Abstract The Cistus ladanifer L. shrub is a widespread species of the Mediterranean region that is available as a feed source for ruminants all the year round, constituting a source of energy and nutrients when most of the vegetation is dry. However, there is no trustworthy information about the fatty acid composition of C. ladanifer , as well as no information about the seasonal and age related changes in their fatty acid composition. Thus, we collected the aerial parts of C. ladanifer plants of two age groups [young vs. older ones (2–6 years old)] during four consecutive seasons to characterize their fatty acid composition. The fatty acid composition of C. ladanifer is dominated by saturated fatty acids including the occurrence of two methyl branched chain fatty acids (BCFA), the iso‐19:0 and iso‐21:0, which as far as we know were detected for the first time in shrubs. Also, we demonstrated that several labdane type compounds might interfere with the fatty acid analysis of C. ladanifer . Marked seasonal changes in BCFA and polyunsaturated fatty acids (PUFA) were found, suggesting that BCFA can replace PUFA in plant lipids at high environmental temperatures.
Cistus ladanifer L. is a shrub from Cistaceae family, widespread in Mediterranean countries. Fatty acids (FA) have multiple roles in plants and are involved in adaption mechanisms to environmental conditions. This work evaluated the FA content and composition of each morphological fraction of C. ladanifer (leaves, stems, flower buds, flowers and seed heads) throughout a full year. Cistus ladanifer plants were collected in southern Portugal, during four consecutive seasons (18 plants/season), and the different morphological plant fractions (leaves, stems, flower buds, flowers and seed heads) were separated. Cistus ladanifer morphological fractions showed distinct FA compositions, being possible to discriminate three groups—the leaves that showed to be dominated by saturated FA (main 20:0) and contain branched-chain FA (iso-19:0 and iso-21:0); the stems that are composed mainly by SFA (main 22:0); and the reproductive organs that showed higher contents of polyunsaturated FA (PUFA) and the 16:0 as the main SFA. The FA composition of leaves changed over seasons, with replacement of the PUFA by monounsaturated FA and branched-chain FA during hot seasons. Regarding the other C. ladanifer morphological fractions, the FA composition was more stable over seasons, suggesting that leaves are more prone to adaptations to environmental changes.
Meat from lambs finished with high-starch diets often contains low concentration of vaccenic (t11-18:1) and rumenic (c9,t11-18:2) acids and high concentration of t10-18:1. We hypothesized that replacing cereals by dehydrated citrus pulp (DCP) and the inclusion of tanniferous feed sources in oil supplemented diets might reduce the accumulation of t10-18:1 and increase the t11-18:1 and c9,t11-18:2 in lamb meat, without affecting the productive performance. In total, 32 lambs were assigned to four diets which combine two factors: basal diet (BD) (cereals v. DCP) and Cistus ladanifer (CL) (0 v. 150 g/kg dry matter). Feed intake, average daily weight gain and carcass traits were not affected by treatments, except for dressing percentage that was reduced with DCP (P=0.046). Both DCP and C. ladanifer reduced tenderness and juiciness of meat, and C. ladanifer also reduced (P<0.001) meat overall acceptability. Intramuscular fat and the concentration of saturated and polyunsaturated fatty acids (FA) were not affected (P>0.05) by diets. However, DCP increased the proportions of odd-chain FA (P=0.005) and several minor biohydrogenation (BH) intermediates in meat lipids. C. ladanifer had few effects on meat FA profile. The proportions of t11-18:1 and c9,t11-18:2 were high in all diets (5.4% and 1.5% of total FA, respectively) and were not influenced by the treatments. Basal diet and CL showed some significant interactions concerning FA composition of intramuscular fat. In diets without C. ladanifer, replacement of cereals by DCP increased the 18:0 (P<0.05) and decreased t10,c12-18:2 (P<0.05), t10-18:1 (P<0.10) and t10-/t11-18:1 ratio (P<0.10) with a large reduction of the individual variation for t10-18:1 and of t10-/t11-18:1 ratio. Combined with cereals, C. ladanifer increased 18:0 and reduced the BH intermediates in meat. Replacement of cereals by DCP seems to promote a more predictable FA profile in lamb meat, reducing the risk of t10-shifted BH pathways in the rumen.