## 1 Introduction  
Meat and meat products are widely considered as a main part of the human diet since they are a resource of bioavailable amino acids, proteins, lipids, minerals, and vitamins. Consumers demand meat products because they are easy to store and cook. In general, they are elaborated mainly with livestock animals like pork, beef, or poultry, but today, consumers look for other unusual species. In this sense, venison meat from wild red deer is a viable alternative to traditional meals in an increasingly demanding market. It is considered a \"natural\" meat, obtained from free-range animals and free of hormone, antibiotics, and other products. Also, its nutritional quality allows consumers to follow a healthy diet due to its low fat and saturated fatty acid content and high protein and trace mineral content [1]. Despite not being widely produced and consumed worldwide, the demand of this meat has increased in Europe over the last few decades; even consumers pay a higher price for it [2]. There is a wide variety of products elaborated with meat; nevertheless, burgers are one of the most popular due to the combination of convenience and low price, along with sensorial properties. However, the grinding process and their high fat content make burgers more susceptible to oxidation and microbial spoilage due to the breakdown of muscle structure. In addition, different processing stages of burgers and the modified atmosphere packaging (MAP) rich in oxygen facilitate the oxidative process [3]. Therefore, the use of additives to prevent deterioration of meat products is necessary to extend their shelf life.  
Although the food industry has commonly employed synthetic additives to maintain the quality of meat products, consumers prefer the use of natural preservatives. Essential oils, aqueous extracts, powders, and other plant products have been proposed as natural additives due to their phenolic content being responsible for the antioxidant and antimicrobial capacities [4]. However, the occurrence of these valuable compounds can also be found in the large amounts of waste generated by food industries. Therefore, the revalorization of agro-food byproducts drives economic advantages and provides new commercial utilities because of their content in bioactive compounds [5].  
In particular, the wine industry produces 2-3 million tons of waste products per year only in Spain, which need to be processed [6]. Consequently, some environmentally friendly technologies have appeared to revalorize these winemaking residues with a high content of bioactive compounds [7]. Wine lees are a water-waste sediment composed of solid and liquid fractions, deposited in the bottom of the tanks or barrels during the vinicification process. They mostly contain microbial biomass, metabolites, and phenolic compounds, which leads a source of wide interesting products [8]. Due to their composition, wine lees can be used in food, pharmaceutical, and cosmetic industries because of their recognized antioxidant, antimicrobial, cardio protective, or anti-inflammatory properties [9].  
Inactive dry yeasts (IDY) from _Saccharomyces cerevisiae_ have been proposed in the food industry as natural antioxidants [10], but few studies have employed natural wine lees in useful applications as functional additive in foodstuff [11; 12]. Nevertheless, other winery byproducts such as seed and grape comace extracts have been used as alternative antioxidants in different meat products [13; 14; 15].  
Taking into account the functional properties of wine lees, this research has been carried out to find an alternative to traditional and synthetic additives in the meat industry. With this aim, the antioxidant and antimicrobial efficiency of wine lees added to deer burgers packed in MAP to enhance their self-life was checked. Also, changes in the chemical and sensorial properties of burgers were studied.