• Title/Summary/Keyword: Titratable Acidity

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Quality Changes of Sterilized Soybean Paste during Its Storage (살균 된장의 저장과정 중 품질변화)

  • 오만진;김종생;최성현;이상덕;이규희
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.28 no.5
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    • pp.1069-1075
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    • 1999
  • The sterilization was attempted to improve the quality deterioration of soybean paste during its storage. For this experiment, soybean paste was sterilized at 80oC for 30 minutes and stored during 6 months at 15oC and 30oC, respectively. The total approximate composition contents were moisture 52.5%, crude protein 11.94%, crude fat 2.0%, amino nitrogen 413.3mg%, sodium chloride 11.61% and ash 15.5%. According to the increase of storage period, pH was decreased gradually because of the increase of organic acids by the metabolism of microorganisms and the acid accumulation by acid forming bacteria, but titratable acidity was increased during storage. Amino nitrogen was rapidly increased for the first one or two month storage period and maintained as the same level for the rest of them. Each amino acid contents of soybean paste, which were glutamic acid, tryptophan, proline, arginine, and aspartic acid, had much higher level than others. In color changes sterilized soybean paste(SSP) was much lower than that of raw ones(RSP). Hunter L and b values on the surface of soybean paste were decreased during storage, and the decreasing levels were higher at 30oC than at 15oC. Hunter a value, however, was increased a little in the initial storage, and thereafter it was decreased. Lactic acid bacteria, yeasts, and molds were disappeared completely by the sterilization. However, the bacteria of aerobes and anaerobes were not disappeared by this processing.

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Quality Characteristics of Yanggaeng added with Freeze-dried Peach Powder (동결건조 복숭아 가루를 첨가한 양갱의 품질 특성)

  • Lee, Won-Gab
    • Culinary science and hospitality research
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    • v.22 no.8
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    • pp.67-77
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    • 2016
  • This study investigated the physicochemical, antioxidative activity, and sensory characteristics of yanggaeng prepared with various amounts of peach powder. According to the results, the pH of yanggaeng was decreased significantly by addition peach powder, but total titratable acidity of yanggaeng was increased significantly by addition peach powder. The sweetness ($^{\circ}brix%$) and moisture content of groups by the addition of peach powder were lower than those of control group. At the result of color measurement, L value of groups by the addition of peach powder was lower than that of control group, but a value and b value of groups by the addition of peach powder were higher. Texture measurement score in terms of hardness and brittleness for yanggaeng were increased significantly by addition peach powder. The contents of DPPH radical scavenging activity, and ABTS radical scavenging activity of groups by the addition of peach powder were higher than those of control group. As peach powder increased, antioxidative activity also became bigger. Sensory evaluation scores in terms of after swallowing, appearance, odor, taste, texture, and overall preference of groups with 4% and 6% peach powder were higher significantly when compared to the control group.

Changes in the Microbiological Characteristics of Oat Extract by Lactic-bacterial Fermentation (귀리추출물의 젖산발효에 의한 미생물학적 특성 변화)

  • Lee, Chan
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.38 no.12
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    • pp.1811-1814
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    • 2009
  • The effect of fermentation with mixed cultures of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus on the microbiological characteristics of oat extract was investigated. Changes in pH, titratable acidity and viable cell populations indicated that growth was better in mixed cultures of L. delbrueckii subsp. bulgaricus and S. salivarius subsp. thermophilus. Growth of S. salivarius subsp. thermophilus in oat extract was more rapid than growth of L. delbrueckii subsp. bulgaricus. Cooperative interaction between two cultures during fermentation of oat extract as in yogurt from cow's milk was observed, but the intensity was relatively weak.

A microbiological investigation of Omija (Schizandra chinesis Baillon) tea spoilage during storage (오미자차액 저장시의 부패와 이에 관여하는 미생물에 관한 연구)

  • 이효선;경규항;유양자;박승애
    • Korean journal of food and cookery science
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    • v.4 no.1
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    • pp.41-46
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    • 1988
  • Omija tea with a pH range of 2.8~3.0 was stored at $25^{\circ}C$ to study its spoilage due to microbial growth. Titratable acidity was increasing during the storage period in the tea stored with the Omija fruits but not in removed of the fruits after extraction. Microbial cells began to show up earlier in the tea without the fruits than that with the fruits. Four strains of yeasts and a strain of mold were isolated from spoiled Omija tea. Morphological, cultural and physiological characteristics of yeasts were investigated and the yeasts were identified as Rhodotorula rubra, Saccharomyces kluyveri, Cryptococcus hungaricus and Candida humicola. Morphological characteristics of the isolated mold was observed and the mold was identified as Mucor circinelloides f. janssenii.

