Browsing by Author "Van den Honert, Mathew Paul"

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    The assessment of the physico-chemical, microbiological and kinetic parameters of acidulants used in the production of acidified dried sausages made from the meat of blesbok (Damaliscus pygargus phillipsi)
    (Stellenbosch : Stellenbosch University, 2015-12) Van den Honert, Mathew Paul; Hoffman, Louwrens C.; Gouws, Pieter Andries; Sigge, G. O.; Stellenbosch University. Faculty of Agrisciences. Dept. of Food Science.
    ENGLISH ABSTRACT: The physico-chemical, microbiological and kinetic parameters of Blesbok (Damaliscus pygargus phillipsi) dry acidified sausage produced by chemical acidification were assessed. Initially, Blesbok meat dry acidified sausage was manufactured using five different concentrations of Glucono-delta-lactone (GdL), notable 0.5, 1.0, 1.5, 2.0 and 3.0%. All of the treatments pHu differed (P<0.05) from one another, although, only 1.5, 2.0 and 3.0% were below 5.0. Water activity aW, mass loss and hardness also differed (P<0.05) where 2.0 and 3.0% had the lowest aW, the highest mass loss and highest hardness values. Microbiologically, only 3.0% was safe to consume although 1.5 and 2.0% would suffice if the spice raw material was not contaminated. The choice of 1.5% was considered the optimal concentration in the dry acidified sausage based on the physico-chemical and microbiological results. Kinetic parameters confirmed that heating at 55°C for 65 min released the acidulant from the encapsulate and fully acidified the dry acidified sausage. A brief comparative study between the probe and sodium iodoacetate method of pH measurement was conducted. Similar regressions were developed however, the simpler probe method had a better fit (R2 = 0.9673) compared to (R2 = 0.8944), resulting in the simpler probe method being chosen for the continuation of the study. Further to this, eight concentrations, one through to eight percent, were produced for each of the three encapsulated acidulants. Upon heating to 55°C for 65 min, the sausage batter was acidified. Measurements for pH enabled linear regressions, E-GdL y = -16.81 x + 6.0214 (R2 = 0.9694); E-Lacic acid y = -13.31x + 5.5864 (R2 = 0.9435); E-Citric acid y = -29.536x + 6.0279 (R2 = 0.9844), to be calculated. Validation of the trend lines ensued using a 4 x 6 block design where masses of encapsulated acidulant were weighed out according to the value calculated from the trend line regression equations based on a final pH of 4.8. The optimal GdL concentration of 1.5% was used as a control. Only the GdL treatment pH at 4.9 ± 0.06 was close to the target pH of 4.8. All other treatments differed (P<0.05) from one another and were lower than the target pH; E-GdL = 3.7 ± 0.02, E-Lactic acid = 4.2 ± 0.04 and E-Citric acid = 3.5 ± 0.08. E-citric acid had an apparent crumbly texture which was confirmed by the Max Force 2 (second compression force) value. All the treatments, although well below the required pH, fell in line with the requirements of dried acidified sausage with mass loss > 30% and moisture loss ca. 30%.