• Title/Summary/Keyword: Titratable Acidity

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The Changes of Microflora During the Fermentation of Takju and Yakju (약.탁주 발효과정 중 미생물 균총의 변화)

  • Seo, Mi-Young;Lee, Jong-Kyung;Ahn, Byung-Hak;Cha, Seong-Kwan
    • Korean Journal of Food Science and Technology
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    • v.37 no.1
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    • pp.61-66
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    • 2005
  • Korean traditional rice wine Takju and Yakju were manufactured using 2-step-brewing method. To investigate microflora involved in fermentation step, number of microorganisms, pH, titratable acidity, and alcohol contents of Takju and Yakju were measured. In Takju and Yakju, although not significantly, $1.1{\times}10^{8}$ and $2.0{\times}10^{6}\;CFU/mL$ lactic acid bacteria at initial stage of second fermentation decreased to $8.3{\times}10^{6}\;and\;1.0{\times}10^{4}\;CFU/mL$ at the end of second fermentation, respectively. For Takju, micrococci and yeast occupied 80 and 20% at initial stage of second fermentation, whereas bacteria and yeast occupied 35 and 65% at the end of second fermentation, respectively. Yeast occupied 88% throughout the second fermentation of Yakju. The main yeast isolated from both Takju and Yakju was identified as Saccharomyces cerevisiae using API 20C AUX kit. The yeast strain Candida magnoliae was also detected during fermentation of Takju and Yakju.

Quality Characteristics of Traditional Kochujang Adding Pear Juices during Fermentation (배즙을 첨가한 전통고추장의 숙성과정 중 품질특성)

  • Yoo, Mi-Young;Jung, Kwon-Hyug;Yang, Ji-Young
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.34 no.8
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    • pp.1226-1231
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    • 2005
  • In order to improve qualities of traditional kochujang, pear juice was added to kochujang, and the physicoche-mical and microbial characteristics of pear-added kochujang were investigated for 2 months of fermentation at 30$^{\circ}C$. Moisture contents of pear-added kochujangs increased except of 9$\%$ pear-added kochujang and crude protein contents of them decreased as the fermentation proceeded. Total sugar contents of pear-added kochujangs did not change during the fermentation period, and reducing sugar contents of them increased remarkably from early stage of fermentation. The pH of pear-added kochujangs decreased and titratable acidity of them increased during fermentation. Amino-nitrogen contents of pear-added kochujangs increased remarkable after 45 days of fermentation. Viable cells counts of yeasts in pear-added kochujangs increased to 2.2$\∼$2.9$\times$$10^{3}$CFU/g, and bacterial cell counts were in relatively constant range of 2.1$\∼$2.9$\times$$10^{7}$CFU/g at the late stage of fermentation. Color of pear-added kochujangs had no difference and 'a' value decreased slightly during fermentation. The result of sensory evaluation showed that 6$\%$ pear added kochujang were more acceptable than others.

Effect of Medicinal Herbs' Extracts on the Growth of Lactic acid bacteria isolated from Kimchi and Fermentation of Kimchi (한약재 추출물이 김치 관련 유산균의 성장과 김치의 숙성에 미치는 효과)

  • Lee, Shin-Ho;Choi, Woo-Jeong
    • Korean Journal of Food Science and Technology
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    • v.30 no.3
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    • pp.624-629
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    • 1998
  • This studies were carried out to investigate antimicrobial activity of 35 kinds of medicinal herbs against lactic acid bacteria isolated from home-made Kimchi. The most isolated lactic acid bacteria were inhibited by ethanol extract of various medicinal herbs such as Schizandra chinensis (SC), Salvia miltiorrhiza (SM), Glycyrrhiza uralensis (GU), Lithospermum erythrorhizon (LE) and Sophrora flavescens AITON (SF). But Cnidium monnier, Pinus densiflora, Paeonia suffruticosa, Acanthopanax sessiliflorum and Rhus chinensis inhibited the growth of only a few isolated lactic acid bacteria. The pH of Kimchi containing 1% of medicinal herbs extracts such as SM, GU, LE and SF was higher than that of control during fermentation for 25 days at $10^{\circ}C$, respectively. Titratable acidity and viable cells of total bacteria and lactic acid bacteria of the Kimchi were lower than that of control during fermentation. The sensory quality (taste, flavor and overall acceptability) of SM, GU, and LE added Kimchi was similar to that of control at 10th day of fermentation. But Sophrora flavescens AITON added Kimchi decreased significantly its sensory quality compared with control(P<0.05).

