• Title/Summary/Keyword: physicochemical and microbiological properties

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Physicochemical and Microbiological Properties of Ginseng-Whey Beverages (인삼 유청음료의 이화학적 및 미생물학적 특성)

  • 기해진;홍윤호
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.22 no.2
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    • pp.208-214
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    • 1993
  • Ginseng-whey beverages were prepared with rennet whey, ginseng, sweetener, honey and Japanese apricot, inoculated with different strains of lactic acid bacteria or unfermented partly. The samples were stored at 4$^{\circ}C$ or 30$\pm$1$0^{\circ}C$ and then physicochemical and microbiological properties were investigated. The yield of whey was 78.8%. The pH-values reduced and acidities increased during the storage period. The contents of solid-substances, ash and lipid in ginseng-whey beverages were 7.90~8.20%, 0.62~0.66% and 0.16%, respectively. The protein contents of ginseng-whey beverages were 0.42~0.56% and the contents were not changed during the storage period. The lactose contents of fermented beverages were higher than those of unfermented beverages. During the storage period (1~5 weeks), the ranges of D(-) - and L(+)- lactic acid contents in fermented ginseng-whey beverages (17.3~156.1 mg/100g, 347.3~1894.2mg/100g) were higher than those of unfermented ginseng-whey beverages (6.2~82.8mg/100g, 7.1~885.5mg/100g). The contents of total saponin in unfermented sample and fermented sample (Lac. casei sub-sp. casei+Str. salivarius sub-sp. thermophilus) were increased during the storage period. But, those of the fermented sample(Lac. acidophilus+Lac. delbrueckii sub-sp. bulgaricus) were reduced. In the electrophoretic results of ginseng-whey beverages, an $\alpha$-lactalbumin and a $\beta$-lactoglobulin bands were shown apparently and there were no changes observed during the storage period. During the storage period (1~3 week) the coliform was not detected and total plate counts and psychrotrophs were increased according to the storage period.

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Physicochemical and Microbiological Properties of Dongchimi added with Citron (Citrus junos) (유자 첨가 동치미의 이화학적 및 미생물학적 특성)

  • 장명숙;김나영
    • Korean journal of food and cookery science
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    • v.13 no.3
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    • pp.286-292
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    • 1997
  • The purpose of this study was to investigate the effect of citron (Citrus junos) on Dongchimi (watery radish kimchi) fermentation. Dongchimi with various levels (0, 1, 2, 4, 6%) of citron was fermented at 10$^{\circ}C$ for 36 days. The pH of Dongchimi decreased slowly in all samples during fermentation, however, it was slightly lower in citron-added Dongchimi. Total acidity and turbidity of Dongchimi increased gradually during formentation, in which the level of increase was greater as the % of added citron increased. However, the total acidity and turbidity of Dongchimt without citron increased dramatically on 36$\^{th}$/ day of fermentation, and reached the values similar to those of Dongchimi with 6% citron. Reducing sugar content increased gradually up to 15∼23 days of fermentation and decreased rapidly for the rest of the period. The content of vitamin C was much higher in citron-added Dongchimi, and especially it was 4 times higher than that of without citron at the beginning of fermentation. The number of lactic acid bacteria reached the maximum on 15$\^{th}$/ day in citron-added Dongchimi and on 30$\^{th}$/ day in Dongchimi without citron, and decreased thereafter.

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Studies on the Quality Changes of Mixed Fruit and Vegetable Juices as Influenced by Processing Conditions during Storage (혼합과채주스의 가공방법에 따른 저장 중 품질특성 변화에 관한 연구)

  • 이준호;석은주
    • Food Science and Preservation
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    • v.5 no.1
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    • pp.41-47
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    • 1998
  • Physicochemical properties and microbiological quality chanties were investigated on mixed fruit and vegetable juices (apple, carrot and cucumber) stored at 4$^{\circ}C$ without pasteurization(NT), with light piasteurization (LP; 66$^{\circ}C$, 10 sec) and with full pasteurization(FP; 90$^{\circ}C$, 60 sec). Effects of ultrafiltration (UF) on the changes during storage were also examined. pH, viscosity, a-value and b-value remained relatively constant and all samples revealed Newtonian characterisitics. Total acidity and turbidity tended to increase slightly; however, total vitamin C content and L-value slowly decreased during storage up to about 2 months. During the first 4 weeks storage, soluble solids content slowly increased and then decreased. Mold and Yeast and Bacteria were not detected in LP, UP and UF treated samples during storage studied; however, E. coli were detected after 24 days storage. No distinctive storage effects were found among samples prepared; however, ultrafiltration had a considerable effect on the color and soluble solids content of mixed fruit and vegetable juice.

