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Systematical characterization of physiochemical and rheological properties of thermal‐induced polymerized whey protein
Author(s) -
Zhang Xuefei,
Sun Xiaomeng,
Gao Feng,
Wang Jiaqi,
Wang Cuina
Publication year - 2018
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.9264
Subject(s) - chemistry , rheology , whey protein , zeta potential , particle size , denaturation (fissile materials) , viscosity , apparent viscosity , whey protein isolate , food science , chromatography , chemical engineering , materials science , nuclear chemistry , nanoparticle , engineering , composite material
BACKGROUND Effects of pH (6–8), protein concentration (60–110, g kg −1 ), heating temperature (70–95 °C) and time (5–30 min) on physiochemical and rheological properties of thermal‐induced polymerized whey protein isolate (PWP) were systematically investigated. Degree of denaturation, particle size, zeta potential, free sulfhydryl group content, surface hydrophobicity and apparent viscosity were determined. RESULTS Heating whey protein above 75 °C at pH 7 or 8 resulted in denaturation of 80–90% whey protein. pH variation had a remarkable influence on particle size of samples ( P < 0.05), whereas heating temperature and time did not generate significant changes. Zeta potential of PWP samples fell in the range of −30 to −40 mV. Free sulfhydryl group content of PWP samples decreased with increasing level regarding each factor. Surface hydrophobicity analysis showed that samples at higher pH or concentration became less hydrophobic, and increasing heating temperature or time resulted in higher hydrophobicity index. Time sweep test revealed that increasing protein concentration, heating temperature or time led to higher apparent viscosity. Flow behavior of PWP samples approached Newtonian character as protein concentration, heating temperature or time decreased. CONCLUSION Systematic data may provide helpful information in designing a heating process for dairy products and application of PWP in the food industry. © 2018 Society of Chemical Industry