Biomechanical and microbiological changes in natural hog casings treated with ozone

The objective of this study was to determine the biomechanical and microbiological effects of exposing natural hog casings to ozonated water ≈7 mg/l for 0, 2 or 4 h at 16 °C. A total of 450 casing segments representing 10 hanks were used over five testing days and arranged in a randomized block split-plot design. For each treatment, pH, temperature, actual ozone concentration, bursting strength, maximum rupture force, and L^∗, a^∗ and b^∗ color space values were determined. The bursting strength and the maximum rupture force values suggested that casings can be treated by ozone up to 2 h without deterioration. After ozone treatments, changes in L^∗, a^∗ and b^∗ color space values made the casings appear lighter than the control samples. Microbiological studies showed that 1 and 2 h ozonation reduced counts of Escherichia coli biotype I, which expressed green fluorescent protein, by 0.4 and 0.6 log₁₀ CFU/25.4 cm casing, respectively.