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Physicochemical Characteristics of Bamboo Smoke Distillates Processed by Mechanical Steel Kiln and Traditional Earth Kiln (기계식 탄화로와 재래식 토요를 이용하여 제조한 죽초액의 이화학적 특성: 식품처리제로서의 특성)

  • 이범수;은종방
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.31 no.2
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    • pp.251-256
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    • 2002
  • Fresh bamboo (Phyllostachys bambuoides sieb. et zucc.) was charred at the mechanical steel kiln and traditional earth kiln with subsequent condensation of its smoke to 10$0^{\circ}C$. It was settled down for 12 months to remove tar components and then the middle layer of the liquid was collected as a bamboo smoke distillates to analyze its chemical composition and physicochemical characteristics for use as food additives or processing aids. The gravity, transmittance, reflectivity, and viscosity were 1.008, 89.05%, 1.36%, and 12.48 cp in the bamboo smoke distillates processed by mechanical steel kiln (MBSD) and 1.012, 98.33%, 1.34% and 9.05 cp in the bamboo smoke distillates by traditional earth kiln (TBSD), respectively. The color of TSBD was brighter than that of MBSD. The pH and titratable acidity, tar and remains were 3.55 and 2.830%, 2.803% and 0.671%, respectively, in the MBSD and 2.93 and 3.470%, 0.051% and 0.004%, respectively, in the TBSD. The major phenolic compounds of bamboo smoke distillates (BSD) were phenol, Ο-cresol, p-cresol, and guaiacol and the major organic acids were acetic acid, propionic acid, iso-butyric acid, and n-butyric acid, and major alcohols were methanol, furfuryl alcohol, and maltol. The contents of phenolic compound and alcohol were more in MBSD than in TBSD whereas the content of organic acid was more in TBSD than in MBSD. Therefore, toxic compounds for the human body, such as methanol from BSD should be removed for use as a food ingredient in the future.

Combined Effects of Sanitizer Mixture and Antimicrobial Ice for Improving Microbial Quality of Salted Chinese Cabbage during Low Temperature Storage (저온 저장 중 절임배추의 미생물학적 품질 향상을 위한 혼합 살균제재와 항균성 얼음 병합처리 효과)

  • Choi, Eun Ji;Chung, Young Bae;Han, Ae Ri;Chun, Ho Hyun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.44 no.11
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    • pp.1715-1724
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    • 2015
  • The combined effects of a sanitizer mixture solution and antimicrobial ice on the quality of salted Chinese cabbages were examined. Salted Chinese cabbages were treated with a sanitizer mixture (comprised 50 ppm aqueous $ClO_2$ and 0.5% citric acid), packed in 2% brine and antimicrobial ice, and stored for 12 days at 4 and $10^{\circ}C$. Microbiological data on the salted Chinese cabbages after washing with the sanitizer mixture indicated that the populations of total aerobic bacteria, and yeast and molds decreased by 2.20 and 1.28 log CFU/g after treatment with the sanitizer mixture. In addition, coliforms population of salted Chinese cabbage after 12 days storage at $4^{\circ}C$ in the combined mixture of the sanitizer and antimicrobial ice was 3.22 log CFU/g, which was a significantly different from that of control (5.46 log CFU/g). The combined treatment of sanitizer mixture, antimicrobial ice, and low temperature at $4^{\circ}C$ suppressed reduction of pH and elevation of titratable acidity, resulting in delaying the growth of lactic acid bacteria. Differences in salinity, hardness, and Hunter's $L^*$, $a^*$, and $b^*$ values among treatments were negligible during storage at $4^{\circ}C$. Therefore, this study suggests that a combination of sanitizer mixture, antimicrobial ice treatment, and low temperature storage could improve the microbial safety and quality of salted Chinese cabbages during storage.

