Evaluation of a natural preservative in a boerewors model system
Journal of Food Processing and Preservation
Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, PO Box 339, Bloemfontein 9300, South Africa
Boerewors is a fresh sausage preserved with 450mg/kg sulfur dioxide (450S). The preservative effect of Citrox (a natural compound) was compared with SO2. Seven boerewors models with different treatments were formulated. Microbial, color, lipid and sensory characteristics were evaluated over a 6-day storage period at 4C. Citrox on its own and in combination with 100S significantly (P<0.001) decreased the total aerobic plate count (TAPC) and coliform counts and was comparable to 450S. It had a significantly (P<0.001) better effect on yeast and mold counts than 450S. Citrox had a negative effect, on its own and in combination with 100S, on the redness color (a* value). Citrox did not have antioxidant capabilities. It resulted in significantly (P<0.001) higher thiobarbituric acid reactive substance values after 100 days of storage at -18C than 450S. Sensory evaluation indicated a slight sour flavor in Citrox models but it was still "liked slightly" to "liked moderately." PRACTICAL APPLICATIONS: This study provided evidence that Citrox may be used as a natural antimicrobial in foods. It was as effective as 450mg/kg SO2 in controlling TAPC, coliform bacteria, and yeasts and molds when 2% Citrox was used. When used in combination with a lowered concentration of SO2 (100mg/kg), which is a 77.8% reduction in SO2, it even controlled the microorganisms better, especially yeasts and molds. It is, however, not a good antioxidant and may influence the taste of food products. It may, however, be used as antimicrobial in foods with a citrus-acidic nature. © 2012 Wiley Periodicals, Inc.
Aerobic plate counts; Different treatments; Natural preservatives; Natural-antimicrobials; Sensory characteristics; Sensory evaluation; Thiobarbituric acid reactive substances; Yeast and mold count; Antioxidants; Coliform bacteria; Food products; Microorganisms; Molds; Sensory perception; Yeast; Sulfur dioxide; Bacteria (microorganisms); Citrus