Effect of date palm coproducts and annatto extract on lipid oxidation and microbial quality in a pork liver pâté.

Dates are an interesting source of bioactive compounds, and coproducts from the date industry are of potential use in the manufacturing of meat products. In the present research, spreadable pork liver pâtés were made using fresh date coproducts (2.5% and 7.5%) as a potential functional ingredient and an ethanolic annatto extract (128 mg/kg) as colorant. The effect of these 2 ingredients on the lipid oxidation and microbial quality of the pâtés was assessed during 21 d of storage. The pâtés containing 7.5% date paste were seen to have the highest content of phenolic compounds during storage. The combination of 2.5% date paste and annatto protected pâtés against lipid oxidation throughout the 21 d of storage, thiobarbituric acid-reactive substances values being 0.47 mg MDA/kg at the end of this period, while other combinations increased oxidation compared to the control pâté. The control and those made with 2.5% date paste alone showed the highest counts of mesophilic aerobic bacteria, while the addition of annatto and/or 7.5% date paste reduced this count. The results suggest that a combination of both ingredients is necessary to reduce oxidation and microbial growth, but whereas the concentration of 2.5% is more appropriate to reduce oxidation, the combination with 7.5% date paste reduces the microbial counts. Both ingredients could have an opportunity of valorization in the meat industry for improving the quality.