## 4 Discussion
The changes in the composition of pig tissues under acorn supplementation and the distinct profile of the volatile compounds that develop during ham processing [39; 40] are considered crucial for the characteristic aromatic and sensory properties of dry-cured products. This was also evidenced by the higher consumer preferences for \"acorn-fed\" dry-cured hams from traditional silvopastoral production systems, based on acorn supplementation [51]. For example, _Montanera_ hams from Iberian pigs fattened outdoors exclusively on acorns and pasture had higher concentrations of aldehydes and ketones and lower concentrations of sulphur-containing compounds than _Campo_ hams from Iberian pigs fattened on concentrate with a high oleic acid content [39], while Tuscan dry-cured ham from _Cinta senese_ pigs fed acorns under free-range conditions had the highest levels of aldehydes and esters compared to hams from their counterpart pigs fed chestnuts or confined pigs fed commercial feed [40]. In the present study, the effect of acorn feeding on the VOCs of dry-cured ham was generally insignificant, with only nonanal (the second most abundant aldehyde after hexanal) exhibiting increased values in association with acorn supplementation. Aldehydes are known to contribute most significantly to the unique flavour of cured ham, due to their low threshold and abundance [52]. Nonanal, a saturated aldehyde associated with the autoxidation of unsaturated fatty acids such as oleic, linoleic, linolenic and arachidonic acids [53], has been shown to contribute to green, greasy, rancid flavours and a rancid odour [54]. This could be the reason why the sensory panel rated the odour of AH as being less typical. In addition, the possible unfamiliarity of the evaluators with the sensory characteristics of meat products from acorn-fed pigs, which are new to the local market, should also be considered. Apart from this finding, the less homogeneous slice colour and the slightly lower BF sweetness, the panel could not perceive any other diet-associated sensory differences. The lack of the acorn diet's effect on the volatile and sensory profile in the present study could also be due to the different amounts and/or types of acorns used. Namely, acorns from the Mediterranean oaks, _Q.__ilex_, _Q.__rotundifolia_ and _Q.__uber_ are characterized by a distinct phenolic and FA composition (e.g., >63% of oleic acid in the total FA) [55]. Moreover, the quantity of acorns consumed by pigs, as part of a mixed diet, in the present study does not seem to be sufficient for appreciable changes in the aroma and sensory characteristics of the dry-cured hams. Regarding the impact of the ham processing method, the present study examined smoke reduction, which has recently been recognised by Croatian consumers as the most widely accepted health-related innovation in traditional meat products with the least negative impact on the perceived traditional character of the product [14]. Unlike most dry-cured hams from other Mediterranean countries, hams in Croatia are usually smoked using hardwood. Smoking gives dry-cured meats the desired sensory characteristics, such as a golden-brown surface colour and the typical flavour and aroma of smoked meat, which are highly preferred by local consumers. When meat is smoked, the desired colour is formed when compounds with a carbonyl group (aldehydes and ketones) are absorbed from the smoke into the moist surface of the meat, reacting with amines from the protein, while the typical flavor and the formation of a \"smoky\" aroma occur mainly due to the absorption of phenolic compounds that are present in smoke and their subsequent diffusion into the deeper portions of the product [56]. In addition, the smoke possesses antimicrobial [57] and antioxidant effects [58] and acts as a barrier against the development of rancidity due to the protective film it creates on the dry-cured ham's surface [59].