Isothermal Calorimetry Study of Calcium Caseinate and Whey Protein Isolate Edible Films Cross-Linked by Heating and γ-Irradiation

• Published in: Journal of agricultural and food chemistry Vol. 50; no. 21; pp. 6053 - 6057
• Main Authors: Letendre, M, D'Aprano, G, Delmas-Patterson, G, Lacroix, M
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 09-10-2002
• Subjects: Agar - pharmacology; Animal, plant, fungal and microbial proteins, edible seaweeds and food yeasts; Biodegradation, Environmental; Biological and medical sciences; Calcium - chemistry; Calorimetry, Differential Scanning - methods; Carboxymethylcellulose Sodium - pharmacology; Caseins - chemistry; Cross-Linking Reagents; Disulfides - chemistry; Drug Interactions; Food industries; Food Packaging; Food Preservation; Fundamental and applied biological sciences. Psychology; Gamma Rays; Glycerol - pharmacology; Hot Temperature; Milk Proteins - chemistry; Pectins - pharmacology; Thermodynamics; Water; Whey Proteins; polysaccharides; Caseinate; heat of wetting; Vehicle(excipient); Glycerol; Agar; Immobilization; Molecular interaction; Pectin; Gamma irradiation; Methylcellulose; Milk protein; Isothermal calorimeter; Heating; Edible film; carboxymethylcellulose; Biofilm; Application method; isothermal calorimetry; Whey protein; edible films; cross-links
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf011689+

The contribution of thermal and radiative treatments as well as the presence of some excipients, namely glycerol, carboxymethylcellulose (CMC), pectin, and agar, on the formation of protein−protein interactions as well as the formation and loss of protein−water interactions was investigated by means of differential scanning calorimetry in an isothermal mode. Protein−water interactions were assessed through measurement of the heat of the wetting parameter. Isothermal calorimetry measurements pointed out that γ-irradiation does not favor protein−water interactions, as reflected by its endothermic contribution (P ≤ 0.05) to the heat of wetting values. Although significant (P ≤ 0.05), the effect of the thermal treatment on endothermic responses using isothermal calorimetry was found to be somewhat lower. Among excipients added to biofilm formulations, glycerol generated the most important losses of protein−water interactions, as inferred by its significant (P ≤ 0.05) endothermic impact on the heat of wetting values. Keywords: Milk protein; isothermal calorimetry; heat of wetting; cross-links; glycerol; carboxymethylcellulose; polysaccharides; edible films