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Optimization of dry-aging conditions for chicken meat using the electric field supercooling system

  • Chang-Hwan Jeong;Sol-Hee Lee;Hack-Youn Kim
    • Journal of Animal Science and Technology
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    • v.66 no.3
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    • pp.603-613
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    • 2024
  • This study was designed to determine the optimal aging conditions after analyzing the physicochemical and microbiological properties of dry-aged chicken breast using an electric field supercooling system (EFSS). Chicken breast was aged for up 5 weeks at three different temperatures (0℃, -1℃, and -2℃). Aging and trimming loss at -2℃ treatment showed lower values than at 0℃ and -1℃ treatments. Thiobarbituric acid reactive substances and volatile basic nitrogen in all treatments increased during the aging process but showed the lowest levels at -2℃. As a result of analysis of aerobic bacteria, it is microbiologically safe to dry-age for up to 2 weeks at 0℃ and up to 3 weeks at -1℃ and -2℃. Therefore, the dry-aged chicken breast with EFSS was optimally aged for 3 weeks at -2℃.

A Study on Habak-kimchi added Fresh Ginseng (수삼을 첨가한 나박김치에 관한 연구)

  • 임희정;신승미;최윤정;권혜순;염초애
    • Korean journal of food and cookery science
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    • v.12 no.3
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    • pp.346-352
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    • 1996
  • This study was conducted to investigate the effect of fresh ginseng on the physicochemical, microbiological and sensory properties of Nabak-kimchi during 33 day fermentation. Nabak-kimchi with the various levels (0, 2, 4, 6%) of fresh ginseng were fermented at 4$^{\circ}C$. During the fermentation, pH was lowered in all Nabak-kimchi samples and pH of Nabak-kimchi added fresh ginseng was a little lower than that of Nabak-kimchi without fresh ginseng. Acidity increased continuously during the entire fermentation. Saltiness was maintained at 1.60-1.67% levels during the whole fermentation. Total vitamin C contents increased drastically on the first day of fermentation and decreased after the first day and then increased during 21-24 day fermentation. Total bacteria increased rapidly at the beginning of fermentation and reached its maximum number on 6th day offermentation and then decreased slowly. Total bacteria of Nabak-kimchi added fresh ginseng was highly main-tained during the entire fermentation periods. As a result of the sensory evaluation, Nabak-kimchi added 4% fresh ginseng was the most palatable one.

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Physicochemical traits of Holstein loin and top round veal from two slaughter age groups

  • Yim, Dong-Gyun;Park, Sang-Woon;Chung, Ku-Young
    • Journal of Animal Science and Technology
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    • v.57 no.7
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    • pp.24.1-24.5
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    • 2015
  • The objective of this study was to investigate the physicochemical and microbial quality of loin (m. longissimus dorsi) and top round (m. Semimembranosus) in Holstein veal produced from two slaughter age groups (5 and 8 months of age). A total of 20 Holstein calves were randomly selected from a local cattle farm. The slaughtered cold carcasses were vacuum-packaged. The samples were analyzed for proximate composition and physicochemical analyses and stored for 1, 7, 10, 20 and 30 days for microbiological analyses. Fat and protein contents of loin for the 8 month group were higher than those for the 5 month groups (p < 0.05). For both loin and top round muscles, the pH, cooking loss and the shear force values for the 5 month group was higher than those for the 8 month group (p < 0.05). On the other hands, the water-holding capacity (WHC) for the 8 month group was higher than those for the 5 month group (p < 0.05). In terms of meat color, CIE $L^*$ (lightness) for both muscle were higher in the 5 month group than in the 8 month groups. On the other hands, $a^*$ (redness) were higher in the 8 month group than in the 5 month groups (p < 0.05). Total aerobic counts in all samples remained up to 30 days at values less than 7 log CFU/g. However, there was no significant difference for both muscles between the two age groups. The results indicate that Holstein muscles from the 8 month group had desirable quality properties than those from the 5 month group.

Microbiological Characteristics of Alcoholfermenting Wild Yeast, Aureobasidium pullulans P-1 and Its Makgeolli Fermentation Characteristics (알코올 발효성 야생 효모, Aureobasidium pullulans P-1의 균학적 특성과 막걸리 발효 특성)

  • Hong, Yong-Cheol;Han, Sang-Min;Lee, Jong-Soo
    • The Korean Journal of Mycology
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    • v.46 no.3
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    • pp.307-314
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    • 2018
  • The goal of this study was to investigate the microbiological characteristics of the ethanol-producing wild yeast, Aureobasidium pullulans P-1, isolated from flowers growing near the Yedang reservoir, Chungnam province, Korea, and in addition, to optimize its fermentation ability for the production of Makgeolli. A. pullulans P-1 was oval-shaped, and formed ascospores and pseudomycelium. The P-1 strain was a halophilic and sugar tolerant yeast which grew in 15% NaCl and 50% glucose-containing yeast extract-peptone-dextrose media. The P-1 strain was also resistant to 20% ethanol. Changes of the physicochemical properties during Makgeolli fermentation by A. pullulans P-1 were investigated. A maximum of 8.45% ethanol was obtained when a mixture of cooked rice, 150% water, and 35% ipguk per cooked rice was fermented by 5% A. pullulans P-1 culture broth at $25^{\circ}C$ for 10 days. Antihypertensive angiotensin I-converting enzyme inhibitory activity in the Makgeolli ferment produced by A. pullulans P-1 reached a high of 71.1% after 10 days.

