Humic substances are organic ubiquitous components arising in the process of chemical and microbiological oxidation, generally called humification, the second largest process of the carbon cycle. The beneficial properties of these various substances can be observed in many fields of life and health, whether it is the impact on the human organism, as prophylactic as well as the therapeutic effects; animal physiology and welfare, which is widely used in livestock farming; or the impact of humic substances on the environment and ecosystem in the context of renewal, fertilization and detoxification. Since animal health, human health and environmental health are interconnected and mutually influencing, this work brings insight into the excellence of the use of humic substances as a versatile mediator contributing to the promotion of One Health.

Humic substances with a high proportion of humic acids (more than 40%) have been classified by the European Commission as feed materials that can be used in animal nutrition since 2013. A protective effect on the intestinal mucosa, as well as anti-inflammatory, adsorptive and antimicrobial properties, were recorded. Nutrient absorption, nutritional status and the immune response in chickens supplemented with HSs were significantly improved. HSs have the ability to enhance protein digestion as well as the utilization of calcium and trace elements. They are known to improve feed digestibility as a result of maintaining an optimal pH in the gut, leading to lower levels of nitrogen excretion and less odor in the husbandry environment. HSs not only increase digestibility and result in greater utilization of the feed ration but also improve the overall quality of the meat produced. They increase the protein content and reduce the fat content in breast muscles. They also contribute to improving the sensory characteristics of the meat produced. Their antioxidant properties improve the oxidative stability of meat during storage. The influence of HSs on fatty acid composition may be one of the reasons that meat has a more beneficial effect on the health of consumers.

The present study aimed to evaluate the lipid content and oxidation of fallow deer (FD), wild boar (WB), and pig meat (PM) at −18 °C for a 360-day storage period. The lowest fat content was observed in thigh meat (TM) of FD (2.53%; p ˂ 0.05). The ratio of polyunsaturated/saturated fatty acids (PUFA/SFA), n-6/n-3, hypocholesterolemic/hypercholesterolemic index (h/H), and the lipid nutritional quality indexes were calculated. The PUFA/SFA ratio of each meat sample was compared with the required value of more than 0.4 while the optimal n-6/n-3 ratio was determined only in shoulder meat (SM) of FD meat samples (3.94; p ˂ 0.001). An atherogenic index of lower than 1.0 was observed in each meat sample and a thrombogenic index of lower than 0.5 was observed only in TM of FD (0.53; p ˂ 0.001). During the storage period, the malondialdehyde (MDA) content of WB and PM samples showed a higher variability than the FD samples. On the initial day as well as on the 360th day of the storage period, the lowest MDA content in the loin of PM was measured. Long-term vacuum packaging resulted in lower lipid oxidation during meat storage (p ˂ 0.01); however, the duration of the storage period significantly affected the level of lipid oxidation (p ˂ 0.001).

The use of plant extracts in the production of fermented meat products can help protect fats from oxidation, improve color stability, and extend their shelf life. The study evaluated the effect of natural extracts (acerola—A, rosemary—R, and their combination—M) on the quality of Tokaj salami stored in MAP at 4 °C for 35 days, compared to negative (N) and positive (K, sodium erythorbate) controls. While the initial chemical composition showed differences due to raw material variability (p < 0.001), fat and protein content remained stable during storage (p > 0.05). In contrast, acidity and water activity (aw) were significantly affected (p < 0.001). Regarding oxidative stability, plant extracts significantly inhibited lipid oxidation during storage (p < 0.05). By day 35, the negative control reached the highest malondialdehyde (MDA) level of 0.67 mg/kg, whereas samples with acerola (A) maintained the lowest values at 0.38 mg/kg, performing comparably to the synthetic antioxidant (0.43 mg/kg; p > 0.05). Acerola extract (A) demonstrated the highest efficacy in stabilizing oxidative changes, with results comparable to the synthetic antioxidant (p > 0.05). Colorimetric analysis revealed that lightness (L*) ranged from 45.98 to 49.75, with L*, a*, and b* parameters significantly influenced by both the antioxidant type and storage phase (p < 0.001). Sensory evaluation remained unaffected by the antioxidants, being affected only by storage time (p < 0.05). These results confirm that acerola and rosemary extracts are viable natural alternatives to sodium erythorbate for maintaining the oxidative and color stability of fermented salami.