Traditional Colonial-type cheese from the south of Brazil: A case to support the new Brazilian laws for artisanal cheese production from raw milk

Artisanal Colonial-type cheese is made from raw milk and is the main cheese produced by rural families of the southern region of Brazil. The aim of this study was to investigate, identify problems, and propose solutions for the current situation of small family farms producing and informally selling artisanal Colonial-type cheese located in the western part of Santa Catarina State in Southern Brazil. A semistructured questionnaire was employed in 12 rural properties to analyze the mode of production. Physical-chemical and microbiological analyses of water, raw milk, and cheese were performed, and it was found that 92, 50, and 100% of the samples, respectively, were outside of the current Brazilian regulatory parameters. None of the cheesemakers involved in this study met the requirements, as established by law, for artisanal cheese production from raw milk. This study concluded that technical support and changes in public policy are needed to ensure the preservation of this artisanal cheese, considering the historical importance and cultural traditions of these local communities and the socioeconomic importance of cheesemaking to family farming. Furthermore, more research on the safety of the cheese produced from raw milk is needed as well as the development of specific microbiological standards for artisanal Brazilian cheeses. Public policies aimed at guaranteeing food safety that formalize the commercialization of these cheeses will increase food security in those communities that currently produce artisanal cheese informally.     

Application of indigenous strains of lactic acid bacteria for semi‐industrial production of autochthonous Montenegrin Njeguši cheese

Most of the traditional dairy products of south‐eastern Europe are produced from unpasteurised milk without addition of selected starter cultures. These artisanal products have an interesting biodiversity of indigenous microbiota. In Montenegro, one of the most popular traditional cheeses is Njegu?i cheese, belonging to the group of hard cheeses. Most of the cheeses are produced from ewes' milk, but cows' milk is also widely used. In Montenegro, there are no existing legal regulations defining the specificities of the production or the raw material used for the production of autochthonous food products. Therefore, the producers make the decision about what type of milk to use for cheese production. One of the priorities of the food producers in Montenegro is to obtain a larger scale, standardised production of traditional food products, which are of good quality and considered safe for the consumers. Therefore, in this study, indigenous strains of lactic acid bacteria isolated from various Montenegrin artisanal dairy products were tested as starter cultures for the production of Njegu?i cheese. Three isolates were selected and used as starter cultures in pilot plant experiments for the production of Njegu?i cheese. When applying an adequate combination of added bacterial strains as starters, the flavour of Njegu?i cheese, produced under pilot plant conditions, was comparable to that of the artisanal origin.     

Identification and first characterization of lactic acid bacteria isolated from the artisanal ovine cheese Pecorino del Poro

A total of 225 lactic acid bacteria, isolated from the artisanal raw ovine milk cheese Pecorino del Poro, were identified and given an initial characterization; the best 18 strains were tested for their antagonistic activity against autochthonous Escherichia coli . An intense antagonistic activity against E. coli growth, induced by strains of Lactobacillus paracasei ssp. paracasei or L. curvatus , was observed; the E. coli inhibition can be ascribed to the production of bacteriocin-like compounds. The lactobacilli seem able to improve the hygienic quality of other artisanal raw milk cheeses.     

On the microbiology of Serra da Estrela cheese: geographical and chronological considerations

Serra da Estrela cheeses, produced following artisanal practices from raw ewe's milk in two consecutive years in five selected dairies, were sampled throughout a 60-day ripening period. The viable numbers of the major microbial groups (Enterobacteriaceae, staphylococci and yeasts, as well as such lactic acid bacteria as lactobacilli, lactococci and enterococci) were determined and statistical significance of the results was assessed. Significant differences in the viable counts of lactococci, lactobacilli, enterococci, Enterobacteriaceae and staphylococci were found for the various geographical locations, whereas the year of manufacture played a significant role only upon the viable numbers of yeasts and staphylococci. These data back up the claim that those microbial families usually implicated with health hazards are prone to a wide variability, which reflects the intrinsic heterogeneity associated with production and handling of raw milk in traditional cheesemaking.     

