Industry-scale microfluidization as a potential technique to improve solubility and modify structure of pea protein

摘要

Modification in solubility and structure of pea protein by industry-scale microfluidization (ISM) at varying pressure (30, 60, 90 and 120 MPa) was investigated. ISM treatment significantly enhanced the solubility and turbidity of pea protein, and solubility was increased by 3.78 folds at 120 MPa. Meanwhile, particle size was reduced, and specific surface area was increased with the increase of pressure. Thick block-like structure was remarkably destructed, which was gradually changed to regular thin fragments. After ISM treatment, bathochromic shift and the increased intensity of intrinsic fluorescence were observed for pea protein. Moreover, surface hydrophobicity and free sulfhydryl groups contents were heightened, indicating protein molecular unfolding/denaturation. SDS-PAGE analysis showed the breaking of disulfide bonds, the degradation of protein fractions into small molecular peptides and the transformation of insoluble protein molecules or aggregates into soluble particles. These findings suggested that ISM treatment would be a potential and effective technique to improve solubility of pea protein, and it would be of great significance to develop pea protein-based food systems. Industrial relevance: Poor solubility of pea protein limited its utilities in food industries. Physical modification has attracted much attention owing to no involve of exogenous substances. One of the greatest challenges of the food industry is to find the feasible physical processing technology which could achieve the aim of industrially improving the solubility of commercial pea protein. An industry-scale microfludizer (ISM) recently designed in our laboratory overcame the drawbacks of small microchannel, low processing capacity and easily been blocked of traditional microfluidizers, which was an industrial scale microfluidizer device. The present research provided information that ISM was a potential and useful industrial technique to improve solubility of pea protein, and pea protein with the enhanced solubility may be beneficial to develop health and nutritional products based on plant protein.