Physical, chemical and flavour quality of non-fat yogurt as affected by a ß-glucan hydrocolloidal composite during storage

In this study, a possible use of ß-glucan hydrocolloidal composite as a fat replacer in the manufacture of non-fat yogurts was investigated. The yogurts with added ß-glucan composite were compared with non-fat yogurt without addition of ß-glucan composite and the samples were analysed for physical, chemical and sensory attributes after 1, 7 or 15 d of storage. Fat and protein contents of the experimental yogurts were identical, while ash content differed. Addition of ß-glucan composite did not show a significant change of pH, titratable acidity, acetaldehyde, volatile fatty acids and tyrosine contents at any storage time. Titratable acidity and tyrosine content increased significantly throughout storage. Gel firmness and water-holding capacity in the yogurts were not influenced by addition of ß-glucan composite, but these variables decreased with storage time. Addition of ß-glucan composite and storage time caused a decrease in whey separation. Viscosity values in the yogurts increased by addition of ß-glucan composite and storage time. Sensory results indicated a preference for control yogurts; however, use of low levels of ß-glucan composite in the production of non-fat yogurt gave satisfactory sensory scores. Yogurts containing 0.25% or 0.50% ß-glucan hydrocolloidal composite were acceptable by expert panels and had scores similar to the control yogurt. © 2007 Elsevier Ltd. All rights reserved.Firat University Scientific Research Projects Management UnitThis work was supported by a grant from the Cukurova University Academic Research Projects Unit (Project No. ZF.2005. BAP.16). The authors wish to thank Professor G.E. Inglett and Dr. G. Konuklar (Cereal Products & Food Science Research Unit, NCAUR, ARS, USDA, Peoria, IL, USA) for supplying ß -glucan hydrocolloidal composite used in the manufacture of low-fat yogurt