Search Results (303)

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

Cheese production is an ancient practice that is associated with the food and cultural identity of different peoples. There are over 500 cheese types globally, including 207 with protected denomination of origin (PDO) and 70 with protected geographical indication (PGI) status in the European Union (EU). Each cheese has various biochemical compositions, production methods, and maturation environments. This study has provided a critical review of the environmental impacts of cheese production, focusing on energy consumption, greenhouse gas (GHG) emissions, and the integration of renewable energy sources as sustainable strategies for this sector. Based on case studies and life cycle assessment (LCA) methodologies, the analysis revealed significant variability in energy use (3.0 to 70.2 MJ/kg) and GHG emissions (up to 22.13 kg CO₂ eq/kg), influenced by factors such as the cheese type, production complexity, system boundaries, and the technological or geographical context. Particular attention was given to heat treatment, refrigeration, and maturation processes, which contribute substantially to the overall energy footprint. The paper also discusses the methodological challenges in LCA studies, including the role of co-product allocation and database limitations. Finally, strategic renewable energy options, such as biogas recovery and solar thermal integration, are discussed as sustainable alternatives to reduce the environmental footprint of the dairy sector and support its sustainability. Full article

Dehydration and storage conditions used to preserve dairy cultures in the industry may negatively impact their viability and functionality. This study investigated the effects of freeze-drying and storage on the metabolic activity of Lacticaseibacillus rhamnosus 73 (L73). The strain’s viability after freeze-drying and storage, its metabolic activity in cultured milk, and its performance as a ripening agent in miniature cheeses were evaluated. Neither the freeze-drying process nor the storage conditions negatively affected its viability, as L73 maintained its initially high levels (>10 log cfu mL⁻¹) throughout the storage period. L73 improved the overall quality of the cheeses, as a reduction in hydrophobic peptides (i.e., potential bitter peptides) was evidenced in cheese manufactured with L73. Furthermore, L73 exhibited protective properties, as evidenced by the decreased availability of compounds that could be used as energy sources by adventitious microorganisms (e.g., galactose, hippuric acid) and the increased production of lactic acid in both cultured milk and cheese. Full article

Biogenic amines (BA) are simple organic bases of low molecular weight, formed during decarboxylation of amino acids. Ripened cheeses provide suitable conditions for the development of bacteria and production of BAs. The aim of the present study was to investigate the presence of eight BAs in ripened cheese samples (n = 125) using a high-performance liquid chromatography with diode array detector (HPLC-DAD). Furthermore, microbiological analyses towards identification of bacteria using matrix-assisted laser desorption ionisation—time of flight mass spectrometry (MALDI-TOF MS) were performed. Cadaverine and putrescine were detected in 28.0% and 20.8% of cheese samples at concentrations ranging from 6.12 to 2871 mg/kg and 5.74 to 441 mg/kg, respectively. High amounts of putrescine and cadaverine in cheeses were associated with the presence of Hafnia alvei. Tyramine was identified in 28.0% of samples in the concentration range of 5.62–646 mg/kg. High concentrations of this amine was found in cheeses containing Enterococcus faecium and Enterococcus faecalis. Histamine content, the only BA restricted in food according to Regulation 2073/2005, was observed above 100 mg/kg in 11.2% of the cheeses. Ripened cheeses available on the local retail market may contain significant levels of biogenic amines and may pose a potential health hazard to consumers. Full article

Biocontrol is one of the most promising alternatives to chemical preservatives for food preservation. This study investigated the biocontrol potential of yeasts isolated from raw milk cheese against spoilage moulds. Eighty-four native yeast strains were screened for antagonistic activity against Penicillium commune, Fusarium verticillioides, and Mucor plumbeus/racemosus via confrontation using a milk-based culture medium. Fifteen strains from the species Pichia jadinii, Kluyveromyces lactis, Kluyveromyces marxianus, and Geotrichum candidum exhibited significant antagonistic activity (inhibition zone > 2 mm) against M. plumbeus/racemosus and F. verticillioides. The modelling of the impact of ripening conditions revealed that temperature was the primary factor influencing yeast antagonism. In addition, notable variability at both species and strain levels was found. The antagonist activity was associated with different mechanisms depending on the species and strains. K. lactis stood out for its proteolytic activity and competition for iron and manganese. Additionally, two strains of this species (KL890 and KL904) were found to produce volatile organic compounds with antifungal properties (phenylethyl alcohol and 1-butanol-3-methyl propionate). G. candidum GC663 exhibited strong competition for space, as well as the ability to parasitise hyphae linked to its pectinase and β-glucanase activity. The latter enzymatic activity was detected in all P. jadinii strains, with P. jadinii PJ433 standing out due to its proteolytic activity. In a cheese matrix, the efficacy of eight yeast strains against three target moulds was assessed, highlighting the potential of G. candidum GC663 and P. jadinii PJ433 as biocontrol agents, exhibiting high and moderate efficacy, respectively, in controlling the growth of F. verticillioides and M. plumbeus/racemosus. Nonetheless, further research is necessary to elucidate their full spectrum of antifungal mechanisms and to validate their performance under industrial-scale conditions, including their impact on cheese quality. Full article

