• Title/Summary/Keyword: reducing sugars

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Physicochemical Properties and Nutritional Components of Fermented Black Jujube (발효 흑대추의 이화학적 특성 및 영양성분)

  • Hong, Ju-Yeon;Nam, Hak-Sik;Yoon, Kyung-Young;Shin, Seung-Ryeul
    • 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.

Biochemical Characteristics of Apple Rot Caused by Macrophoma sp. (I) -Disease Development, Carbohydrate and Amino Acid Contents in Infected Fruits- (Macrophoma sp.에 의(依)한 사과 부패(腐敗)의 생화학적(生化學的) 특성(特性) (I) -병진전(病進展)과 감염(感染)과일의 탄수화물(炭水化物), 아미노산(酸) 함량(含量)-)

  • Hwang, Byung-Kook;Lee, Yong-Se
    • The Korean Journal of Mycology
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    • v.10 no.4
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    • pp.181-185
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    • 1982
  • Immature apple fruits of cultivars Fuji and Miller were completely resistant to Macrophoma sp. until 10 July. When inoculated on 31 July, apples became susceptible to this fungus, irrespective of cultivar. This fungus grew better on Fuji than Miller. Lesion enlargement on apple at $25^{\circ}C$ was remarkably pronounced relative to $20^{\circ}C$. In both cultivars, the amount of total soluble carbohydrates or reducing sugars in apple fruit flesh was gradually increased as apples became mature. The healthy apples of cultivar Fuji had a higher amount of carbohydrates than those of Miller. The infected apples contained more soluble carbohydrates in comparison to the healthy ones. In healthy apples, there were no consistent differences between Fuji and Miller in amount of total soluble amino acids. With increasing age of apples, the amount of soluble amino acids declined in the fruit flesh of both cultivars. Levels of carbohydrates and amino acids in apple fruits were discussed in association with the immature fruit resistance to Macrophoma sp.

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Studies on Yukwa Processing Conditions and Popping Characteristics (유과 제조조건 및 팽화요인에 관한 연구)

  • Shin, Dong-Hwa;Choi, Ung
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.19 no.6
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    • pp.617-624
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    • 1990
  • Proper processing condition of Yukwa(oil popped rice snack) for mass production and pop-ping mechanism of it were tested with Shinsun (waxy, Japonica type rice) which was excellent for Yukwa making. Optimum steaming time of dough was 15 min among 4 to 60 min and reasonable moisture content of the dough before steaming was 4895 among 48 to 53% which had good and fine texture. Acceptable stirring time of steamed dough was not significantly different among 1 to 4 min, but no stirring with much larger volume was shown very poor and too soft in texture. At the simplification test of milling method, wet milling was better then dry milling in expansion rate and high temperature treatment of dough at 6$0^{\circ}C$ gave negative effect on their quality. Extending high temperature treatment of dough, reducing sugars in the dough increased and it might be caused of starch degradation. In addition of some other protein sources to dough, Yukwa quality were in proportion to the protein content of the beans. At the long term storage of the Yukwa base, moisture absorption was different depending upon RH of atmosphere and the quality of Yukwa was inferior by storage time. By addition of some alcoholic beverage, such as Makkoli, Soju and Chungju, expansion rate and their texture were somewhat improved by increasing addition amount of them from 15% to. 30% on dough (w/w).

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Prevention of Swelling and Quality Improvement of Sunchang Traditional Kochujang by Natural Additives (천연첨가물을 이용한 전통고추장의 유통중 팽창억제 및 품질개선)

  • 정도연;송미란;신동화
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.30 no.4
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    • pp.605-610
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    • 2001
  • To suppress the gas forming caused by some yeast in the pack of traditional kochujang prepared at Sunchang area, which is the most severe problem during distribution of commercial products, mustard or horseradish powder as natural preservatives was mixed to the ingredients of kochujang and left for fermentation in clay pot as commercial scale for 180 day. The composition changes including quality and gas formaing in the kochujang containing those additives were monitored physicochemically and organoleptically. The fermented kochujang containing those additives were monitored physicohemically and organoleptically. The fermented kochujang containing 0.6% of horseradish showed lower organic acid content than that of the control but amino type nitrogen content, which is one of the important quality reference of kochujang, was higher in the one containing 0.6% natural preservatives. No color changed in the kochujang containing mustard but L and a value were increased in the kochujang containing horseradish. No difference of free reducing sugars was showed by the addition of those natural preservatives and the addition of 0.6% horseradish to kochujang had completely stopped gas forming during fermentation. The overall quality of the kochujang containing 0.6% horseradish was superior than that of the other treatments.

