Search Results (114)

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

Traditional coagulant calf rennet, which is used in cheese production, is currently facing the problem of an unsustainable source. In addition, the production of cheese with calf rennet produces whey with high biochemical (BOD) and chemical oxygen demand (COD) values. For these reasons, plant extracts have been investigated as sustainable sources of coagulants for milk. However, there are few reports on the changes in the COD and BOD of whey when plant extracts are used. For this reason, this study investigated the potential of extracts from two Hechtia species native to Mexico (H. glomerata and H. podantha) as sustainable milk coagulants for cheese production, with the aim of simultaneously reducing the pollutant load of residual whey. The milk coagulation efficiency of the extracts of the two Hechtia species was investigated, and in addition, their effects on cheese texture and color, and the composition of the residual whey, including BOD and COD, were evaluated. Most extracts of H. podantha showed adequate milk coagulation and yielded fresh cheese with textural properties comparable to those of cheese produced with conventional calf rennet. A significant reduction in carbohydrate content was achieved when H. podantha extracts were used. As a result, a significant decrease in the BOD and COD values was achieved. In some cases, a reduction of up to 1.78 times compared with those of the control was achieved. The results of this study show that H. podantha is a promising source of natural coagulants for sustainable cheese production, offering a dual benefit by providing an alternative to conventional rennet and reducing the environmental impact of whey. Full article

The assessment of milk coagulation properties (MCPs) is crucial for enhancing goat cheese production and quality. In this study, 501 bulk goat milk samples were collected from various farms to evaluate the MCPs. Traditionally, cheesemaking aptitude is evaluated using lactodynamographic analysis, a reliable but time-consuming laboratory method. Mid-infrared spectroscopy (MIRS) offers a promising alternative for the large-scale prediction of goat milk’s technological traits. Reference MCP measurements were paired with mid-infrared spectra, and prediction models were developed using partial least squares regression, with accuracy evaluated through cross- and external validation. The ability of MIRS to classify milk samples by coagulation aptitude was evaluated using partial least squares discriminant analysis. Only the model for rennet coagulation time obtained sufficient accuracy to be applied for screening (R²_CrV = 0.68; R²_Ext = 0.66; RPD = 2.05). Lower performance was observed for curd-firming time (R²_CrV = 0.33; R²_Ext = 0.27; RPD = 1.42) and curd firmness (R²_CrV = 0.55; R²_Ext = 0.43; RPD = 1.35). Classification of high coagulation aptitude achieved balanced accuracy values of 0.81 (calibration) and 0.74 (validation). With further model refinement and larger calibration datasets, MIRS may become a resource for the dairy-goat sector to monitor and improve milk suitability for cheesemaking. Full article

This study assessed the effect of ultrafiltration (UF) on the quality of soft white cheese made from goat skim milk (GSM) and aimed to identify the optimal UF parameters for protein concentration while minimizing energy consumption. UF was applied to pasteurized GSM by altering transmembrane pressure (TMP) and permeate flux density (J) while monitoring the volume reduction factor (VRF). The acidity, viscosity, dry extract, proteins and Ca, Na, K, Mg and Fe contents increased significantly during concentration. Post-ultrafiltration, both UF and non-UF GSMs were coagulated using modified rennet doses (150, 200 and 300 µL/L). The resulting cheeses underwent chemical analysis, yield calculation and textural property assessment. The findings highlighted that milk protein concentration was the primary limiting factor for coagulation, with rennet dose having a lesser impact. The UF-GSM produced the best results, yielding approximately 30% cheese with a soft texture and greater nutritional value (proteins, Ca, Mg and Fe). Full article

