Edible blueberry anthocyanin-loaded soybean protein nanofibers/sodium alginate hydrogel beads: Freshness detection of high protein drinks.

In this study, blueberry anthocyanins were embedded in soybean protein nanofibers/sodium alginate hydrogel (SNF/SA) to prepare an edible pH-responsive chromogenic hydrogel bead for freshness monitoring of milk, soybean milk and dual protein drinks. The results showed that the encapsulation rate of blueberry anthocyanins was 87.43 %. The loading of blueberry anthocyanins achieved the pH-response color development of SNF/SA hydrogel beads. SS/B hydrogel beads (SNF/SA loaded with 0.1 g anthocyanins) showed good color stability when stored in different environments for 96 h. When the SS/B hydrogel beads were used for detecting the protein drinks freshness, fresh drinks and spoiled drinks could be clearly distinguished by color of hydrogel beads. In addition, SS/B hydrogel beads promoted protein digestibility of protein drinks and protected anthocyanins from degradation in the stomach environment. Therefore, the hydrogel bead was accessible and edible, it could provide a possibility for monitoring the quality changes of fresh protein drinks.