In food processing, non-destructive and non-invasive characterization is a powerful tool for monitoring processes and controlling quality. Cheeses consist of a large variety of products whose nutritional and sensory properties depend on the source materials, cheesemaking procedures, and biochemical transformations occurring during maturation and storage. In this study, proton magnetic resonance relaxation time correlation maps (2D ¹H-NMR T₁–T₂) are used to investigate the effect of the ripening degree on Pecorino cheese and evaluate its evolution during storage in a refrigerator under vacuum-packaging conditions. NMR relaxometry has allowed for non-invasive monitoring of packaged Pecorino cheese slices, and the results were compared with those obtained with the two widely used techniques, i.e., Differential Scanning Calorimetry (DSC) and Attenuated Total Reflectance Fourier-Transform Infrared Spectroscopy (ATR-FTIR). The analysis of variance and simultaneous component analysis (ASCA), separately applied to 2D ¹H-NMR T₁–T₂ correlation maps, DSC, and ATR-FTIR data, suggests that the results obtained with the NMR approach are consistent with those obtained using the two benchmark techniques. In addition, it can distinguish cheeses stored for different durations (storage time) irrespective of their original moisture content (ripening degree), and vice versa, without opening the vacuum-package, which could compromise the integrity of the samples. Full article

This study aimed to verify, under real operating conditions, the effectiveness of protective lactic acid bacteria (LAB) culture in counteracting the development of late blowing defects in Valtellina Casera PDO cheese and its impact on product sensory characteristics. Thirty-four LAB isolated from Bitto and Valtellina Casera PDO cheeses were screened for anti-Clostridium activity. Lacticaseibacillus casei VC201 was able to inhibit all the indicator strains through organic acid production. Valtellina Casera PDO cheese-making was performed twice in three dairy farms using a commercial autochthonous starter culture with and without the addition of the protective culture VC201. Cheese was ripened both at 8 °C and 12 °C and analyzed after 70 and 180 days for LAB population, proteolysis, and lipolysis evolution as well as sensory impact. Cheeses with the addition of the VC201 strain showed higher contents of rod-shaped LAB throughout the ripening at both temperatures. The protective culture decreased the production of butyric acid at 70 days, especially at 8 °C (−15.4%), while butyric fermentation was occasionally lightly observed at 12 °C. The sensory profile was favorably impacted by the higher relative proportion of short-chain fatty acids (SCFFAs, C2–C8), which was especially pronounced at 8 °C and persisted for 180-day ripening (23.91% vs. 18.84% at 70 days and 23.84 vs. 21.71 at 180 days of ripening). The temperature and time of ripening had a significant effect on the free fatty acid content of the cheese samples in all three classes (SCFFA, MCFFA, and LCFFA). The cheese made with Lcb. casei VC201 was preferred, according to the sensory evaluation, being perceived as less acidic, less bitter, tastier, and with more intense flavor. Protective cultures can represent a practical way to reduce late blowing defects in Valtellina Casera cheese production while maintaining adherence to its PDO regulatory requirements. Full article

Cheese ripening involves microbial changes, with starter lactic acid bacteria (SLAB) initiating fermentation and nonstarter lactic acid bacteria (NSLAB) driving flavor and texture development. However, heat-resistant spores of Clostridium and Bacillus can survive pasteurization and cause spoilage during ripening. This study evaluated NSLAB dynamics in the presence of spores during cheese ripening. Cheddar cheese samples at pilot-scale level (110 L) with four treatments, namely control, with spores of B. licheniformis (T1), with spores of Cl. tyrobutyricum (T2), and both spores (T3) at 2.0 Log₁₀ CFU/mL, were ripened at 7 °C for six months. SLAB declined from 8.0 to 0.2 Log₁₀ CFU/g, while NSLAB increased from 2.0 to 8.5 Log₁₀ CFU/g by month three and maintained their counts up to six months, unaffected by spore presence. Spore counts were ≤1.45 Log₁₀ CFU/g in controls but reached 2.94 ± 0.02 (T2) and 2.48 ± 0.03 (T3), correlating with spoilage signs after five months. MALDI-TOF identified L. rhamnosus (up to 37%) and L. paracasei (up to 25%) as dominant NSLAB across treatments. Physicochemical parameters were not significantly affected by higher spore levels. While NSLAB dominated, they were inadequate to prevent spoilage in spore-inoculated samples exceeding 2.0 logs during cheese ripening. Full article

