Pectin Fraction Interconversions:  Insight into Understanding Texture Evolution of Thermally Processed Carrots

Abstract

In situ changes in pectin fractions for thermally processed carrots were related to textural changes. The texture of pretreated and subsequently thermally processed carrot disks was determined. Alcohol insoluble residue (AIR) was extracted from the pretreated and thermally processed tissues. The AIR was characterized in terms of the degree of methylation (DM) and changes in pectin fractions. Distinct differences in texture and DM were observed during thermal processing. Pretreatment conditions that induced a significant decrease in DM showed better textures. Demethoxylation caused interconversion of pectin fractions, water soluble pectin (WSP) changing into water insoluble pectin [chelator (CSP) and alkali (NSP) soluble pectin]. This process was reversed during cooking accompanied by remarkable alterations in molecular weight (MW) distribution patterns. The WSP depicted polydisperse MW distribution patterns, strongly dependent on the pretreatment condition. Confirmatory results of interconversions of pectin fractions (WSP, NSP) were demonstrated by the MW distribution patterns and neutral sugar profiles. All thermal related transformations of pectin structural parameters were decelerated by lowering the DM.

The Antioxidant Properties of Pectin Fractions Isolated from Vegetables Using a Simulated Gastric Fluid

“…These differences may result from the ultrafiltration procedure used in the present study, which leads to the removal of components with low molecular weight and insoluble fibre. The Mw of the obtained pectins (Table 1) were similar to those of the sodium carbonate-soluble pectins of white cabbage, carrot, and onion obtained in previous studies [32][33][34]. BO-P, DC-P, AC-P, and CA-P were hydrolyzed with 2 M TFA to release the monosaccharides typically present in pectins.…”

Process–Structure–Function Relations of Pectin in Food

“…High-temperature processing of solid plant-based foods has been demonstrated to induce a shift from water-insoluble pectin to WSP in green beans (Recourt et al 1996) and carrots (De Roeck et al 2008;Ng and Waldron 1997;Sila et al 2006a;Siliha et al 1996). In addition, the applied thermal treatments altered the neutral-sugar content and composition of the different pectin fractions (De Roeck et al 2008;Ng and Waldron 1997;Sila et al 2006a;Siliha et al 1996) Figures 5 A and B respectively.…”

Enzyme infusion prior to thermal/high pressure processing of strawberries: Mechanistic insight into firmness evolution

“…In order to extract the water soluble pectin fraction (WSP), boiling deionized water (45 mL) was added to AIR (0.25 g) on a heated stirring plate (Sila, Doungla, Smout, Van Loey, & Hendrickx, 2006). The mixture was boiled for 5 min, then cooled under running tap water and filtered.…”