Milk Cheese Research Articles

Colostrum in cheese milk: Effects on physicochemical and microbiological characteristics of milk, whey and fresh cheese

Colostrum presence in milk may cause problems in industrial processes. The objective of this study was to evaluate the characteristics of cheese whey and model-fresh cheeses made from milk containing up to 10% colostrum. Physicochemical and microbiological characteristics of colostrum, milk, cheese and cheese whey were evaluated. IgG content in colostrum, milk and cheese whey was also analyzed. The colostrum presence changed cheese milk composition, physicochemical parameters, IgG content and microbial counts. As the presence of colostrum increased, cheeses had higher protein and moisture contents, while aerobes mesophiles and coliform counts decreased. The cheese and cheese whey color were slightly to noticeably different when up to 10% colostrum was added to the cheese milk. The whey IgG concentration increased significantly when the cheese milk contained 5% and 10% colostrum. This should be taken into consideration when this by-product be potentially used in the production of value-added dairy or nutraceutical products.

Specificity of the AMP-6000 Method for Enumerating Clostridium Endospores in Milk.

Enumeration of endospores of butyric acid-forming clostridia in cheese milk is an essential part of milk quality monitoring for cheese producers to avoid late blowing, severe spoilage caused by clostridia during ripening. However, due to the lack of an internationally standardized method, different methods are used and it is important to consider how the choice of method affects the results. This is particularly relevant when clostridial spore counts in milk are considered for quality payments. The aim of this study was to evaluate the specificity of the AMP-6000 method for the enumeration of endospores of cheese spoiling clostridia in milk. First, to assess the prevalence of Clostridium diversity and to determine potential non-target species, we identified isolates from positive reactions of the AMP-6000 method used to quantify clostridial endospores in raw milk and teat skin samples by MALDI-TOF MS. Based on these results, a strain library was designed to evaluate method inclusivity and exclusivity using pure cultures of target and non-target strains according to ISO 16140-2:2016. Most target Clostridium tyrobutyricum strains, as well as all tested C. butyricum and C. sporogenes strains were inclusive. However, C. beijerinckii may be underestimated as only some strains gave positive results. All non-target strains of bacilli and lysinibacilli, but not all paenibacilli, were confirmed to be exclusive. This study provides performance data to better understand the results of microbiological enumeration of butyric acid-forming clostridia in milk and serves as a basis for future methodological considerations and improvements.

A Metabolomics Study by 1H HRMAS NMR: From Sheep Milk to a Pressed-Curd Cheese: A Proof of Concept

For the first time, High-Resolution Magic Angle Nuclear Magnetic Resonance spectroscopy (NMR-HRMAS) was applied to directly identify specific metabolites from a Spanish raw ewe’s milk and enzymatic coagulation pressed-curd cheese (Protected Geographical Indication: Castellano) manufactured by two procedures (traditional/artisanal vs. industrial) and including the ewe’s raw milk. The NMR parameters were optimized to study the complex matrixes of this type of cheese. In addition, conventional overcrowded 1H-NMR-HRMAS spectra were selectively simplified by a Carr–Purcell–Meiboom–Gill (CPMG) sequence or a stimulated echo pulse sequence by bipolar gradients (DIFF), thus modulating spin–spin relaxation times and diffusion of molecular components, respectively. 1H-NMR-HRMAS spectroscopy displayed important information about cheese metabolites, which can be associated with different manufacturing processes (industrial vs. traditional) and ripening times (from 2 to 90 days). These results support that this spectroscopy is a useful technique to monitor the ripening process, from raw milk to commercial ripened cheese, using a minimum intact sample, implying the absence of time-consuming sample pretreatments.

Risk Factors Associated with Human Brucellosis: A Systematic Review and Meta-Analysis.

