کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
605325 880343 2013 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Sequential preheating and transglutaminase pretreatments improve stability of whey protein isolate at pH 7.0 during thermal sterilization
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی شیمی کلوئیدی و سطحی
پیش نمایش صفحه اول مقاله
Sequential preheating and transglutaminase pretreatments improve stability of whey protein isolate at pH 7.0 during thermal sterilization
چکیده انگلیسی

Whey protein isolate (WPI) is a potential ingredient to manufacture shelf-stable transparent beverages if proteins are heat stable, i.e., without causing turbidity, precipitation and gelation after the required thermal processing to obtain commercial sterility (138 °C for 8 s or longer). However, information is lacking about stability of WPI during heating at 138 °C. Furthermore, novel technology and mechanistic understanding on how to produce clear products after heating systems with >5% WPI, particularly with salt, is needed. In this work, 5% w/v WPI was pretreated by microbial transglutaminase (mTGase) at three levels for 1–15 h at 50 °C, with and without prior preheating at 80 °C for 15 min. Heat stability of the pretreated samples at pH 7.0 and 0, 50, and 100 mM NaCl was evaluated at 138 °C. Samples pretreated by mTGase for a greater extent demonstrated improved heat stability. Samples subjected to sequential preheating and mTGase pretreatments produced clear dispersions even after heating at 138 °C for 30 min in the presence of 0 and 50 mM NaCl at pH 7. All pretreatments increased the magnitude of zeta-potential and resistance against thermal denaturation. The sequentially-pretreated WPI was the most heat-resistant, having decreased hydrodynamic diameter (<36 nm) during extended heating at 138 °C and 50 mM NaCl. The present study demonstrates the feasibility of using sequential preheating and mTGase pretreatments to develop sterilized beverage products with a high content (5% w/v) of whey protein and yet of transparent appearance at ambient temperatures.

Figure optionsDownload as PowerPoint slideHighlights
► Sequential preheating and mTGase pretreatments improved UHT stability of WPI.
► Hydrodynamic diameter (d4,3) increased after sequential pretreatments.
► Cross-linked proteins are resistant against aggregation during UHT.
► Cross-linked proteins are dissociated during UHT and restructured to bigger particles.
► Transparent dispersions corresponded to d4,3 smaller than 40 nm.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Food Hydrocolloids - Volume 31, Issue 2, June 2013, Pages 306–316
نویسندگان
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