• Title/Summary/Keyword: total titratable acidity

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A Comparative Study on the Manufacturing Processes of Red Wine (포도주(葡萄酒) 제조방법(製造方法)에 관(關)한 비교연구(比較硏究))

  • Byun, Sang-Sook
    • Journal of Nutrition and Health
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    • v.13 no.3
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    • pp.139-144
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    • 1980
  • A study was conducted to examine the physical and chemical changes of wines fermented from three different varieties by three different methods. The products were evaluated by twenty subjects on color, aroma, and taste. The results were as follows; 1) The moisture contents of those varieties were ranged from 90. 70 to 90.82% The Brix sugar and sugar contents were in order of Muscat Bailey A>Alden>Cambell Early. The titratable acidity was higher in Muscat Bailey A and Alden than in Cambell Early while PH of Cambell Early was higher than those of the two others. 2) The specific gravities of the products were slightly decreased as the fermentation progressed. 3) The yeast-fermentation showed the higher degree of alcoholic contents compared to the natural fermentations. of the natural fermentations, the washed-natural fermentation resulted in the lower alcoholic contents than unwashed one. 4) The PH's were also higher in the yeast-fermentation products than in the natural fermentation groups. The difference, however, was smaller as the fermentation progressed further. 5) The total ester coutents of the yeast fermentation group were slightly higher at the beginning of the fermentation than those of the natural fermentation products and the contents were increased during the fermentation in overall. 6) Twenty panel mentors judged the ripe wine products and the order of preference was Alden>Muscat Baliey A>Cabell Early. They preferred the yeast-fermentation wine to the natural fermentation products.

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Preparation of Soymilk Yogurt and the Related Studies (고형 두유 요구르트의 제조에 관한 연구)

  • Oh, Hea-Sook;Lee, Kyung-Hea;Yoon, Sun
    • Journal of Nutrition and Health
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    • v.14 no.4
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    • pp.175-181
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    • 1981
  • This study was carried out to investigate the feasibility of production of soy yogurt, which is inexpensive and high protein product with an acceptable flavor, from soy milk using lactic acid bacteria. Utilization of various carbohydrates by Lactobacillus acidophilus, Streptococcus thermophilus and Lactobacillus bulgaricus was stuied. Sucrose, the major carbohydrate in soymilk, was fermented by L. acidophilus and S. thermophilus. None of the testing microorganisms was able to ferment melibiose and raffinose. Growth of lactic acid bacteria in soymilk was examined every 4 hour. L. acidophilus exhibited the highest growth rate during the early stage. After 16 hours of incubation, however, all the cultures with the exception of L. bulgaricus grew at nearly equal rates. Microscopic examination of mixed cultures showed that the presence of S. thermophilus was much more pronounced than that of L. bulgaricus. All the cultures with the exception of L. bulgaricus formed acid rapidly during 16 hours of incubation, bringing the titratable acidity to 0.6% and pH to 4.3, which was sufficient to cause coagulation of soymilk. L. bulgaricus produced acid to a much lesser extent and caused coagulation of soymitk after 30 hours at earliest. Three kinds of yogurts were prepared from 100% soymilk, 100% milk and 50% soy-50% milk combination by S. thermophilus and were evaluated by taste panel. Soy yogurt received a significantly lower mean odor score than milk yogurt. Soy yogurt had custardlike texture, while milk yogurt was syrupy. However the scores for texture as well as those for color and flavor did not differ significantly among the treatment. The mean total scores for yogurts were not significantly different and were equivalent to ratings between good and high fair.

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Antioxidant activities and physicochemical properties of chocolate fermented by Lactobacillus plantarum CK10 (Lactobacillus plantarum CK10을 이용한 초콜릿 발효 산물의 항산화 활성 및 성분 분석)

  • Kang, Hye Rim;Koh, So Yae;Ryu, Ji-yeon;Osman, Ahmed;Lee, Chang Kyu;Lim, Ji Hee;Kim, Hyeon A;Im, Geun Hyung;Cho, Somi Kim
    • Food Science and Preservation
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    • v.23 no.4
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    • pp.576-584
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    • 2016
  • In this study, antioxidant activities and physicochemical properties of chocolate fermented with Lactobacillus plantarum CK10 were investigated. The pH level decreased from $5.26{\pm}0.02$ to $3.98{\pm}0.06$ during fermentation while titratable acidity increased from $5.36{\pm}0.19$ to $13.31{\pm}0.34$. The total polyphenol and flavonoid contents slightly increased during fermentation, but it was numerically negligible. Slight increase and decrease in the radical scavenging activities of chocolate, against DPPH-, ABTS-, and alkyl-radical, were observed during 32 hr of fermentation, but the changes were not statistically relevant. Composition ratios (% area by GC analysis) of lactic acid, xanthosine, and theobromine increased with fermentation time while hydroxymethylfurfural (HMF) and caffeine decreased after 32 hr of fermentation, in the order of xanthine (22.7%), theobrome (20.0%), lactic acid (14.9%), HMF (9.1%) and caffeine (9.0%). However, there was no remarkable changes in theobromine and caffeine contents in chocolate during fermentation.

