RoBUTCHER project cooperates with meat quality project
The development of the RoBUTCHER systems has required conduction of experiments with cutting of pig carcasses. With the aim to utilize the pig carcasses better, the hams produced in the RoBUTCHER cutting experiments has been used for a cooling experiment in another project called “Enduring Growth! Quality defect in ham”.
“In the project “EG! Quality defect in ham” we study the effect of different parameters on quality defects in ham. Typical symptoms of quality defects in the raw material are low ultimate pH, pale colour, dissolved muscle structure, reduced firmness, and increased drip loss. It is uncertain why these quality defects arise, and it is likely that there are many factors triggering them. Chilling of the carcass is one of the factors that the EG-project will study further.”, explains project leader Stefania Gudrun Bjarnadottir.
The goal with chilling is to remove heat from the carcass as soon as possible after slaughter. Rapid chilling of meat is also important for the final quality of the product, since chilling can affect appearance, tenderness, weight loss and drip loss. In living animals, there are enzymes that induce muscle growth and repair muscle damage. After slaughter, these enzymes will instead induce the breakdown of proteins in muscle fibres and connective tissue. The enzyme activity is often at its peak at body temperatures and neutral pH levels. When chilling lowers the body temperature, the enzyme activity is reduced. This leads to reduced breakdown of muscle proteins and the conversion of energy stores into lactic acid, resulting in slower pH drop. The rate of pH drops after slaughter, as well as the final pH, is important for the technical quality of the meat. The best meat quality is obtained by a steady pH drop. If the pH drops too fast or too slow, it can result in meat with quality defects. For example, too fast pH drop can result in the development of PSE-meat, that is pale, soft, and exudative. Rapid chilling of the carcass after slaughter makes it possible to regulate both the temperature and the pH drop in the carcass. Thus, the unfortunate combination of high temperature and low pH in the carcass can be avoided, thereby making it possible to prevent quality defects in the meat.
The pH values registered showed that lack of chilling the first hours after slaughter resulted in a faster drop of pH – which is consistent with the literature. There were clear differences in the pH drop between groups. However, there were no clear differences between groups regarding subjective assessment of colour and fibre damage – two typical symptoms of quality defects in ham. Hams from carcasses following normal chilling after slaughter, also showed signs of both defect colour and defect fibre structure. Thus, in our small data set, it was not explicit that lack of/abnormal chilling resulted in defect meat quality and good chilling resulted in good meat quality – the results were mixed.
The data material was somewhat reduced due to a corona quarantine, but the aim is to repeat the experiment in the autumn with more individuals. The RoBUTCHER project intends to reduce meat wastage and a cooperation with another project gives an opportunity to achieve this goal.