Serra da Estrela cheese (a raw ewe’s milk) ripened for 45 days was treated at 600 MPa for 6 min (P1) and at 450 MPa for 6 (P2) and 9 min (P3) and kept in refrigerated storage for 15 months. Lactobacillus and Lactococcus viable cell numbers were reduced in 3.2–3.6 and 2.7–3.6 log cycle units, respectively. Lower reductions were verified for total aerobic mesophilic and Enterococcus viable cell numbers in cheeses treated at 450 MPa (2.4–2.5 and 1.2 log reductions, respectively). In HPP cheeses, yeasts and moulds were below the enumeration limit up to 6 months of storage, but at 15 months 3.6–4.2 log cfu/g were quantified in all cheeses, while Enterobacteriaceae were inactivated to below the quantification limit. The increment of pressure treatment caused a greater impact on the microbiota’s viability than the increase in time under pressure. During storage, minor total colour differences were determined for HPP P3 cheese surface relative to control cheeses, Ch_C, at 45 days of ripening. HPP can thus be a good process to apply after cheese manufacture, since it offers a good potential to render raw-milk cheese microbiologically safer, with minimal changes in quality. Full article

Sixteen long-ripened, high-quality Cabrales cheeses from independent producers underwent a comprehensive biochemical and microbiological characterisation. Significant variations in total microbial counts and specific microbial groups were observed among the cheeses. A metataxonomic analysis identified 249 prokaryotic amplicon sequence variants (ASVs) and 99 eukaryotic ASVs, respectively, which were classified into 52 prokaryotic and 43 eukaryotic species. The predominant species included bacteria of the genera Tetragenococcus, Lactococcus (of which Lactococcus lactis was used as a starter), and Staphylococcus, followed by Brevibacterium and Corynebacterium species. The starter mould Penicillium roqueforti was highly abundant in all cheeses; Debaryomyces hansenii, Geotrichum candidum, and Kluyveromyces spp. constituted the subdominant fungal populations. Glutamic acid (≈20 mg g⁻¹) was the most abundant free amino acid in all samples, followed by lysine, leucine, and valine (≈10–13 mg g⁻¹). Moderate-to-high amounts of the biogenic amines tyramine and ornithine were detected. A large variation between cheeses of the main organic acids (lactic, acetic, or butyric) was detected. Differences between samples were also observed for the majority volatile compounds, which included organic acids, alcohols, esters, and ketones. Positive and negative correlations between bacterial and fungal species were detected, as well as between microbial populations and key biochemical markers. Among the latter, Tetragenococcus halophilus correlated positively with ethyl caprylate and hexanoic acid, and Loigolactobacillus rennini correlated positively with γ-aminobutyric acid. Conversely, Staphylococcus equorum showed a strong negative correlation with ethyl caprylate and capric acid. These microbial and biochemical insights enabled us to propose a microbiota-based starter culture comprising prokaryotic and eukaryotic components to enhance Cabrales cheese quality. Full article

A comprehensive characterization of two pressed-curd cheeses produced from ewe’s milk using enzymatic coagulation—Manchego cheese (with Protected Designation of Origin, PDO) and Castellano cheese (with Protected Geographical Indication, PGI)—was performed throughout the manufacturing process (industrial or traditional) and ripening stages (2, 9, 30, 90, and 180 days). Proton high-resolution magic angle spinning nuclear magnetic resonance (¹H HRMAS NMR) spectroscopy, combined with Principal Component Analysis (PCA) and cluster analysis, was applied to intact cheese samples. The combination of this spectroscopic technique with chemometric methods allows for the characterization of each type of sheep milk cheese according to its geographical origin and production method (artisanal or industrial), as well as the estimation of ripening time. The results demonstrate that HRMAS NMR spectroscopy enables the rapid and direct analysis of cheese samples, providing a comprehensive profile of their metabolites—a metabolic ‘fingerprint’. Full article

