The changes in gliceridic fractions of sweaty fat and weight loss during ripening time of Iberian dry-cured ham

In this contribution, we studied the weight loss of Iberian hams during dry-curing process and determined the composition of fatty acids, triacylglycerols, diacylglycerols (DGs), monoacylglycerols and free fatty acids in their sweaty fat collected during processing. Ten Iberian hams were used in the study and kept throughout all processes. Humidity, temperature and weight were measured and the sweaty fat of each ham was collected. During dry-curing process, Iberian hams underwent a weight loss with a logarithmic trend and the coefficients depended on the characteristics of the initial raw material and processing conditions. The percentage of weight that hams lost in dry-curing process ranges between 28.83 and 35.91% (mean 33.06%), whereas they lost between the 0.29 and 1.28% (mean 0.79%) of sweaty fat. Concerning the composition of sweaty fat, this was influenced by the composition of ham fat and by the different melting points of compounds sweated. The monounsaturated fatty acids were the most abundant in sweaty fat, especially C18:1 ω9, followed by the saturated and polyunsaturated fatty acids. Triacylglycerols represented 13.4-24.6% of the sweaty fat, characterized by a high amount of species with doubled bound number 2, especially POO. The free fatty acid species found were C18:1 and C16:0 and their percentage ranged similar in all periods, being between 14.45 and 26.94%. The only specie of monoacylglycerol detected was 1-monoolein, being present between 1.24 and 10.65%. The diacylglycerols (DGs) most abundant were 1,2-OP and 1,2-OO (O = oleic acid, P = palmitic acid). In the first period of sweating, there was a higher amount of 1,2-DGs, whereas similar amounts of 1,2- and 1,3-DG species were found in the second and third periods of sweating. When there was a higher amount of diacylglycerols, there were higher quantities of monoacylglycerols and free fatty acids in this fat.