Search Results (53)

Somatic cell count (SCC) in milk is widely used as an indicator of intramammary infections in dairy sheep and is routinely monitored by the dairy industry as a marker of milk quality. This study aimed to evaluate the effect of SCC levels on milk production, composition, colour, coagulation properties, and cheese-making ability in Manchega dairy sheep. A total of 752 individual milk samples were analysed. To normalise SCC distribution, the somatic cell score (SCS) was calculated and samples were classified into SCS classes. Increasing SCS significantly reduced daily milk yield and lactose content, increased milk pH, and decreased lightness (L*). Higher SCS was also associated with impaired coagulation properties, including longer rennet clotting time (RCT) and curd firming rate (k₂₀), as well as reduced curd firmness (A₃₀, A₆₀). Similar effects were observed for modelled coagulation parameters, with delayed RCTeq and reduced kCF and CFp. Regarding cheese-making ability, SCS significantly affected curd humidity and protein recovery, whereas no significant effects were detected for dry curd yield or fat recovery. Overall, elevated somatic cell counts were associated with a reduction in the technological quality of Manchega sheep milk, particularly affecting coagulation behaviour and curd characteristics. These results underline the importance of controlling SCC levels in dairy sheep systems for both udder health monitoring and maintaining milk suitability for cheese-making. Full article

Plant-derived coagulants are increasingly explored as alternatives to animal rennet. This study provides the first evaluation of the coagulation kinetics and technological properties of Onopordum platylepis Murb. in ewe’s milk. Response surface methodology was applied to optimize temperature (30, 33, and 36 °C), pH (5.5, 6.0, and 6.5), and calcium chloride concentration (2, 4, and 6 mM). The optimal conditions for minimizing milk-clotting time were 36 °C, pH 5.5, and 6 mM CaCl₂. Under standardized activity (50 IMCU/L), the Rheological properties of gels produced by Onopordum platylepis were compared with Cynara cardunculus, Cynara humilis, animal rennet, a commercial plant coagulant, and fermentation-produced chymosin. Onopordum platylepis showed slower curd-firming rates than animal rennet and Cynara cardunculus, but similar behavior to Cynara humilis. Gels produced with Onopordum platylepis exhibited firmness comparable to commercial plant coagulants. The water-holding capacity was similar to other coagulants, though protein losses were higher for Onopordum platylepis, Cynara humilis, and Cynara cardunculus than animal rennet. Overall, Onopordum platylepis demonstrates potential for ewe’s milk cheese production, in which highly proteolytic coagulants are used. Full article

Background: Silybin, the primary active constituent of the milk thistle extract silymarin, has been historically recognized for its hepatoprotective properties. More recently, its potential effects on blood coagulation have garnered attention, suggesting a broader pharmacological profile. Methods: This study aimed to investigate silybin’s impact on hemostasis using rotational thromboelastometry (ROTEM) in normal human plasma. ROTEM enables the dynamic assessment of clot formation, providing a detailed analysis of coagulation processes in real-time. We specifically focused on the effects of silybin concentrations of 10 µM, 50 µM, and 100 µM on the ROTEM parameters compared to controls using normal human plasma with 0.1% dimethyl sulfoxide (DMSO). The parameters derived from the tests included clotting time (CT), α-angle (α), and amplitude at 10 and 20 min (A10 and A20) for each of the three channels: intrinsic pathway thromboelastometry (INTEM), extrinsic pathway thromboelastometry (EXTEM), and fibrinogen thromboelastometry (FIBTEM). Each measurement was performed four times. Results: Analysis of the INTEM assay results demonstrated that silybin at concentrations of 10 µM and 50 µM significantly reduced clotting time (CT) compared to the control. Additionally, all tested silybin concentrations significantly decreased the α-angle in the INTEM test. In the EXTEM assay, no significant effect on CT was observed at any silybin concentration. However, consistent with the INTEM findings, all silybin concentrations resulted in a significant reduction in the α-angle. In the FIBTEM assay, silybin at 10 µM and 50 µM significantly shortened CT. Furthermore, all tested concentrations led to a significant decrease in the α-angle and A20, while a reduction in A10 was observed only at the 50 µM concentration compared to the control. Conclusions: This study demonstrates that silybin modulates ROTEM parameters in a manner that tends to vary with concentration, with the strongest effects observed at lower concentrations (10–50 µM), notably reducing CT, α-angle, and clot firmness (A10, A20). These findings suggest a potential role of silybin in influencing coagulation dynamics. Full article

