Effect of Soy Protein Isolate on Physicochemical Properties, Lipid Oxidation and Sensory Quality of Low-Fat Pork Patties Stored in Vacuum, MAP and Frozen State

Abstract

The effect of 2, 5 and 10% soy protein isolate (SPI) addition on selected quality indices of low-fat pork patties was studied. Patties with SPI showed a higher protein content and lower fat content than the control sample. Water activity was not influenced by SPI addition. The SPI significantly inhibited lipid oxidation in patties during storage. The patties with 10% SPI added showed a detectable level of beany flavor, were more cohesive, harder and less juicy than the other patties. They also received the lowest scores for the overall quality. These results suggest that SPI can be used at levels up to 5% in low-fat pork patties without adverse effect on their quality. Vacuum storage was the more effective method of lipid oxidation inhibition during 28 days of patties storage than modified atmosphere packaging and freezing but when longer storage time was involved frozen storage was more efficient. Practical Applications Consumption of low-fat meat products allows to meet the recommendations of health authorities regarding lower intake of dietary fat, but reduction in fat content can negatively influence the sensory quality of meat products. Numerous studies showed that incorporation of plant proteins to such products improves their flavor, texture and juiciness. Positive influence of soybean on human health is fully acknowledged by the professionals, but its excessive use in meat processing triggers off the consumers' reluctance similar to that directed toward other food additives. Therefore, the production of low-fat meat products that contain relatively low amounts of soybean protein could satisfy both nutritionists and consumers. Moreover, the choice of the most effective storage method could improve the quality of stored products.