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Characteristics of Sweet Persimmon Treated with Protopectinase from Bacillus subtilis EK11 (Bacillus subtilis EK11 유래 Protopectinase를 처리한 단감의 특성)

  • 이대희;이승철;황용일
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.32 no.1
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    • pp.29-34
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    • 2003
  • In development of the processed food, it is important not only to make the food delicious but to enhance its storage span and thermal stability without change in color, which greatly affects the tastes. Protopectinase (PPase) from Bacillus subtilis EK11 hydrolyses or dissolves protopectin in the middle lamella of plant tissues with the resultant separation of plant cells from each other, called enzymatic maceration. With the PPase, persimmon was enzymatically macerated to separate cells to primary cell wall without damage. Recovery rates of persimmon treated with PPase and mechanical maceration were 95% and 85%, respectively. Total and reducing sugars, crude protein and fat in the enzymatic maceration were well preserved as in the mechanical maceration. Importantly, over 50% of vitamin C, which is the most unstable component during the mechanical maceration, remained with an intact form for one day after the enzymatic treatment. When the suspensions of persimmon macerated with both treatments were stored at 4$^{\circ}C$ for 9 days, the mechanically macerated persimmon suspension was decolorized, whereas decolorization, was not found in the enzymatically macerated persimmon suspension. Moreover the mechanically macerated persimmon was greatly deteriorated after heat treatment at 10$0^{\circ}C$ for 60 min, whereas cells of the enzymatically separated persimmon suspension appeared to be stable, indicating increased thermal stability Thus, the PPase treatment of persimmon could be a better choice for preparation of highly valuable and functional processed food as well as for increase in preservation period.

Effect of Gamma Irradiation on the Sterilization of Red Pepper Powder (고추가루의 살균(殺菌)을 위한 ${\gamma}$-선(線) 조사효과)

  • Kwon, Joong-Ho;Byun, Myung-Woo;Cho, Han-Ok
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.13 no.2
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    • pp.188-192
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    • 1984
  • In order to investigate the hygienic status of commercial red pepper powder, one sample was directly prepared from raw red pepper which was purchased at market and the other one was a commercial red pepper powder. They were used for the investigation upon the status of microbial contamination, effect of irradiation for sterilization and physicochemical changes during 3 months of storage. Total bacterial counts of commercial red pepper powders were 3.83 to $6.68{\times}10^6$ per gram and coliform group was shown to be positive in some products. Total bacteria and coliform group were sterilized by the irradiation of 9 kGy and 3 kGy, respectively and no microorganisms were grown up until 3 months of storage at room temperature. The $D_{10}$ values of total viable bacteria in red pepper powders were 1.52 to 1.58 kGy. Chemical components such as moisture, total and reducing sugars were slightly decreased during the storage period. The contents of capsanthin and capsaicin were partly affected by the high dose irradiation but the difference between unirradiated and irradiated groups was diminished with the elapse of storage period.

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The Comparison of Food Constituent in Different Parts of Pumpkin (늙은 호박의 부위별 성분 비교)

  • Jang, Sang-Moon;Park, Nan-Young;Lee, Joo-Baek;Ahn, Hong
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.30 no.6
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    • pp.1038-1040
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    • 2001
  • This study was conducted to investigate the constituents of pumpkin, to develop of health food using pumpkin. Crude protein contents of skin (19.82%) and fiber (16.43%) were higher than that of flesh. Crude lipids contents of skin (2.84% ) was higher than those of flesh and fiber. Major free sugars in pumpkin were sucrose, fructose and glucose. Total sugar contents in the flesh was higher than that of fiber. This tendency was opposite to reducing sugar contents. Also, free sugar contents in pumpkin were flesh (30.19 mg/100 g), fiber (22.99 mg/100 g) and skin (15.67 mg/100 g), respectively. The total Phenol and carotenoid contents in 100 g of fiber revealed 379.8$\pm$9.76 mg and 43.71$\pm$1.46 mg, corresponding to 47% and 62% of the total phenol and carotenoid contents of pumpkin. Total flavonoid content in 100 g of skin revealed 81.5$\pm$3.56 mg.

