30 Meat refrigeration 2.2 Measurement of drip Many methods have been used to measure drip loss from meat. Data obtained using different methods can be used to determine trends but the values obtained are not directly comparable The most important factor that affects the measurement of drip is the ra tio of cut surface to weight or volume. It is clear that the free water has to move to the surface before it can drip from the meat and therefore the more cut surface to volume there is, the less distance the water has to travel. In 1956. Howard and Lawrie reported that drip from beef quarters, domes- tic joints and small samples in the laboratory ranged from 0.3 to 1, 1. 2 to 2, nd 4 to 10% of weight, respectively. Howard(1956) showed that pieces with the same cross-section but l and 3cm thick lost 8 and 6% as drip, respectively. The drip is also reduced if the pieces are cut along the direc tion of the fibres rather than across it. Pressure applied to slices or blocks of meat increases the amount of drip and so does an absorbent material placed on the cut surfaces because of the increase in hydrostatic pressure It is therefore important that an appropriate method is used in order to obtain data that are directly applicable to a commercial situation. Weigh ing unwrapped samples of meat provides information on total weight loss However, some of the loss is due to evaporation from the surface, not drip One simple method is to hang the preweighed meat, using a nylon mesh to support it. A polythene bag is then placed round the sample but not in contact with it to prevent evaporation. The system is then kept in a con trolled environment and the sample reweighed after a set time. For experimental purposes more information and better reproducibility can usually be obtained from methods where force is applied rather than the simple method of measuring"free'drip(Penny, 1974). These include the press method of Grau and Hamm(1953)or methods depending on centrifugation 2.3 Factors affecting the amount of drip Some factors that affect the amount of drip are inherent in the animal and include the breed of the animal and the position of the meat within the animal. Treatment of the animal before slaughter, especially in the case of ork, can influence drip production by producing DFD or PSE meat. The conditions in and the length of the refrigerated cold chain will further influ- ence the resulting drip 2.3.1 Animal factors 2.3 Breed In pigs especially, there are large differences in drip loss from meat from different breeds. Taylor(1972)measured drip loss from leg joints from four2.2 Measurement of drip Many methods have been used to measure drip loss from meat. Data obtained using different methods can be used to determine trends but the values obtained are not directly comparable. The most important factor that affects the measurement of drip is the ratio of cut surface to weight or volume. It is clear that the free water has to move to the surface before it can drip from the meat and therefore the more cut surface to volume there is, the less distance the water has to travel. In 1956, Howard and Lawrie reported that drip from beef quarters, domes￾tic joints and small samples in the laboratory ranged from 0.3 to 1, 1.2 to 2, and 4 to 10% of weight, respectively. Howard (1956) showed that pieces with the same cross-section but 1 and 3cm thick lost 8 and 6% as drip, respectively. The drip is also reduced if the pieces are cut along the direc￾tion of the fibres rather than across it. Pressure applied to slices or blocks of meat increases the amount of drip and so does an absorbent material placed on the cut surfaces because of the increase in hydrostatic pressure. It is therefore important that an appropriate method is used in order to obtain data that are directly applicable to a commercial situation. Weigh￾ing unwrapped samples of meat provides information on total weight loss. However, some of the loss is due to evaporation from the surface, not drip. One simple method is to hang the preweighed meat, using a nylon mesh to support it. A polythene bag is then placed round the sample but not in contact with it to prevent evaporation. The system is then kept in a con￾trolled environment and the sample reweighed after a set time. For experimental purposes more information and better reproducibility can usually be obtained from methods where force is applied rather than the simple method of measuring ‘free’ drip (Penny,1974).These include the press method of Grau and Hamm (1953) or methods depending on centrifugation. 2.3 Factors affecting the amount of drip Some factors that affect the amount of drip are inherent in the animal and include the breed of the animal and the position of the meat within the animal. Treatment of the animal before slaughter, especially in the case of pork, can influence drip production by producing DFD or PSE meat. The conditions in and the length of the refrigerated cold chain will further influ￾ence the resulting drip. 2.3.1 Animal factors 2.3.1.1 Breed In pigs especially, there are large differences in drip loss from meat from different breeds. Taylor (1972) measured drip loss from leg joints from four 30 Meat refrigeration