title: Impact of nitrogen flushing and oil choice on the progression of lipid oxidation in unwashed fried sliced potato crisps.
abstract: Unwashed, sliced, batch-fried potato crisps have a unique texture and are growing in popularity in the UK/EU premium snack food market. In this study, the storage stability of unwashed sliced (high surface starch) potatoes (crisps) fried in regular sunflower oil (SO) or in high oleic sunflower oil (HOSO) was compared over accelerated shelf life testing (45°C, 6 weeks); with and without nitrogen gas flushing. Primary oxidation products (lipid hydroperoxides) were measured with a ferrous oxidation-xylenol orange (FOX) assay and volatile secondary oxidation products (hexanal) were quantified by using solid phase micro-extraction gas chromatography mass spectrometry (HS-SPME-GC/MS). Results revealed that crisps fried in SO were the least stable. Flushing the stored crisps with nitrogen gas proved to be effective in slowing down the oxidation rate after frying with sunflower oil, significantly stabilizing the crisps. However, crisps fried in HOSO were the most stable, with the lowest rate of development of oxidation markers, and this has previously not been shown for crisps with a high free starch content.
authors.affiliation: School of Biosciences, University of Nottingham, Loughborough, Leicestershire LE12 5RD, UK; Pipers Crisps Ltd, Wellington House, Lincolnshire DN20 0SP, UK.
authors.forename: E
authors.initials: E
authors.lastname: Marasca
authors.affiliation: School of Biosciences, University of Nottingham, Loughborough, Leicestershire LE12 5RD, UK.
authors.forename: D
authors.initials: D
authors.lastname: Greetham
authors.affiliation: Pipers Crisps Ltd, Wellington House, Lincolnshire DN20 0SP, UK.
authors.forename: S D
authors.initials: SD
authors.lastname: Herring
authors.affiliation: School of Biosciences, University of Nottingham, Loughborough, Leicestershire LE12 5RD, UK. Electronic address: ian.fisk@nottingham.ac.uk.
authors.forename: I D
authors.initials: ID
authors.lastname: Fisk
mesh_terms: D005230:Fatty Acids, Nonesterified / Q000032:analysis; D008401:Gas Chromatography-Mass Spectrometry; D008055:Lipids / Q000737:chemistry*; D009584:Nitrogen; D010084:Oxidation-Reduction; D010938:Plant Oils; D011198:Solanum tuberosum / Q000737:chemistry*; D000074242:Sunflower Oil
chemical_list: D005230:Fatty Acids, Nonesterified; D008055:Lipids; D010938:Plant Oils; D000074242:Sunflower Oil; D009584:Nitrogen
keywords: Crisps; High oleic sunflower oil; Oxidation products; Shelf-life tests; Sunflower oil