title: Comparison of physicochemical and functional properties of duck feet and bovine gelatins.
abstract: BACKGROUND
  Previous studies have indicated that duck feet are a rich source of gelatin extractable from avian sources. In this study, the physicochemical and functional properties of avian gelatin extracted from duck feet (DFG) with acetic acid were compared with those of commercial bovine gelatin (BG).
  
  
  RESULTS
  The yield of DFG obtained in this study was 7.01 ± 0.31%. High-performance liquid chromatography analysis indicated that the imino acid content was slightly lower for DFG compared with BG (P < 0.05). Differences in molecular size and amino acids between DFG and BG were also observed. The isoelectric points of DFG and BG were at pH 8 and 5 respectively, and the overall protein solubility of BG was higher than that of DFG. Gels prepared from BG exhibited higher bloom strength, viscosity and clarity and were darker in colour compared with DFG gels (P < 0.05). The gelling and melting points of BG were 21.8 and 29.47 °C respectively, while those of DFG were 20.5 and 27.8 °C respectively. BG exhibited slightly better emulsifying and foaming properties compared with DFG.
  
  
  CONCLUSIONS
  Although some differences between DFG and BG were observed, the disparities were small, which indicates that DFG could be exploited commercially as an alternative source of gelatin. © 2016 Society of Chemical Industry.
authors.affiliation: Food Biopolymer Research Group, Food Technology Division, School of Industrial Technology, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia.
authors.forename: Yau-Hoong
authors.initials: YH
authors.lastname: Kuan
authors.affiliation: Food Biopolymer Research Group, Food Technology Division, School of Industrial Technology, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia.|Food Biopolymer Research Group, Food Science and Technology Department, Damghan Branch, Islamic Azad University, Damghan, Semanan, Iran.
authors.forename: Abdorreza Mohammadi
authors.identifier: http://orcid.org/0000-0002-6065-5098
authors.initials: AM
authors.lastname: Nafchi
authors.affiliation: Food Biopolymer Research Group, Food Technology Division, School of Industrial Technology, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia.
authors.forename: Nurul
authors.initials: N
authors.lastname: Huda
authors.affiliation: Food Biopolymer Research Group, Food Technology Division, School of Industrial Technology, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia.
authors.forename: Fazilah
authors.initials: F
authors.lastname: Ariffin
authors.affiliation: Food Biopolymer Research Group, Food Technology Division, School of Industrial Technology, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia.
authors.forename: Alias A
authors.initials: AA
authors.lastname: Karim
mesh_terms: D019342:Acetic Acid; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002417:Cattle; D004372:Ducks; D063427:Food Quality; D005528:Foot; D005780:Gelatin / Q000737:chemistry*; D007098:Imino Acids / Q000032:analysis; D012212:Rheology; D012995:Solubility
chemical_list: D000596:Amino Acids; D007098:Imino Acids; D005780:Gelatin; D019342:Acetic Acid
keywords: bovine gelatin; duck feet gelatin; emulsifying properties; foaming properties; physicochemical properties; rheological properties