Artisanal and experimental Pecorino Siciliano cheese: microbial dynamics during manufacture assessed by culturing and PCR-DGGE analyses

Traditional artisanal Pecorino Siciliano (PS) cheeses, and two experimental PS cheeses were manufactured using either raw or pasteurised ewes' milk with the addition of starter cultures. The bacterial diversity and dynamics of the different cheese types were evaluated both by culturing and characterisation of isolates, and a culture-independent approach based on the 16S ribosomal RNA (rRNA) gene. Following cultivation, artisanal and experimental cheese types showed similar microbial counts, and isolates belonging to Lactococcus lactis, Streptococcus thermophilus, Enterococcus faecalis and Leuconostoc mesenteroides were identified by phenotypic characterisation and comparison of the restriction fragment length polymorphism (RFLP) of the 16S rRNA gene to that of reference species. The culture-independent fingerprinting technique PCR and denaturing gradient gel electrophoresis (DGGE) of V6 to V8 regions of the 16S rRNA gene of samples taken during artisanal PS cheese manufacture, from raw milk to the ripened cheese, indicated relevant shifts in the microbial community structure. The dominance of Streptococcus bovis and Lactococcus lactis species in the traditional artisanal PS was revealed by 16S rRNA gene sequencing. Comparison of DGGE profiles of samples from milk to ripened cheese, derived from artisanal procedure and the two experimental PS cheeses during production showed similar trends with the presence of intense bands in common. Nevertheless, the profiles of several artisanal cheeses from different farms appeared more diverse, and these additional species are probably responsible for the generally superior flavour and aroma development of traditional PS cheese.     

Cholesterol content and lipid composition of low fat dairy products

The lipid composition of different products obtained from the same raw milk was investigated. The cholesterol content of skim milk (0.05% total fat) and butter milk (0.57% total fat) lipids was 4.20% and 1.31%, respectively, while raw milk lipids and butter fat contained 0.34% or 0.30%, respectively. As the cholesterol content of these low fat milk products increases with decreasing fat content, equations were derived to estimate the fat-related cholesterol content from the value analysed in butter fat. In contrast to the fat-related cholesterol content, the product-related content is still relatively small in skim and butter milk. Their fat-related cholesterol content was found to be influenced by drying. The high content of phospholipids in skim and butter milk led to considerable changes in the fatty acid composition and affected the detection of foreign fat by butyric acid as well as by triglycerides. Skim and butter milk lipids contained only 2.41% or 2.33% butyric acid, respectively, instead of 3.36% found in raw milk lipids. Further, the overlap of phospholipids as well as cholesterol with the gas chromatographic triglyceride pattern resulted in calculated foreign fat contents of more than 20%.     

Method to assess the carbon footprint at product level in the dairy industry

A model to calculate the farm-to-customer carbon footprint (CF) for different dairy product groups is presented. As the largest share of the CF of dairy products occurs at farm level, it is decisive how the emissions from raw milk production are allocated between different products. Impacts associated with raw milk are allocated based on a weighted fat and protein content (1:1.4). Data from the dairy company Arla Foods give 1.1, 8.1, 6.5, 7.4 and 1.2 kg carbon dioxide equivalents per kg of fresh dairy product, butter and butter blend, cheese, milk powder and whey based product, and other, respectively. One critical aspect is how the by-product ‘whey’ is dealt with. No emissions are allocated to the milk solid whey, which is why products containing whey have an apparent low impact. Underlying methodological assumptions are open to debate and further research is needed concerning the CF impact of different milk components.     

Marketing premium milk and products for specialist groups

The problems faced by the producers of Channel Islands premium-quality milk in maintaining their market share are considerable. To counteract a fall in liquid milk sales on the doorstep. there have been increased sales in cartons through supermarkets where a separate product identity can be established. New product types with the Gold Top image have been developed and successfully marketed: frozen double cream, UHT semi-skimmed milk and dairy ice creams containing butter fat from Channel Islands milk. An unsalted butter gave keeping quality problems, but it is hoped that improved raw milk quality control will allow the product to be re-introduced.     

Potential for improving the carbon footprint of butter and blend products

To reduce the environmental impact of a product efficiently, it is crucial to consider the entire value chain of the product; that is, to apply life cycle thinking, to avoid suboptimization and identify the areas where the largest potential improvements can be made. This study analyzed the carbon footprint (CF) of butter and dairy blend products, with the focus on fat content and size and type of packaging (including product waste at the consumer level). The products analyzed were butter with 80% fat in 250-g wrap, 250-g tub, and 10-g mini tub, and blends with 80% and 60% fat in 250-g tubs. Life cycle assessment was used to account for all greenhouse gas emissions from cow to consumer. A critical aspect when calculating the CF is how emissions are allocated between different products. Here, allocation of raw milk between products was based on a weighted fat and protein content (1:1.7), based on the price paid for raw milk to dairy farmers. The CF (expressed as carbon dioxide equivalents, CO₂e) for 1 kg of butter or blend (assuming no product waste at consumer) ranged from 5.2 kg (blend with 60% fat content) to 9.3 kg of CO₂e (butter in 250-g tub). When including product waste at the consumer level, the CF ranged from 5.5 kg of CO₂e (blend with 60% fat content) to 14.7 kg of CO₂e (butter in mini tub). Fat content and the proportion of vegetable oil in products had the greatest effect on CF of the products, with lower fat content and a higher proportion of vegetable oil resulting in lower CF. Hence, if the same functionality as butter could be retained while shifting to lower fat and higher proportions of vegetable oil, the CF of the product would be decreased. Size and type of packaging were less important, but it is crucial to have the correct size and type of packaging to avoid product losses at the consumer. The greatest share of greenhouse gas emissions associated with butter production occurred at the farm level; thus, minimizing product losses in the whole value chain—from cow to consumer—is essential for efficient production.     

