• Title/Summary/Keyword: Milk Acidity

Search Result 200, Processing Time 0.032 seconds

Preparation and Quality Characteristics of Curd Yogurt Added with Chlorella (클로렐라를 첨가한 요구르트의 제조와 품질특성)

  • Sung, Yun-Mi;Cho, Ja-Rae;Oh, Nam-Soon;Kim, Dong-Chung;In, Man-Jin
    • Applied Biological Chemistry
    • /
    • v.48 no.1
    • /
    • pp.60-64
    • /
    • 2005
  • Yogurt base was prepared from skim milk added with $0.2{\sim}1.0%\;(w/v)$ chlorella powder and fermented with lactic acid bacteria (the mixed strain of Lactobacillus acidophilus, Bifidobacterium longum and Streptococcus thermophilus) at $40^{\circ}C$ for $12{\sim}18\;h$. Quality characteristics of the yogurt were evaluated in terms of acid production (pH and titratable acidity), number of viable cells, viscosity and sensory properties. The addition of chlorella powder stimulated the growth of lactic acid bacteria and remarkably enhanced the acid production. After 12 h incubation, titratable acidity of chlorella yogurt was $1.16{\sim}1.33%$ and was higher than that (1.02%) of yogurt made with only skim milk. However, the viscosity of yogurt was decreased by the addition of chlorella powder. The sensory score of yogurt added with 0.2% chlorella powder was similar to ordinary yogurt in taste and overall acceptability. When chlorella yogurt was kept at $4^{\circ}C$ for 15 days, its quality-keeping properties except for number of viable cells were relatively good. According to sensory score and storage ability, the optimum concentration of chlorella powder was around 0.2%.

Preparation and Quality Characteristics of Yogurt with Black Garlic Extracts (흑마늘 농축액을 첨가한 요구르트의 제조와 품질특성)

  • Shin, Jung-Hye;Kim, Gyoung-Min;Kang, Min-Jung;Yang, Seung-Mi;Sung, Nak-Ju
    • Korean journal of food and cookery science
    • /
    • v.26 no.3
    • /
    • pp.307-313
    • /
    • 2010
  • Yogurt base was prepared from skim milk added with 0.5, 1.0 and 1.5% (w/v) black garlic extracts(BGE, 60 brix), fellowed by fermentation with Lactic acid bacteria (the mixed strain of Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus) at $42^{\circ}C$ for 24 hr. The yogurt products were evaluated for acid production (pH, titrable acidity), number of viable cells, viscosity, color value, and sensory properties. The pH of yogurt with BGE was below 6.0 at 6 hr fermentation, after which it was rapidly acidifies. Aftert 24 hr, the titratable acidity of yogurt with 1.5% BGE was 0.74%, which was 5.7 times higher than that before fermentation. There was no significant difference in viable cell count between the samples after 3 hr fermentation. The viscosity of yogurt was decreased by the addition of BGE. As the percentage of BGE increased, the L value (lightness) decreased while the a value (redness) and b value (yellowness) increased. The overall sensory score of yogurt with BGE was lower than that of yogurt with only skim milk. Therefore, moderate addition of BGE was below 1% for the preparation of yogurt.

Changes in Lactic Acid Bacteria and Physicochemical Properties of Yogurt Made with High Pressure Processing Treated Milk (고압처리 원유로 제조한 발효유의 저장 중 유산균 수 변화와 이화학적 특성)

  • Ahn, Sung-Il;Chung, In-Ae;Chung, Woon-Si;Jhoo, Jin-Woo;Kim, Gur-Yoo;Jeon, Jung-Tae
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.45 no.6
    • /
    • pp.889-893
    • /
    • 2016
  • This study was carried out to investigate the physicochemical and fermentation properties of yogurt made from high pressure processing (HPP) treated milk. Raw milk and commercial yogurt starter were used to make yogurt. Raw milk was HPP treated at 350 or 450 MPa (HPP 350 or 450) for 15 min or heat treated at $80^{\circ}C$ for 10 min. The numbers of lactic acid bacteria of the HPP treated group (HPP yogurt) rapidly increased during 2~4 h, whereas there was not significant difference from control (P<0.05). Titratable acidity of all samples increased, and pH decreased during storage from 0.99 to 1.24%, as well as from 4.59 to 4.20, respectively. It is confirmed that these values are in general ranges for yogurt. Control showed higher viscosity than HPP 350. Syneresis was significantly lower than that of the control (P<0.05). Based on the data obtained from the present study, HPP treatment was effective to enhance the quality of yogurt.

