| Titles |
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English :
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A trial for improving quality of bio-yoghurt using transglutaminase
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Arabic :
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استخدام انزيم الترانس جلوتامينيز في محاولة لتحسين جودة اليوجورت الداعم للحيوية
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| Abstract |
The aim of the present study was to investigate impact of adding transglutaminase (TGase) under different conditions on making bio-yoghurt. The TGase was added before (B) and after (A) heat treatment of milk (92 °C/10min), followed by pre-incubation at 40°C (B1, A1) or 50°C (B2, A2) for 1h and inactivation at 80°C/2min. Bio-yoghurt was prepared by inoculation the milk with yoghurt starter and B. infantis (1:1). Chemical properties of the bio-yoghurt were affected by both heat treatment of milk and pre-incubation temperatures of the enzyme. TGase mostly increased values of pH, NPN/TN and TVFA and decreased the acidity values. Viscosity and water holding capacity (WHC) were significantly increased when TGase was added, especially, after heat treatment of milk, followed by pre-incubation at 50 ºC/1 h (A2). The highest WHC values were correlated with minimum susceptibility to syneresis (STS). The control bio-yoghurt had the lowest WHC and the highest STS.
The maximum L. delbrueckii subsp. bulgaricus and B. infantis counts were found in fresh and stored bio-yoghurt made with TGase when added after heat treatment of milk with pre-incubation at 50°C/1h (A2). This increased counts of B.infantis throughout storage period and their populations remained above 107 cfu/g.
The higher scores for all sensorial properties were recorded for bio-yoghurt made with TGase added after heat treatment of milk (A1, A2), while the lowest scores were given for the control. Generally, bio-yoghurt of acceptable quality can be made from heated milk (92°C/10min) followed by treatment with TGase (0.07%) with activation of the enzyme at 50oC/1 h before fermentation.
Keywords: Transglutaminase, Bifidobacteria, Bio-yoghurt.
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| Publication year |
2011
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| Pages |
345-356
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| Availability location |
معهد بحوث الانتاج الحيوانى-شارع نادى الصيد- الدقى- الجيزة
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| Availability number |
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| Organization Name |
Animal Production Research Institute (APRI)
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| City |
المنصورة
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| serial title |
Journal Food and Dairy Science, Mansoura University
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| ISSN |
2090-3650
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| Author(s) from ARC |
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AGROVOC
TERMS |
Enzymes.
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| Proposed Agrovoc |
Bio-yoghurt;Bifidobacteria;Transglutaminase;
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| Publication Type |
Journal
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