Background: Brucellosis is a zoonosis disease that can affect humans and a wide range of domestic and wild animals. Susceptibility to brucellosis in humans can be related to various factors, such as nutritional and occupational factors. This study evaluated factors related to brucellosis and identified influential risk factors for human infection. Methods: We performed a systematic literature review and meta-analysis of studies in PubMed, Web of Science, and Scopus. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were used to measure the strength of the association between some potential factors and the risk of brucellosis. Results: From 277 initial studies, 19 case-control studies were included in this review. Significant risk factors for brucellosis included occupation (OR 3.31, 95% CI 1.68-6.55), having aborted animals (OR 4.16, 95% CI 2.03-8.50), consumption of meat (OR 2.17, 95% CI 1.44-3.36), unpasteurized milk (OR 3.86, 95% CI 1.81-8.23), and raw cheese (OR 4.20, 95% CI 1.63-10.85). Conclusion: The results of this study advance the understanding of the etiology of brucellosis. In this meta-analysis, we found the association of different environmental factors with the risk of brucellosis. Additional high-quality prospective studies are needed to determine whether these factors cause brucellosis and to identify other factors.

New Genetic Determinants for qPCR Identification and the Enumeration of Selected Lactic Acid Bacteria in Raw-Milk Cheese.

Lactic acid bacteria (LAB) play an important role in the ripening of cheeses and contribute to the development of the desired profile of aroma and flavor compounds. Therefore, it is very important to monitor the dynamics of bacterial proliferation in order to obtain an accurate and reliable number of their cells at each stage of cheese ripening. This work aimed to identify and conduct a quantitative assessment of the selected species of autochthonous lactic acid bacteria from raw cow's milk cheese by the development of primers and probe pairs based on the uniqueness of the genetic determinants with which the target microorganisms can be identified. For that purpose, we applied real-time quantitative PCR (qPCR) protocols to quantify Lactobacillus delbrueckii subsp. bulgaricus, Streptococcus thermophilus, and Lactococcus lactis subsp. cremoris cells in cheese directly after production and over three-month and six-month ripening periods. While L. lactis subsp. cremoris shows good acidification ability and the ability to produce antimicrobial compounds, L. delbrueckii subsp. bulgaricus has good proteolytic ability and produces exo-polysaccharides, and S. thermophilus takes part in the formation of the diacetyl flavor compound by metabolizing citrate to develop aroma, they all play an important role in the cheese ripening. The proposed qPCR protocols are very sensitive and reliable methods for a precise enumeration of L. delbrueckii subsp. bulgaricus, S. thermophilus, and L. lactis subsp. cremoris in cheese samples.

Factors affecting the coagulation of milk protein during quark cheese processing in Vietnam

In recent years, cheese consumption in Vietnam is markedly rising, leading to the attention of local milk processors on cheese making. Quark-type cheese, a traditional food in Central Europe, is a type of well-known acid-coagulated cheese product. Milk coagulation properties (MCPs) play an important role to the success of the cheese-making process and are influenced by different parameters. In this study, the quality of raw milk for cheese making and the coagulation conditions in quark-type cheese processing were investigated. Raw milk collected from Phu Dong dairy farm met the requirement of Vietnamese standard for cheese making. The appropriate conditions for coagulation were identified: the heat treatment of milk at 60°C for 15 minutes, coagulation temperature at 40oC and pH 5.5, CaCl2 concentration at 0.04g/l. Under these conditions, a short coagulation time (72.33 seconds) and high curd yields (50.70%) were obtained. These results suggested that quark-type cheese using raw milk in Vietnam could be successfully developed at larger scale.

Staphylococcal food poisoning outbreaks occurred in Sicily (Italy) from 2009 to 2016.

Notification of foodborne outbreaks has been mandatory in Europe since 2005, and surveillance is carried out along the entire food chain. Here we report the results obtained from laboratory investigations about four cases of foodborne outbreaks that occurred in Sicily between 2009 and 2016, deemed to be related to staphylococcal enterotoxins (SEs) and coagulase-positive Staphylococci (CPS) by the Local Public Health Authority. Primosale cheese samples were processed by culture methods for enumeration of CPS and immunoenzymatic assays for detection and differentiation of the SEs possibly contained in food samples. In all cases, the mistrusted foods were found to be contaminated by CPS at bacterial loads between 5 and 8 log CFU/g and contained SE type C (SEC). The reported data confirm the risk of staphylococcal food poisoning associated with the consumption of raw milk cheese. SEC is the most commonly occurring SE in goat milk and dairy products and the most represented enterotoxin in Sicilian dairy products. Our results highlighted the need for improving the current monitoring efficiency and implementing the available laboratory methods to collect more faithful epidemiological data on the current prevalence of staphylococcal toxins in the food chain, including SEs currently not detectable by validated analytical methods.

