title: Preparation and Characterization of Antioxidant Peptides from Fermented Goat Placenta.
abstract: The goat placenta was fermented by Bacillus subtilis and the optimal fermentation parameters of strongest antioxidant capacity of peptides were obtained using response surface methodology (RSM). The effects of fermentation time, initial pH value and glucose content on the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity of the goat peptides were well fitted to a quadric equation with high determination coefficients. According to the data analysis of design expert, the strongest DPPH radical scavenging capacity value was obtained with the following conditions: content of glucose was 2.23%, initial pH value was 7.00 and fermentation time was 32.15 h. The DPPH radical scavenging capacity commonly referring antioxidant activity showed a concentration dependency and increased with increasing peptide concentration. The effects of temperature and pH were assessed to determine the stability of antioxidant peptides prepared from goat placenta. Antioxidant peptides showed good stabilities when temperature was lower than 70℃. However, the antioxidant peptides lost antioxidant activities rapidly under alkaline and excessive acid condition. Ultrafiltration technique was performed to separate fermentation broth with different Mw (molecular weight). It was found that peptides in the range of < 3 KDa mainly accounted for the antioxidant activities.
authors.affiliation: College of Food Science, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Yinchen
authors.initials: Y
authors.lastname: Hou
authors.affiliation: College of Food Science, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Jiejing
authors.initials: J
authors.lastname: Zhou
authors.affiliation: College of Food Science, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Wangwang
authors.initials: W
authors.lastname: Liu
authors.affiliation: College of Food Science, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Yongxia
authors.initials: Y
authors.lastname: Cheng
authors.affiliation: College of Food Science, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Li
authors.initials: L
authors.lastname: Wu
authors.affiliation: College of Food Science, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Gongming
authors.initials: G
authors.lastname: Yang
keywords: Bacillus subtilis; antioxidant; fermentation; goat placenta; peptide