title: Characteristics and gel properties of gelatin from goat skin as affected by pretreatments using sodium sulfate and hydrogen peroxide.
abstract: BACKGROUND
  Goat skin can be used as an alternative raw material for gelatin production, in which pretreatment conditions can determine the characteristics or properties of the resulting gelatin. The present study aimed to investigate the effect of pretreatment using sodium sulfate (Na2SO4) and hydrogen peroxide (H2O2) on properties of goat skin gelatin.
  
  
  RESULTS
  Pretreatment of skin using Na2SO4 (0-1 mol L(-1)) increased the yield of gelatin in a concentration-dependent manner. When skins with prior Na2SO4 treatment were bleached using H2O2 (0-2 mol L(-1)), the resulting gelatin showed higher yield and gel strength than those without prior Na2SO4 treatment. All gelatins had α-chain as a major component, followed by β-chain. The degradation induced by H2O2 was lower in gelatin with prior Na2SO4 treatment. L* values increased with increasing H2O2 concentrations (P < 0.05) due to the bleaching effect of H2O2. With Na2SO4 and H2O2 pretreatments, gelatin gel had a finer and more ordered microstructure. Gelatin had an imino acid content of 217 residues/1000 residues with gelling and melting temperature of 22.49 and 32.28 °C, respectively.
  
  
  CONCLUSIONS
  The optimal pretreatment conditions for gelatin extraction from goat skin included soaking the skin in 0.75 mol L(-1) NaOH, followed by treatment using 0.75 mol L(-1) Na2SO4 and subsequent bleaching with 2 mol L(-1) H2O2. This resulted in gelatin with superior quality to the untreated counterpart.
authors.affiliation: Department of Food Technology, Faculty of Agro-Industry, Prince of Songkla University, Hat Yai, Songkhla, 90112, Thailand.
authors.forename: Sulaiman
authors.initials: S
authors.lastname: Mad-Ali
authors.affiliation: Department of Food Technology, Faculty of Agro-Industry, Prince of Songkla University, Hat Yai, Songkhla, 90112, Thailand.
authors.forename: Soottawat
authors.initials: S
authors.lastname: Benjakul
authors.affiliation: Department of Material Product Technology, Faculty of Agro-Industry, Prince of Songkla University, Hat Yai, Songkhla, 90112, Thailand.
authors.forename: Thummanoon
authors.initials: T
authors.lastname: Prodpran
authors.affiliation: Department of Food Science, College of Food and Agriculture, United Arab Emirates University, Al-Ain, 15551, United Arab Emirates.
authors.forename: Sajid
authors.initials: S
authors.lastname: Maqsood
mesh_terms: D000818:Animals; D005780:Gelatin / Q000737:chemistry*; D006041:Goats; D006861:Hydrogen Peroxide / Q000737:chemistry*; D008297:Male; D012867:Skin / Q000737:chemistry*; D013431:Sulfates / Q000737:chemistry*
chemical_list: D013431:Sulfates; C012036:sodium sulfate; D005780:Gelatin; D006861:Hydrogen Peroxide
keywords: gel strength; gelatin; goat skin; hydrogen peroxide; sodium sulfate