Physicochemical and Sensory Characterization of Whey Protein-Enriched Semihard Cheese.

In view of potential future changes of German food legislation with regard to cheese product quality parameters, this study aimed to evaluate the quality of whey protein-enriched semihard cheese (WPEC). Model WPEC was produced in a pilot plant and on an industrial scale by adding defined amounts of high-heat (HH) milk to the cheese milk and comprehensively analyzed during cheese processing. The dry matter, total protein, pure protein, fat, and sodium chloride content of six-week ripened cheese samples were not significantly different (p < 0.05) when the technologically necessary heating of the curd was adapted to the amount of HH milk. However, the ripening, firmness, and melting behavior of WPEC was different compared to cheese without HH milk. During ripening, no formation of whey protein peptides was observed, but differences in the amount of some bitter peptides deriving from the casein fraction were found. Sensory data suggested a slightly more bitter taste perception by the panelists for the WPEC. Further technological adjustments are recommended to obtain marketable WPEC.

Bacterial proteome adaptation during fermentation in dairy environments

The enzymatic repertoire of starter cultures belonging to the Lactococcus genus determines various important characteristics of fermented dairy products but might change in response to the substantial environmental changes in the manufacturing process. Assessing bacterial proteome adaptation in dairy and other food environments is challenging due to the high matrix-protein concentration and is even further complicated in particularly cheese by the high fat concentrations, the semi-solid state of that matrix, and the non-growing state of the bacteria. Here, we present bacterial harvesting and processing procedures that enable reproducible, high-resolution proteome determination in lactococcal cultures harvested from laboratory media, milk, and miniature Gouda cheese. Comparative proteome analysis of Lactococcus cremoris NCDO712 grown in laboratory medium and milk revealed proteome adaptations that predominantly reflect the differential (micro-)nutrient availability in these two environments. Additionally, the drastic environmental changes during cheese manufacturing only elicited subtle changes in the L. cremoris NCDO712 proteome, including modified expression levels of enzymes involved in flavour formation. The technical advances we describe offer novel opportunities to evaluate bacterial proteomes in relation to their performance in complex, protein- and/or fat-rich food matrices and highlight the potential of steering starter culture performance by preculture condition adjustments.

Trend of raw milk collection, milk processing constraints and opportunities in Ethiopia

Ethiopia is awarded from nature with cattle resource that brings it to the first stage from Africa and fifth from the world. Dairy production in Ethiopia is mainly rural small farming system with low productive indigenous cattle breed and an animal having multipurpose usage. Modern dairy product processing industries still infant and mostly dominated by traditional milk and milk products processing, due to regardless attention is given for dairy processing sector in the Ethiopia. Although modern dairy processing industries emerged in different part of the country, there is no constant in number of dairy processing industries which is up and down throughout different years due to disintegrated milk supply chain, poor milk quality, informal marketing, limit milk product processing technology, limited infrastructure and sociocultural impacts etc. are some of the limitation factors. Traditional milk product produced in Ethiopia are fermented yoghurt, traditional butter and butter milk, ghee and Cottage cheese. Whereas, modern milk and milk products are pasteurized milk, different type of yogurt and different kind of cheeses. Although, there are milk collection and milk product processing development constraints in Ethiopia, unexploited livestock resources in the country will an opportunities of milk and milk products processing investment. There for, this review paper is attempt to indicate the available dairy products processing investments opportunities and technical and non- technical constraints of milk collection and milk products processing in Ethiopia.

Production of Acid and Rennet-Coagulated Cheese Enriched by Olive (Olea europaea L.) Leaf Extract-Determining the Optimal Point of Supplementation and Its Effects on Curd Characteristics.

