title: Evaluation of tilapia skin gelatin as a mammalian gelatin replacer in acid milk gels and low-fat stirred yogurt.
abstract: Tilapia skin gelatin (TSG) was studied in a 3-stage process (cooling, annealing, and heating) for pure gelatin gels and in a 4-stage process (acidification, cooling, annealing, and heating) for acid milk gels and cultured yogurt. The aim was to evaluate the use of TSG as a replacement for mammalian gelatin in yogurt. In pure TSG gels, stronger gels with higher melting temperatures were formed with increasing TSG concentrations. Compared with bovine gelatin (BG), which gelled at a concentration of 2.5%, TSG gels had lower gelling (14.1°C) and melting (24°C) temperatures but comparable storage moduli during annealing. In acid milk gels, addition of TSG increased the firmness of the gels with increasing concentration. Gelling and melting points of TSG in milk gels were observed at sufficient concentrations during cooling and heating. Strands and sheets were observed in the electron micrographs of milk gels with 1% TSG and a very dense structure was observed with 2.5% TSG. Yogurt with 0.4% TSG had similar viscosity, consistency, pseudoplasticity, and thixotropy as yogurt containing 0.4% BG; no difference was perceived by sensory panelists according to a triangle test. Addition of 0.4% TSG completely prevented whey separation from the acid milk gel and yogurt. The results suggest that TSG could be a suitable replacement for mammalian gelatin in low-fat stirred yogurt.
authors.affiliation: Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Technology and Business University, Beijing 100048, China; School of Agriculture and Food Sciences, The University of Queensland, Brisbane, 4072, Australia.
authors.forename: Zhihua
authors.initials: Z
authors.lastname: Pang
authors.affiliation: School of Agriculture and Food Sciences, The University of Queensland, Brisbane, 4072, Australia.
authors.forename: Hilton
authors.initials: H
authors.lastname: Deeth
authors.affiliation: Food Science and Technology Programme, Department of Chemistry, National University of Singapore, 117543, Singapore; National University of Singapore (Suzhou) Research Institute, Suzhou, Jiangsu 215123, China.
authors.forename: Hongshun
authors.initials: H
authors.lastname: Yang
authors.affiliation: School of Agriculture and Food Sciences, The University of Queensland, Brisbane, 4072, Australia.
authors.forename: Sangeeta
authors.initials: S
authors.lastname: Prakash
authors.affiliation: School of Agriculture and Food Sciences, The University of Queensland, Brisbane, 4072, Australia. Electronic address: n.bansal@uq.edu.au.
authors.forename: Nidhi
authors.initials: N
authors.lastname: Bansal
mesh_terms: D000818:Animals; D002417:Cattle; D005780:Gelatin; D005782:Gels / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D008892:Milk / Q000737:chemistry*; D012212:Rheology; D017210:Tilapia; D014783:Viscosity; D015014:Yogurt
chemical_list: D005782:Gels; D005780:Gelatin
keywords: microstructure; rheology; sensory; tilapia skin gelatin; yogurt