• Title/Summary/Keyword: Titratable Acidity

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Changes in Chemical Components of Milk during Microwave HTST Pasteurization (마이크로파 고온단시간 살균시 우유의 화학적 성분 변화)

  • Kim, Suk-Shin
    • Korean Journal of Food Science and Technology
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    • v.31 no.6
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    • pp.1518-1522
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    • 1999
  • This work was to determine the quality changes of milk with respect to the chemical components when HTST pasteurized by microwave energy. Raw milk was HTST pasteurized $(at\;72^{\circ}C\;for\;15\;sec)$ by three methods; by heating in a stainless steel tube immersed in a hot water bath (MP0), by heating in a microwave cavity to a desired temperature and then holding in a hot water bath (MP1) and by both heating and holding in a microwave cavity (MP2). There were no significant differences in pH and titratable acidity before and after pasteurization and among the different pasteurization methods. MP1 or MP2 showed better retention or less destruction than MP0 with respect to vitamin A, vitamin $B_1$, ascorbic acid and lysine content. The higher retention of nutrients of the MP1 or MP2 supports the possibility of using microwave energy for the pasteurization of milk and other fluid food products.

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Fermentation Characteristics of Kochujang Prepared with Various Salts (소금의 종류를 달리한 고추장의 발효 특성)

  • Kim, Dong-Han;Yang, Sung-Eun;Rhim, Jong-Whan
    • Korean Journal of Food Science and Technology
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    • v.35 no.4
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    • pp.671-679
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    • 2003
  • Effects of sun-dried, refined, seaweed, and bamboo salts on the quality of kochujang were studied by measuring enzymatic, microbial, and physicochemical characteristics of kochujang during 12 weeks of fermentation. Yeast count was low in the bamboo-salt kochujang, whereas that of aerobic bacteria was low in the seaweed-salt kochujang. Acid protease activity was high in the bamboo-salt kochujang, whereas amylase activity did not show any remarkable difference. Color change was lowest in the bamboo-salt kochujang. Water activities of all kochujangs decreased during fermentation with the lowest shown in the refined-salt kochujang. Consistency of seaweed-salt kochujang was the highest. Total sugar content was higher, whereas ORP was lower in the seaweed- and bamboo-salt kochujangs. Titratable acidity changed slightly in the bamboo-salt kochujang. Reducing sugar content was the lowest, whereas ethanol content was the highest in the refined-salt kochujang. Amino and ammonia nitrogen contents of kochujangs increased up to the middle of fermentation period then decreased with lower changes observed in the sun-dried and refined-salt kochujangs. Results of sensory evaluation indicated that the bamboo-salt kochujang was more acceptable than the sun-dried salt kochujang in taste, color, and overall acceptabilities.

Preparation and Physicochemical Characteristics of Abalone Meat Aged in Kochujang (고추장 숙성 전복의 제조 및 이화학적 특성)

  • Koh, So-Mi;Kim, Hae-Seop;Cho, Young-Chul;Kang, Seong-Gook;Kim, Jeong-Mok
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.38 no.6
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    • pp.773-779
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    • 2009
  • The physicochemical characteristics of abalone meat aged in Kochujang at $20^{\circ}C$ were studied. Moisture contents of Kochujang, which contained raw, roasted, and steamed abalone, increased to 14.9, 10.7, and 7.8%, respectively, compared to control at day 1. The moisture contents of all products were equilibrated at 53.5% approximately after 2 weeks. Hunter's L, a, and b values increased in all products. Total microbial counts were 5.74, 5.70, and 5.83 log CFU/g in the products and increased to 0.28, 0.30, 0.11 log CFU/g, respectively, after 28 days storage at $20^{\circ}C$. After 8 days, the pH in the steamed abalone meat decreased gradually from 5.48 to 5.16 and the titratable acidity was the highest at day 14. Volatile base nitrogens of raw, roast, and steamed abalone were 1.4, 0.9, and 2.7 mg%, but the values in the Kochujang products were 14.0, 13.8, and 11.6 mg% at day 1, and 15.5, 13.3 and 11.3 mg% at day 8, respectively. Quality of the product prepared with steamed abalone was the most acceptable by sensory evaluation.

Changes in the Physicochemical Properties of Tomato Wine by Alcohol Fermentation (토마토 과실주의 알코올발효조건에 따른 이화학적 특성 변화)

  • Kim, Ok-Mi;Jang, Se-Young;Woo, Seung-Mi;Jo, Yong-Jun;Choi, Myung-Sook;Jeong, Yong-Jin
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.39 no.10
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    • pp.1516-1521
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    • 2010
  • This study was conducted to investigate the physicochemical and quality characteristics of alcohol fermentation of tomato. For yeast, Saccharomyces bayanus Lalvin EC-1118 displayed the highest alcohol content (11.8%), whereas titratable acidity and pH did not differ significantly between different yeasts. Alcohol fermentation conducted at higher temperature ($25^{\circ}C$) resulted in higher alcohol content and lower sugar level. The highest alcohol content was produced using 11.4% sucrose and 11.1% fructo-oligosaccharide. These two saccharides were suitable for tomato alcohol fermentation. Lycopene levels were similar regardless of sugar type, and were approximately 4.2 mg%. To improve lycopene content, three types of fruit wine with low-dose lycopene (LDL), medium-dose lycopene (MDL), and high-dose lycopene (HDL) were made. Their alcohol contents were not significantly different (10.0~10.8%). Lycopene contents of LDL, MDL, and HDL wine were 4.25 mg%, 11.40 mg%, and 20.45 mg%, respectively. Therefore, HDL tomato wine should be manufactured.

