Preparation and characterisation of wheat starch-based aerogels for procyanidin encapsulation to enhance stability

Procyanidins (PC) are formed by the polymerisation of flavan-3-ol monomers, which have excellent bioactivity and present great health benefits. However, the application range of the PC is greatly limited due to their poor stability. Therefore, in this study, starch aerogels were used as carriers to encapsulate PC. After screening, wheat starch aerogel (WSA) was finally chosen to encapsulate PC. Afterward, characterization (SEM, XRD, FT-IR, TGA and BET), stability testing, investigations on antioxidant activity, and in vitro tests simulating digestion were carried out. The results of relevant characterization showed that the micro surface structure of the procyanidin wheat starch aerogel (PC-WSA) presented a network structure, and PC were encapsulated in WSA. In addition, PC-WSA allows PC to be released in the final stage of simulated digestion. Meanwhile, the results of antioxidant experiments indicate that PC-WSA exhibits antioxidant activity after encapsulating PC. Moreover, the retention of PC in PC-WSA was still 53.63 ± 3.23% when stored at 70 °C for 20 days. After 6 days of light exposure, the retention of PC in PC-WSA under different light sources was all above 85%, which was higher than that of PC. In conclusion, the wheat starch aerogel could improve the stability of PC and has great potential for application.