Effect of Growth Stimulating Agent in Lactic Acid Bacteria Fermented Food Prepared from Egg White Powder and Casein (난백분말과 카제인으로 만든 젖산균 발효식품에서 생육촉진물질의 효과)

  • Ko, Young-Tae;Lee, Eun-Ju
    • Korean Journal of Food Science and Technology
    • /
    • v.31 no.2
    • /
    • pp.509-515
    • /
    • 1999
  • Lactic acid bacteria (LAB) fermented foods were prepared from egg white powder (EWP), casein and growth stimulating agents (GSA). The effects of GSA on acid production and growth of Lactobacillus were studied. The effects of GSA on sensory properties and viscosity of LAB fermented foods were also studied. Acid production by Lactobacillus was stimulated by addition of GSA (0.3% or 1%, W/V). Although stimulating effect differed among each GSA, some GSA increased the acidity up to the level of fermented milk. However, stimulating effect of GSA on viable cells was not noticeable. Acid production by L. acidophilus was generally higher than other Lactobacilli. The optimum concentration of GSA added to substrate was 1% (W/V). Sensory evaluation showed that the optimum fermentation time was 18hr. The sensory properties of GSA samples were evaluated as slightly lower than that of fermented milk because GSA samples showed whey separation and taste and smell of GSA. Apparent viscosity of GSA samples was significantly lower than that of fermented milk and control sample (p<0.05). There was no significant difference of apparent viscosity among GSA samples. GSA samples, fermented milk and control sample showed thixotropic flow characteristics.

  • PDF

Antioxidant activities of Rhus verniciflua seed extract and quality characteristics of fermented milk containing Rhus verniciflua seed extract (옻씨 추출물의 항산화 활성과 옻씨 추출물을 첨가한 발효유의 품질특성)

  • Jin, Hee-Yeon;Choi, Yu-Jin;Moon, Hye-Jung;Jeong, Jae-Hee;Nam, Joong-Hyun;Lee, Sang-Cheon;Huh, Chang-Ki
    • Food Science and Preservation
    • /
    • v.23 no.6
    • /
    • pp.825-831
    • /
    • 2016
  • This study was carried out to investigate the quality characteristics of fermented milk containing Rhus verniciflua seed (RVS) extracts (0.0%, 0.1%, 0.3% and 0.5%) and antioxidant activity of RVS extracts. The proximate composition of RVS was moisture (4.76%), crude ash (1.40%), crude fat (5.33%) and crude protein (11.10%). A total polyphenol content of 70% ethanol extract of RVS ($554{\pm}2.64mg/g$) was higher than that of RVS water extract ($145{\pm}3.47mg/g$). 70% ethanol extract ($1103{\pm}6.42mg/g$) of RVS showed higher content in the total flavonoids ($37{\pm}2.30mg/g$) and activities on DPPH free radical scavenging (73.23%) and ABTS free radical scavenging (83.47%) when compared with water extracted of RVS. The quality characteristics, such as pH, titratable acidity, and the number of lactic acid producing bacteria were not remarkably different between the fermented milk samples subjected to treatments with and without the addition of RVS extracts.

Studies on the Manufacture of Adlay Yoghurt I. The Physicochemical and Microbiological Properties of Adlay Yoghurt (율무 Yoghurt 제조에 관한 연구 I. 율무 Yoghurt의 이화학적 및 미생물학적 성질)

  • 김상범;임종우
    • Food Science of Animal Resources
    • /
    • v.20 no.1
    • /
    • pp.56-63
    • /
    • 2000
  • This study was investigated the effects of the addition of adlay with levels of 1%(T1), 2%(T2), 3%(T3) and 4% (T4) in skim milk substrate on the physicochemical and microbiological properties of yoghurt during fermentation and storage period at 4$\pm$1$^{\circ}C$. Adlay yoghurt were fermented with the mixed cultures of YC-380, ABT-4 and ABT-D. Titratable acidity and pH values of all treatments were increased and decreased significantly(p<0.05) with fermentation period, respectively and increased and decreased slightly during the storage period, respectively. There were increased and decreased in order of all treatments fermented with YC-380, ABT-4 and ABT-D. Viscosity of adlay yoghurt increased rapidly in order of T4, T3, T2 and T1 during fermentation and slowly in order of T1, T2, T3 and T4 during the storage period. There were increased in order of all treatments fermented with ABT-D, YC-380 and ABT-4. The counts of viable cells of lactic acid bacteria in all treatments were rapidly and slightly increased during fermentation and storage period, respectively. There were increased in order of fermented with ABT-D, ABT-4 and YC-380 in all treatments. The counts of E. coli were not found in adlay yoghurt. In all treatments, T1 showed slightly high compared to that of control. Based on the results of this experiment, the optimum level of addition of adlay were 1% (w/v) for production of acid production, pH, viscosity and the counts of viable cells of lactic acid bacteria.

