Mechanistic understanding of the improvement of the digestive retention of anthocyanins by modified pectin after high-pressure homogenization of strawberry pulp

The physical property and retention of anthocyanins (ACNs) during digestion of strawberry pulp after high-pressure homogenization (HPH) (20/60/100/140 MPa) were analyzed, and their correlations with the three pectin samples—water-soluble (WSP), chelator-soluble (CSP) and sodium carbonate-soluble (NSP)—were evaluated. Compared to the control, the particle size and apparent viscosity of the pulp decreased, and the retention of total ACNs increased, reaching the highest at 100 MPa, with an increase of 15.41%. After HPH treatment, the alcohol-insoluble residue (AIR) and WSP content increased, while the molecular weight (Mw), and microstructural tightness of the three pectin samples decreased. The homogalacturonan (HG) region of WSP increased, and the degree of methylesterification (DM) of CSP decreased. Furthermore, the important role of the modified pectin in the increased retention of ACNs during digestion was reaffirmed by the binding ratio and retention of ACNs in pectin-ACNs complexes. The effect of HPH treatment on the quality attributes of fruits and vegetable juice attracted a lot of attention. This study confirmed that the modification of pectin in HPH-treated strawberry pulp, which promoted its interaction with ACNs, could effectively enhance the retention of ACNs during digestion. Consequently, this study provides the fundamental theory and technological support for the potential to elevate the nutritional value of fruits and vegetables.