Preparation and Quality Characteristics of Makgeolli Made with Black Garlic Extract and Sulgidduk (설기떡을 이용한 흑마늘 막걸리의 제조와 품질 특성)

  • Kim, Gyoung-Min;Jung, Woo-Jae;Shin, Jung-Hye;Kang, Min-Jung;Sung, Nak-Ju
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.40 no.5
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    • pp.759-766
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    • 2011
  • We conducted this study to develop a high value black garlic Makgeolli that was made of black garlic extract (BGE) and Sulgidduk. We investigated the quality characteristics of Makgeolli made with three different combinations of materials (control, Sulgidduk only; A, Sulgidduk combined with 15% BGE and water; B, Sulgidduk combined with 15% BGE instead of water). The pH of A and B were higher than the control, but the titratable acidity of A and B were lower. The sugar and alcohol contents of A and B increased during fermentation. A similar growth pattern was observed invisible cells, yeast, and lactic acid bacteria in all three Makgeolli. In A and B, the quantity of lactic acid bacteria was relatively higher than the yeast. The L value (lightness) was highest in the control, and the a value (redness) and b value (yellowness) were higher in A and B. The antioxidant properties of the three types of Makgeolli were evaluated using DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS (2,2'-azino-bis[3-ethylbenzthiazoline-6-sulfonic acid]) radical scavenging activities. In these assays, B showed significantly higher radical scavenging activities than the other two Makgeolli.

Improvement of Antioxidative Activity by Enzyme Treatment and Lactic Acid Bacteria Cultivation in Black Garlic (효소 처리와 유산균 배양에 의한 흑마늘의 항산화 활성 향상)

  • Chae, Hee-Jeong;Park, Dong-Il;Lee, Sung-Chul;Oh, Chul-Hwan;Oh, Nam-Soon;Kim, Dong-Chung;Won, Sun-Im;In, Man-Jin
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.40 no.5
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    • pp.660-664
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    • 2011
  • We investigated the improvement of the antioxidative activity of black garlic with enzymatic treatment and lactic acid bacteria cultivation conditions. Celluclast, a commercially-available polysaccharide hydrolyase, was selected to obtain high total polyphenol content in a black garlic suspension. A lactic acid bacterial strain showing fast growth and high acid production in a black garlic suspension was isolated from Kimchi. This strain was identified as Lactobacillus pentosus 310-7. Enzymatically hydrolyzed black garlic was fermented using the L. pentosus 310-7 strain at $30^{\circ}C$ for 15 hr. The pH and titratable acidity achieved were 4.24 and 0.35%, respectively, after 15 hr fermentation. The viable cell population of L. pentosus 310-7 slowly increased to 7.54 log CFU/g. The polyphenolic compound content, known antioxidants, in black garlic was enhanced with Celluclast treatment and L. pentosus 310-7 cultivation. Total polyphenolic compounds were increased to approximately 60% of the initial concentration, and electron donating ability was also improved, from 39.8 to 65.9%.

Stability of antibody during heat treatment and storage in immunized milk with Helicobacter pylori antigen (Helicobacter pylori 항원을 이용한 면역우유의 열처리와 저장 중 항체의 안전성)

