Effect of by-products-based diet and intramuscular fat content on volatile compounds from pork

This study evaluated the effects of a fibre- and fat-rich by-products-based diet and the intramuscular fat (IMF) content on volatile compounds in pork. Meat samples were collected from sixteen gilts included in a feeding trial. Half of the animals were fed a conventional diet based on wheat, maize, barley and soybean meal, whereas the other half were fed a by-products-based diet that contained corn germ meal, malt sprouts, crispbread meal and proticorn, but no cereals or soya. Within each dietary treatment, four meat samples were selected from pigs in the upper quartile of IMF content (average 2.40 % ± 0.18 %, n = 8) and four from the lower quartile of IMF content (average 1.45 % ± 0.10 %, n = 8). SPME-GC-MS was used to evaluate the volatile profile of pork. A total of 45 volatile compounds were identified in the cooked pork samples. Aldehydes were the predominant chemical class in terms of the number of identified volatile compounds. No diet × IMF interaction was observed for the abundance of volatile compounds. Dietary treatment and IMF content significantly influenced the abundance of one and two aldehydes, respectively. Hexanal was more abundant in the meat of animals fed the conventional diet compared to the diet based on by-products. Tridecanal and tetradecanal were less abundant in pork with higher IMF levels. As precursors of volatile compounds, fatty acids were also analysed in the raw meat samples by GC. The concentrations of most fatty acids were higher in pork with higher IMF content but were not affected by diet. In conclusion, the volatile compounds profile of pork was only marginally affected by IMF content and feeding a by-products-based diet in the present study.