This study investigated the potential of olive leaf extract (OLE), as a functional ingredient, to improve cheese properties, because it is rich in phenols. Milk and dairy products are poor in phenolic compounds. The main objective was to determine the most effective coagulation method and timing of OLE supplementation to maximize retention in the cheese matrix. Experimental cheeses were produced using the rennet and acid coagulation methods, with OLE added either directly to the cheese milk or to the curd phase. Three OLE effective concentrations corresponding to 25%, 50%, and 75% inhibition of DPPH reagent (EFC25, EFC50, and EFC75, respectively) were added, i.e., 11.5 mg GAE L-1, 16.6 mg GAE L-1, and 26.3 mg GAE L-1, respectively. The results showed that OLE significantly increased the concentration of total phenols, total flavonoids, and antioxidant activity in all cheese samples and in the residual whey, especially at higher effective concentrations (EFC 50 and EFC 75). Rennet-coagulated cheese to which OLE was added prior to coagulation (EM 25, EM 50, EM 75) exhibited higher hardness, gumminess, and chewiness but lower elasticity, suggesting alterations in the paracasein matrix. OLE did not adversely affect acidity, water activity, or cheese yield. However, higher EFC resulted in significant colour changes (∆E* > 3.0). In conclusion, the enrichment of cheesemaking milk with OLE and the application of the rennet coagulation method are the most suitable to optimise the production of OLE-enriched cheese. This research shows the potential to improve the nutritional value of cheese while maintaining its desired characteristics.

The Influence of Bioactive Compounds in Food Products

Demand for healthy and nutritious food is growing worldwide. The aim is to produce food products that not only satisfy the need for food but also provide many nutritional benefits to the health of the consumer. The current study aims to produce a food product with high nutritional value. For this purpose, a fresh cow's milk cheese was fortified with grape powder. The amount of powder added was different, with 3 samples plus a control sample in which no powder was added. The resulting products were sensory analysed to determine consumer acceptability. The samples were also analysed physico-chemically and enzymatically, measuring pH, lactose and lactic acid content over a storage period of 14 days. Fresh cow's cheese samples with added grape powder obtained superior results compared to the control sample during the whole storage period. The grape powder added to fresh cow's cheese positively influenced the sensory and enzymatic characteristics of the finished product.

Assessment of the Functional Potential of Two Autochthonous Lactic Strains of Lactobacilli Isolated from Algerian Dairy Products

Background: In cheese-making technology, lactic coagulation of milk is an essential stage in which the use of a ferment may be a selected strain or a mixture of strains that do not all have the same performance and technological properties, resulting in a wide variation in the quality of the cheese product. Methods: The aim of this study was to highlight the technological aptitudes of two strains of lactic acid bacteria, LAB, indigenous to our Algerian dairy products, Lactobacillus acidophilus and Lactobacillus brevis. The study monitored their growth kinetics, hydrogen ion concentration, fermentation profile and proteolytic activity on cheese milk. Result: Both strains gave good results, with very good growth kinetics, a good hydrogen ion concentration for cheese processing and an excellent proteolytic profile (proteolytic activity at 1, 2 and 3%). These 02 LAB revealed good technological performance in terms of cheese application, for lactic fermentation, lactic coagulation and also through their noted proteolytic activity can lead to good cheese maturation during ripening. This assessment leads us to conclude that these strains could be used for cheese applications in single or mixed cultures and with the possibility of being used in a cheese processing technology with lactic dominance for fresh cheeses or mixed enzymatic and lactic dominance for soft and pressed cheeses.

Cross-sectional, commercial testing, and chromatographic study of the occurrence of antibiotic residues throughout an artisanal raw milk cheese production chain

This study investigated antibiotic utilization in artisanal dairies and residue occurrence throughout the raw milk cheese production chain using commercial testing (Charm KIS and Eclipse Farm3G) and UHPLC-QqQ-MS/MS and LC-QqQ-MS/MS. The cross-sectional survey results revealed gaps in the producers’ knowledge of antibiotic use. Commercial testing detected antibiotic levels close to the LOD in 12.5 % of the samples, mainly in raw milk and whey, with 10.0 % testing positive, specifically in fresh and ripened cheeses, indicating that antibiotics are concentrated during cheese-making. Chromatographically, several antibiotics were identified in the faeces of healthy animals, with chlortetracycline (15.7 ± 34.5 µg/kg) and sulfamethazine (7.69 ± 16.5 µg/kg) predominating. However, only tylosin was identified in raw milk (3.28 ± 7.44 µg/kg) and whey (2.91 ± 6.55 µg/kg), and none were found in fresh or ripened cheeses. The discrepancy between commercial and analytical approaches is attributed to compounds or metabolites not covered chromatographically.