The Accumulation of Rare Earth Elements Fertilizer and its Subsequent Effects on Apple Fruit Quality at Harvest and During Storage (희토류비료 시비가 사과 과실내 축적과 수확 및 저장 중 사과품질에 미치는 영향)

  • Zheng, Wei-Wei;Park, Mu-Young;Hirst, Peter;Yoon, Tae-Myung;Chun, Ik-Jo
    • Journal of Bio-Environment Control
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    • v.21 no.4
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    • pp.452-458
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    • 2012
  • Rare earth elements fertilizer and Ca were sprayed on eight-year-old 'Fuji'/M.9 apple trees during two consecutive seasons, and fruit quality was quantified at harvest and 5-month long storing in a commercial cooling house at $4^{\circ}C$ and 80~85% RH. In the first season, single-sprayed of rare earth elements fertilizer showed appreciable accumulations of its elements (La, Pr, Gd, and Nd) in the fruit. In the following season, application of higher doses accumulated higher amount, indicating that the accumulation of rare earth elements was dose-dependent. However, rare earth elements did not affect the accumulations of Ca, Mg, and K in 'Fuji' apple fruit showed that there was no interaction between rare earth elements and these macronutrients. Double-spray of 0.2% rare earth elements increased fruit redness at harvest and had exhibited better color. Although at harvest it did not show significant effects on fruit weight, pulp firmness and titratable acidity (TA), but had pronounced effects on inhibiting fruit softness and retarded decrease of TA during storing. Furthermore, it reduced respiration rate and inhibited ethylene production during storing indicated that rare earth elements may be an alternative for prolonging the shelf life of 'Fuji'/M.9 apple fruit.

Multiple Applications of Lime Sulfur for Fruit Thinning of 'Fuji' and 'Hongro' Apple Trees (석회유황합제의 다중처리에 따른 '후지' 및 '홍로' 사과의 적과 효과)

  • Chun, Ik-Jo;Zheng, Wei-Wei;Choi, Cheol;Song, Yang-Yik;Kwang, In-Kye;Hirst, Peter
    • Journal of Bio-Environment Control
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    • v.21 no.4
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    • pp.445-451
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    • 2012
  • The thinning effects of lime sulfur either alone or combined with fish oil on two apple cultivars 'Fuji'/M.9 and 'Hongro'/M.9 were investigated during two consecutive seasons. Either 1% or 2% lime sulfur at full bloom decreased the amounts of both terminal and axillary fruits compared with unsprayed 'Fuji' control trees in the first year. However, 1% or 2% lime sulfur did not decrease terminal fruit set in the second year. Only, triple applications of 1% lime sulfur significantly reduced the number of terminal and axillary fruits in both years. Multiple application of 1% lime sulfur was the most effective in thinning of 'Hongro'. In the first year, double or triple applications of 1% lime sulfur was effective in thinning terminal or axillary fruit, but one time applications of 1% or 2% lime sulfur was not reduced axillary fruit in 'Hongro' apple trees. In the second season, all treatments reduced terminal or axillary fruit in 'Hongro' clusters, except single application of 1% lime sulfur. Fish oil did not always improve the thinning effects of lime sulfur in 'Fuji' or 'Hongro' apple trees. None of treatments caused significant russeting in the harvested fruits. Most of thinning treatments had little effect on 'Fuji' or 'Hongro' fruit quality in terms of fruit weight, firmness, soluble solids concentration or titratable acidity.

The Effect of Mixed Medicinal herb Extracts with Antimicrobial Activity on the Shelf-life of Kimchi (항균활성이 있는 한약재의 복합첨가가 김치 숙성에 미치는 영향)

  • Lee, Shin-Ho;Cho, Ok-Ki;Choi, Woo-Jeong;Kim, Soon-Dong
    • Korean Journal of Food Science and Technology
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    • v.30 no.6
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    • pp.1404-1408
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    • 1998
  • These studies were carried out to investigate the effect of mixed medicinal herbs, such as Curcuma longa and Lithospermum erythrorhozon (CL), Lithospermum erythrorhozon and Sophrora flavescens AITON (LS), Sophrora flavescens AITON and Glycyrrhiza uralensis (SG), and Glycyrrhiza uralensis and Schizandra chinensis (GS) on shelf-life of kimchi. The pH of kimchi containg 1% of medicinal herb extracts such as CL, LS, SG and GS was higher than that of control during fermentation for 25 days at $10^{\circ}C$ Titratable acidity, viable cells count of total bacteria and lactic acid bacteria in the kimchi were changed more slowly than in control. Shelf-life of kimchi was extended by addition of 1% mixed medicinal extracts such as CL, LS, SG and GS (1:1), respectively. The sensory quality (taste, flavor, crispness and overall acceptability) of CL, LS, SG and GS added kimchi was similar to that of control at 10 days of fermentation. But the sourness of LS, SG and GS (1%) added kimchi was more slowly developed than control after 15 days of fermentation, respectively. The effect of LS, SG and GS mixture on shelf-life in kimchi was significant. But the medicinal herb extracts added kimchi decreased its sensory quality with increasing concentration of the extracts.