Characteristics of Domestic and Imported Red Wines (국산 및 수입 적포도주의 품질특성)

  • Chang, Eun-Ha;Jeong, Seok-Tae;Park, Kyo-Sun;Yun, Hae-Keun;Roh, Jeong-Ho;Jang, Han-Ik;Choi, Jong-Uck
    • Food Science and Preservation
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    • v.15 no.2
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    • pp.203-208
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    • 2008
  • This study was conducted to evaluate quality of domestic wines, with a long-tenn goal of improving their quality. We compared the characteristics of 19 domestic and imported red wines. The titratable acidity of imported wines ranged from 0.5-0.6% and that of domestic wines ranged from 0.4-0.8%. The sugar content of domestic wines ranged from 4-10% whereas all imported wines had a sugar content below 1.0%. Red color value and tannin contents were generally high in imported wines and some domestic wines had similar tannin levels. For ratio of total sulfite contents below 10 mg/L, domestic wines were higher with 36.8% than imported wines with 5%. Volatile acid contents were higher in domestic wines than in imported wines, which may be due to contamination of domestic wines by acetic acid bacteria.

Effect of Temperature on Changes of Maesil (Prunus mume) Liqueur During Leaching and Ripening (침출온도가 매실리큐르의 품질 변화에 미치는 영향)

  • Chae, Myeung-Hee;Park, La-Young;Lee, Shin-Ho
    • Food Science and Preservation
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    • v.15 no.2
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    • pp.311-316
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    • 2008
  • We studied changes in a high-proof maesil liqueur during a 5 month leaching and ripening period at $10^{\circ}C,\;20^{\circ}C$, and $30^{\circ}C$. Titratable acidity increased after 2 months at all temperatures, but pH only changed after 2 months at $30^{\circ}C$. The absorbance at 420 nm increased significantly during a high temperature leaching and ripening period. The alcohol concentration was similar for maesil liqueurs held at $10^{\circ}C$ and $20^{\circ}C$ for 2 months. The levels of reducing sugars and polyphenols were also higher for liqueurs stored at higher temperatures. The major free sugars present after one month (in order of decreasing concentration) were fructose, glucose, sucrose, and maltose. The major organic acids were citric, lactic, malic, succinic and acetic acid The total organic acid content of maesil liqueur decreased after 1 month at $10^{\circ}C$ but increased until 2 months at $20^{\circ}C$ and $30^{\circ}C$.

Changes in Fruit Quality of Hallabong Tangor (Citrus kiyomi ${\times}$ ponkan) by Film Packaging during Storage (포장재 처리에 따른 한라봉 감귤의 저장 중 품질변화)

  • Lee, Sang-Hyup;Kim, Jong-Hyun;Jeong, Hee-Chan;Koh, Jeong-Sam
    • Food Science and Preservation
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    • v.15 no.2
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    • pp.185-190
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    • 2008
  • We investigated changes in fruit quality of Hallabong tangor (Citrus Kiyomi ${\times}$ ponkan) that was packaged with Si+CaO and LDPE film. The flesh ratio during storage was 74.33% (${\pm}3.66$) to 81.56% (${\pm}1.38$). Firmness of M16A, a variant of Hallabong tangor, was higher 100g-force than that of Hallabong tangor, changes of firmness was not shown among film packages. A fruit juice was $12-14^{\circ}$Brix, and this increased somewhat at the end of storage without film packaging. The titratable acidity of the M16A variety was 0.2% lower than that of the Hallabong tangor. Hallabong and M16A maintained freshness and taste for 120 and 60 days, respectively. The level of reducing sugars in the Hallabong tangor was 1% higher than that of the M16A variety. Reducing sugars increased at room temperature storage without film packaging. Total sugar content was 9.19% (${\pm}2.03$) to 12.78% (${\pm}0.75$). The content of vitamin C declined slowly after 105 days of storage. In conclusion, storage of Hallabong tangor with film packaging coated with Si+CaO was effective for maintaining freshness and quality.

Characteristics of Alcohol Fermentation in Citrus Hydrolysates through Narirutin Addition (Narirutin첨가에 따른 감귤가수분해물의 알코올 발효 특성)

  • Sung, Na-Hye;Jo, Yong-Jun;Park, Chan-Woo;Woo, Seung-Mi;Jang, Se-Young;Choi, In-Wook;Jeong, Yong-Jin
    • Food Science and Preservation
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    • v.19 no.1
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    • pp.153-158
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    • 2012
  • The characteristics of the narirutin-added alcohol fermentation of citrus hydrolysates were investigated to produce functionally improved citrus wine. The pH of narirutin-added citrus wine ranged from 3.38 to 3.51, and the titratable acidity was about 0.55% which show no significant differences attributable to the narirutin quantity. With regard to the color and brown color, with the addition of more narirutin, the a value was decreased while the b value and brown color increased. The sugar content decreased from 24 to 8.0-8.5 $^{\circ}Brix$ after alcohol fermentation, and the alcohol content appeared to be between 14.5 and 14.6% in all the sections. For the free sugar contents, the glucose and fructose contents were relatively high in every section. For the total polyphenol content, it was shown to increase when more narirutin was added. and the 2%-narirutin-added section showed the highest polyphenol content(46.44 mg%). The results of sensory evaluation were that the color, flavor and bitterness increased while the sweetness and overall acceptability were reduced by the additional narirutin. Functionally improved citrus wine can be produced by using narirutin, but more researches regarding quality improvement should be carried out to overcome the bitterness.