The enzymatic coagulation of milk, crucial in cheese production, entails the hydrolysis of κ-casein and subsequent micelle aggregation. Conventional assessment standards, such as the Berridge method, depend on visual inspection and are susceptible to operator bias. Recent methods for the identification of milk-clotting time rely on optical, ultrasonic, and image-based technologies. In the present work, the composition of milk was evaluated through standard methods from ISO and AOAC. Milk coagulation time (MCT) was measured through viscosimetry, Berridge’s operator-driven technique, and a machine learning approach employing computer vision. Coagulation was additionally observed using the Optigraph, which measures micellar aggregation through near-infrared light attenuation for immediate analysis. Sheep milk samples were analysed for their composition and coagulation characteristics. Coagulation times, assessed via Berridge (BOB), demonstrated high correlation (R² = 0.9888) with viscosimetry (Visc) and machine learning (ML). Increased levels of protein and casein were linked to extended MCT, whereas lower pH levels sped up coagulation. The calcium content did not have a notable impact. Optigraph assessments validated variations in firmness and aggregation rate. Principal Component Analysis (PCA) identified significant correlations between total solids, casein, and MCT techniques. Estimates from ML-based MCT closely align with those from operator-based methods, confirming its dependability. This research emphasises ML as a powerful, automated method for evaluating milk coagulation, presenting a compelling substitute for conventional approaches. Full article

The main objective of this research consists in finding a rapid method for cheese lipidomics based on NMR data. This study plays an important role in differentiation and characterization of cheese samples in accordance with fat composition, especially in the case of fat substitution with exogenous animal or vegetal fat. Our findings play an important role in relation to religious requirements regarding non-allowed foods (pork fat, for example, in some cultures) and in the correct characterization of foods according to their lipidic profile. The approach consists in establishing a fingerprint region (0.86–0.93 ppm from ¹H-NMR spectra) and then creating a database of the results obtained. The evaluation of the long-chain saturated fatty acids and the saturated short-chain fatty acids (C4 to C8) was established with a newly developed set of equations that make the computation possible even when mixtures of fats from different sources are present. This was accomplished by developing a new method for quantification of the fatty acid composition of different types of cheese, based on ¹H-NMR spectroscopy. Principal component analysis (PCA) was applied to 40 cheese samples with varying degrees (0%, 5%, 12%, or 15%) of milk fat substitution (pork fat, vegetable fat, hydrogenated oils) and different clotting agents (calcium chloride or citric acid). The best sample discrimination was achieved using fatty acid profiles estimated from ¹H-NMR data (using a total of six variables), explaining 89.7% of the total variance. Clear separation was observed between samples containing only milk fat and those with added fats. These results demonstrate that the integration of ¹H-NMR spectroscopy with principal component analysis (PCA) provides a reliable approach for discriminating cheese samples according to their fat composition. Full article

Consumer interest in vegetarian, ethical, and clean-label foods is reviving the use of plant-derived milk coagulants. Cardosins from Cynara cardunculus (“thistle”) are aspartic proteases with strong clotting activity, yet their technological impact in cheese remains under-explored. This study compared a commercial thistle extract (PC) with traditional bovine rennet rich in chymosin (AC) during manufacture and 60-day ripening of Caciotta cheese. Classical compositional assays (ripening index, texture profile, color, solubility) were integrated with scanning electron microscopy, three-dimensional surface reconstruction, and descriptive sensory analysis. AC cheeses displayed slower but sustained proteolysis, yielding a higher and more linear ripening index, softer body, greater solubility, and brighter, more yellow appearance. Imaging revealed a continuous protein matrix with uniformly distributed, larger pores, consistent with a dairy-like sensory profile dominated by milky and umami notes. Conversely, PC cheeses underwent rapid early proteolysis that plateaued, producing firmer, chewier curds with lower solubility and darker color. Micrographs showed a fragmented matrix with smaller, heterogeneous pores; sensory evaluation highlighted vegetal, bitter, and astringent attributes. The data demonstrate that thistle coagulant can successfully replace animal rennet but generates cheeses with distinct structural and sensory fingerprints. The optimization of process parameters is therefore required when targeting specific product styles. Full article

