was carried out to investigate the changes of physicochemical characteristics of Schizandra chinensis during postharvest ripening for 8 days at various temperatures. The juice yield of S. chinensis, which was 55.7% before postharvest ripening, was unchanged $(55.3{\pm}0.6-56.3{\pm}0.6%)$ at $4^{\circ}C$ storage, but was decreased at the level of 6 and 7% at $25^{\circ}C$ and room temperature (RT), respectively. During storage at $25^{\circ}C$ and RT, the titratable acidities of S. chinensis were the highest at $7.49{\pm}0.03$ and $7.20{\pm}0.03%$ after 6 days of postharvest ripening, respectively. During storage at $25^{\circ}C$ and RT, the soluble solid content of S. chinensis was increased from $8.2{\pm}0.1%$ at initial stage to a peak of $12.2{\pm}0.15%$ at 6-day storage, after which it decreased. L values (lightness) of S. chinensis were increased in all treatments during storage, and a values (redness) of $25^{\circ}C$ and RT treatments were increased from 5.04 initially to 6.77 and 7.65 at 8-day storage, respectively. The major free sugars of S. chinensis were fructose (0.55%), glucose (0.56%), and sucrose (0.50%). During storage at $25^{\circ}C$ and RT, the fructose and glucose contents were continually increased with increasing storage period, while the sucrose contents decreased after 6-day storage. Major non-volatile organic acids of S. chinensis were succinic (1.21%), citric (0.17%), and malic (0.07%) acids. Changes in the organic acids contents of S. chinensis at various temperatures showed a similar tendency to that of the free sugars. We estimated that the best conditions for the postharvest ripening of S. chinensis were 8 days at $4^{\circ}C$ storage, and 6 days at $25^{\circ}C$ and RT.

• Korean Journal of Food Science and Technology
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• v.42 no.5
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• pp.613-619
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• 2010

Three varieties of taro flours (Altoran, Josaengjong, and Jaeraejong) were analyzed to evaluate their nutrient composition and physicochemical properties. Moisture contents of the three taro cultivars varied from 5.74-10.30%. Among the three cultivars, Altoran flour had higher protein and fat contents than other cultivars. There were 17 kinds of amino acids in the three taro flours. The major fatty acids in the three taro flours were linoleic acid (46.5-51.4%), palmitic acid (21.7-25.8%), and oleic acid (12.3-18.7%), and two thirds of the total fatty acids were unsaturated fatty acids. Potassium, phosphorus, magnesium, and calcium were the most plentiful minerals in the three taro flours, and the free sugars were glucose, fructose, and sucrose. The total dietary fiber contents of the three taro flours ranged from 12.97 to 17.60%. From these results, Altoran contained a high level of dietary fiber, minerals, essential amino acids, and free sugars. Jaeraejong showed the highest water absorption index. The water soluble index of Altoran was higher than that of the other cultivars. From the differential scanning calorimeter results, the gelatinization temperatures of the three taro flours were $84.98-89.91^{\circ}C$. The pasting temperature of the three taro flours was from 46.77 to $49.30^{\circ}C$ by rapid visco-analyzer. Among these varieties, Josaengjong had the highest peak viscosity and final viscosity, whereas Altoran had the lowest. These taro cultivars are expected to be potential material for application in taro processed foods, due to their gelatination and pasting properties.