In this study, Malatya cheeses were produced using cow’s milk, sheep’s milk, and a cow–sheep milk mixture (1:1), were stored in brine solutions, and samples from both the cheeses and their brines were collected and analyzed at 0, 30, 90, and 180 days of storage to investigate the impact of the milk type and storage time on the cheese characteristics. Cheese made from cow’s milk exhibited a lower fat content (14.5%), whereas cheese made from sheep’s milk had a lower protein content (17.5%). During storage, salt and ash contents increased. Water-soluble nitrogen (WSN) and trichloroacetic acid-soluble nitrogen (TCASN) levels decreased during the first 90 days of storage, followed by a subsequent increase. Cow’s milk cheese demonstrated higher ripening extension index (REI) values, indicating early-stage proteolysis, whereas sheep milk cheese showed higher ripening depth index (RDI) values, reflecting more advanced ripening. The total concentration of volatile compounds in the headspace increased over time, rising from 576.7–1060.2 to 5795.1–7360.1 µg/kg dry matter by day 180 of storage, with acids being the dominant volatile group in both quantity and diversity. Free fatty acids (FFAs) were the predominant volatiles and branched-chain acids and alcohols associated with proteolysis were particularly notable in cow’s milk cheeses. Additionally, the transfer of proteins and volatile compounds into the brine increased throughout the storage period. Overall, storage time significantly influenced the cheese characteristics, while milk type also played a role, albeit to a lesser extent. Full article

Serra da Estrela cheese, with a Protected Denomination of Origin (PDO), is one of the most appreciated traditional raw milk Portuguese cheeses, and it is well known for its unique flavor and texture, which are derived from the use of raw ewe’s milk and its production process. In this work, 45-day-old ripened Serra da Estrela cheeses were processed by high-pressure processing (HPP) at 600 MPa/6 min (P1), 450 MPa/6 min (P2) and 450 MPa/9 min (P3) to study the effect of HPP initially and during 15 months of storage at 4 °C. The proteolysis indexes were, in general, lower in the HPP-treated cheeses than in the control cheeses. The P1 cheeses kept their ripening extension index throughout the 15 months of storage close to that of non-processed cheese at month 0. Progression of the ripening depth and free amino acids indexes was also slowed down by HPP. HPP had no immediate effect on the cheese texture parameters, and minor changes were found up to 3 months of storage; moreover, the P2 cheeses maintained their hardness and consistency levels during the 15-month storage period at values close to those of the control cheeses at month 0. Sensory evaluation by trained panelists showed that the P2 cheeses were softer than the control cheeses; furthermore, for the P3 cheeses, there were no observed treatment effects on the sensory attributes evaluated at the end of storage. Overall, the results uphold the potential of HPP in rendering Serra da Estrela cheese proteolysis levels similar to those of control cheese at 45 days of ripening with minor effects on texture. Full article

The characterization of volatile compounds in cheese is crucial for understanding sensory properties and consumer acceptance. Camembert cheese, a surface-ripened variety, presents a complex aroma profile shaped by biochemical and microbial interactions. Despite advances in analytical methods such as gas chromatography–mass spectrometry (GC–MS) and gas chromatography–olfactometry (GC–O), the metabolic pathways and microbial interactions defining Camembert’s aroma remain incompletely understood. This review explores the synergistic roles of microbial communities, enzymatic activity, and environmental conditions in volatile compound formation. A systematic literature review was conducted using Scopus, Web of Science, and Google Scholar to analyze the classification of volatile compounds, biochemical pathways of aroma formation, and microbial contributions. The findings highlight the essential role of Penicillium camemberti and lactic acid bacteria in aroma modulation, particularly in sulfur compounds, esters, and short-chain fatty acids. Emerging technologies such as solid-phase microextraction (SPME) and metabolomics provide new insights into volatile compound dynamics. Understanding these mechanisms may enhance aroma control in cheese production through microbial engineering and biochemical monitoring. This review underscores the need for integrated approaches to optimize fermentation and ensure sensory standardization, contributing to improved quality and consumer acceptance of Camembert cheese. Full article

Cheese ripening is a time-consuming process that can lead to spoilage and product loss. The objective of this study was to evaluate the spoilage of Mozzarella-type cheese over 14 days at 4 °C, packaged with polyurethane-based films containing curcumin as an antioxidant agent. A series of physicochemical analyses were conducted, including lipid, crude fiber, and crude protein content, as well as color measurements, weight loss, moisture content, water activity, pH, titratable acidity, total and non-protein nitrogen, proteolysis index, and cheese oxidation (measured by thiobarbituric acid reactive substances—TBARS). Additionally, microbiological tests were performed to assess mesophilic bacteria, total coliforms, fungi, and yeasts. The results indicated that the polyurethane-based packaging helped maintain the Mozzarella-type cheese’s weight by significantly reducing water loss; after 14 days, the packaged cheese reached a weight loss of approximately 3%, compared to 27% of unpackaged cheese. However, that also increased moisture retention inside the package, which accelerated Mozzarella-type cheese spoilage compared to the negative control. The moisture content of packaged cheese was maintained at approximately 42%, compared to 22% of unpackaged cheese. Furthermore, the polyurethane-based films with curcumin did not exhibit any significant antioxidant effect on the cheese. It can be concluded that these polyurethane-based films are not suitable for foods with high moisture content. Full article