title: Acidogenic fermentation characteristics of different types of protein-rich substrates in food waste to produce volatile fatty acids.
abstract: In this study, tofu and egg white, representing typical protein-rich substrates in food waste based on vegetable and animal protein, respectively, were investigated for producing volatile fatty acids (VFAs) by acidogenic fermentation. VFA production, composition, conversion pathways and microbial communities in acidogenesis from tofu and egg white with and without hydrothermal (HT) pretreatment were compared. The results showed HT pretreatment could improve the VFA production of tofu but not for egg white. The optimum VFA yields were 0.46g/gVS (tofu with HT) and 0.26g/gVS (egg white without HT), respectively. Tofu could directly produce VFAs through the Stickland reaction, while egg white was converted to lactate and VFAs simultaneously. About 30-40% of total protein remained in all groups after fermentation. Up to 50% of the unconverted soluble protein in the HT groups was protease. More lactate-producing bacteria, mainly Leuconostoc and Lactobacillus, were present during egg white fermentation.
authors.affiliation: School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310012, PR China; Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, Hangzhou 310012, PR China.
authors.forename: Dongsheng
authors.initials: D
authors.lastname: Shen
authors.affiliation: School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310012, PR China; Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, Hangzhou 310012, PR China. Electronic address: jun.yin77@gmail.com.
authors.forename: Jun
authors.initials: J
authors.lastname: Yin
authors.affiliation: School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310012, PR China; Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, Hangzhou 310012, PR China.
authors.forename: Xiaoqin
authors.initials: X
authors.lastname: Yu
authors.affiliation: School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310012, PR China; Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, Hangzhou 310012, PR China.
authors.forename: Meizhen
authors.initials: M
authors.lastname: Wang
authors.affiliation: School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310012, PR China; Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, Hangzhou 310012, PR China.
authors.forename: Yuyang
authors.initials: Y
authors.lastname: Long
authors.affiliation: School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310012, PR China; Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, Hangzhou 310012, PR China.
authors.forename: Jiali
authors.initials: J
authors.lastname: Shentu
authors.affiliation: School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310012, PR China; Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, Hangzhou 310012, PR China.
authors.forename: Ting
authors.initials: T
authors.lastname: Chen
mesh_terms: D000818:Animals; D004529:Egg White / Q000737:chemistry; D005232:Fatty Acids, Volatile / Q000737:chemistry / Q000378:metabolism*; D005285:Fermentation; D005502:Food; D007773:Lactates / Q000737:chemistry / Q000378:metabolism; D059013:Microbial Consortia / Q000235:genetics / Q000502:physiology; D011506:Proteins / Q000737:chemistry / Q000378:metabolism; D045730:Soy Foods; D018505:Waste Management / Q000379:methods*
chemical_list: D005232:Fatty Acids, Volatile; D007773:Lactates; D011506:Proteins
keywords: Acidogenic fermentation; Hydrothermal pretreatment; Protein; Stickland reaction; Volatile fatty acid