Supramolecular structure of gel-forming systems of pectins of different origin

• Published in: Food hydrocolloids 1998, Vol.12 (3), p.309-312
• Main Authors: Bogatyrev, Vladimir A, Shchyogolev, Sergei Yu, Dykman, Lev A, Shkodina, Olga G, Ptitchkina, Natal’ya M
• Format: Article
• Language: English
• Subjects: chemical structure; Citrus; gelation; particle size; pectins; pumpkins; temperature; turbidity
• ISSN: 0268-005X; 1873-7137
• DOI: 10.1016/S0268-005X(98)00019-8

Two pectin preparations (citrus ‘Copenhagen Pectin’ and that derived from pumpkin) that formed opalescing suspensions in aqueous media were investigated. The values of concentration and mean size of supramolecular particles determined by a spectroturbidimetric method were used as indicators of the structural heterogeneity of the preparations. According to these criteria, the pumpkin pectin preparation had a higher degree of structural heterogeneity than that of the citrus pectin. The process of gel formation in the systems studied did not cause any significant turbidimetric effects that could have pointed to the formation of particles of a new phase. Resuspended fractions of the supramolecular particles, which were obtained from the pumpkin preparations by centrifugation, formed gels in acid solutions of sucrose. In this case, the temperature of gel formation was close to that recorded for the initial preparations. However, it was about 10°C below the temperature of gel formation registered for the supernatants of pumpkin pectin preparations that remained after removal of the supramolecular particles by centrifugation.