• Title/Summary/Keyword: Titratable Acidity

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Development of Korean Red Wines Using Various Grape Varieties and Preference Measurement (포도 품종을 달리한 한국산 포도주의 제조 및 기호도 분석)

  • Lee, Seung-Joo;Lee, Jang-Eun;Kim, Sung-Soo
    • Korean Journal of Food Science and Technology
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    • v.36 no.6
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    • pp.911-918
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    • 2004
  • Three dry red, four sweet red, and two white wines were prepared with domestic grape varieties: Gerbong (G), Campbell Early (C), Muscat Bailey A (M), Seredan (Sd), Seibel (Sb), and Neo-muscat (N). Sample wines were analyzed for titratable acidity, ethanol, pH, sugar content, color intensity and hue, and total phenolic content. Preferences of color, aroma, and overall acceptability were determined by 97 panelists using 9-point hedonic scale. Sweetness, sourness, astringency levels of developed wines were evaluated using 9-point just-about-right (JAR) scale. Mean overall acceptability score of C (6.49) was highest among dry red wines (p<0.05). Among sweet red wines, mean overall acceptability score of Sd (3.27) was significantly lower than those of other wines (p<0.05). In white wines, overall acceptability score of Sb (5.20) was slightly higher than that of N (4.92). Overall sourness levels in dry red wines were higher than optimum level. Based on the results, should be lowered, and sweetness and sourness levels of white wines need to be adjusted sweetness levels of C, G, and Sd for the production of sweer redwines. C and M varieties were considered to be suitable for Korean red wine production.

Quality Characteristics of Tofu Added with Basil Water Extracts (바질 물추출물을 첨가한 두부의 품질특성)

  • 임정교;박인경;김순동
    • Korean journal of food and cookery science
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    • v.20 no.2
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    • pp.144-150
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    • 2004
  • This study was conducted to investigate the quality characteristics and shelf-life of tofu added with basil water extract (BWE). BWE was selected from 11 kinds of herbs based on estimations of antimicrobial activity, taste and flavor. The amount of waster was 7 times greater than that of raw soybean, BWE concentration against soybean juice was 20 mg% and GDL concentration was 0.3% as the optimal preparation conditions of tofu added with BWE (BWE-tofu). Color L*, a* and b* values of BWE-tofu were 78.11, 0.78 and 19.10, respectively, indicating that light green color was lower in the L* value, and higher in the at and b* values compared to control products. Savory taste and overall acceptability of the tofu were higher than those of control products evaluated by sensory test. Shelf-life of the tofu at 10$^{\circ}C$ was 8 days, which was prolonged by 4 days compared to control products evaluated by pH, titratable acidity and total microbes.

Changes in Nutritional Composition and Physicochemical Properties of Mustard Leaf (Brassica juncea) Kimchi during Fermentation (갓김치(Brassica juncea) 숙성 중 영양성분 및 이화학적 특성 변화)

  • Jang, Hye-Lim;Park, Seo-Yeon;Lee, Jong-Hun;Hwang, Myung-Jin;Choi, Youngmin;Kim, Haengran;Hwang, Jinbong;Seo, Dongwon;Kim, Sanghee;Nam, Jin-Sik
    • The Korean Journal of Food And Nutrition
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    • v.29 no.5
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    • pp.706-715
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    • 2016
  • Nutritional composition and physicochemical properties changes in mustard leaf kimchi were investigated during fermentation of up to 3 months. The pH decreased, and the titratable acidity gradually increased according to increase of fermentation periods. Fructose and glucose were the major free sugars in mustard leaf kimchi, and their amounts were significantly decreased with fermentation periods (p<0.05). Lactic acid content showed a significant increase with maximum increase at 3 months. All types of kimchi contained 20 amino acids, but the content of most amino acid fluctuated during fermentation. Except for K and Zn, the content of other ingredients including Ca, Fe, Mg, Na, Se were the highest in kimchi fermented for 2 months. The unsaturated fatty acid of mustard leaf kimchi was higher than that of saturated fatty acid, and total fatty acid of kimchi significantly decreased after 2 months (p<0.05). Most vitamin contents showed a tendency to decrease with fermentation, in particular, vitamin B complex except for $B_2$ significantly decreased after 3 months (p<0.05). The results provide fundamental data for determining the appropriate fermentation period to improve the quality of kimchi.

