Natural antioxidant active packaging film and its effect on lipid damage in frozen blue shark (Prionace glauca)

The capacity of a natural antioxidant derived from barley husks to retard oxidation of PUFA in blue shark muscle was investigated. Blue shark slices were packaged in low density polyethylene (LDPE) film containing the natural antioxidant (sample C1 = 7 mg/dm(2) film, and sample C2 = 24 mg/dm(2) film) or in LDPE film without the antioxidant (control sample) and frozen for 12 months. Peroxide value was significantly higher in control samples during the first six months than in samples Cl and C2. The free fatty acids content was significantly higher in the control samples than in samples Cl and C2 during the 12 months of the study. Up to the sixth month of storage, the concentrations of thiobarbituric acid reactive substances in Cl and C2 were significantly lower than in the control sample. The results demonstrate that hydrolytic activity and lipid oxidation are sensitive to antioxidant content and storage time. The results confirm the efficacy of active packaging with a natural antioxidant derived from barley husks to slow the progress of lipid hydrolysis and increase oxidative stability in blue shark muscle. Industrial relevance: The use of barley husks, which is a residue the brewing process unwieldy and unhelpful, is optimized to obtain a crude extract antioxidant. Natural extracts of phenolic compounds with high antioxidant activity was obtained after prehydrolysis and delignification of barley husks. The raw extracts show more than twice higher antioxidant capacity than BHT in terms of EC50. The crude extract antioxidant has as important feature his high content of p-coumaric and ferulic acid. The results demonstrated the efficacy of an active packaging with a natural antioxidant derived from barley husks. The extract dosed on the surface of the film shows and maintains an excellent antioxidant capacity and is not separated of film in aqueous or oily media, so these can be used in a wide type of food. (C) 2011 Elsevier Ltd. All rights reserved.