Chemical properties of water-soluble pectins in hot- and cold-break tomato pastes

• Published in: Food chemistry Vol. 93; no. 3; pp. 409 - 415
• Main Authors: Lin, Huajuan, Qin, Xiaoming, Aizawa, Koichi, Inakuma, Takahiro, Yamauchi, Ryo, Kato, Koji
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.12.2005; Elsevier
• Subjects: acid hydrolysis; Biological and medical sciences; cell wall components; Chemical properties of pectins; chemical structure; Cold-break tomato paste; extraction; Food additives; food composition; Food industries; food processing; fractionation; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; galacturonans; General aspects; homogalacturonan; Hot-break tomato paste; pasting properties; pectins; physicochemical properties; polygalacturonase; rhamnogalacturonan; sugars; tomato paste; water solubility; Water-soluble pectins; yields; Chemical properties of pectins; Cold-break tomato paste; Water-soluble pectins; Hot-break tomato paste; Water; Cold; Pectin; Food additive; Gelling agent; Tomato concentrate; Chemical properties; Dietary fiber; Polysaccharide
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2004.12.009

Tomato fruit paste prepared by hot-or cold-break processing was extracted with water to obtain a water-soluble pectin (HP or CP) and a water-insoluble matter (HR or CR). HP yield was approximately twice that of CP, while those of the water-insoluble matters were similar. Comparing sugar compositions, HP (GalA-rich) was remarkably different from CP (neutral sugars-rich), although their water-insoluble matters were similar. This result indicates that the solubilizations of cell-wall-associated pectins in HB and CB were similar, but the release of GalA by endogenous pectin-degrading enzymes in CB was remarkable. Fractions separated by a DEAE–cellulose column from HP (HP3, HP4, HP5) were also rich in GalA, while those from CP (CP2, CP3, CP4) were all rich in neutral sugar. However, the ratios of individual sugars of CP fractions were very different. Unlike the neutral sugar-rich fractions, the GalA-rich ones treated with polygalacturonase were mostly degraded. In addition, the chemical structure of HP5 (homogalacturonan) and CP4 (rhamnogalacturonan) were compared after mild acid hydrolysis.