Experiences Using Ethereum and Quorum Blockchain Smart Contracts in Dairy Production

feta cheese is a Greek protected designation of origin (PDO) product that is produced in three main phases: milk collection, cheese preparation and maturation, and product packaging. Each phase must be aligned with quantitative rules, stemming from the legislation framework and best practices. The production complexity, the increased production cost, centralised and monolithic traceability systems, and the lack of a systematic monitoring framework have made dairy products a commodity with increased frequency of food fraud. Given the context of the dairy section in Greece, this study aims to examine (a) whether it is possible to model the end-to-end process of PDO feta cheese considering production rules to develop a trustworthy blockchain-based traceability system (b) how to associate the (‘easy-to-retrieve’, operational) traceability data with the (difficult-to-assess) product characteristics meaningful to the consumer, (c) how to design a technical solution ensuring that information is accessible by the stakeholders and the consumer, while minimising blockchain-related delay, and (d) how to design a graphical user interface and offer tools to consumers so that traceability information is communicated effectively and they can verify it through access to the blockchain. In terms of methods, we analyse and model the process steps, identify measurable, operational parameters and translate the legislative framework into rules. These rules are designed and codified as blockchain smart contracts that ensure the food authenticity and compliance with legislation. The blockchain infrastructure consists of the private Quorum blockchain that is anchored to the public infrastructure of Ethereum. Mechanisms to address scalability in terms of dynamic data volumes, effective data coding, and data verification at the edge as well as relevant limitations are discussed. Consumers are informed about traceability information by using QR codes on food packaging and can verify the data using the blockchain tools and services.

Assessment of some chemical residues in Egyptian raw milk and traditional cheese.

The assessment of risks related to food safety is becoming a challenge in developing countries with its consequent health hazards. Chemical risk assessment in dairy products is important to maintain consumer health locally and internationally. Since milk and dairy products are essential foods for a wide range of customers, mostly children, patients, and pregnant women, it is very important to estimate the risks of some chemical residues, such as pesticides, some heavy metals, and aflatoxins. This work aims to determine the levels of chemical contamination in milk and traditional Egyptian cheese. Heavy metals were determined in samples by atomic absorption spectrometry. GC-mass spectrometry (MS)/MS and LC-MS/MS were also used for measuring pesticide residues. The Aflatoxin M1 was determined by enzyme-linked immune-sorbent assay. Raw milk samples were tested and showed elevated concentrations of lead and cadmium, (46% and 4%, respectively). The heavy metals detected in the Egyptian cheese samples were variable depending on the type of cheese. Moreover, p.p.-DDE phenofose was present in 45% and 29% of raw milk and Ras cheese samples, respectively. For Aflatoxin M1, only 7% of milk samples and 2.9% of Ras cheese samples exceeded the acceptable limits. More surveying and risk assessment of chemical residues in milk and milk products are essential for controlling health risks to consumers.

Antibacterial effect of Moringa oleifera on Staphylococcus aureus and Pseudomonas aeruginosa isolated from raw milk and some dairy products with special reference to biofilm gene expression.

Pseudomonas aeruginosa (P. aeruginosa) and Staphylococcus aureus (S. aureus) are well defined as food poisoning pathogens that are highly resistant and need continuous studies. The purpose of the work was to examine phenotypic and genotypic characteristics of both P. aeruginosa and S. aureus, and treatment trials with medicinal plants. Samples were examined for isolation of P. aeruginosa and S. aureus on selective media followed by biochemical confirmation, biofilm formation, genes detection, and expression of P. aeruginosa pslA biofilm gene was performed by quantitative real-time polymerase chain reaction after treatment with 0.312 mg/ml Moringa oleifera aqueous extract as a minimum inhibitory concentration. The highest isolation rate of P. aeruginosa was 20% from both raw milk and Kariesh cheese, followed by 16% and 12% from ice cream and processed cheese, respectively, while the highest isolation rate of S. aureus was 36% from raw milk followed by 28% in ice cream and 16% in both Kariesh cheese and processed cheese. 30% of P. aeruginosa isolates were biofilm producers, while only 21% of S. aureus isolates were able to produce biofilm. The P. aeruginosa isolates harbor virulence-associated genes nan1, exoS, toxA, and pslA at 100%, 80%, 40%, and 40%, respectively. Staphylococcus aureus SEs genes were examined in S. aureus strains, where SEA and SEB genes were detected with 60%, but no isolate harbored SEC, SED, or SEE. The significant fold change of P. aeruginosa pslA expression was 0.40332 after treatment with M. oleifera aqueous extract. Pseudomonas aeruginosa and S. aureus harbor dangerous virulence genes that cause food poisoning, but M. oleifera extract could minimize their action.

