Application of prickly pear fruit extract to improve domestic shelf life, quality and microbial safety of sliced beef

The research aimed to expand the knowledge on the use of natural bioactive compounds for food preservation. First-crop fruit of prickly pear were subjected to water extraction and evaluated for total polyphenol content, antioxidant activity, in vitro antimicrobial performance against food spoilage and pathogenic bacteria, and betacyanin and betaxanthin content. The extract was then applied by dipping technique to packed sliced beef, to evaluate its effect on physical and chemical parameters, color and texture maintenance, as well as on microbial growth during shelf life at domestic storage conditions. The in vitro antimicrobial assay of prickly pear fruit extract evidenced a wide spectrum activity, since it inhibited the growth of all Gram positive and negative targeted strains. In vivo application of extract effectively reduced microbial growth during refrigerated storage; total mesophilic count was maintained below the limit established by Commission Regulation (EC) No 2073/2005 of 5 × 106 log CFU/g of beef up to 8 d, in comparison to control sample that reached the mentioned limit after 4 d. Moreover, extract addition preserved beef color and texture over the considered storage period, supporting the potential prospect to utilize the extract to improve overall quality and to prolong domestic shelf life of sliced beef.