Influence of Dissolved Gases and Heat Treatments on the Oxidative Degradation of Polyunsaturated Fatty Acids Enriched Dairy Beverage

• Published in: Journal of agricultural and food chemistry 2008-07, Vol.56 (14), p.5710-5716
• Main Authors: Giroux, Hélène J, Acteau, Geneviève, Sabik, Hassan, Britten, Michel
• Format: Article
• Language: English
• Subjects: air; beverages; Beverages - analysis; Biological and medical sciences; Chemical Changes Induced by Processing/Storage; chemical treatment; Dairy beverage; dairy products; Dairy Products - analysis; degradation; dissolved gas; dissolved oxygen; enriched foods; Fatty Acids, Unsaturated - chemistry; Food Handling - methods; Food industries; food processing; food quality; Fundamental and applied biological sciences. Psychology; gases; heat treatments; Hot Temperature; hydrogen; Hydrogen - chemistry; linseed oil; Linseed Oil - analysis; lipid oxidation; Lipid Peroxidation; nitrogen; Nitrogen - chemistry; oxidation; Oxidation-Reduction; Oxygen - chemistry; pasteurization; polyunsaturated fatty acids; redox potential; shelf life; sterilizing; storage quality
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf800516x

The combined effect of dissolved gas composition and heat treatment on the oxidative degradation of a dairy beverage enriched with 2% linseed oil was studied. The dairy beverage was saturated with air, nitrogen, or a nitrogen/hydrogen mixture (4% hydrogen) before pasteurization or sterilization. Saturation with either nitrogen or a nitrogen/hydrogen mixture decreased the dissolved oxygen concentration in dairy beverages (Δ = 7.7 ppm), and the presence of hydrogen significantly reduced the redox potential (Δ = 287 mV). Heat treatments also reduced the oxygen content and redox potential, sterilization being more effective than pasteurization. Both pasteurization and sterilization induced the oxidative degradation of the beverages. On average, the propanal concentration increased by a factor of 2.3 after pasteurization and by a factor of 6.2 after sterilization. However, during storage, sterilized beverages resisted light-induced oxidation better than unheated or pasteurized beverages. Furthermore, saturation with nitrogen or a nitrogen/hydrogen mixture significantly reduced oxidative degradation and provided some protection against color changes during storage.