## 3 Results and Discussion
### Fatty Acid Composition
Specifically, the type and quality of pasture affects the ratio of 18:3 fatty acids in meat because linolenic acid (18:3 n-3) has been shown to be one of the main components of the total lipid content of grass [41]. In our study, the higher C18:3 n-3 in MP and ML than lambs raised using concentrate was observed \(p\) < 0.05; Table 3). On the other hand, as reported by [PERSON] and [PERSON] [42], grass lipids are found inside organelles (chloroplast) that remain intact during the ruminal digestion processes, thus providing a natural protection for n-3 PUFAs against biohydrogenation in the rumen. The high content of PUFA observed in the meat of suckling lambs may be due to the fact that in the traditional production systems of the Spanish islands of the Mediterranean area, the main source of food for ewes is grass, and consequently, the PUFA content in mothers' milk is expected to be high. The consumption of lamb and other red meat is associated with diets with a high fat content, especially those containing saturated fatty acids. Indeed, certain saturated fatty acids have been linked to cardiovascular disease [43] while an intake of PUFA (mainly n-3 PUFA) is recommended to prevent coronary artery disease. Recommendations about healthy eating include reducing n-6/n-3 ratios in the human diet. In fact, public health recommendations advise consuming a maximum of five n-6 PUFA to every one n-3 PUFA [44]. The n-6/n-3 nutritional quality indicator related to the health of consumers in the meat of lambs from the Spanish islands of the Mediterranean raised in the traditional way has shown favourable values of less than 5. According to the recommendations proposed by [PERSON] [43], only the production system of the Mallorquina breed, which is based on the use of concentrated feed, has shown an unfavourable ratio for the consumption of lamb meat (slightly higher than seven n-6 PUFA to one n-3 PUFA). The Atherogenic index (AI) can be considered a suitable measure of the nutritionally healthy value of meat [45]. Usually, ranges of 0.5 to 1 in meat fats are reported [46], while values of <0.5 have been described in vegetable oils. In meat from Mallorquina and Roja Mallorquina lamb breeds, the AI (0.72-0.93) was higher than the range described by [PERSON] et al. [47] in the meat of Churra lambs (0.71) or suckling kids (range 0.70-0.75) of four autochthonous Spanish breeds. Significant differences in the AI between light lambs were also observed. According to [PERSON] et al. [48], differences in AI are mainly associated with genetic and feeding factors. The best AI was observed in the meat of the light Roja Mallorquina lamb breed and sucking lambs from the Mallorquina breed. Most of the compounds detected in cooked meat from the Mallorquina and Roja Mallorquina breeds come from the lipid oxidation reactions (aliphatic aldehydes, ketones, hydrocarbons, and alcohols) and Maillard reaction (pyrazines, pyrroles, carboxylic acids, furans and other sulphur compounds) [50]. Most of the volatile compounds obtained in the lamb meat in the current study were included in aliphatic aldehydes (\(n=11\) volatile compounds and total relative percentage abundance in the range of 67.48-78.33%), aliphatic ketones (\(n=13\) volatile compounds and relative percentage abundance in the range of 5.93-8.53%) and aliphatic alcohols (\(n=9\) volatile compounds and total relative percentage abundance in the range of 5.25 to 7.37). These ranges are in accordance with the relative percentage abundance showed by [PERSON] et al. [51] (84.79 of relative percentage abundance) in light lambs from the Rasa Navarra breed raised on concentrate and forage. The most frequently represented compound in the lamb meat from the Mallorquina and Roja Mallorquina breeds is hexanal, as has been observed in lambs of other native breeds such as Rasa Navarra [51] and Churra [52]. According to the Flavornet database, this aliphatic compound is said to provide aromas related to green grass, and a fruity smell in meat [53].