In dairy cattle, abomasal ulcers are a serious but sometimes disregarded ailment that can have detrimental effects on health and cause financial losses. Due to inconclusive clinical symptoms, abomasal ulcers are typically misdiagnosed and treated improperly. Specialized diagnostic methods should be considered to ensure a correct diagnosis and the well-being of cattle. This report focuses on a 4-year-old Holstein-Friesian cow which began her third lactation two weeks before she started showing general clinical signs of an elevated fat–protein ratio in the milk and was diagnosed with an abomasum displacement. The clinical signs can also be mistaken for other conditions such as traumatic reticuloperitonitis and left dislocated abomasum. The patient was brought to the LUHS Large Animal Clinic, and after a short while, sudden death occurred. The autopsy concluded that death had occurred due to hypovolemic shock caused by abomasal ulcer perforation, which caused bleeding into the abomasum and intestines. Also, the type 3 ulcer caused severe peritonitis and anemia, and feed and fibrin could be seen on the outside of organs in the abdomen. Blood clots mixed with feed had formed in the inside of the abomasum and intestinal tract. Based on the work of previous scientific studies, it has been established that the occurrence of ulcers is more frequent in dairy cows during the first four to six weeks of lactation. And the most probable cause could be intensive feeding and dietary changes. Ulcers in the abomasum are very difficult to diagnose, because they require special diagnostic equipment such as an ultrasound or surgical interventions. Due to the similarity with other diseases, this pathological condition of the abomasum is most frequently only identified in post-mortem examinations. Full article

This study demonstrates that Bacillus subtilis GDAAS-A32-derived postbiotics (BSP) enhance yogurt production by optimizing lactic acid bacteria (LAB) viability and functionality. BSP enhanced the growth kinetics and biomass accumulation of Streptococcus thermophilus and Lactobacillus bulgaricus in both an anaerobic and aerobic pure system. The addition of BSP significantly increased the viable cell counts of S. thermophilus and L. bulgaricus, milk-clotting activity, sensory properties, and extracellular polysaccharide content and improved the rheological properties. Moreover, BSP elevated viable counts of S. thermophilus and L. bulgaricus to 6.18 × 10⁸ CFU/g and 1.03 × 10⁸ CFU/g, respectively, by day 7—representing 11.3-fold and 9.3-fold increases versus controls at 20% supplementation. Metabolomic signatures confirmed peptidoglycan reinforcement and flavor enhancement. Mechanistically, BSP supplementation might reduce urate and H₂O₂ toxicity through NH₃-mediated proton neutralization and oxygen scavenging, while establishing a pyrimidine salvage network and redirecting one-carbon metabolism, resulting in enhanced stress tolerance and significant improvements in bacterial viability. Full article

The process of camel milk’s transformation into cheese is a delicate operation due to various difficulties in achieving coagulation. This study investigates the processing challenges of camel milk in the production of camel milk cheese using chicken gizzard inner lining extract (CGLE) as a coagulant. The crude extract presents an extraction yield of 55.05 ± 1.8% and a pH = 4.40 ± 0.05. The optimal coagulation conditions were pH 5 and temperature 45 °C. A fresh camel milk cheese was produced using CGLE and characterized as CME. The cheese yield of the CME was 26.88 ± 0.42%, which was higher than that obtained with chymosin (CC) at 12.66 ± 0.12%. The pH and acidity were 5.29 ± 0.09 and 56.25 ± 1.25°D. The gross composition of camel cheese (CME) was determined in comparison to (CC) fat (13.50 ± 2.82%), proteins (11.61 ± 0.19%), and dry matter (38.85 ± 1.22%). The sensory analysis demonstrated significant differences (p < 0.05) between the CME and CC in terms of white color, acidic taste, and consistency. Therefore, CME presents an overall acceptability in comparison to the control. The chicken gizzard inner lining extract could be used as an efficient coagulant for the production of fresh camel cheese. Full article

