title: Rheology and microstructure of binary mixed gel of rice bran protein-whey: effect of heating rate and whey addition.
abstract: BACKGROUND
  Rice bran protein (RBP) is a valuable plant protein which has unique nutritional and hypoallergenic properties. Whey proteins have wide applications in the food industry, such as in dairy, meat and bakery products.
  
  
  RESULTS
  Whey protein concentrate (WPC), RBP and their mixtures at different ratios (1:1, 1:2, 1:5 and 1:10 w/w) were heated from 20 to 90 °C at different heating rates (0.5, 1, 5 and 10 °C min(-1) ). The storage modulus (G') and gelling point (Tgel ) of WPC were higher than those of RBP, indicating the good ability of WPC to develop stiffer networks. By increasing the proportion of WPC in mixed systems, G' was increased and Tgel was reduced. Nevertheless, the elasticity of all binary mixtures was lower than that of WPC alone. Tgel and the final G' of RBP-WPC blends were increased by raising the heating rate. The RBP-WPC mixtures developed more elastic gels than RBP alone at different heating rates. RBP had a fibrillar and lentil-like structure whose fibril assembly had smaller structures than those of WPC.
  
  
  CONCLUSIONS
  The gelling structure of the mixed gel of WPC-RBP was improved by adding WPC. Indeed, by adding WPC, gels tended to show syneresis and had lower water-holding capacity. Furthermore, the gel structure was produced by adding WPC to the non-gelling RBP, which is compatible with whey and can be applied as a functional food for infants and/or adults. © 2015 Society of Chemical Industry.
authors.affiliation: Department of Food Processing, Research Institute of Food Science and Technology (RIFST), PO Box 91735-147, Mashhad, Iran.
authors.forename: Ali
authors.initials: A
authors.lastname: Rafe
authors.affiliation: Department of Food Science and Technology, College of Agriculture and Food Science, Ayatollah Amoli Branch, Islamic Azad University, Amol, Iran.
authors.forename: Elnaz
authors.initials: E
authors.lastname: Vahedi
authors.affiliation: Department of Food Science and Technology, College of Agriculture and Food Science, Ayatollah Amoli Branch, Islamic Azad University, Amol, Iran.
authors.forename: Azadeh Ghorbani
authors.initials: AG
authors.lastname: Hasan-Sarei
mesh_terms: D055598:Chemical Phenomena; D019587:Dietary Supplements / Q000032:analysis / Q000191:economics; D005511:Food Handling / Q000379:methods*; D005525:Food-Processing Industry / Q000191:economics; D019648:Foods, Specialized / Q000032:analysis / Q000191:economics; D005782:Gels; D006358:Hot Temperature / Q000009:adverse effects; D006801:Humans; D007220:Industrial Waste / Q000032:analysis* / Q000191:economics; D007492:Iran; D055595:Mechanical Phenomena; D009753:Nutritive Value; D012275:Oryza / Q000737:chemistry*; D019441:Plant Epidermis / Q000737:chemistry*; D014674:Plant Proteins, Dietary / Q000737:chemistry* / Q000191:economics / Q000648:ultrastructure; D012212:Rheology / Q000379:methods; D012639:Seeds / Q000737:chemistry*; D013997:Time Factors; D044366:Transition Temperature; D014867:Water / Q000032:analysis; D000067796:Whey / Q000737:chemistry* / Q000191:economics; D000067816:Whey Proteins / Q000737:chemistry / Q000191:economics / Q000648:ultrastructure
chemical_list: D005782:Gels; D007220:Industrial Waste; D014674:Plant Proteins, Dietary; D000067816:Whey Proteins; D014867:Water
keywords: gel; gelling point; heating rate; microstructure; rice bran protein; whey protein