QUALITY CHARACTERISTICS OF BEEF JERKY MADE IN LABORATORY CONDITIONS

Abstract

Beef jerky is a traditional meat product that is preserved by means of salting (curing) and drying, i.e. reduction of water activity (aw). This study was carried out to investigate the quality characteristics of beef jerky made in laboratory conditions. In order to prepare the meat for drying, the beef muscle (M. Semimembranosus) was firstly cut into thin slices and then into strips (approx. 10 x 1.5 x 0.5cm). The strips were marinated by dipping in a solution containing salt and flavoring ingredients (three types of marinade – S1, S2, S3). Heat processing of jerky was conducted using constant climate chamber, Model KBF 115 (BINDER GmbH, Germany), and it was comprised in two distinct steps: “cooking phase” (temperature of 70°C during 2h and 15min; relative humidity ranged from 80% to 93.4%, being ≥90% for at least 1h.) and “drying phase” (temperature ranged between 60°C to 65°C; relative humidity gradually decreased from 70% to 35% during 4h and 15 min). Quality and safety characteristics of obtained beef jerky were verified by microbial analyses, determination of water activity (aw), moisture-protein-ratio (MPR), as well as nutritive value. Pathogenic bacteria (Salmonella spp., Escherichia coli and Enterobacteriaceae), yeasts and molds, were not detected in any sample. Water activity (aw) (0.786 - 0.814) and MPR (0.61 - 0.66) in final products, were lower than recommended maximal values, being 0.85 and 0.75, respectively (FSIS Compliance Guideline, 2014). The protein content of the analyzed samples ranged from 47.61% to 49.96%, which makes jerky a rich source of protein. In the same time, the lipid content was very low, ranging from 5.67% to 6.29%. The energy value of produced beef jerky ranged between 267 (S1) and 280 (S3) kcal/100g, amounting approx. 11% of average daily energy requirement for normal adult person.