The Quality Characteristics and Antioxidant Properties of Sun-dried Venison Jerky with Green Tea Powder during Storage

  • Nam, Ki Chang;Kim, Hyun Cheul;Cha, Jusu;Yim, Dong Gyun
    • Food Science of Animal Resources
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    • v.36 no.5
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    • pp.626-634
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    • 2016
  • This study was conducted to compare the physicochemical, microbiological and antioxidant activities of sun-dried venison amended with green tea powder (T1-3: 0, 0.5, and 1%) and Hanwoo beef jerky. Sliced beef and venison shank were marinated and sun-dried at 28-30℃ and 30-35% RH for 3.5 h. The venison jerky had a higher ash and protein content, and lower moisture and fat content than the control (p<0.05). T3 (venison+green tea powder 1%) showed a lower aw than all other samples during storage for 10 and 20 d (p<0.05). Hunter’s color a* and b* values of T2 and T3 were lower than those of T1 and the control at day 0 (p<0.05). Saturated fatty acid was significantly higher in T1, while PUFA was higher in T2 and T3 (p<0.05). Overall sensory scores of venison jerky were lower than those of the control, except for T2, which had a similar color, flavor, saltiness and acceptability as the control. T2 and T3 showed a significant decrease in TPCs after storage for 20 d (p<0.05). The TBARS values of T3 jerky were lower than those of other jerky samples (p<0.05).

Physicochemical Properties and Microorganisms on the Waste Composts of Mushroom (버섯 폐상퇴비의 이화학성과 미생물 조사)

  • Joo, Gil Jae;Woo, Cheol Joo;Rhee, In Koo
    • Current Research on Agriculture and Life Sciences
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    • v.20
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    • pp.49-54
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    • 2002
  • This study was conducted to investigate physicochemical and microbiological properties on waste composts of mushroom. The waste compost of mushroom consisted of 43.29% organic matter(O.M.), 27.0 O.M./Nitrogen, 1.60% total nitrogen, 46.48% water content, 0.64% salt content, 1.32% $P_2O_5$ 1.18% $K_2O$ and dry base. The microorganisms in the waste compost of mushroom were counted $1.6{\times}10^{10}cfu/g$. The main population of aerobic bacteria were Bacillus lentimobus, B. coagulans, B. brevis, Clostridium thermocellum, Escherichia coli, Streptomyces thermovulgaris, S. thermofuscus, Micropolyspora faeni, Aspergillus sp. and Penicillum sp..

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Effect of Powder-type Dried Alaska Pollack Addition on the Quality of Kimchi (북어 가루 첨가가 김치의 품질특성에 미치는 영향)

  • 이하영;백재은;한영실
    • Korean journal of food and cookery science
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    • v.19 no.2
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    • pp.254-262
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    • 2003
  • Powder-type dried pollack was added to Kimchi, the groups were stored at 4$^{\circ}C$, respectively, physicochemical, microbiological, and sensory properties of the Kimchi were examined according to the stored durations. The pH appeared to have almost similar values in the early stages of the fermentation. Generally, the groups with the additional powder-type dried Pollack had high pHs in the later stages of the fermentation. For the changes in the acidity, until the optimum edible period was reached, the groups with the additional powder-type dried Pollack required longer than those groups with additional fluid anchovy sauce. With regard to the salinity, there were no significant differences between the respective groups. For changes with regard to the reducing sugar, from the early to late fermentation stages, the greatest content was shown in the no additional protein source group, however, after the optimum edible period, there were no significant differences between the treated groups. In the case of free amino acids, the total quantities of Serine, Glycine, Threonine, Proline and Alanine, which all have a sweet taste, were usually found to have increased too almost twice those in the control groups, on the addition of 0.80% powder-type dried Pollack to the Kimchi. As a result of examining the microbiological properties, the time spent reaching the maximum numbers was longer in the additional powder-type dried Pollack groups. Similarly, the maximum numbers of lactic acid bacteria also appeared at the same time, but the difference between the treated groups was small, compared with the total numbers of microorganisms. As a result of the sensory evaluation, the treated groups generally gained better evaluations for several items. corresponded to the addition of 0.65% powder-type dried Pollack.