Changes in properties of nano protein particles (NPP) of fish muscle stored at 4 °C and its application in food quality assessment

Abstract

Nano protein particles (NPP) in solutions of myofibrillar protein extracted from northern snakeheads (Channa argus) were studied. The results revealed that their particles size kept growing from 177 ± 2 nm at day 0–218 ± 5 nm at day 3 after slaughter while the corresponding ζ-potential enhanced from −19.0 ± 0.2 mv to −9.0 ± 1.2 mv. In addition, NPP became compact during this period, as inferred by their fractal dimension (df). These changes could be ascribed to the myofibrillar protein's structural alteration, including protein molecule conformation change. The simultaneous food quality assessments upon fish muscle illustrated that they all had very strong positive correlations to those two properties of NPP (r ≥ 0.87). This indicates that these two properties (particle size and ζ-potential) have potential to food quality assessment.