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Comparison of Quality of ESL and non-ESL Milk Depending upon Sensory Evaluation (관능검사를 통한 ESL(Extended Shelf Life)우유와 non-ESL우유의 품질 비교)

  • Han, Mi-Yeong;Jung, Byeong-Mun;Kim, Eung-Ryul;Kim, Wan-Sik;Jung, Hu-Gil;Chun, Ho-Nam;Yeo, Gyeong-Eun
    • Journal of Dairy Science and Biotechnology
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    • v.21 no.2
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    • pp.81-87
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    • 2003
  • This study was conducted to correlate the quality depending upon sensory evaluation of ESL(extended shelf life) and non-ESL milk during the shelf life. The most important quality assurance is sensory evaluation for dairy products. ESL and non-ESL milk were stored at $5^{\circ}C$ and $10^{\circ}C$ for 14 days. In order to compare physicochemical and sensory properties, pH, TA(titratable acidity), protein, fat, lactose, FFA(free fatty acid), and other organoleptic characteristics were measured. The results showed that physicochemical properties were not significantly changed during storage. On the other hand, the freshness was affected by storage conditions. The most freshness depending upon sensory evaluation was monitored at 5 days storage. Descriptive and acceptability analysis showed that more acceptable milk was ESL milk than non-ESL milk because of off-flavor and after taste of non-ESL milk. According to these results, it was shown that the freshness of milk products depends on sensory. And ESL milk was fresher than non-ESL milk after storage.

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Effect of Soil Sulfur treatment on Apple Valsa Canker (유황토분 처리가 사과 부란병에 미치는 영향)

  • Chun, Ik-Jo;Park, Seung-Min
    • Korean Journal of Organic Agriculture
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    • v.25 no.1
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    • pp.125-134
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    • 2017
  • This study was carried out to examine the effects of soil sulfur mixture on the control apple valsa canker in apple orchard for two years. In organic apple orchard, The recovery percentages of apple valsa canker were compared among control (no treatment), lime sulfur, and soil sulfur in organic orchards. In conventional apple orchards, those of recovery percentages were compared among control, neoasozin, lime sulfur, and soil sulfur. Compared with control, soil sulfur treatments significantly improved the recovery percentages of apple valsa canker infected trees in organic orchard. However, there were no differences between lime sulfur and soil sulfur treatment in organic apple orchard, except BongHyun orchard experiment in 2013. Compared with control fruit qualities, fruit skin red color and fruit firmness were improved in lime sulfur and soil sulfur treatment, respectively. In conventional orchard, apple trees treated with lime sulfur, soil sulfur or neoasozin improved recovery percentages, compared with those of control trees. Soil sulfur treatments recovered 87.5~97.5% of infected 'Fuji'/MM106 apple trees in organic and conventional apple orchards. The trees applied with neoasozin showed significant lower shoot growth than those of soil sulfur treatment in conventional orchard. Soli sulfur treatment improved fruit red color, but did not affected fruit weight, fruit firmness, soluble solids concentrations, and titratable acidity.

Fruit Quality of 1-Methylcyclopropene Treated 'Formosa' Plum on the Shelf Life at Ambient Temperature (1-Methylcyclopropene이 'Formosa' 자두의 품질과 유통기간 연장)

  • Jung, Jae-Hoon;Kim, Young-Chil;Jung, Seok-Kyu
    • Horticultural Science & Technology
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    • v.28 no.3
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    • pp.429-433
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    • 2010
  • The effects of 1-methylcyclopropene (1-MCP) for controlling ripening processes such as weight loss, fruit softening, soluble solids content (SSC), titratable acidity (TA), and fruit skin color were investigated and also the possibility that 1-MCP can inhibit the development of brown rot was explored in 'Formosa' plum ($Prunus$ $domestica$ L.). Fruit were treated with $1{\mu}L{\cdot}L^{-1}$ 1-MCP on the day of harvest and one day after harvest for 16 h at ambient temperature ($20^{\circ}C$), followed by 14 days of shelf life. 1-MCP treatment delayed fruit softening, weight loss and changes in skin color and TA during the shelf life period, but did not affect SSC. These 1-MCP effects were similar with and without delayed treatment. 1-MCP treatment inhibited the development of brown rot caused by $Monilinia$ $laxa$ during storage. Our data shows that treatment delays of ${\geq}1$ day before 1-MCP application had no negative effect of fruit softening, fruit skin color, and TA at ambient temperature ($20^{\circ}C$). Overall, these results indicate that 1-MCP can be used to maintain the quality of non-refrigerated plums.