Stabilization of a collagen peptide-cranberry juice by three functional polysaccharides with different charge characteristics

Preventing the precipitation of collagen peptide-fruit juice drinks during production and storage is a current challenge. This study investigated the efficiency and mechanism of β-glucan, low methoxyl pectin, and chitosan (a neutral, anionic, and cationic polysaccharide, respectively) for enhancing the stability of a fish collagen peptide-cranberry juice drink. The effects of mixing sequence, mixing temperature, pH, and polysaccharide concentration on stability were studied by conducting centrifugal precipitation rate, turbidity, relative turbidity, zeta potential, rheology, confocal laser scanning microscopy, and storage (4 °C, 25 °C, 40 °C, 14 d) experiments. All three polysaccharides effectively improved the stability of the drink mixture, but to different extents, as the stability was highly dependent on pH and the type and concentration of the polysaccharide. Steric hindrance, electrostatic repulsion, and increased viscosity were the main reasons underlying the improvements in the stability of the system. The stability mechanisms were also related to a competition or ternary complex mechanism. The results of storage experiments showed that chitosan could only temporarily stabilize system (25 °C, 2d), whereas β-glucan (4 °C, 14d) and low-methoxyl pectin (4 °C, 25 °C, 14d) provided the continuous stability. Overall, these results can provide important guidance for the application of these three polysaccharide types in the beverage industry to develop and select ideal formulations for collagen peptide-juice drinks.