This study examined the impact of extensive and intensive farming systems on the rheological behavior of rennet-induced goat milk coagulation in the indigenous Greek Skopelos goat breed. Milk samples were obtained from Skopelos dairy goats reared under extensive and intensive farming systems at two farms in Greece. Rennet-induced coagulation kinetics (at 35 °C) and curd rheological properties were assessed using dynamic rheometry. Milk from the extensive system exhibited longer rennet coagulation time (RCT) but resulted in curds with higher storage modulus (G′) and complex viscosity (η*), indicating formation of stronger coagulated structures compared to curds from the intensive system. The differences can be attributed to variations in milk composition and the structural characteristics of protein components, e.g., casein fractions, between the two systems. Principal component analysis (PCA) revealed that the farming systems could be differentiated based on the rheological properties of the curds, specifically on structure-related parameters (loss tangent, tanδ, apparent yield stress, τ_y). Strong correlations (p < 0.01) were noted between G′max and caseins/total proteins (positive), as well as with pH (negative), in both farming systems. These findings offer valuable insights into animal farming practices and cheese production, providing evidence of the relationships between goat-rearing systems and rheological properties of rennet-coagulated milk products. Full article

This review contributes to the knowledge on the complex and adaptive microbial ecosystems within cheese, emphasizing their critical role in determining cheese quality, flavor, and safety. This review synthesizes the current knowledge on the microbial interactions and the dynamics of lactic acid bacteria (LAB), encompassing both starter (SLAB) and non-starter (NSLAB) strains, which are pivotal to the curd fermentation and ripening processes. The adaptability of these microbial consortia to environmental and technological stressors is explored, highlighting their contributions to acidification, proteolysis, and the development of distinctive organoleptic characteristics. Historical and technological perspectives on cheesemaking are also discussed, detailing the impact of milk treatment, starter culture selection, and post-renneting procedures on microbial activity and biochemical transformations. This review underscores the importance of microbial diversity and cooperative interactions in fostering ecosystem resilience and metabolic functionality, and it addresses the challenges in mimicking the technological performance of natural starters using selected cultures. By understanding the ecological roles and interactions of cheese microbiota, this review aims to guide improvements in cheese production practices. Additionally, these insights could spark the development of innovative strategies for microbial community management. Full article

The aim of this research was to compare the chemical composition and the technological characteristics of milk for Parmigiano Reggiano cheese produced in herds with different numbers of cows. The research was carried out on 5760 Italian Friesian herd milk samples collected from a total of 160 farms (one sample per month in each farm for three years). On each milk sample, lactose, fat, protein, casein, titratable acidity, total bacterial count, somatic cells, coliform bacteria, clostridia spores, and rennet coagulation properties were determined. Increasing herd size was positively correlated with milk production and with milk somatic cell and clostridia spores’ contents (8133 kg/cow/lactation, 5.280 Log₁₀cells/mL and 1.782 spores/L for herds with less than 30 cows; 9109 kg/cow/lactation, 5.548 Log₁₀cells/mL and 2.138 spores/L for herds with more than 200 cows, respectively). Moreover, herd size was negatively correlated with milk fat content and with total bacterial and coliform bacteria counts (3.73 g/100 g, 4.931 Log₁₀CFU/mL and 3.176 Log₁₀CFU/mL for herds with less than 30 cows; 3.51 g/100 g, 4.770 Log₁₀CFU/mL and 3.121 Log₁₀CFU/mL for herds with more than 200 cows, respectively). Farms with more than 100 cows raised were characterised by higher milk production per cow per lactation, but the milk produced by them was also characterised by lower fat content. Finally, milk produced in the herds with a higher number of cows showed a higher frequency of optimal lactodynamographic types (better rennet-coagulation properties) than milk produced in the other herds. Full article

This study aims at the use of freeze-dried camel rennet extract (FDCR) in the manufacture of fresh cheeses from a mixture of camel and goat milk in comparison with the microbial coagulating agent (FDMC). Physical properties, chemical composition, microstructure, and sensory analysis of the cheeses were performed. The recommended amount of FDCR for coagulation of camel–goat milk mixture was 0.2 g/L. The cheese obtained was mainly characterized by dry matter 34.99 ± 0.57% and protein content 36.26 ± 1.75%/DM. Texture profile analysis revealed that the obtained cheese was mainly characterized by cohesiveness 0.32 ± 0.01 and springiness 14.25 ± 0.63 mm. The microstructure showed that the obtained cheese had more and wider pores. FTIR was used to monitor the differences in the gross composition of the obtained cheese compared to that coagulated with FDMC. The main difference was the presence of amide I in the cheese coagulated with FDCR. For X-ray diffraction, the results noted that the use of FDCR as a natural extract in the coagulation of camel–goat milk mixture did not lead to the appearance of crystalline structure in the cheese. For sensory evaluation, the panelists preferred the cheese coagulated with FDCR with a score of 9/15. Full article

