Feeding Dairy Ewes with Fresh or Dehydrated Sulla (Sulla coronarium L.) Forage. 2. Effects on Cheese Enrichment in Bioactive Molecules

Microbial dynamics and quality characteristics of spontaneously fermented salamis produced by replacing pork fat with avocado pulp

The aim of this study was to develop a novel and healthier fermented meat product by replacing pork fat with avocado pulp (AVP) during salami production. Experimental salamis were produced under laboratory conditions by substituting pork fat with AVP partially (10-AVP) and totally (20-AVP), while control salamis (CTR) remained AVP-free. The microbial composition of control and experimental salamis was assessed using a combined culture-dependent and -independent approach. Over a 20-days ripening period, lactic acid bacteria, coagulase-negative staphylococci, and yeasts dominated the microbial community, with approximate levels of 9.0, 7.0 and 6.0 log CFU/g, respectively. Illumina technology identified 26 taxonomic groups, with leuconostocs being the predominant group across all trials [constituting 31.26-59.12 % of relative abundance (RA)]. Gas Chromatography-Mass Spectrometry (GC-MS) analysis revealed changes in fatty acid composition and volatile organic compounds due to the substitution of pork fat with AVP. Specifically, monounsaturated fatty acids and terpene compounds increased, while saturated fatty acids and lipid oxidation products decreased. Although AVP influenced the sensory characteristics of the salamis, the highest overall satisfaction ratings were observed for the 10-AVP salamis. Consequently, substituting pork fat with AVP emerges as a viable strategy for producing healthier salamis and diversifying the meat product portfolio.

Comparison of the targeted metabolomics and nutritional quality indices of the probiotic cheese enriched with microalgae

The objective of this study is to evaluate the influence of mixed L. acidophilus LA-5 and enrichment with microalgae (C. vulgaris and A. platensis) on metabolomic formation in a brined cheese matrix. Microbiological, compositional, and metabolomic characterization were investigated during the ripening. It was found that the nutritional quality indices of the samples were based on amino acid and fatty acid characterization. Fifty-six metabolomics including fatty acids, amino acids, organic acids, minerals, and vitamins were detected using the HPLC-DAD, GC-MS, and ICP-OES-based methods. The results indicated that the enrichment with probiotic strain and microalgae led to an increase in the nutritional quality indices such as EAAI, NI, BV, MUFA/SFA, h/H, and DFA. The chemometric analysis (e.g. HCA and PCA) presented the variance between the cheese samples based on their attributes. The identification of cheese metabolomics throughout the ripening could be used for a better understanding of the functional ingredients-cheese matrix relationships and as a directive approach for novel dairy products in other metabolomic-related studies.

Effect of commission implementing regulation (EU) 2020/1319 on the bacterial composition of PDO Provola dei Nebrodi cheese

In this study, PDO Provola dei Nebrodi cheese was deeply characterized for its bacterial community and chemical composition. Four dairy factories (A-D) were monitored from milk to ripened cheese. Wooden vat biofilms were dominated by thermophilic rod LAB (4.6-6.5 log CFU/cm²). Bulk milk showed consistent levels of total mesophilic microorganisms (TMM) (5.0-6.0 log CFU/mL) and, after curdling, a general increase was recorded. The identification of the dominant LAB in wooden vat biofilms and ripened cheeses showed that the majority of wooden vat LAB were lactococci and Streptococcus thermophilus, while cheese LAB mainly belonged to Lacticaseibacillus paracasei and Enterococcus. Illumina sequencing identified 22 taxonomic groups; streptococci, lactococci, lactobacilli and other LAB constituted the majority of the total relative abundance % of the wooden vat (69.01-97.58 %) and cheese (81.57-99.87 %) bacterial communities. Regarding chemical composition, the effect of dairy factories was significant only for protein content. Inside cheese color was lighter and yellower than surface. Differences in fatty acids regarded only myristic acid and total amount of monounsaturated fatty acids. The sensory evaluation indicated some differences among cheeses produced in the four dairies regarding color, homogeneity of structure, overall intensity, salty, spicy, and hardness. The integrated approach applied in this study showed that PDO Provola dei Nebrodi cheese characteristics are quite stable among the dairy factories analyzed and this has to be unavoidably imputed to the application of the same cheese making protocol among different dairies.

Effects of Sulla Flexuosa Hay as Alternative Feed Resource on Goat's Milk Production and Quality

Sulla flexuosa (Hedysarum flexuosum L.) is an endemic legume growing in some Mediterranean areas in rainfed and cold mountainous conditions. It could be used in goat diets as an alternative protein source instead of alfalfa to supplement forest rangeland. This study aimed to test the effects of incorporating Sulla flexuosa (SF) hay in the diet of Beni Arouss goats on their milk production and quality. The hay was introduced at two levels, i.e., 35 or 70% (SF70), on a DM basis; it partially or totally replaced the alfalfa hay of the control diet. Sulla flexuosa incorporation did not affect milk production or physicochemical composition. However, milk FA content varied in proportion to the percentage of SF incorporation. The SF70 diet was associated with increased milk levels in C18:1n-9, C18:2n-6, C18:3n-3, and C22:6n-3 and total monounsaturated, polyunsaturated, and n-3 fatty acids. As a consequence, atherogenic and thrombogenic indices were improved. Additionally, better antioxidant capacity was observed in SF70.