  • Jeong Eun-Ju;Park La-Young;Bae Man-Jong;Lee Shin-Ho
    • Food Science and Preservation
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    • v.13 no.2
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    • pp.223-227
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    • 2006
  • Optimal heat treatment conditions for maintaining the immune-activity of immunized milk with Helicobacter pylori antigen were studied Total bacterial count of immunized milk with H. pylori antigen decreased according to the increasing heating temperature and time. The viable tell number of immunized milk was $10^3\;CFU/mL$ after heat treatment for 30 min at $60^{\circ}C$, and coliform bacteria did not appear in immunized milk after heat treatment Immune-activity measured in terms of IgG concentration was maintained up to 99.99% after heat treatment for 30min at $60^{\circ}C$, but decreased rapidly below 50% after heat treatment above $70^{\circ}C$. The quality characteristics of immunized milk were examined during storage at $2^{\circ}C,\;4^{\circ}C\;and\;10^{\circ}C$. The pH, titratable acidity and total bacterial count were not changed significantly during 21 day storage at $2^{\circ}C\;and\;4^{\circ}C$, but rapidly changed after 7 day storage at $10^{\circ}C$. The immune-activity was kept well for 14 day storage at $2^{\circ}C,\;4^{\circ}C\;and\;10^{\circ}C$ but decreased rapidly after 14 days at every temperatures tested.

Effects of Edible Coatings on the Quality of Fresh-cut Pears (가식성 코팅처리가 신선절단 배의 품질에 미치는 영향)

  • 최맑음;황태영;손석민;문광덕
    • Food Science and Preservation
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    • v.8 no.1
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    • pp.37-46
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    • 2001
  • To examine the effects of edible coatings on the quality of fresh-cut fruits, Shingo pear was coated with several concentration of albumin, WSF(whole soy flour), dextrin and SPE (sucrose polyester) solution and quality characteristics, sensory evaluation and respiration rate were determined during storage at $4^{\circ}C$ for 10 days. Weight loss rate was reduced in coated fresh-cut pears. 2% dextrin and 1% WSF for pears were more effective in reducing weight loss rate during storage. In preventing the browning of fresh cut fruits, browning was inhibited by coating with 0.5% WSF, 1% albumin, 3% dextrin for pears. Compared with non-coated pears, 0.5% WSF, 1% albumin and 3% dextrin coating were effective in inhibiting the color changes. Even if hardness had a tendency to decrease in coated and no71-coated fruits during storage dextrin coating induced texture softening in fresh-cut pears. The changes in decrease of titratable acidity and vitamin C content and increase of pH and soluble solid were recessed by coatings but there was no differences in accordance with coating materials. Sensory evaluation of coated pears was conducted in according to coating materials and concentrations. Pears coated with 0.5% albumin, 4% dextrin, 1.0% SPE and 0.5% WSF recorded high sensory score. Among the tested coating materials and concentrations, 4% dextrin was the best in all organoleptic quality of coated pears. Respiration rate was repressed by coating with WSF and dextrin in pears.

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The short-term storage characteristics of cut kimchi cabbages treated with Ca2+ (Ca2+처리 절단배추의 소포장 단기 저장 특성)

  • Kim, Sang-Seop;Seong, Gi-Un;Hwang, Hee-Young;Jeong, Moon-Cheol;Chung, Shin-Kyo
    • Food Science and Preservation
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    • v.21 no.2
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    • pp.157-162
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    • 2014
  • To enhance the commercialization of fresh cut kimchi cabbage, the short-term storage effect of cut kimchi cabbage treated with $Ca^{2+}$ was studied. Cut kimchi cabbages ($3{\times}3$ cm) were treated with 2% calcium chloride (Ca), ascorbic acid (As), citric acid (Ct), and calcium chloride and citric acid (Ca/Ct), were put inside LDPE bags, and stored at $5^{\circ}C$ for 6 weeks. The weights reduced about 0.13~0.72%, and the ratio was the lowest in the Ca/Ct treatment. The reduction ratios of soluble soilds were 18.85~35.00%, and were the lowest in the Ca/Ct treatment. The titratable acidity decreased in all the treatments. The L values decreased, but a and b values of Hunter colorimeter increased in all the treatments. The preference for Ca/Ct treatment was the highest among all the treatments in the sensory evaluation. The marketing shelf-life of cut kimchi cabbage can be prolonged by the combination treatment of $Ca^{2+}$ and citric acid.