Structural characterization of chelator-soluble and alkali-soluble pectins: Implications for juice quality

Pectin is a critical structural component in fruit juices, influencing various juice quality attributes. The current study investigates the chelator-soluble pectin (CSP) and alkali-soluble pectin (ASP) extracted from different juices and their relation to juice quality. This study also explored the impact of high-pressure homogenization (HPH) on the structural characteristics of CSP and ASP. Results indicate that HPH processing induced structural changes in CSP and ASP, leading to a reduction in branched rhamnogalacturonan-I (RG-I) structures. Furthermore, HPH was found to decrease both the degree of methyl-esterification (DM) and acetylation (DA) of CSP, resulting in distinct distribution patterns of methyl esters. Regarding the influence of pectin structure on juice quality, more non-methyl-esterified galacturonic acid blocks in CSP may lead to increased aggregation in juice. Additionally, the side chain structure of CSP plays a significant role in determining the particle size of the juice, and a lower homogalacturonan to RG-I ratio in CSP may enhance physical stability.