Physicochemical and Sensorial Properties of Probiotic Yogurt as Affected by Additions of Different Types of Hydrocolloid

  • Bahrami, Masoud;Ahmadi, Dariush;Alizadeh, Mohammad;Hosseini, Fakhrisadat
    • Food Science of Animal Resources
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    • v.33 no.3
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    • pp.363-368
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    • 2013
  • The main attributes of yogurt that affect consumer satisfaction are taste, consistency, and a firm texture. This study evaluates the influence of xanthan gum, barley beta-glucan, and guar gum in concentrations of 0.05%, 0.1%, 0.2%, and 0.3% on probiotic yogurt. The set-type yogurt samples were prepared by using raw cow's milk. The statistical analysis showed that none of these gum additions had any marked effect on pH, titratable acidity, total solids content, and probiotic bacteria counts of yogurt samples. Evaluations for syneresis and water-holding capacity (WHC) in the yogurt samples were affected by the type and concentration of the stabilizer. Yogurts treated with 0.1% xanthan gum and 0.3% beta-glucan recorded the highest WHC and the least syneresis. The largest amount of gel firmness was recorded in yogurt samples treated with 0.2% xanthan gum and 0.3% beta-glucan. Yogurt samples treated with 0.1% xanthan gum and 0.3% beta-glucan were considered acceptable by trained panelists and gained the highest scores in sensory evaluations. The correlation coefficient between the amount of syneresis, WHC and stiffness of texture was significant compared to scores for sensory evaluation (p<0.01). Results for effects of guar gum on the tested parameters were contrary to the results expected from a gum. According to this study, the use of xanthan gum and beta-glucan are highly recommended for low-fat yogurt production.

Biochemical, Microbiological, and Sensory Characteristics of Stirred Yogurt Containing Red or Green Pepper (Capsicum annuum cv. Chungyang) Juice

  • Kang, Su-Hyun;Yu, Mi-Sang;Kim, Jeong-Mee;Park, Sung-Kwon;Lee, Chi-Ho;Lee, Hong-Gu;Kim, Soo-Ki
    • Food Science of Animal Resources
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    • v.38 no.3
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    • pp.451-467
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    • 2018
  • Hot pepper has anti-obesity effects by controlling appetite and reducing blood fat level. To reduce the pungency of capsaicin, red or green hot pepper juice was fermented with Bacillus licheniformis SK1230. Fermented hot pepper juice was then added into yogurt at different ratios. The pH of yogurt added with hot pepper juice was decreased from 4.61 to 4.48. Titratable acidity and counts of lactic acid bacteria were increased with increasing amount of pepper juice added. However, the viscosity was decreased significantly compared to the control. On chromaticity test, when more pepper juice was added, $L^*-value$ was decreased whereas $a^*$- and $b^*$- values were increased significantly (p<0.05). The spectrum of antimicrobial activity of yogurt was slightly changed compared to using pepper juice. Total polyphenol contents and antioxidant activity were increased with increasing amount of pepper juice added. Stirred yogurt added with fermented red pepper juice at 3% or green pepper juice at 1% showed high scores in flavor, appearance, texture, and overall acceptance in sensory test. Yogurt added with fermented pepper juice with reduced pungency showed also good palatability during storage at $4^{\circ}C$. Yogurt with added hot pepper juice can be play an important role in functional food relative to anti-obesity.

Effect of Green Tea Extract on Quality of Fermented Pan Bread (빵에 첨가한 녹차가 품질에 미치는 영향)

  • 김정수;박정숙
    • The Korean Journal of Food And Nutrition
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    • v.15 no.1
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    • pp.12-15
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    • 2002
  • Green tea extract(GTE) was added to pall bread, prepared by the straight-dough method, and its effects on shelf-life(moisture, pH, titratable acidity, antimicrobial activity) and sensory quality of pan bread were evaluated. The results of those characteristics for staling indicated that quality of pan bread was significantly extended by addition of GTE. Growth of microorganisms was significantly inhibited by adding GTE to pan bread, and sensory quality on pan bread added GTE was no significant differ in color, flavour, hardness, chewiness and overall-quality than that of control group(0% GTE). These results suggest that the shelf- life of pan bread was extended by GTE.

Effect of Ripening and Peeling Methods on Composition and Quality of Canned Freestone Peaches

  • Chung, J.I.;Luh, B.S.
    • Korean Journal of Food Science and Technology
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    • v.4 no.1
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    • pp.6-12
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    • 1972
  • Fay Elberta freestone peaches were harvested at four maturity levels as judged by skin color and firmness. They were ripened at $68^{\circ}F$ under 80 percent relative humidity for 4, 6, 8 and 10 days respectively prior to canning. Results indicate that both harvest maturity and ripening conditions are important factors influencing quality, flavor and composition of canned freestone peaches. Peaches harvested at $18{\sim}24$ pounds on a Magness-Taylor pressure tester with a 7/16' plunger(M1) failed to ripen satisfactorily. Fruits harvested at $13{\sim}17$ pounds (M2) pressure test ripened successfully at $68^{\circ}F$ within 6 to 8 days; and those harvested at 6 to 12 pounds (M3) needed 4 days for ripening at $68^{\circ}F$. Tree-ripened fruits (M4) were undesirable for canning because of the high percentage of bruised fruits. The optimum firmness for canning appears to be in the range of 1.5 to 3.0 pounds. The titratable acidity of peaches decreased during maturation and ripening. The tannin content of peaches at M1 maturity decreased with ripening at $68^{\circ}F$. But no appreciable change was observed in the M2 and M3 series which were ripened at $68^{\circ}F$ for 4 to 10 days. The volatile reducing substances (V.R.S.) increased as the peaches developed on the tree and also during post-harvest ripening. The effect of harvest maturity and post-harvest ripening on color grade of the canned peaches is presented. Little difference was found in the flavor and composition of peaches peeled by the cup-down lye peeling and the steam-peeling methods. The cup-down lye-peeling method might be most advantageous because of its higher peeling efficiency.