Влияние пробиотиков на молочную продуктивность и технологические свойства молока коз зааненской породы

The article presents the results of experimental studies to study the effect of feeding probiotic feed additives Kluver Pro and BeneFIT Basic on milk productivity, composition and technological properties of milk from Saanen goats. It has been established that feeding probiotics Kluver Pro and BeneFIT Basic as part of the diets of lactating goats of the Saanen breed helps to increase milk yield by 9,5‑4,4% (p≤0,001), the mass fraction of fat in milk - by 0,73% (p≤0,05) and 0,11%, mass fraction of protein in milk - by 0,25% (p≤0,05) and 0,19%, as well as milk clotting time - by 7,3% and 5,4% (p≤0,001) and the formation of a denser rennet curd, which is a desirable property in the production of fermented milk products and cheese making

Explorando o queijo de leite de cabra: uma revisão sistemática das técnicas e inovações de produção (2013-2023)

Abstract The global demand for milk and dairy products is rising, with cow's milk dominating production. However, goat dairy products have gained attention due to their nutritional value and bioactive components. Goat milk, in particular, is priced attractively, leading to increased interest from producers and investors. Goat milk-based products like yogurt, cheese, and fermented milk are available in the market and prepared using advanced processing technologies. Goat milk's exceptional quality, nutritional composition, and adaptability make it a superior choice, containing essential minerals and vitamins. The gourmet market has elevated goat cheese to a refined culinary delight. Therefore, this systematic review aims to summarize the state of successful research on goat milk cheese production from 2013 to 2023. The bibliographic search was carried out in September 2023 in electronic databases of scientific journals, namely Google Scholar, Science Direct, PUBMED, SCIELO, and Web of Science. Twenty (20) articles were included to discuss results that addressed the research question, meeting the inclusion and exclusion criteria. The content presented provides a comprehensive overview of the cheese manufacturing process, encompassing stages such as filtration, pasteurization, addition of lactic cultures, coagulation (using various methods such as enzymatic, rennet, charcoal, or enzymes), cutting the curd, molding, salting, and maturation. The inclusion of bibliographic references further enhances understanding, highlighting the evolution of practices over time. These contributions are essential for improving the quality and efficiency of goat milk cheese production, offering valuable insights for researchers, producers, and industry enthusiasts.

Sensory Attributes and Instrumental Chemical Parameters of Commercial Spanish Cured Ewes' Milk Cheeses: Insights into Cheese Quality Figures.

The external appearance of some of the Protected Designation of Origin (PDO) cured cheeses is similar to other cheese samples made in Spain: 1 kg and 2.5-3 kg formats, cylindrical, and with or without a pleita mark on the surface. In this work, commercial cured ewe's milk cheese samples with a similar external appearance were analyzed, including five PDO and five non-PDO samples. The parameters analyzed were color, texture, pH, humidity, water activity, and the volatile profile. Additionally, a descriptive and consumer-sensory analysis of the cheese samples was carried out. Statistical analysis of the results showed that luminosity, color coordinates a* and b*, percentage of deformation, humidity, water activity, and acid contents were significantly higher in non-PDO cheese samples. The breaking force, maximum force, and the content of esters were significantly higher in those cheese samples with PDO. In addition, PDO cheese samples showed higher scores for all attributes evaluated by consumers, except for color. These results suggest that PDO cheeses are placed on the market with a higher degree of ripening than non-PDO ones and that consequently they are more positively valued by consumers.