Graduate Student Literature Review: Current understanding of the influence of on-farm factors on bovine raw milk and its suitability for cheesemaking

Relationships between dairy farm practices, the composition and properties of raw milk, and the quality of the resulting cheese are complex. In this review, we assess the effect of farm factors on the quality of bovine raw milk intended for cheesemaking. The literature reports several prominent farm-related factors that are closely associated with milk quality characteristics. We describe their effects on the composition and technological properties of raw milk and on the quality of the resulting cheese. Cow breed, composite genotype, and protein polymorphism all have noticeable effects on milk coagulation, cheese yield, and cheese composition. Feed and feeding strategy, dietary supplementation, housing and milking system, and seasonality of milk production also influence the composition and properties of raw milk, and the resulting cheese. The microbiota in raw milk is influenced by on-farm factors and by the production environment, and may influence the technological properties of the milk and the sensory profile of certain cheese types. Advances in research dealing with the technological properties of raw milk have undoubtedly improved understanding of how on-farm factors affect milk quality attributes, and have refuted the concept of one milk for all purposes. The specific conditions for milk production should be considered when the milk is intended for the production of cheese with unique characteristics. The scientific identification of these conditions would improve the current understanding of the complex associations between raw milk quality and farm and management factors. Future research that considers dairy landscapes within broader perspectives and develops multidimensional approaches to control the quality of raw milk intended for long-ripening cheese production is recommended.     

高钙液态奶中试加工工艺的研究

对高钙液态奶中试加工工艺进行了研究。通过向原料奶中添加乳钙、奶油粉、酪蛋白磷酸肽、维生素D3等物质，在一定条件下生产高钙液态奶。通过中试试验确定了各种物质的添加量和生产工艺。生产的高钙牛奶具有比普通牛奶更好的口感和香味．没有一般高钙类产品常见的涩味，产品在保质期内稳定性好。     

Probiotic potential and biochemical and technological properties of Lactococcus lactis ssp. lactis strains isolated from raw milk and kefir grains

Lactococcus lactis ssp. lactis is one of the most important starter bacteria used in dairy technology and it is of great economic importance because of its use in the production of dairy products, including cheese, butter, cream, and fermented milks. Numerous studies have evaluated the biochemical and probiotic properties of lactococci; however, limited studies on the probiotic characteristics of lactococci were conducted using strains originating from raw milk and dairy products. Characterizing the probiotic properties of strains isolated from raw milk and fermented milk products is important in terms of selecting starter culture strains for the production of functional dairy products. In this study, biochemical properties (including antibiotic sensitivity, lipolytic activity, amino acid decarboxylation, antioxidant activity) and probiotic properties (including antimicrobial activity, growth in the presence of bile salts, bile salts deconjugation, and hydrophobicity) of 14 Lactococcus lactis strains isolated from raw milk and kefir grains were investigated. Strains originating from kefir grains had better characteristics in terms of antimicrobial activity and bile salt deconjugation, whereas strains from raw milk had better hydrophobicity and antioxidant activity characteristics. None of the strains were able to grow in the presence of bile salt and did not show amino acid decarboxylation or lipolytic activities. Biochemical and probiotic properties of L. lactis strains varied depending on the strain and some of these strains could be used as functional cultures depending on their properties. However, these strains did not possess all of the properties required to meet the definition of a probiotic.     