  • PDF

Studies on Production of Soy Yogurt - Keeping Quality of Yogurt Beverage Prepared from Defatted Soy Flour - (대두요구르트의 제조에 관한 연구 - 탈지대두(脫脂大豆)로 제조된 유산균음료의 저장성 -)

  • Ko, Young-Tae;Kim, Young-Bae;Paik, Jung-Ki
    • Applied Biological Chemistry
    • /
    • v.27 no.3
    • /
    • pp.163-168
    • /
    • 1984
  • Soy yogurt beverage (SYB) was prepared from defatted soybean flour and flavor, effect of stabilizers on sedimentation and change of acidity and cell concentration during storage of SYB were investigated. The flavor of SYB rated significantly different and slightly inferior to milk yogurt although flavors added to SYB improved the acceptability. The curd in SYB precipitated greatly during the first 24 hours of storage. The sedimentation of curd was reduced by the addition of CMC of 0.4% or PGA of 0.1%. SYB can be kept at $5^{\circ}C$ for 48 days without significant change in viable cell count of lactic acid bacteria. pH, titratable acidity and viable cell count of SYB was significantly changed for 48 days at $25^{\circ}C$. Some of SYB samples were contaminated by yeast and mold.

  • PDF

Changes of Undenatured Whey Protein and Available Lysine Contents in Heat Treated Market Milks (열처리에 따른 시편우유의 불편성 유청단백질과 유호성 Lysine 함량변화)

  • 홍윤호;박영희
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.20 no.6
    • /
    • pp.546-550
    • /
    • 1991
  • Changes of pH, titratible acidity, undenatured whey protein contents and the rates of loss of available lysine in market milks were investigated to find out the effective indicators for identification and classification of different heat treatment. There showed no change of both pH and titratiable acidity among the heating methods in market milks. The contents of undenatured wheyprotein per 100ml serum were determined as 413.7mg(LTLT), 341.3mg(HTSP), 6.9mg(UHT pasteurized) and 96.6mg(UHT sterilized), respectively. Distinct differences of underatured whey protein contents accoriding to the heating method could be observed. The rates of loss of available lysine in heated milks compared to raw milk showed 1.4% (LTLT), 0.2%(HTST), 6.3%(UHT pasteurized) and 4.9%(UHT sterillized), respectively. The rates of loss of available lysine were not suitable to classify the UHT heating method.

  • PDF

Quality Characteristics of Commercial Yoghurt Powder Marketed in Korea (국내 시판 요구르트 분말의 품질 특성)

  • Lee, Jeae;Jeun, Gihoon;Lim, Kwangsei;Oh, Sejong;Park, Dong June;Imm, Jee-Young
    • Journal of Dairy Science and Biotechnology
    • /
    • v.32 no.2
    • /
    • pp.157-161
    • /
    • 2014
  • Quality characteristics of commercial yoghurt powder products marketed in Korea were compared. According to the product type classification, no product met the product identity of "fermented milk powder" (six were identified as "other processed product" and nine as "sugar product"). Titratable acidity of products (10%, w/v) varied from 0.11 to 0.82% while numbers of lactic acid bacteria varied from 0 to $1.4{\times}10^8CFU/g$. There were significant differences in hydration properties and viscosity of yoghurt powder products. Some regulations are required to avoid consumer misunderstanding of beneficial health effects of yoghurt powder products.

  • PDF

Effect of Slander Glasswort Extract Yogurt on Quality during Storage (함초 추출물 첨가가 요구르트 저장 중의 품질 특성에 미치는 영향)

  • Cho, Young-Sim;Kim, Soon-Im;Han, Young-Sil
    • Korean journal of food and cookery science
    • /
    • v.24 no.2
    • /
    • pp.212-221
    • /
    • 2008
  • This study was performed in an effort to create a functional and stable yogurt product containing slander glasswort extract. The extract was added to milk at concentrations of 0.25, 0.5, and 1.0% (w/v), which was then fermented with lactic acid bacteria (Lactobacillus bulgaricus and Streptococcus thermophilus) at $42^{\circ}C$ for 6 hr. During a period of 15 days of storage, the quality characteristics of the yogurt samples were evaluated in terms of acid production (pH and titratable acidity), levels of lactic acid bacteria, color values, viscosity, and sensory characteristics. There were no significant differences in pH during the storage period; however, the control yogurt presented the highest pH value. The 1.0% slander glasswort yogurt had the highest titratable acidity; but again, there were no significant differences among the yogurts. The 1.0% slander glasswort yogurt also had the highest level of lactic acid bacteria, and both the control and slander glasswort-containing yogurts had increasing levels of lactic acid bacteria over the storage period. The 1.0% slander glasswort yogurt had the lowest L-value and highest a- and b-values. And the slander glasswort yogurts presented lower viscosity values than the control. In sensory evaluations, the 0.25% slander glasswort yogurt scored higher than the other groups for color, flavor, viscosity, sweetness, sourness, and overall palatability. The final sensory results indicated that the 0.25% slander glasswort yogurt was superior.