Influence of the herb extract on inhibition of beef meat spoilage-potential source of natural preservative

Abstract

Raw beef can be contaminated by microorganisms and support the growth of pathogens, and may lead to serious food-borne diseases. In many cases, plant extracts exibit antimicrobial and antioxidant activity. We investigated the inhibitory activity of 2.5% ethanol extract of Serbian herb Kitaibelia vitifolia against ATCC strains: Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli, Proteus hauseri, Proteus mirabilis, Bacillus subtilis and fungi Candida albicans and Aspergillus niger, in a lean beef meat. We prepared samples (48 pieces per 25 g), according the sterility demands, from one piece of beef (2 kg). We organized 3 experimental group: samples from first (I - control) group are non-treated; II - samples immersed in sterile water and III - samples immersed in above mentioned herb extract. Analysis was carried out during storage at 4 0C and 25 0C (0. d, after 2, 4 and 7 d). Longest sustainability shows samples from experimental group III, on both temperature of storage, determined by method for proving spoilage (Nessler). Antimicrobial activity evaluated by their minimum inhibitory concentrations (MIC). The above mentioned extract showed strong inhibitory activity against E.coli (7.820 mg/mL), S. aureus, P. mirabilis and K. pneumoniae (15.625 mg/mL). Moderate sensibility on applyed herb extract shown P. hauseri (31.250 mg/mL) and minimum of inhibitory activity against B. subtilis (62.500 mg/mL). Among fungi, A.niger is very susceptible (7.820 mg/mL), unlike the C. albicans (62.500 mg/mL). This extract may be further investigated as a natural preservative to the food industry.