The composition and consistency of pig backfat as it affects the quality of vacuum‐packed rindless bacon rashers

Abstract

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 whereas the unsatisfactory packs come from backfat of medium consistency.

Significance of Porcine Fat Quality in Meat Technology: A Review

“…No criteria is currently available for the peroxidizability index. Enser et al (22) and Whittington et al (13) found that the mono-unsaturated fatty acid/saturated fatty acid and (C16:1 + C18:1c9)/(C16:0 + C18:0) ratio were better related to the variation in melting and slip point of the lipids and the consistency of pig adipose tissues and may be independent of carcass fatness. (20) The mono-unsaturated fatty acid/saturated fatty acid ratio was negatively correlated with fat firmness.…”

“…(14) Although Ellis and Isbell (30) indicated that large amounts of C18:2 in the pig diets leads to soft fat, this effect results from changes in the proportion of saturated fatty acids, which affects the consistency because of their high melting point and through changes in the distribution of the fatty acids in the triacylglycerol. (22) Backfat consistency was shown to be inversely correlated with the C18:2 concentration. (13) Whittington et al, (13) Enser, (25) Ellis and Isbell, (30) and Wood (36) set the limit for C18:2 to be less than 15% to result in good quality fat.…”

“…(13,22) Wood et al (33) indicated that C18:0 content was the single best predictor of firmness. Stearic acid was positively correlated with consistency of the backfat.…”

“…(29) Individual fatty acids, as well as combinations and ratios thereof, are used to predict fat quality. (6,13,15,20,22,23,30,31) Individual Fatty Acids. Malmfors et al (32) indicated that Myristic acid (C14:0) and Palmitic acid (C16:0) were negatively correlated with good flavour.…”

“…He indicated that products made from these fats will exhibit a granular surface on cutting, not the desired smooth surface associated with processed meat. Enser et al (22) proposed that contribution of fat-free dry matter (± 5%) to consistency of the fat, is the most important factor, since the degree or type of collagen cross-links that form the structural network in adipose tissue differs.…”