Plant-derived rennet sources have been recognized as effective alternatives to traditional animal-derived rennet in cheese processing, producing various cheeses for vegetarians and Halal consumers. The aim of the present study was to assess the quality and identify potential chemical and sensory markers of Canestrato cheese made from pasteurized mixed cow/sheep milk (50:50 ratio) using a kiwifruit extract (prepared in the laboratory) as a rennet source of vegetable origin. The milk was curdled with an aqueous kiwi extract (cK group), with commercial calf rennet (cT group), or with commercial microbial rennet obtained from the controlled fermentation of Rhizomucor miehei (cH group). For each cheesemaking process, 30 L of mixed milk was used, resulting in 10 forms, each weighing approximately 1 kg. Cheese produced using kiwifruit rennet exhibited improved nutritional characteristics, such as lower total lipid, cholesterol, and sodium content and greater levels of polyphenols, potassium, and phytosterols compared with the cheese of the cT group. The cheese of the cK group had a slightly more pronounced bitterness compared to cheeses made with conventional rennets (cH and cT). Overall, the use of kiwifruit extract as a milk coagulant has proved to be a promising alternative, improving both the nutritional profile and functional properties of the resulting cheese. Full article

The aim of this study was to investigate the effect of the addition of wild garlic leaves on the sensory quality, volatiles, color, and texture of sheep milk soft rennet-curd cheese. The sensory evaluation of color, appearance, texture, odor, and taste was performed using a 5-point scale. The intensity of selected taste and odor discriminants was also assessed. Volatiles were analyzed by the GC-MS method. Color and textural characteristics were determined instrumentally. The wild garlic addition had no effect on the sensory characteristics of the cheese (p > 0.05). However, cheese with herbs exhibited a less intensive sour odor (p ≤ 0.05), sheep’s milk odor, and taste (p ≤ 0.01). (E)-7-methyl-4-decene, dichloroacetic acid undecyl ester, and 3,5-dimethyl-octane, described as creamy, acetic, and acid pungent in smell, were not detected in the cheese with wild garlic while they were present in the natural one. Moreover, herbal cheese was more piquant (p ≤ 0.01). PCA showed that the differences in volatiles resulted both from the use of wild garlic and the time of storage. Herbal addition affected almost all color characteristics, except for the hue angle (h), but caused an increase only in hardness and chewiness. In conclusion, wild garlic leaves can be recommended as an additive in the production of soft sheep’s milk rennet-curd cheese. 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

This study investigated the production of rennet gels from β-casein-depleted retentates obtained through cold microfiltration (MF) of skim milk (SM) that was treated beforehand to ensure microbial safety. The treatments included thermization (65 °C, 20 s), pasteurization (72 °C, 15 s), and microfiltration (50 °C; 1.4 μm pore size). The reduction in β-casein content was 0.98, 0.51 and 0.90%, respectively. All treatments resulted in the partial aggregation of serum proteins, which were slightly concentrated in the retentates obtained post cold MF process. This aggregation, along with concentration effect, likely inhibited β-casein dissociation from casein micelles and permeation, particularly in pasteurized milk. Renneting and coagulation properties of the retentates were comparable to those of the respective SM samples, with no significant differences in syneresis, water-holding capacity, or protein hydration. Notably, the retentate from thermized SM, which showed the best performance with the highest β-casein reduction (0.98%), demonstrated shorter coagulation time compared to retentate from pasteurized milk or the corresponding unfiltered SM. Textural analysis revealed greater firmness, cohesiveness, and viscosity of retentate-based rennet gels compared to gels made from unfiltered SM, attributed to protein concentration during cold MF. Overall, this study successfully produced rennet gels from cold MF retentates without compromising their physicochemical properties. Full article

