Effects of enzymolysis and fermentation on the antioxidant activity and functional components of a coarse cereal compound powder based on principal component analysis and microstructure study

Abstract

In this study, a coarse cereal compound powder (CCCP) was prepared through enzymolysis, fermentation, and joint treatment with 10 coarse cereal types as raw materials. Using 10 evaluation indices, namely the scavenging capacity of 1,1-diphenyl-2-picrylhydrazyl (DPPH•), 2,2′-azino-bis-(3ethylbenzthiazoline-6-sulfonic acid) (ABTS + ), hydroxyl (OH•) and superoxide anion (O 2 -), the Fe 2+ chelating capacity, the content of anthocyanin, flavone, soluble dietary fiber, reducing sugar and protein, antioxidant activity, and functional components of CCCP prepared by different methods were compared. Principal component analysis (PCA) was performed to establish a quality evaluation model of CCCP. Then, the effects of different treatments on the microstructure of CCCP were investigated. Two principal components (PCs) were extracted from PCA, with a cumulative contribution rate of 97.014%. In addition, the analysis of thermodynamic properties indicated that the initial gelatinization temperature of CCCP decreased after enzymolysis and fermentation and that it was easier to gelatinize. Particle size analyses revealed that different treatments could reduce the sample particles to different degrees. The average particle size in the three study groups decreased. Scanning electron microscopy (SEM) revealed that after different treatments, the samples were destroyed to different extents, which facilitated easy dissolution of active substances. Fourier-transformedinfrared spectroscopy (FTIR) revealed that the changes of CCCP functional groups after fermentation and joint treatment were more significant than those after enzymolysis.

Effect of fermentation on structural properties and antioxidant activity of wheat gluten by Bacillus subtilis

“…As the fermentation process progressed, the pores in the microstructure of the samples at 168 h gradually became dense and the surface gradually took on a fragmented appearance compared to the previous sheet. A tight 3D network structure was formed and it is hypothesized that these microstructural changes were due to proteolysis caused by proteases produced by Bacillus subtilis fermentation (27). The presence of a large number of pores in the microscopic samples also verified the experimental results of previous experiments in which protein degradation produced large amounts of FAA (28).…”

“…The α-helix consists of amino acid residues of N-H forming hydrogen bonds with the amino side and three amino acid residues of C=O. Since all peptide chain peptide bonds can form hydrogen bonds, the α-helix is very stable and the hydrogen bonds between amino acid residues of the significantly reduced α-helix conformation after fermentation are disrupted and gradually exposed to irregular structure by the action of microorganisms (25,27). This result explains that the microstructure of gluten becomes looser after fermentation and confirms that the large increase in FAA after fermentation is associated with changes in protein conformation.…”

Chemical profile and antioxidant activity of bidirectional metabolites from Tremella fuciformis and Acanthopanax trifoliatus as assessed using response surface methodology

“…The method described in Chen et al ( 31 ) was used with minor modification. Briefly, 50 μL of fermentation supernatant was collected in a 5 mL brown centrifuge tube, and then 1.5 mL of 0.07 mg/mL DPPH⋅ was added to each centrifuge tube, the samples were mixed, and then placed in the dark for 30 min.…”

Study on sensory properties and efficacy evaluation of whole wheat biscuits supplemented with peony seed oil and chia seed

“…DPPH radical scavenging activity increased when the content of PSO and CS increased. The increase in the free radical scavenging might be due to an increase in the content of polyphenols and carotenoids through the incorporation of PSO and CS (Ajila et al, 2008;Munoz et al, 2013;Chen et al, 2022). In addition, the observed increases with increasing PSO and CS content suggested the excellent antioxidant effect of PSO and CS in vitro (Santa Cruz Olivos et al, 2021;Lou et al, 2021).…”