Fermentation and Quality Characteristics of Kimchi Prepared Using Various Types of Maesil(Prumus mume Sieb. et Zucc) (매실의 첨가 형태에 따른 배추김치의 발효 및 품질 특성)

  • Kim, Gyu-Ran;Park, La-Young;Lee, Shin-Ho
    • Food Science and Preservation
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    • v.17 no.2
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    • pp.214-222
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    • 2010
  • The fermentation and quality characteristics of kimchi prepared using various types of maesil, including freshly sliced maesil (FSM), freshly ground maesil (FGM),and dried maesil powder (MP), were investigated during 25-day fermentation at 10C. The pH value decreased rapidly in the control fermentation but only slowly in maesil-supplemented kimchi. Titratable acidity values changed in the same manner. The addition of maesil significantly inhibited the growth of total aerobes, and lactic acid bacteria during fermentation over 10 days. The color (L, a, and b values) of kimchi did not differ between control and maesil-supplemented kimchi samples regardless of maesil type or concentration. Kimchi hardness did not initially differ among the various samples but decreased during fermentation. However, the hardness of maesil-supplemented kimchi was higher than that of control samples. Thus, kimchi supplemented with either 6% (w/w) MP or 6% (w/w) FGM maintained optimal hardness during fermentation. The antioxidant activity of kimchi was increased in a dose-dependent manner by addition of maesil. Kimchi supplemented with 6% (w/w) FGM showed the highest antioxidant activity. The sensory qualities (taste, flavor, color, and overall acceptability) of FSM-supplemented kimchi were better than those of control samples.

Effects on the Quality Characteristics of Mul-kimchi with Omija (Schizandra chinensis Baillon) Water Extract (오미자 물 추출물을 이용한 물김치의 품질특성)

  • Jeong, Tae-Seong;Jeong, Eun-Ju;Lee, Shin-Ho
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.37 no.10
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    • pp.1301-1306
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    • 2008
  • The physiological and microbiological characteristics of various mul-kimchis prepared with omija (Schiznadra chinensis) water extract (1, 2, 3 v/w%) (omija mul-kimchi ) or water (control) were investigated during fermentation for 21 days at $10^{\circ}C$. The pH of omija mul-kimchi was lower than that of control and lowered with increasing the concentration of omija between 1% and 3%. The pH did not change significantly during fermentation in omija mul-kimchi compared with control. The changes in titratable acidity were similar in pH. The change of total microbs and lactic bacteria during fermentation was similar in various mul-kimchis and the viable cell numbers in omija mul-kimchi were lower than in control. The viable cell of mul-kimchi decreased with increasing the concentration of omija water extract. The texture of various mul-kimchi such as hardness, cohesiveness, chewiness and springiness, was decreased but the texture of 1% omija mul-kimchi was maintained significantly higher than that of control during fermentation. The DPPH radical and nitrite scavenging activity of omija mul-kimchi were higher than those of control and the activities increased with increasing concentrations of omija water extract. The sensory quality of 1% omija mul-kimchi showed the highest value in taste and overall acceptability among the tested mul-kimchis.

Quality and Consumer Perception of White Bread Baked with Hallabong Powder (한라봉 분말을 첨가한 식빵의 제빵 특성과 소비자 검사)

  • Bing, Dong-Joo;Chun, Soon-Sil
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.42 no.2
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    • pp.306-312
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    • 2013
  • The purpose of this study was to evaluate the physicochemical and sensory characteristics of white bread and added 2%, 4%, 6%, or 8% Hallabong powder. Dough pH of the control group was 5.65, and it decreased as increasing amounts of Hallabong powder were added. Also, total titratable acidity of dough significantly increased with increases in Hallabong powder. The fermentation power and dough expansion significantly increased with increasing incubation time; the control was highest at 98.67%. White bread pH, specific volume, and baking loss decreased significantly as with increased Hallabong powder content. The bread moisture content was not significantly different between samples, differing only from 40.61~41.83%. Water activity was 0.960 Aw in the 6% Hallabong powder mixture, which was the highest in samples. In color, lightness of crust significantly decreased with increased Hallabong powder content, whereas redness showed the reverse effect. Lightness of crumbs significantly decreased, with increased Hallabong powder content, whereas redness and yellowness showed the reverse effect. In texture, hardness and fracturability significantly increased, while resilience showed the reverse effect. In the sensory evaluation, citrus flavor, bitterness, astringency, and off-flavor significantly increased with increased Hallabong powder content, and the control sample showed the highest score in color, flavor, softness and overall acceptability. The 2% and 4% samples showed more than average scores. Based on these results, Hallabong powder could be considered a functional material. The optimum amount of Hallabong powder to add for baking bread would be 2~4%.