Contributions Of Packaging To The Extension Of Shelf Life Of Processed Grasscutter Meat (Thyronomys Swinderianus).

ABSTRACT

This research was carried out to assess the physico-chemical properties, storage stability and acceptability of cured grasscutter meat (Thyronomys swinderianus) products which were smoked and packaged with different plastic films (High Density Polyethylene and Polypropylene). Live grasscutter was slaughtered, dressed, cut-up and divided into three portions. One portion was treated with a solution of 5% salt; second portion was cured with a solution containing sodium nitrite, potassium sorbate, salt and Onion (Allium cepa) extract, while the last portion which was not cured served as control. They were all hot smoked for nine (9) hours at 78+2 0C. Following smoking and cooling, each portion was further divided into three sets. One set was not packaged, while another set was packaged with High Density Polyethylene and the last set was packaged with Polypropylene. Following smoking and cooling, samples were analysed for physico-chemical, microbial and sensory properties before storage. During storage at ambient conditions for 92days, samples were withdrawn at 21day intervals for evaluation of quality changes. Results show that smoking, with or without salting and curing of fresh grasscutter meat appeared to be an effective means of preservation. Samples smoked after curing had the least microbial count and high chemical/anti-oxidative stability followed by the samples smoked after salting. The control had the highest microbial load and least anti-oxidative stability. Hot smoking reduced the moisture content and water activity, but increased per unit weight the protein, fat, ash, pH, vitamins (such as vitamin A and C) and minerals (such as iron, sodium and potassium), presumably due to concentration effect. The sensory analysis showed that the samples smoked after salting were generally preferred to the other two samples, based on the colour, flavour and general acceptability. Although no Significant difference (P > 0.05) were found among the samples. During storage, samples packaged in polypropylene were found to have more oxidative stability with the least TBARS, peroxide and acid values. The water activity values were low. Microbial analysis of these packaged samples during storage gave the least mould and total viable counts. Unexpectedly, the vitamin and mineral contents were retained more in the High Density Polyethylene packaged samples throughout the storage period compared to Polypropylene packaged samples. Also, sensory analysis during storage showed no significant differences due to packaging (P>0.05).