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A8-P: OXIDATIVE STABILITY OF WHEY-BASED SALAD DRESSINGS: INFLUENCE OF SUNFLOWER OIL QUALITY AND ANTIOXIDANTS

M. Pavlović (1), M. Pucarević (2), V. Mićović (1), M. Živić (3),
S. Zlatanović (1), S. Gorjanović (1), J. Gvozdenović (4)

1 Institute of General and Physical Chemistry,  Studentski trg 12/V,  Belgrade, Serbia

2 Faculty of Environmental Governance and Corporate Responsibility,
Vojvode Putnika bb., Sremska Kamenica, Serbia

3 State University of Novi Pazar, Maksima Gorkog 30, Novi Pazar, Serbia

4 Faculty of Technology, Novi Sad, Bul. Cara Lazara 1, Serbia

 

Genetic alterations of sunflower oil quality, developed by conventional breeding, are directed both towards increase and stability in oleic acid content [1], increased β tocopherol level [2], resistance to main sunflower pathogens and good agronomic characteristics [3, 4]. Oxidative stability of high-oleic oils with a and β tocopherol was not studied yet in emulsion systems. Whey protein isolates (WPI) and whole sweet whey was found to stabilize o/w emulsions when pH was lower than pIof the whey proteins [5]. Ascorbic acid exerts its antioxidative activity as hydrophylic radical scavenger or O2 scavenger, and is used in emulsion systems for its ability to regenerate tocopherol or act as metal chelator [6]. Addition of ethylen diamine tetraacetic acid (EDTA) has been found to inhibit peroxide and volatile formation in emulsions [6].

The objective of this study was to compare ascorbic acid and EDTA, as potential antioxidants, in salad dressings based on whey and oils from high-oleic sunflower hybrides with aproximately 50% a and 50% β tocopherol [3]. The effect of ascorbic acid and EDTA on oxidative stability of salad dressings based on sweet whey and linoleic acid/a tocopherol type of sunflower oil or high-oleic sunflower oils with increased β tocopherol content, was investigated. In dressings, based on linoleic type of sunflower oil, primary lipid oxidative products, measured by peroxide value, enhanced during six month period of storage at 4oC, while formation of secondary oxidation products, was observed as hexanal enhancement, after 12 months of storage. Antioxidants: ascorbic acid and EDTA had shown strong antioxidative effects in all emulsions based on linoleic type of sunflower oil: Ascorbic acid (250-4000 ppm), induced 89-100% reduction in peroxide value. EDTA (75 ppm) induced 75-85% reduction in peroxide value. The optimum antioxidative effect on hexanal formation was at lowest (250 ppm) additional level of ascorbic acid (ranging from 250-1000 ppm). Increase in volatile oxidation products was not observed in dressings, based on high- and medium-oleic types of sunflower oils, with 50% β tocopherol content, at 4oC. Slight enhancement in primary and secondary oxidation products was found in dressings based on medium-oleic type of sunflower oil (with 50% β tocopherol) at 25 oC, after 3 months of storage, and was reversed by both ascorbic acid (500 ppm) or EDTA (75 ppm). High-oleic types of sunflower oil based salad dressings were oxidatively stable in salad dressings, (the formation of primary and secondary oxidation products was not observed).

References

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