The revalorization of food processing by-products not only reduces the environmental impact of their disposal, but also generates added economic value. Cava lees consist of inactive cells of Saccharomyces cerevisiae, and though regarded as a valueless winery by-product, they are rich in fiber and phenolic compounds. In this study, a challenge test was performed to assess the effect of cava lees and a phenolic extract (LPE) derived therefrom on the behaviour of technological microbiota (lactic acid bacteria used as a starter culture) and the foodborne pathogens Salmonella spp. and Listeria monocytogenes during the fermentation and ripening of pork sausages. Ten batches of fermented sausages were prepared with and without cava lees or the LPE, and with or without different strains of Latilactobacillus sakei (CTC494 or BAP110). The addition of cava lees reduced the pH values of the meat batter throughout the fermentation and ripening process. No growth-promoting effect on spontaneous lactic acid bacteria (LAB) or the starter culture was observed. In contrast, the presence of cava lees prevented the growth of the tested pathogens (Salmonella and L. monocytogenes), as did the starter culture, resulting in significantly lower counts compared to the control batch. In addition, the combination of cava lees with L. sakei CTC494 had a bactericidal effect on Salmonella. LPE supplementation did not affect the pH values or LAB counts but reduced the mean counts of Salmonella, which were 0.71 log10 lower than the control values at the end of the ripening. The LPE did not exert any additional effect to that of the starters applied alone. The revalorization of cava lees as a natural ingredient to improve the microbiological safety of fermented sausages is a feasible strategy that would promote a circular economy and benefit the environment.

The growing trend of circular economy has prompted the design of novel strategies for the revalorization of food industry by-products. Cava lees, a winery by-product consisting of non-viable cells of Saccharomyces cerevisiae rich in β-glucans and mannan-oligosaccharides, can be used as a microbial growth promoter, with potential food safety and health applications. The aim of this study was to assess in vitro the effect of cava lees on the growth of 21 strains of lactic acid bacteria (LAB) species commonly used as starter cultures and/or probiotics. Firstly, 5% of cava lees was selected as the most effective amount for enhancing microbial counts. After screening different LAB, statistically significantly (p < 0.05) higher microbial counts were found in 12 strains as a consequence of cava lees supplementation. Moreover, a greater and faster reduction in pH was observed in most of these strains. The growth-promoting effects of cava lees on LAB strains supports the potential revalorization of this winery by-product, either to improve the safety of fermented products or as a health-promoting prebiotic that may be selectively fermented by probiotic species.

Vegetarian and vegan diets are increasingly being adopted in Spain, a trend mainly driven by ethical concerns for animal welfare and the environment. This has resulted in a growing market for plant-based substitutes of meat products. However, available data on the nutritional value of such meat analogues in Mediterranean countries are still limited. In this study, the labelling information of four categories of plant-based meat analogues (n = 100) and the corresponding conventional meat products (n = 48) available on the Spanish market was surveyed and compared. The nutrient content of plant-based meat analogues varied significantly, due to the wide range of ingredients used in their formulation. Some of these products were found to have a low protein content, which in others was enhanced by the addition of cereals and legumes. Compared to the meat products, the plant-based analogues contained lower levels of total fat as well as saturated fat, which ranged from 30% of total fat in burgers to less than 15% in meatballs, sausages, and nuggets; in contrast, they contained higher amounts of fiber and complex carbohydrates. Overall, the meat analogues cannot be considered as nutritionally equivalent substitutes to conventional meat products due to a high variability of protein content and other nutrients.

Food safety can be compromised by some bioactive compounds such as biogenic amines that can be specially found in fermented foods due to the bacterial decarboxylation of some amino acids by fermentative or spoilage bacteria. Cava lees are a winery by-product rich in fiber and phenolic compounds and previous works have raised their revalorization from a food safety point of view. The aim of the current work was to investigate whether the use of cava lees can help to control biogenic amine formation in bread and fermented sausages. In bread, only very low levels of biogenic amines (putrescine, cadaverine, and/or spermidine) were found, whose content did not vary with the addition of different amounts of lees. However, the addition of lees in fermented sausages significantly reduced the formation of tyramine and cadaverine. In sausages spontaneously fermented and inoculated with Salmonella spp., the presence of cadaverine and putrescine diminished by 62 and 78%, respectively, due to the addition of cava lees. The addition of cava lees phenolic extract also showed an anti-aminogenic effect (21% for cadaverine and 40% for putrescine), although in a lesser extent than cava lees. Cava lees and their phenolic extract were shown to be an effective strategy to control the undesirable accumulation of high levels of biogenic amines during the production of fermented products.