Both hydrodynamic cavitation (HC) and temperature elevation are important pretreatments for improving the performance of liquid food processing by reducing viscosity. In this study, we assessed the impact of HC and elevated temperature on the functionality of milk protein concentrate powder with 80% protein (MPC80) prepared from nanofiltration (NF) of ultrafiltration (UF) retentate. Skim milk was concentrated using UF, and the retentate was further subjected to HC and concentrated using NF, then spray dried to obtain MPC80 powder. The functionality of these powders processed using NF at 22 °C, NF at 50 °C, HC and NF at 22 °C, and HC and NF at 50 °C were evaluated. Rennet coagulation time of reconstituted MPC80 from different NF treatments was like skim milk when treated with 0.1% CaCl₂. High-temperature NF reduced the water solubility of MPC80 powder (70.03 to 79.20%) at room temperature, but it was similar when measured at 50 °C (86.05 to 92.91%). The HC improved foaming (92.22 to 112.89%) but did not impact the emulsifying capacity (59.58 to 61.38%) and heat stability (18.04 to 20.22 min). Results showed that the HC and high-temperature NF utilized to increase the production efficiency of MPC80 also maintained the functionality of the powders after spray drying. Full article

The microbiological and biochemical properties of a goat cheese produced using Helianthus annuus (sunflower) seed extract as a coagulant and the potentially probiotic autochthonous culture Limosilactobacillus mucosae CNPC007 were examined in comparison to a control cheese devoid of the autochthonous culture. Throughout a 60-day storage period at 6 ± 1 °C, lactobacilli maintained a count of above 8 log CFU/g. Additionally, its viability in cheeses subjected to the in vitro gastrointestinal conditions demonstrated improvement over this period. Specifically, the recovery of lactobacilli above 6 log CFU/g was observed in 16.66% of the samples in the first day, increasing to 66.66% at both 30 and 60 days. While total coliforms were detected in both cheese trials, this sanitary parameter exhibited a decline in L. mucosae cheeses during storage, falling below the method threshold (<3 MPN/g) at 60 days. This observation suggests a potential biopreservative effect exerted by this microorganism, likely attributed to the higher acidity of L. mucosae cheeses at that point (1.80 g/100 g), which was twice that of the control trial (0.97 g/100 g). Furthermore, distinct relative proportions of >30 kDa, 30–20 kDa, and <20 kDa proteins during storage was verified for L. mucosae and control cheeses. Consequently, either the H. annuus seed extract or the L. mucosae CNPC007 autochthonous culture influenced the biochemical properties of the cheese, particularly in terms of proteolysis. Moreover, L. mucosae CNPC007 acidification property resulted in a biopreservative effect throughout the storage period, indicating the potential as a promising source of probiotics for this product. Full article

Onopordum nervosum subsp. platylepis Murb. is an Asteraceae species found in Tunisia, Algeria, and Libya. It has been studied for its potential use as a vegetable rennet alternative to animal-derived rennet, making it important to understand its germination characteristics. This species often shows low germinability due to dormancy, which limits its large-scale cultivation. In preliminary experiments, many factors were analyzed to evaluate the seed germination of this thistle including physical stratification with abrasive paper and high-temperature water, chemical treatments with hydrogen peroxide (H₂O₂) or sulfuric acid (H₂SO₄), and the exogenous use of the growth regulator gibberellic acid (GA₃). Based on the obtained results and subsequent analysis, GA₃ and cold stratification durations were selected for the second experiment, which used a full factorial RSM design with three levels for each factor. Additionally, the total polyphenol content (TPC), total flavonoid content (TFC), condensed tannin content (CTC), and DPPH assay were analyzed during the optimization process and for ungerminated seeds. The findings revealed that 14 days of cold stratification followed by 750 ppm GA₃ was the most efficient method for breaking the dormancy of these thistle seeds. The highest TPC was recorded in ungerminated seeds. However, germinated Onopordum nervosum ssp. platylepis seeds showed higher levels of TFC and CTC (14.83 mg QE/g DW and 6.49 mg EC/g DW, respectively) compared to the non-germinated ones and demonstrated the greatest potency in inhibiting free radicals (DPPH EC₅₀ = 0.018 mg/mL) at the identified optimal germination conditions. Ungerminated seeds indicated significant phenolic content (TPC) and a limited ability to reduce oxidants, which could explain their low germination percentage. Our findings on the seed germination and dormancy characteristics of this endemic thistle will aid in the protection and development of its germplasm. Full article