Effects of "nine steaming nine sun-drying" on proximate composition, protein structure and volatile compounds of black soybeans. (May 2022)

• Record Type: Journal Article
• Authors: Liao, Xianyan; Wang, Shanshan; Li, Yingqiu; Michael Olajide, Tosin; Zhai, Xiaolin; Qian, Jiana; Miao, Song; Huang, Junyi
• Is Part Of: Food research international. Volume 155(2022)
• Publication Date: 2022-05
• Subjects: Black soybeans -- Heat treatment method -- Protein structure -- SPME-GCMS -- Principal component analysis; Food -- Analysis -- Periodicals; Food industry and trade -- Periodicals; Food industry and trade -- Canada -- Periodicals; Food Technology -- Periodicals; Food -- Periodicals; Food-Processing Industry -- Periodicals; Aliments -- Industrie et commerce -- Périodiques; Aliments -- Industrie et commerce -- Canada -- Périodiques; Aliments -- Recherche -- Périodiques; Food industry and trade; Canada; Periodicals; Electronic journals; 664.005
• DOI: 10.1016/j.foodres.2022.111070
• Languages: English
• ISSNs: 0963-9969

Abstract

Graphical abstract: Highlights: The effect of traditional processing technique "nine steaming nine sun-drying" on black soybeans (BS) was evaluated. Proximate composition, protein structure and volatile compounds were determined. Based on the PCA results, the effect of nine steaming and nine sun-drying on the volatile compounds of BS was discussed. Abstract: Nine steaming nine sun-drying is a traditional processing technology for food or medicinal materials. The dynamic changes of the proximate composition, protein structure and volatile compounds during nine-time steaming and sun-drying of black soybeans (BS) were studied. The proximate composition results showed that the content of protein, carbohydrate and fat of BS decreased after processing, whereas the relative content of amino acids remained basically unchanged. Protein structure was evaluated using Fourier transform infrared spectroscopy (FT-IR), Ultraviolet absorption spectroscopy (UV) and Fluorescence spectroscopy. FT-IR result revealed that the relative contents of β-sheet and β-turn of the secondary structure of black soybean protein isolate (BSPI) decreased but the relative contents of α-helix and random coil increased after steaming and sun-drying. The results of UV and fluorescence spectroscopy confirmed changes in the protein conformation. In addition, SPME-GCMS analysis demonstrated that hydrocarbons, alcohols and aldehydes were the main volatile compounds. The relative contents of 1-octen-3-ol and hexanal, which are the main sources of beany flavor decreased significantly compared with raw BS. Principal component analysis (PCA) results showed that the volatile compounds of nine steamed and nine sun-dried BS could be well distinguished during the process. These findings may therefore provide a scientific basis for the application of nine-time steamed and sun-dried BS in food industry and contribute to the understanding of process-induced chemical transformations in this ancient processing technique.