Effect of olive by-products feed supplementation on physicochemical and microbiological profile of Provola cheese

Introduction

With the purpose to evaluate the effects of dietary olive cake, a source of bioactive phenolic compounds, as feed supplementation of lactating dairy cows on fatty acid composition, volatile organic compounds, and microbiological profiles of Provola cheese, we performed a two-arm study where control and experimental administered cows derived dairy have been compared.

Methods

Our panel of analyses include metabolomics, physicochemical detected variables, culture dependent and independent analyses, and a stringent statistical approach aimful at disclosing only statistically significant results.

Results and discussion

Looking at the physicochemical variable's profiles, a higher content of unsaturated fatty acids, polyunsaturated fatty acid, and conjugated linoleic acids as well of proteins were observed in experimental cheese samples, indicating the beneficial effect of dietary supplementation. Furthermore, based on volatilome composition, a clear cluster separation between control and experimental cheeses was obtained, mainly related to terpenes degradation, able of influencing their aroma and taste. Microbiological results showed a decrease of some spoilage related microbial groups in experimental cheeses, probably due to the inhibitory effect exerted by polyphenols compounds, that contrarily did not affect the core taxa of all cheese samples. This paper confirmed the promising utilization of olive by-product in farming practices to obtain more sustainable and safe dairy food products with lower environmental impact, mainly in Sicily and Mediterranean area, where waste disposal poses serious environmental and economic problems.

Feeding Dairy Ewes with Fresh or Dehydrated Sulla (Sulla coronarium L.) Forage. 1. Effects on Feed Utilization, Milk Production, and Oxidative Status

Simple Summary

Sulla forage, containing condensed tannins, is renowned in the Mediterranean area for its excellent chemical composition and agronomic traits, the suitability for grazing or hay production, and favorable impact on ruminants’ productivity. Condensed tannins of sulla forage exert various positive effects, because they contribute to reducing methanogenesis in the rumen, protect dietary proteins from rumen degradation, limit the ruminal biohydrogenation of polyunsaturated fatty acids, and ensure animal health by anthelmintic action. Moreover, the antioxidant activity of condensed tannins may contribute to improving the antioxidant status of animals, as well as the oxidative stability and antioxidant properties of animal products, with important health benefits for human consumers. The conservation methods of sulla forage, such as dehydration and the hay-making process, can influence the content and bioavailability of condensed tannins. In this research, the performance of dairy ewes fed with pelleted dehydrated sulla forage, in terms of feed intake, digestibility, milk production, and oxidative status, were compared with those of ewes fed diets based on sulla hay and fresh sulla forage. The results confirmed the positive effects of sulla forage, also when fresh sulla forage is replaced with dehydrated forage. On this basis, the storage and use of sulla dehydrated pellets represent a valid opportunity to exploit the potential of sulla forage in periods of low availability of grazing sources.

Abstract

Feeding dairy ewes with fresh sulla forage (FSF), a legume species containing condensed tannins (CT), has been shown to increase feed intake, milk yield, and casein and enhances the oxidative status of animals. Dehydration of FSF could be an alternative to hay-making to preserve the nutritional properties. This research aimed to compare the responses of dairy ewes fed with diets based on sulla hay (SH), pelleted dehydrated sulla forage (DSF), or FSF in terms of efficiency of feed utilization, milk production, and the balance between oxidant (reactive oxygen metabolites (ROMs)) and antioxidant (biological antioxidant potential (BAP)) substances at the plasma level. Ten first-lambing (FL) and ten third-lambing (TL) ewes of the Valle del Belice breed at 60 days in milk were allocated into five homogeneous groups fed with different diets in a partial 5 × 2 Latin square design with two phases. The diets differed for the forage basis: SHL = SH ad libitum; DSF2 = 2 kg/day DSF per head plus SH ad libitum; FSF2 = 2 kg/day FSF per head plus SH ad libitum; FSF4 = 4 kg/day FSF per head plus SH ad libitum; FSFL = FSF ad libitum. A commercial concentrate was provided to FL (0.8 kg/day per head) and TL (1.2 kg/day per head) ewes. Dehydration induced slight variations in the content of protein and fiber, showed no loss of vitamin E and polyunsaturated fatty acids, and decreased the level of CT and polyphenols. The DSF2 diet resulted in a higher intake of dry matter, protein, and vitamin E compared to the other diets, whereas, compared to the FSFL diet, its intake was analogous for net energy and was lower in CT and polyphenols. The DSF2 diet was comparable to FSF4 and FSFL diets for milk yield, and to all diets for casein content and the clotting ability of milk. Ewes fed a DSF2 diet exhibited lowest values of ROMs and oxidative stress index (OSI = ROMs/BAP), indicating a better oxidative status, presumably due to the antioxidant protection exerted by the higher vitamin E intake and CT metabolites. These results confirmed the positive effects of FSF on milk production, especially due to CT intake, in improving the efficiency of dietary protein utilization, and showed how favorable effects also occur when FSF is replaced by DSF instead of SH.