Dry heating of whey proteins: Structures, Aggregation and Gelling properties

Abstract : Dry heating is intensively used in pharmaceutical and food industry for viral and microbial decontamination of thermosensible proteins. It is rapidly developing as a pre-texturization process in food ingredient industry because it constitutes a means for improving the food proteins functionalities.[1] In this study, we investigated the chemical and structural changes that occur during dry heating under controlled physicochemical conditions and their consequences on the gelling properties of whey proteins. The water activity of the powder before dry heating and heat intensity (temperature/times) strongly accelerate the kinetic of denaturation/aggregation of whey proteins. The proteins composition and pH are the major factors that affect the structure of denatured and aggregated proteins. The kinetic of denaturation/aggregation of whey proteins was enhanced at pH 2.5 as compared to pH 6.5.[2] However, the presence of traces of lactose, as in case of commercially available WPI powders, modifies such kinetic order. At pH 2.5 the protein molecules were mainly linked together by intermolecular disulfide bonds, while at pH 6.5, covalent cross-links other than disulfide bonds were also involved in the formed aggregates. Stable non-native monomeric species of ?-Lg and ?-La exhibiting mass loss of 18 Da were generated during the course of dry heating, the proportion of which depends on pH. This mass loss has been attributed to N-term cyclisation for ?-La and to an internal cyclic imide formation for ?-Lg. Interestingly, the gelling properties were found to be highly dependent on the relative proportion of non-native monomers, soluble and insoluble aggregates that can be controlled by dry-heating pH. These results give new insight into the complex dry-heat induced modifications and aggregation pathways of whey proteins. They also give indications for a better control of physicochemical parameters of the powders at the industry to maintain the reproducibility of functionality of dry heated proteins ingredient.
Type de document :
Communication dans un congrès
5. International Symposium on Spray Dried Dairy Products, Jun 2012, Saint Malo (FR), France
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https://hal-agrocampus-ouest.archives-ouvertes.fr/hal-00849258
Contributeur : Céline Martel <>
Soumis le : mardi 30 juillet 2013 - 15:04:58
Dernière modification le : mercredi 21 mars 2018 - 16:08:07

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  • HAL Id : hal-00849258, version 1

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M. Gulzar, S. Bouhallab, M-H. Famelart, Valérie Lechevalier-Datin, Thomas Croguennec. Dry heating of whey proteins: Structures, Aggregation and Gelling properties. 5. International Symposium on Spray Dried Dairy Products, Jun 2012, Saint Malo (FR), France. 〈hal-00849258〉

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