###### Abstract  
Oidation is one of the major reasons for impaired quality of meat and meat products but can be prevented by the addition of antioxidants. In the present study, the effect of dietary sweet chestnut wood extract and hop cones on the quality and oxidative stability of meat and dry-cured products was investigated. Control pigs (N = 11) were fed a commercial diet (13.1 MJ) metabolizable energy, 15.5% crude protein), while the other two experimental groups were supplemented with 3% of sweet chestnut wood extract (Tannin; N = 12) or 0.4% of hop cones (Hops; N = 11). The quality of meat and dry-cured products was evaluated by means of chemical composition, water holding capacity, objective color, and lipid and protein oxidation. No major effects of sweet chestnut wood extract or of hops supplementation were observed, nevertheless, some indications of improved water holding capacity could be attributed to antioxidants supplementation. The color evolution of dry-cured bellies from Tannin and Hops groups of pigs during refrigerated storage was also indicative of an improved oxidative stability.  
tannin extract; hops; pigs; meat; dry-cured products; oxidation +
Footnote †: journal: Medical  
compounds, which are structurally related but vary in quantity and type, depending on the source [4]. Two potential sources of natural antioxidants, which are easily available and economically important in Slovenia, are sweet chestnut (_Castanea sativa_ Mill.) and hops (_Humulus lupulus_ L.). Sweet chestnut wood extract, consisting mainly of hydrolysable tannins, is commonly used as a feed additive. It has been shown to possess antioxidant properties in vitro [5] and in vivo in different animal species [6; 7]. As a result, an improved oxidative stability of meat from animals fed diets supplemented with sweet chestnut wood extract was reported, however, its efficiency depends on the animal species and the dose used; higher doses may exert even pro-oxidant effects [8; 9]. Hops are also reported to serve as a potential source of antioxidants [10]. Hop cones are primarily utilized in the brewery industry due to the preservative attributes and the contribution to bitterness, and the characteristic hoppy aroma of beer [11; 12]. Hop cones contain many active phenolic compounds, which have been shown to exert antioxidant activities in vitro [13; 14] or after their addition to meat products [15]. However, only a few studies have examined the stability of meat with controversial results; reduced lipid oxidation rates [16; 17], no effect [18], or even pro-oxidant activity [19].  
Scientific studies on the potential of incorporating health promoting bioactive compounds derived from sweet chestnut wood extract and hops into meat and meat products, via dietary supplementation, especially regarding the supplementation with hops, are limited and further investigation is warranted. Moreover, no studies are available where the effect of supplementing pigs' diet with sweet chestnut wood extract or hops on quality and oxidative stability of pork dry-cured products was investigated. The objective of the present study was to assess the effect of dietary supplementation of pig diets with sweet chestnut wood extract or hop cones on pork and dry-cured products quality, with an emphasis on oxidative stability.