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Characterization of fermented milk added with green whole grains of barley, wheat, glutinous rice and common rice powders (녹색 홀그레인 보리, 밀, 찹쌀, 멥쌀 분말을 첨가한 발효유의 특성)

  • Bae, Hyoung-Churl;Renchinkhand, Gereltuya;Ku, Ja-Hyeong;Nam, Myoung-Soo
    • Korean Journal of Agricultural Science
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    • v.38 no.3
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    • pp.485-491
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    • 2011
  • Yogurt was prepared from skim milk added with 2, 4 or 6% of green whole grain of barley, wheat, glutinous rice and common rice, respectively. Changes in pH, titratable acidity, viable cell counts and viscosity during fermentation were monitored and its sensory evaluation was also performed. The optimum level of additives such as green whole grain of barley, wheat, glutinous rice and common rice for yogurt manufacture was selected to 2%. The samples added with green whole grain of barley and wheat powders reached pH 4.5 in 12 hours. After 4 hours of fermentation, pH, the viable cell counts and viscosity in samples added with 2% green whole grain of barley, wheat, glutinous rice and common rice powders were the highest. Especially, in overall sensory evaluation using 5 parameters, the sensory scores of glutinous rice and common rice 2% yogurts were significantly high. From this experiment, the additives optimum level of glutinous rice and common rice powders was selected to be 2%.

The Effect of Angelica gigas Water Extract on the Growth of Lactic Acid Bacteria (당귀가 유산균의 생육에 미치는 영향)

  • Oh Youn-Jeong;Lee Su-Han;Jung Seung-Won;Noh Wan-Seob
    • Journal of the East Asian Society of Dietary Life
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    • v.16 no.3
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    • pp.344-348
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    • 2006
  • This study was carried out to survey the effect of medicinal herbs on the growth of 3 strains of lactic starter cultures in MRS broth by the addition of 0, 1, 3, 5, and 10% water extract, after 30 hrs incubation. The pH, titratable acidity and O.D. of lactic acid bacteria were investigated to obtain fundamental knowledge for the development a new product. The effects of medicinal herbs extracts on the growth of lactic acid bacteria were variable depending upon the species of lactic acid bacteria and medicinal herbs extract. Growth of Str. thermohilus was activated by addition of 1 and 3% Angelica gigas water extract, but the basal medium plus 5 and 10% extract and growth of L. acidophilus and Bif. longum were depressed by the addition of extract. The pH and acid production ability dropped slightly in the basal medium plus 1 and 3% of extract. The other samples following the same trend as the control.

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A Study on Effect of Acanthopanax sessiliflorum Seeman Water Extract on the Growth of Lactic Acid Bacteria (오갈피(Acanthopanax sessiliflorum Seeman) 추출액이 유산균의 생육에 미치는 영향)

  • Kim Sun-Young;Park Keun-Sil;Lee Su-Han;Jung Seung-Won;Noh Wan-Seob
    • Journal of the East Asian Society of Dietary Life
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    • v.16 no.3
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    • pp.357-363
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    • 2006
  • This study examined the effect of medicinal herbs on the growth of 3 strains of lactic starter cultures in a MRS broth by adding a 0, 1, 3, 5, and 10% water extract. The pH, titratable acidity and OD of lactic acid bacteria were investigated in order to obtain fundamental knowledge for the development a new product, box thorn yogurt. In the case of adding the Acanthopanax sessiliflorum Seeman water extract, Streptococcus thermophilus was largely activated by the addition of the 5% extract. The growth of Lactobacillus acidophilus was activated by the extracts but it was depressed by the addition of the 3% Acanthopanax sessiliflorum Seeman water extract. Compared with the control, the growth of Bifidobacterium longum was largely activated by the addition of the 10% extract but it was depressed by the addition of the 5% Acanthopanax sessiliflorum Seeman water extract.

