Abstract:
The hydrolysis and solubilisation of meat tissue has been examined. The action of a variety of proteolytic enzymes on ground beef was investigated and the enzyme preparation Alcalase was chosen as the most suitable. Enzymes were compared on the basis of both the solubilisation achieved and the cost effectiveness. The optimum conditions for Alcalase have been determined to be pH 8.5 and 60°C for a reaction time of five hours. Under those conditions 84% of the meat solids were solubilised. The effect of other reaction variables on the enzyme reaction were investigated. Reaction progress curves indicated that during the initial stages of reaction a largo portion of the meat tissue was rapidly hydrolysed, and solubilised. The later stages of the reaction occurred comparatively slowly. Hydrolysis and solubilisation» increased with increasing enzymes meat ratio. However, even for a very high enzyme «meat ratio total solubilisation was not achieved. Maximum solubilisation measured was about 94%. Increasing the meat liquid ratio had little effect on the hydrolysis of mo but decreased the solubilisation markedly. The solubilisation of undiluted meat was shown to be feasible. The hydrolysis and solubilisation of the three moat protein fractions were investigated. A significant portion of the water-soluble meat protein fraction (sarcoplasmic protein) was heat insolubilized during heating to 60°C. After three hours hydrolysis some of this protein was still insoluble The degree of solubilisation and hydrolysis of connective tissue increased markedly between 55 and 60°C, and at 60°C almost total solubilisation was achieved. A significant portion of the myofibrillar tissue fraction remained insoluble after three hours reaction indicating that the majority of the insoluble solids remaining after whole moat hydrolysis are from the myofibrillar tissue fraction. Pilot plant experiments were conducted using minced sheep heads. Ho major problems were encountered when undiluted raw material. was hydrolysed and further processed to obtain a hydrolysate powder. The position of the process in the meat industry has been discussed. The potential of the enzyme hydrolysis process to upgrade waste meat tissues and possible product applications have also been considered. She kinetics of the enzymatic hydrolysis of insoluble meat proteins has been modelled. Two kinetics equations have been derived; one based on classical enzyme kinetics techniques and the other based on enzyme adsorption considerations. The assumptions inherent in the derivation of each equation have been discussed. Initial rate data for meat hydrolysis showed that the equation based on enzyme adsorption best fitted the situation. However both equations provided satisfactory fits to eleven experimentally determined reaction progress curves over three to five hours hydrolysis.