Effect of heat tretment and homogenization on the rheological properties of aqueous parsnip suspensions

Summary, in English

Parsnip (Pastinaca sativa) suspensions, at concentrations corresponding to a dilute and concentrated regime, were subjected to pasteurization, and heat treatments that favored beta-elimination reactions and pectin methyl esterase activity. The different heat treatments were combined with homogenization. Physicochemical properties such as content of insoluble/soluble material and insoluble/soluble pectin were measured together with particle and rheological properties. Pectin methyl esterase activity led to a high yield of insoluble material and insoluble pectin, whereas beta-elimination led to a high yield of soluble material and solubilized pectin. Homogenization after heat treatment resulted in increased solubilization of the pectin, especially after beta-elimination reactions. Parsnip suspensions subjected to pectin methyl esterase activity exhibited the highest elastic modulus most likely due to the cross-linked pectin conferring rigidity to the cell walls. The content of insoluble material and the particle properties such as size and rigidity are important factor for the rheological properties of concentrated parsnip suspensions.

• Author: Alejandra Castro; Björn Bergenståhl; Eva Tornberg
• Department/s: Division of Food and Pharma; Department of Food Technology, Engineering and Nutrition
• Publishing year: 2013
• Language: English
• Pages: 383-392
• Publication/Series: Journal of Food Engineering
• Volume: 117
• Issue: 3
• Full text: - 617 kB; Download statistics
• Links: http://dx.doi.org/10.1016/j.jfoodeng.2013.02.008
• Document type: Journal article
• Publisher: Elsevier
• Topic: Food Engineering
• Keywords: pectin; beta-elimination; pectin methyl esterase; homogenization; rheological properties
• Status: Published
• ISBN/ISSN/Other: ISSN: 0260-8774