THE COMPOSITION AND CONSISTENCY OF PIG BACKFAT AS IT AFFECTS THE QUALITY OF VACUUM-PACKED RINDLESS BACON RASHERS

Samples of adipose tissue from unsatisfactory, soft, vacuum-packs of rindless bacon rashers were compared with satisfactory harder samples to determine the factors responsible for the difference in consistency. Lipid from unsatisfactory packs contained significantly higher mean concentrations of unsaturated fatty acids, lower mean concentrations of saturated fatty acids and had a lower mean melting point and mean slip point. Discriminant analysis revealed that the samples were best differentiated according to their proportion of linoleic acid or by the ratio of stearic acid to linoleic acid. Linoleic acid was the best discriminator although stearic acid and palmitic acid were correlated best with the melting point and slip point of the lipid and with the force required to puncture the intact adipose tissue by a probe attached to an Instron materials testing machine. Samples which would give satisfactory firm packs, based on the data from discriminant analysis, required a puncture force greater than 7N. In terms of the spectrum of backfat consistency in British pigs, satisfactory bacon comes from hard backfat; the unsatisfactory packs come from backfat of medium consistency.