کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6484096 169 2013 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Proteases supplementation to high gravity worts enhances fermentation performance of brewer's yeast
ترجمه فارسی عنوان
مکمل پروتئازها به گرانش های بالا سبب افزایش عملکرد تخمیر مخمر آبجو می شود
کلمات کلیدی
تخمیر مخمر، پروتئاز، اتانول، آزاد آمونیو نیتروژن، کفپوش آبجو
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی بیو مهندسی (مهندسی زیستی)
چکیده انگلیسی
Nitrogen limitation, particularly prevailing in the case of high gravity beer brewing, results in poor yeast viability and even stuck or sluggish fermentations. Although wort contains abundant proteins and longer chain peptides, brewer's yeast does not assimilate them due to the fact that cells hardly secrete proteases during fermentation. The objective of this study was to investigate the possibility for utilizing unavailable nitrogen from two types of high gravity worts (20 °P and 24 °P) by adding three food-grade commercial proteases (Neutrase, Flavorzyme and Protamex) at the beginning of fermentations, respectively. Results showed that proteases supplementation significantly increased the FAN level and thus the amount of cell suspension in the later stages of fermentations (ca. 10 days later for 20 °P and 25 days later for 24 °P) (p < 0.05). Among the studied three proteases, we found that fermentations with Flavorzyme supplementation exhibited the best fermentation performance in terms of significantly improved wort fermentability, higher ethanol yield and flavor volatiles formation (p < 0.05). Furthermore, the foam of final beers produced by adding proteases was as stable as that of the control at each of the corresponding gravities.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochemical Engineering Journal - Volume 77, 15 August 2013, Pages 1-6
نویسندگان
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