Simona Rinaldi

This study evaluated the effects of dietary supplementation with goji berries (Lycium barbarum) on the nutritional profile, oxidative stability, and shelf life of rabbit meat. Thirty-two rabbits were assigned to two dietary treatments: a control diet (CN) and the same diet supplemented with 3% dried goji berries (GJ). Proximate composition and fatty acid profile of the Longissimus thoracis et lumborum muscle were determined at dissection, whereas physical, microbiological, and biochemical parameters were evaluated during refrigerated storage (4 °C; 1, 4, and 10 days) and frozen storage (−20 °C; 60 and 120 days). Dietary supplementation significantly modified the lipid profile of the meat, reducing saturated fatty acids and increasing long-chain n-3 and n-6 polyunsaturated fatty acids. During refrigerated storage, lipid peroxidation increased in both groups; however, meat from the GJ group showed significantly lower TBARS values after 10 days (0.22 vs. 0.33 mg MDA/kg; p < 0.001), indicating improved oxidative stability. Lower accumulation of total volatile basic nitrogen (TVB-N), reduced formation of biogenic amines, and slower growth of spoilage-related microbial populations, particularly Pseudomonas spp., were also observed in GJ samples. Overall, the GJ diet improved fatty acid composition and delayed degradative processes during storage, suggesting its potential as a functional feed ingredient to enhance rabbit meat quality and shelf life.

In recent years, natural bioactive compounds have been increasingly investigated as functional feed additives to enhance livestock production. The present study aims to provide an update on the potential use of these compounds to enhance animal health and the quality of animal products, while critically assessing their principal limitations and future practical applicability. The review is based on peer-reviewed articles published between 2020 and 2025 and retrieved from the Scopus database, ensuring the inclusion of recent and high-impact scientific contributions. Phytogenic feed additives, including polyphenols, terpenoids, and alkaloids, exert beneficial effects on animal health by modulating oxidative stress and inflammatory pathways. Improvements in milk and meat quality are mainly associated with enhanced antioxidant capacity and lipid stability, rather than with the direct transfer of phytochemicals into animal-derived products. In ruminants, selected bioactive compounds may also contribute to methane mitigation through modulation of rumen fermentation and microbial ecology. However, their efficacy remains highly context-dependent and requires precise characterization of composition, dosage, and species-specific application. Future research should therefore prioritize deeper elucidation of metabolic mechanisms, systemic physiological responses, and productive outcomes to better define the conditions under which these compounds exert consistent and biologically meaningful effects.

Sialic acids (SIAs) are bioactive compounds present in glycoproteins and glycolipids, playing key roles in human physiology. N-acetylneuraminic acid (Neu5Ac), the only sialic acid synthesized by humans, contributes to neurodevelopment and immune function, whereas N-glycolylneuraminic acid (Neu5Gc), acquired from animal-derived foods, is potentially harmful, showing pro-inflammatory properties. Accordingly, a high Neu5Ac/Neu5Gc ratio represents an important nutritional indicator. This study quantified the two main forms of SIA in five commercial cheese types (mozzarella, stracchino, caciotta, robiola, ricotta) produced from cow (C), buffalo (B), and goat (G) milk, as well as in laboratory cheesemaking from 1000 g of milk from each species. Neu5Gc concentrations were significantly higher in G cheeses (p < 0.001), while Neu5Ac was more abundant in C cheeses (p < 0.05). Consequently, the Neu5Ac/Neu5Gc ratio was markedly higher in C and B cheeses (24.11 and 21.57, respectively) than in G (1.29), reflecting species-specific glycosylation patterns. Among cheese types, ricotta produced from whey exhibited the highest SIA concentrations among all species, followed by robiola, mozzarella and stracchino. In contrast, caciotta showed the lowest SIA levels. The laboratory cheesemaking trial confirmed that most SIAs remained bound to whey proteins. These findings highlighted the combined effect of milk species and cheesemaking on sialylation, with potential nutritional implications.