Milk coagulants play a crucial role in defining curd characteristics. The objective of this study was to compare the coagulation dynamics of two commonly used coagulants in cheesemaking: cardoon flower extract (Cynara cardunculus L.) and commercial chymosin, using sheep milk from four different origins in the Baixo Alentejo region of Portugal, as the substrate. Milk composition was determined using the MilkoScan 133B, while the milk-clotting time (MCT) was measured following ISO 23058/IDF 199:2006 guidelines with slight modifications and coagulation kinetics, and technological properties were evaluated using the Optigraph apparatus. The results demonstrate that the type of coagulant impacts the coagulation properties of sheep milk. Pearson’s correlation analysis indicated that milk samples with higher protein content exhibited longer coagulation times but resulted in firmer curds. On the other hand, the use of cardoon flower extract introduced greater variability compared to chymosin, with a delayed onset of coagulation, reduced curd firmness, and increased variability in enzymatic kinetics. These results suggest that cardoon extract, while traditional, introduces greater heterogeneity in curd formation compared to the more consistent action of chymosin. Full article

This study explores the extraction and characterization of proteolytic enzymes from brewer’s spent grain (BSG) and their potential as sustainable coagulants in the dairy industry. BSG samples from various beer types (Blonde Ale, IPA, Kölsch, Honey, and Porter) were obtained from two artisanal breweries in Mar del Plata, Argentina. Optimization of caseinolytic activity (CA) and protein extraction was conducted using a Plackett–Burman design, followed by a Box–Behnken design. Optimal protein concentration was achieved at intermediate pH and high temperature, while CA peaked at pH 8.0. The specific caseinolytic activity (SCA) varied among the extracts, with BSG3 showing the highest activity (99.6 U mg⁻¹) and BSG1 the lowest (60.4 U mg⁻¹). Protease inhibitor assays suggested the presence of aspartic, serine, metallo, and cysteine proteases. BSG3 and BSG4 showed the highest hydrolysis rates for α-casein (70% and 78%). For κ-casein, BSG1, BSG2, and BSG3 demonstrated moderate activity (56.5%, 49%, and 55.8), while BSG4 and BSG5 exhibited the lowest activity. Additionally, the milk-clotting activity (MCA) of BSG extracts was comparable to plant-based coagulants like Cynara cardunculus and Ficus carica. These findings highlight the potential of BSG-derived proteases as alternative coagulants for cheese production, offering a sustainable link between the brewing and dairy industries. Full article

The objective of this study is to investigate how different factors, such as lactic acid bacteria, prebiotics (flaxseed powder, watercress seed powder, okra mucilage), and coagulation temperature influence the final quality of curd by conducting three optimization experiments and implementing a structured experimental plan. In the first phase, milk coagulation was assessed at 45 °C with various combinations of lactic acid bacteria (probiotics) and prebiotics (powdered flaxseed and watercress). In the second investigation phase, the effects of lowered probiotic and prebiotic (powdered flaxseed and watercress) concentrations were examined at the coagulation temperature of 38 °C. We investigated the concentration of lactic acid bacteria at 3 mg/mL of milk and the effects of temperature and prebiotics (okra mucilage and flaxseed powder). We observed short milk clotting time (2 s) using the optimized mixture (0.18 mg of probiotics, 1.5 mg of flaxseed powder, and 1.147 mg of watercress powder) per 10 mL of milk. It contrasts with the classical coagulation way optimized at (5.9 and 9.5 s), which were generated at optimal temperatures of 45 and 45.7 °C, respectively. Our new mixture improves the fermentation process of camembert cheese at 38 °C. This cheese had a high flavonoid content, fewer lactic bacteria and molds, a homogeneous texture, and no outer crust, and exceptional sensory attributes such as a creamy and fluid paste. These attributes suggest its potential benefits as a dairy product for individuals with cardiovascular and gastrointestinal conditions. Full article