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Effect of Ingredients on the Sensory Characteristics of Dongchimi (부재료가 동치미의 관능특성에 미치는 영향)

  • Lee, Su-Han;Kim, Jung-Hoan
    • Korean Journal of Food Science and Technology
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    • v.41 no.2
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    • pp.162-166
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    • 2009
  • In an effort to determine the effect of ingredients on the sensory characteristics of dongchimi, 10 different samples of dongchimi were prepared in various combinations of 4 ingredients most notably red pepper, garlic, ginger, and green onion and their physicochemical, microbiological, and sensory characteristics were assessed. Each ingredient utilized for the preparation of dongchimi did not affect changes in pH and titratable acidity, but exerted significant effects on sensory scores of overall acceptability, acid odor, salty, and hot taste. In cluster analysis using the 'Ward' method, dongchimi samples were classified into three groups. The first group was the samples prepared with a variety of ingredients including garlic, and the second group included samples prepared with the sole ingredient, except for red pepper. The third group had features similar to those of the sample prepared without other ingredients. It was determined that garlic played a crucial role in the sensory properties of dongchimi, and the addition of various ingredients enhanced hot taste and reduced acid odor, sourness, moldy odor, and carbonated taste by their interaction.

Potential of Initial CA Condition on Quality Maintenance of 'Fuji' Apples during Export Simulation after Long-term Storage

  • Park, Youn-Moon;Park, Hyo-Geun
    • Horticultural Science & Technology
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    • v.30 no.4
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    • pp.400-408
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    • 2012
  • Effects of initial controlled atmosphere (CA) treatment on quality maintenance of 'Fuji' apples were assessed and compared with 1-methylcyclopropene (1-MCP) treatment and continuous CA storage. Apples were harvested twice at different maturity, treated with 1 ${\mu}L{\cdot}L^{-1}$ 1-MCP and then stored for 8 months at $0^{\circ}C$ under 3 conditions: air, CA for the first month followed by air (initial CA), and continuous CA (full CA). CA storage was performed with 1.5 kPa $O_2$ and < 1.0 kPa ($N_2$ balance). Following long-term storage, export simulation, refrigerated shipment and local distribution, were performed by holding apples at $0^{\circ}C$ for 2 weeks and on the shelf at $20^{\circ}C$ for 7 days. Both the application of 1-MCP and CA storage reduced ethylene production and respiration rates. Initial CA storage was also effective on reducing the metabolism although the effects were not as noticeable as full CA. Full CA storage with or without 1-MCP treatment maintained titratable acidity, flesh firmness, and sensory quality at the acceptable to excellent level even after the export simulation following 8-month storage regardless of harvest maturity. In contrast, effects of initial CA storage were limited to the maintenance of firmness and texture in early-harvested apples. Overall results indicated that harvest maturity is the critical factor for export fruit quality after long-term storage when separate treatment of initial CA storage or 1-MCP treatment is applied as a postharvest program.

Characteristics of Functional Fermented Milk by Mixed Starters of Lactobacillus bulgaricus and Kluyveromyces marxianus (Lactobacillus bulgaricus와 Kluyveromyces marxianus의 혼합 스타터를 이용한 기능성 발효유의 특성)

  • Yoon Won-Ho;Nam Bo-Ra;Kim Jin-Man;Kim Chang-Han
    • Food Science of Animal Resources
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    • v.26 no.2
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    • pp.252-256
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    • 2006
  • This study was carried out to investigate characteristics of acid and alcohol fermented milk by mixed starters made by Lactobacillus bulgaricus (KCTC 3635) and Kluyveromyces marxianus (KCTC 17212) for 36 hours when the curds were formed. Final pH and titratable acidity were about 4.5 and 0.68%, respectively. The viable cell counts of lactic acid bacteria and yeast for alcohol fermented milk were increased to $3.2{\times}10^9 CFU/mL$ and $5.3{\times}10^9 CFU/mL$, respectively. The ethanol contents increased to 0.35% during fermentation. Antitumor activities of the fermented milk against tumor cell lines, such as HEp-2, HEC-1B, SW-156 and SK-MES-1 showed to 86.6, 70.3, 60.4 and 57.14%, respectively.