Impact of high-pressure homogenization on the homogalacturonan and rhamnogalacturonan-I regions of pectin in strawberry pulp and their interaction with anthocyanins.

The effects of high-pressure homogenization (HPH, 100 MPa) on the physicochemical and structural characteristics of homogalacturonan non-de-esterified (HG-ND), homogalacturonan de-esterified (HG-D), and rhamnogalacturonan-I (RG-I)-enriched fractions of pectin in strawberry pulp were investigated. Furthermore, the relationship between these pectin fractions and the binding and digestive stability of anthocyanins (ACNs) was analyzed. Following HPH-100 MPa treatment, the yields of the HG-ND, HG-D, and RG-I-enriched fractions significantly increased, accompanied by a slight decrease in the molecular weight (Mw). The HG regional proportion (%) in the HG-ND and HG-D-enriched fractions and the RG-I regional proportion (%) in the RG-I-enriched fraction exceed 90 %. Overall, HPH-100 MPa treatment had a limited impact on the structure of both the HG and RG-I regions. The HG-ND and HG-D-enriched fractions exhibited greater digestive stability and binding affinity to ACNs compared to the RG-I-enriched fraction. The results provide insights into the interactions between the structural regions of pectin and ACNs.