This study aimed to compare the chemical composition of aqueous extracts from different aerial plant parts (leaves, stems, and flowers) of Onopordum nervosum ssp. platylepis growing in different regions (Sousse, Kairouan, and Nabeul) in Tunisia, as well as their antioxidant and milk-clotting properties for both spontaneously grown and cultivated plants. Results showed that phenolic composition varies significantly among ecotypes and plant organs (p < 0.05), with flowers containing the highest amounts of total phenols and flavonoids in both plant types. The flowers from Nabeul (NA) region showed the highest amounts of total phenols and higher phenolic contents compared to leaves and stems, with 44.75 mg GAE/g and 39.79 mg GAE/g in spontaneous and cultivated plants, respectively. However, flowers of spontaneously plants grown in Sousse (SO) showed the highest total flavonoid contents (11.42 mg QE/g). Additionally, the findings indicated that flowers contained higher concentrations of mono- and disaccharides than leaves and stems. The antioxidant activity showed that the radical scavenging activity of O. platylepis aqueous extracts is significantly affected by the organ and genotype (p < 0.05). NA genotype revealed the highest potency in inhibiting free radicals, with flowers having the lowest IC50s values in 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) tests, registering 0.13 ± 0.02 and 0.14 ± 0.01 mg/mL, respectively. Milk-clotting activity was limited to flowers of this thistle. Moreover, SO and NA genotypes were identified as the most potent populations to coagulate milk in spontaneous and cultivated plants. The principal component analysis confirms the organ and genotype variability in this thistle, with the first two axes explaining 64.15% of the variance and highlighting a distinct flower group. The obtained results suggest that the domestication of this thistle could be useful for the conservation of biodiversity and the promotion of genotypes with potential technological properties. Full article

Agroindustrial by-products constitute an alternative source of feed livestock, and their use contributes to the sustainability of livestock systems and the circular bioeconomy. The effects of replacing cereal (0%, 40%, and 80%) with dehydrated orange pulp (DOP) in the diet of goats on the antioxidant and fatty acid (FA) contents of cheeses were evaluated. For a more suitable understanding of the role of coagulant enzymes in establishing the properties of the cheese, the effect of milk-clotting with animal and vegetable rennet was also analysed. The rennet did not substantially affect the FA or the antioxidant compounds, and the use of DOP did not affect the FA contents. However, the α-tocopherol levels, total phenolic compounds (TPC), and total antioxidant capacity (TAC) in cheeses increased as the percentage of DOP replacing cereals increased. Moreover, the high correlation obtained between the TAC and the TPC (r = 0.73) and α-tocopherol (r = 0.62) contents indicated the important role played by these compounds in improving the antioxidant capacity of the cheese. In conclusion, DOP is a suitable alternative to cereals in the diet of goats and improves the antioxidant status of the cheese produced. Full article

The transformation of milk into cheese largely depends on the technological properties of the raw material, with breed being a crucial factor that influences both the composition and coagulation properties of the milk used for cheesemaking. This study uses canonical correlation analysis to explore the relationships between physicochemical traits and coagulation properties in milk from various Spanish breeds, aiming to identify both common and breed-specific patterns that impact milk technological aptitude. A total of 832 milk samples from Manchega, Assaf, Merino de Grazalema, and Merino de Los Pedroches breeds were analyzed. The milk characteristics investigated included pH, composition (fat, protein, lactose, total solids), and coagulation properties (curd firmness—A₆₀, rennet clotting time—RCT, curd firming time—k₂₀, and individual laboratory curd yield—ILCY). The results reveal a shared correlation structure across breeds and unique covariation patterns in some breeds that deviate from the general trend. While Assaf and Merino de Los Pedroches follow the common correlation pattern, Manchega and Merino de Grazalema exhibit distinct patterns. This research underscores the need for in-depth study and suggests that the dairy industry could benefit from shifting from the traditional focus on maximizing fat and protein for higher curd yields to considering technological traits for selective breeding. Full article