Changes on the Structural and Physicochemical Properties of Conjugates Prepared by the Maillard Reaction of Black Bean Protein Isolates and Glucose with Ultrasound Pretreatment

Abstract

The conjugates of black bean protein isolate (BBPI) and glucose (G) were prepared via the wet heating Maillard reaction with ultrasound pretreatment. The physicochemical properties of UBBPI-G conjugates prepared by ultrasound pretreatment Maillard reaction had been compared with classical Maillard reaction (BBPI-G). The reaction rate between BBPI and glucose was speeded up by ultrasound pretreatment. A degree of glycation (DG) of 20.49 was achieved by 2 h treatment for UBBPI-G, whereas 5 h was required using the classical heating. SDS-PAGE patterns revealed that the BBPI-G conjugates with higher molecular weight were formed after glycosylation. The results of secondary structure analysis suggested that the α-helix and β-sheet content of UBBPI-G were lower than that of BBPI-G. In addition, UBBPI-G conjugates had exhibited bathochromic shift compared with BBPI by fluorescence spectroscopy analysis. Finally, UBBPI-G achieved higher level of surface hydrophobicity, solubility, emulsification property and antioxidant activity than BBPI and BBPI-G (classical Maillard reaction).

The Effect of (−)-Epigallocatechin-3-Gallate Non-Covalent Interaction with the Glycosylated Protein on the Emulsion Property

“…As provided in Table 1, compared with BBPI, the ordered structure (α-helix structure + β-sheet structure) content of BBPI-G decreased significantly, while the disordered structure (β-turn structure + random coil structure) content increased significantly. The results showed that the secondary structure of BBPI changed significantly after Maillard reaction and turned to a more disordered direction [14]. This may be due to the fact that the interaction between BBPI and polysaccharide molecules affected the hydrogen bonding and van der Waals forces between molecules, which broke up the stability of the protein secondary structure [29].…”

“…As shown in Figure 3, after the Maillard reaction, the EAI and ESI of BBPI increased from 42.53 m 2 /g and 18.98 min to 52.82 m 2 /g and 22.44 min, respectively. This may be because glucose was a hydrophilic sugar with a polyhydroxy structure and the –OH group of glucose in BBPI-G promoted the adsorption between proteins and water molecules through its hydrogen bonding ability [14]. At the same time, based on the infrared data above, we could obtain that the covalent grafting of the sugar chain led the protein structure to be more disordered, which optimized the emulsification performance [4].…”

“…The Maillard reaction products were named as BBPI-G. In our previous study [14], the graft degree (DG) of glycosylated black bean protein under this condition was 18.83%. The BBPI-G was characterized by SDS-PAGE and fluorescence spectroscopy.…”

“…The infrared spectrum with a wave number range of 4000–400 cm −1 was determined with a resolution of 4 cm −1 and a scanning frequency of 64 times. The curve fitting process of the FTIR spectra was computed by Peakfit Version 4.12 (SeaSolve software company, San Jose, CA, USA) [14].…”

Glycation of Animal Proteins Via Maillard Reaction and Their Bioactivity

“…Different researchers affirm that glycation via Maillard reaction could cause structural changes in protein molecules, which could generate a wide range of compounds or Maillard reaction products (MRP), which would lead to the formation of conjugates and that these could contribute to the generation or increase of antioxidant capacity [59].…”