Bovine colostrum is naturally rich in antimicrobial and antioxidant compounds, making it a promising candidate for improving the safety and quality of fresh meat products. This study aimed to evaluate the effect of incorporating bovine colostrum at 1%, 3%, and 5% (w/w) into ground rabbit meat patties on the growth potential of Listeria monocytogenes and on meat quality during refrigerated storage at 4 ± 2 °C. Microbiological analyses revealed that bovine colostrum significantly reduced (p < 0.001) the growth potential of Listeria monocytogenes in a dose-dependent manner, with the 5% formulation showing the slowest growth rate (μ = 0.055 h⁻¹; doubling time = 12.5 h) compared with the control (μ = 0.063 h⁻¹; doubling time = 10.9 h). In parallel, physicochemical analyses demonstrated that patties containing bovine colostrum, particularly at 5%, had a lower peroxidability index (p < 0.05), reduced lipid oxidation (p < 0.001), and higher sulfhydryl group content (p < 0.001), indicating improved oxidative stability in fresh meat. These findings demonstrate that bovine colostrum, particularly at 5%, effectively inhibits microbial growth while preserving lipid and protein integrity. Overall, bovine colostrum shows strong potential as a natural antimicrobial and antioxidant ingredient in fresh meat, supporting its use in multi-hurdle preservation strategies to extend shelf life and improve consumer safety.

Olive leaf by-products may be an important feed source for ruminants in the Mediterranean area, due to their nutritional value and high levels of functional metabolites. Additionally, their use can enhance the environmental and economic sustainability of the productions. To evaluate the effect of olive leaf supplementation on the fatty acid profile of sheep cheese, two farms with Comisana breed sheep with free access to pasture and fedwith 300 g/head/day of concentrate were considered. One farm supplemented the feed with clover hay ad libitum (NOL) and the other farm replaced hay with olive leaves (OLI) in the autumn period. Cheese analyses were performed at 15, 30, and 60 days of ripening. Saturated fatty acids were lower in OLI cheese than NOL cheese, while MUFA and PUFA n-3 and n-6 were higher in OLI cheese. Myristic acid (C14:0) and palmitic acid (C16:0) were lower in OLI cheese compared to NOL (8.31% vs. 8.90% and 21.52% vs. 24.95%, respectively), while oleic acid (C18:1 cis-9) was higher in OLI cheese (20.66% vs. 18.78%). Also, CLA cis-9 trans-11 (0.98% vs. 0.84%), and other isomers were higher in OLI cheese. Health indexes, such as the thrombogenic and atherogenic index, were lower in OLI than in NOL cheese (1.96 vs. 2.38 and 1.69 vs. 2.05, respectively) showing the improvement in the health quality of cheese due to olive leaf integration in directly on farm sheep feeding.

Cheese is an important source of protein in the human diet, and its digestibility depends on its macro and microstructure. This study investigated the effect of milk heat pre-treatment and pasteurization level on the protein digestibility of produced cheese. An in vitro digestion method was used considering cheeses after 4 and 21 days of storage. The peptide profile and amino acids (AAs) released in digestion were analyzed to evaluate the level of protein degradation following in vitro digestion. The results showed the presence of shorter peptides in the digested cheese from pre-treated milk and 4-day ripening while this trend was not observed after 21 days of storage, showing the effect of storage period. A significantly higher content of AAs was found in digested cheese produced from milk subjected to a higher temperature of pasteurization, and there was a significant increase in total AA content in the cheese after 21 days of storage, confirming the positive effect of ripening on protein digestibility. From these results emerges the importance of the management of heat treatments on the digestion of proteins in soft cheese.

Milk fat depression (MFD) syndrome, a consistent decrease in milk fat content, is related to important changes in fatty acid composition due to feed imbalances and the consequent ruminal metabolism alteration. Milk produced in two different farming systems was compared: Holstein Friesian fed with unified in intensive production and Podolica raised on a pasture in an extensive system. Milk chemical characteristics and fatty acid composition were determined comparing milk with a normal fat level (>3.8%) to milk with a low fat level (trans-11 and increase in trans-10 C18:1 (shift from trans-11 to trans-10 C18:1) in low fat with respect to normal fat milk with a consequent decrease in the trans-11/trans-10 C18:1 ratio. Even conjugated linoleic acid (CLA), C18:2 cis-9, trans-11, was lower while CLA trans-10, cis-12 was higher in low fat milk than in normal fat milk from Holstein Friesian. These changes, that are indicators of MFD syndrome, were not found in Podolica milk between fat levels. Holstein Friesian milk showed less short-chain fatty acids (9.48 % vs. 11.05%, p < 0.001), trans vaccenic acid (C18:1 trans-11, 0.51% vs. 3.39%, p < 0.001), rumenic acid (CLA C18:2 cis-9, trans-11, 0.32% vs. 1.45%, p < 0.001) and total CLA (0.53% vs. 1.91%, p < 0.001) contents than Podolica milk. Further losses of these human healthy nutrients in low fat Friesian milk reduced the nutritional quality of the milk, while the milk from animals raised on the pasture was of better quality even when the level of fat was low.