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Analysis on the Components of the Elaeagnus multiflora Thunb. Leaves (뜰보리수 잎의 유용성분 분석)

  • Yoon, Kyung-Young;Hong, Ju-Yeon;Shin, Seung-Ryeul
    • Food Science and Preservation
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    • v.14 no.6
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    • pp.639-644
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    • 2007
  • This study analyzed components of the leaves of Elaeagnus multiflora as part of studies on the nutritional and functional materials of fruits and leaves of this plant. The moisture content of the leaves was 71.6% and the carbohydrate, crude protein, lipid and ash contents were 24.1, 1.4, 0.4 and 2.5%, respectively. Concentrations of reducing sugars, soluble proteins and polyphenols were 460.0, 503.3 and 805.6 mg/100 g, respectively. Fructose was the dominant free sugar, and arabinose, maltose, glucose, and a small amount of trehalose were also detected. Malic acid was the main organic acid in E. multiflora leaves, and acetic acid, citric acid, lactic acid, and succinic acid were also present. E. multiflora leaves were high in K, Ca and Mg. Of hydrolyzed amino acids, alanine was present at the highest concentration (112.0 mg/100 g), with threonine, leucine, valine and phenylalanine being the next most common. Glutamic acid and ornithine were the dominant free amino acid and amino acid derivative, respectively.

Changes in Chemical Components of Red Ginseng Processed from the Fresh Ginseng Stored at Low Temperature (저온저장 후 제조한 홍삼의 성분변화)

  • 장진규;박채규;심기환
    • Food Science and Preservation
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    • v.10 no.2
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    • pp.158-161
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    • 2003
  • The six-year old fresh ginseng harvested at earlier October was stored for 10 weeks in the rendition of 4$^{\circ}C$${\pm}$1$^{\circ}C$ and RH 87∼92%, and the sugar content and the change of color was investigated in an interval of one week by taking sample of it after processed it to red ginseng. The total sugar content was 62.71% before it was stored and was a little reduced to 54.58% after 10 weeks of storage. The reducing sugar content was 11.69% before it was stored and was a little reduced to 9.92% after 7 weeks of storage. For the free sugars, the content of fructose was 0.47% before storage and gradually increased to 4.70% after 10 weeks of storage, and the contents of glucose and sucrose were gradually decreased after they have their peak value of 2.31% and 25.89% at five and three weeks of storage. The content of maltose was 6.62% before storage and it gradually reduced to 1.37% after 10 weeks of storage. The color intensity was generally increased with the storage time, and the total rotor value(ΔE) has its peak value of 8.89 after 9 weeks of storage. For the browning pigment, the absorbance of 420nm and 440nm was increased after 6 weeks of storage. The similar trend was observed at 285nm where the precursor of browning pigment was investigated, however, the change was not observed for the freeze dryed ginseng.

Quality Comparison of Commercial Cider Vinegars by Their Acidity Levels (시판 사과식초의 산도에 따른 품질특성 비교)

  • Jo, Deokjo;Park, Eun-Joo;Kim, Gui-Ran;Yeo, Soo-Hwan;Jeong, Yong-Jin;Kwon, Joong-Ho
    • Korean Journal of Food Science and Technology
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    • v.44 no.6
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    • pp.699-703
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    • 2012
  • The quality of commercial cider vinegars was compared according to their acidity levels (low, general, double strength and triple strength). The pH, reducing sugar content and brown color intensity decreased, while the total acidity increased with the increasing acidity levels, which may be resulted from difference in formulation and manufacturing procedures. The free sugars were mainly composed of fructose and glucose, which were the highest in low acidity vinegar, followed by double strength, general, and triple strength acidity vinegars. Acetic acids and malic acids were identified as the major organic acids. The citric acid concentration was the highest in triple strength vinegars. The contents of total phenolics and flavonoids were the highest in low acidity vinegars, which indicated their dependence on the apple juice content. DPPH and ABTS radical scavenging abilities were the highest in low acidity vinegars, that showed high amounts of antioxidants.