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Effect of Cellulose Coatings on Postharvest Storage Qualities of Plums(Prunus salicina L.) (셀룰로오스코팅이 자두의 저장중 품질특성에 미치는 영향)

  • Song, Tae-Hee;Kim, Chul-Jai
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.4 no.2
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    • pp.45-57
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    • 1998
  • Immature and mature plums(Prunus salicina L.) were coated with calcium-added methylcellulose(CaMC) and hydroxypropylmethyl-cellulose-15(CaHPMC-15). Physicochemical, nutritional and sensory characteristics were compared during the 8-day storage period at $30^{\circ}C$. Irrespective of maturity, pH of plums increased and the titratable acidity decreased during storage. Free sugars such as glucose, fructose, sucrose and sorbitol were eventually decreased during storage, but Ca-added cellulose coatings influenced on the prevention of free sugars from decreasing especially in mature plums. Vitamin C contents in immature and mature plums became decreased during storage, but the coatings took effective on its retention. Changes of malic acid, the major organic acid in plums were appeared the same tendency as vitamin C during storage. Results of sensory evaluation showed the development of red color in peel and the softening of plum tissue, and also showed that the overall eating quality and appearance generally decreased during storage. However, the coated plums either CaMC or CaHPMC-15 exhibited the better sensory characteristics. As though the significant difference in postharvest storage quality were not found between the two coatings, CaMC and CaHPMC-15 coatings significantly contributed to the improvement of overall storage quality, especially the retention of vitamin C and organic acids only on the mature plums.

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ACE-inhibitory Effect and Physicochemical Characteristics of Yogurt Beverage Fortified with Whey Protein Hydrolysates

  • Lim, Sung-Min;Lee, Na-Kyoung;Park, Keun-Kyu;Yoon, Yoh-Chang;Paik, Hyun-Dong
    • Food Science of Animal Resources
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    • v.31 no.6
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    • pp.886-892
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    • 2011
  • This study investigated the ACE-inhibitory effect of yogurt beverage fortified with hydrolysates as well as the suitability of hydrolysates as a nutraceutical additive to yogurt beverage. Three whey protein hydrolysates hydrolyzed by alcalase, protamex, and trypsin were each added to yogurt beverage at concentrations of 1.25, 2.5, and 5 mg/mL. Yogurt beverage fortified with 2.5 mg/mL of hydrolysates had 61-69% ACE-inhibitory activity, whereas yogurt beverage fortified with 5 mg/mL of hydrolysates showed 74% ACE-inhibitory activity. There were no significant differences in ACE-inhibitory activity between the alcalase or protamex hydrolysates during storage; however, trypsin hydrolysate exhibited significant differences. On the other hand, physicochemical characteristics such as pH (3.47-3.77), titratable acidity (0.81-0.84%), colority, viable cell count, and sensory qualities were not significantly different among the tested yogurt beverage samples during storage. These results showed that yogurt beverage fortified with whey protein hydrolysates maintained antihypertensive activity and underwent no unfavorable changes in physicochemical characteristics regardless of enzyme type.

Development of Functional Yogurts Prepared with Mulberries and Mulberry Tree Leaves

  • Lee, An-Cheol;Hong, Youn-Ho
    • Food Science of Animal Resources
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    • v.30 no.4
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    • pp.649-654
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    • 2010
  • In order to develop new functional yogurts using mulberries and mulberry leaves, which were cultivated in Hwasun-gun, Jeonnam Province, Korea, the nutritional compositions, fermentation conditions, sensory properties, and storage stabilities of the yogurts were analyzed. The mulberry powder yogurt contained 87.96% moisture, 3.21% carbohydrate, 4.52% protein, 3.63% lipid, and 0.68% ash, and the mulberry leaf yogurt contained 86.36% moisture, 4.13% carbohydrate, 4.87% protein, 3.79% lipid, and 0.85% ash. A yogurt base was fermented for 13 h with 0.01% ABT-5 starter inoculum at $40^{\circ}C$. To prepare the mulberry jam and mulberry leaf yogurts, a variety of mulberry jam and mulberry leaf samples were added to the yogurt base. The sensory evaluation results of the yogurts containing the mulberry jam and mulberry leaves indicated that a product made with 15% mulberry jam was more strongly preferred than other samples. When the mulberry jam and mulberry leaf yogurts were stored at $4^{\circ}C$ for 15 d, there were no significant changes in pH, titratable acidity, or viable cell numbers of lactic acid bacteria and Bifidobacterium bifidum.