HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Thomas, M. E. C. Articles by Desobry, S. Search for Related Content PubMed PubMed Citation Articles by Thomas, M. E. C. Articles by Desobry, S.

Lactose/ß-Lactoglobulin Interaction During Storage of Model Whey Powders

Laboratoire de Physico-chimie et Génie Alimentaires, ENSAIA-INPL, 54500 Vandoeuvre-Lès-Nancy, France

Corresponding author: M. E. C. Thomas; e-mail: marie.thomas{at}ensaia.inpl-nancy.fr.

The objective of this study was to evaluate the presence or absence of interaction between lactose and ß-lactoglobulin during storage of model whey powders at different water activities (a_w). Model whey powders were prepared by colyophilization of lactose with increasing quantities of ß-lactoglobulin. These colyophilized ß-lactoglobulin:lactose powders, assigned as BL powders, were stored from 0.11 to 0.95 a_w. The water sorption behavior of BL powders was studied gravimetrically, and the state of lactose was investigated using differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). Before storage, BL powders were amorphous. After storage, a loss of water was observed on moisture sorption isotherms of BL powders. It was related to the formation of lactose crystals, detected by DSC and SEM analysis, and to the structural collapse of the powders. Water loss due to lactose crystallization was shifted to higher a_w with increasing ß-lactoglobulin content in BL powders. Moreover, kinetics of moisture sorption demonstrated that ß-lactoglobulin was also responsible for a slower crystallization process in BL powders. Then, the water sorption behavior of BL powders was very different from the behavior of the 2 compounds mixed after separate lyophilization. All these results pointed out interaction between lactose and ß-lactoglobulin, which appeared during lyophilization and still occurred during storage. This lactose/ß-lactoglobulin interaction stabilized model whey powders against lactose crystallization.

Key Words: ß-lactoglobulin • storage • lactose crystallization • co-lyophilization

Abbreviation key: a_w = water activity, BL powders = colyophilized ß-LG:lactose powders, B + L powders = powders composed of lactose and ß-LG lyophilized separately and mixed, BL(10:90) = colyophilized ß-LG:lactose powder with 10% ß-LG and 90% lactose, BL(40:60) = colyophilized ß-lactoglobulin:lactose powder with 40% ß-lactoglobulin and 60% lactose, DSC = differential scanning calorimetry, SEM = scanning electron microscopy

This article has been cited by other articles:

				A. Nasirpour, V. Landillon, B. Cuq, J. Scher, S. Banon, and S. Desobry Lactose Crystallization Delay in Model Infant Foods Made With Lactose, {beta}-Lactoglobulin, and Starch J Dairy Sci, August 1, 2007; 90(8): 3620 - 3626. [Abstract] [Full Text] [PDF]

				A. Nasirpour, J. Scher, M. Linder, and S. Desobry Modeling of lactose crystallization and color changes in model infant foods. J Dairy Sci, July 1, 2006; 89(7): 2365 - 2373. [Abstract] [Full Text] [PDF]