Mediterranean Berries as Inhibitors of Lipid Oxidation in Porcine Burger Patties Subjected to Cooking and Chilled Storage

The efifciency of extracts from Arbutus unedo L. （AU）, Crataegus monogyna L. （CM）, Rosa canina L. （RC）, and Rubus ulmifolius Schott. （RU） to inhibit lipid oxidation in raw, cooked and cooked and chilled （2°C/12 d） porcine burger patties, was investigated. The modiifcation of the fatty acid proifle during processing treatments （cooking and chilling）, the quantitative measurements of thiobarbituric acid reactive substances （TBA-RS）, and lipid-derived volatiles, were used as indicators of lipid oxidation. Polyunsaturated fatty acids （PUFA） gradually decreased during cooking and the subsequent storage of cooked burger patties with this decrease being signiifcantly greater （P〈0.05） in control patties than in those with added berry extracts. In accordance, the control patties showed signiifcantly higher TBA-RS numbers and counts of lipid-derived volatiles in all treatments when compared to the berry-added counterparts （P〈0.05）. Results from the present work show, for the ifrst time, that extracts from A. unedo, C. monogyna, R. canina, and R. ulmifolius are promising antioxidants which could enhance the nutritional, safety and sensory properties of porcine burger patties.

Application of Natural Antioxidants from Strawberry Tree(Arbutus unedo L.) and Dog Rose(Rosa canina L.) to Frankfurters Subjected to Refrigerated Storage

The effect of the addition of natural antioxidants from strawberry tree （Arbutus unedo L.; AU） and dog rose （Rosa canina L.; RC）, in frankfurters elaborated with or without the addition of antioxidant additives （sodium ascorbate and nitrite） was studied. Six different types of experimental frankfurters were prepared depending on the addition of phenolic-rich extracts from RC and AU and the presence （P） or absence （C） of antioxidant additives. Thiobarbituric acid reactive substances （TBARS）-numbers signiifcantly increased during chilled storage of C-frankfurters while additives and fruit phenolics inhibited lipid oxidation in P-frankfurters. The amount of protein carbonyls signiifcantly increased in all treatments except in P-AU frankfurters. The discoloration process that occurred during the chilled storage was reduced by the addition of substances with proven antioxidant activity （P-frankfurters）. Texture characteristics as hardness, springiness, cohesiveness and gumminess also suffered a signiifcant deterioration in C-frankfurters. The use of phenolic fruit extracts in combination with traditional antioxidant additives is a successful strategy to enhance the oxidative stability of frankfurters without modifying their color and texture properties.