Antioxidant activity of co-products from milk fat processing and their enzymatic hydrolysates obtained with different proteolytic preparations

Different co-products are generated from bovine milk during the manufacture of butter or anhydrous milk fat. Those co-products have a similar composition to milk, though they are enriched in fat and components from the milk fat globule membrane. The antioxidant activity of some commercial products (skim milk, butter serum and buttermilk) and raw buttermilk was assayed using the 2,2-diphenyl-1-picrylhydrazyl radical scavenging assay. Commercial co-products showed higher antioxidant activity than raw buttermilk when tested at >10 mg mL⁻¹. These products were incubated with Alcalase, Prolyve and Corolase PP to determine the effect of enzymatic hydrolysis on their antioxidant activity; hydrolysates obtained were characterised by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and reverse-phase high performance liquid chromatography. Hydrolysis with Corolase PP produced the hydrolysates with the highest antioxidant activity. Products derived from milk fat processing and their hydrolysates may therefore be considered as a natural source of antioxidant compounds for application as value-added ingredients.     

Characterization of the lactic acid bacteria in ewe's milk and cheese from northwest Argentina

Indigenous lactic acid bacteria in ewe's milk and artisanal cheese were studied in four samples of fresh raw milk and four 1-month-old cheeses from the provinces of northwest Argentina. Mean growth counts on M17, MRS, and MSE agar media did not show significant differences (P < 0.05) in raw milk and cheeses. Isolates of lactic acid bacteria from milk were identified as Enterococcus (48%), lactococci (14%), leuconostocs (8%), and lactobacilli (30%). All lactococci were identified as Lactococcus lactis (subsp. lactis and subsp. cremoris). Lactobacilli were identified as Lactobacillus plantarum (92%) and Lactobacillus acidophilus (8%). Enterococci (59%) and lactobacilli (41%) were isolated from cheeses. L. plantarum (93%), L. acidophilus (5%), and Lactobacillus casei (2%) were most frequently isolated. L. lactis subsp. lactis biovar diacetylactis strains were considered as fast acid producers. L. lactis subsp. cremoris strains were slow acid producers. L. plantarum and L. casei strains identified from the cheeses showed slow acid production. The majority of the lactobacilli and Lactococcus lactis strains utilized citrate and produced diacetyl and acetoin in milk. Enzyme activities (API-ZYM tests) of lactococci were low, but activities of L. plantarum strains were considerably higher. The predominance of L. plantarum in artisanal cheese is probably important in the ripening of these cheeses due to their physiological and biochemical characteristics.     

Influence of bacterial dynamics upon the final characteristics of model Portuguese traditional cheeses

The microbiological profile in raw milk cheeses is typically characterized by a multitude of microbial groups, with interactions among them throughout ripening that are not fully understood to date. Incidence of undesired microorganisms in raw cheesemaking milk, as is the case of either spoilage or even pathogenic ones, is a common trait in Portuguese traditional cheeses. Hence, they will likely contribute to the physicochemical changes occurring therein and, consequently, to the characteristics of the final product. In order to gain insight into their role, model cheese systems, manufactured as far as possible according to artisanal practices (except that the initial microbial load and biodiversity were controlled), were experimentally tested. Single contaminants, or a consortium thereof, were inoculated at two levels in sterilized raw ewe's milk, and duly combined with inocula containing one or two lactic acid bacteria normally found in those traditional cheeses. The physicochemical composition, organic acid profile, and evolution of both protein breakdown and rheology were monitored throughout a 60 d-ripening period. Modifications brought about within the cheese matrix as a result of microbial metabolism, especially those arising from the interaction between lactic acid bacteria and unwanted microorganisms, included the enhanced release of peptides and free amino acids, which in turn led to higher viscoelastic moduli. The final model cheeses could be well discriminated, based on the impact of the various inocula considered upon the levels of organic acids. Conversely, proteolysis and viscoelastic properties appeared to be essentially independent of the initial microflora.     

Gamma-glutamyl transpeptidase in milk and butter as an indicator of heat treatment

Naturally present γ-glutamyl transpeptidase (GGTP) in whole and skim milk was inactivated by heat treatment at >79°C for 16 s. Of the total activity in whole milk, 72% was found in the skim milk fraction. Little seasonal variation was noted in either whole or skim raw milk over a period of 300 days. Using a commercially available test kit for GGTP, as little as 0·1% raw milk or cream could be detected in pasteurized skim milk and butter. An alternative GGTP method examined was less sensitive than the commercial method. However, it was necessary for cream products with low GGTP activity since cream interfered with the commercial assay. No reactivation of GGTP was found in whole milk or butter under a variety of conditions. Commercial milk and cream samples were negative for GGTP activity. The results suggest that GGTP analysis could be useful for monitoring the heat-treatment give to fluid milk products.     

Buttermaking and the churning of blended fat emulsions

The methods used to manufacture butter (the Fritz process and batch-wise churning) basically transform cream into butter grains and buttermilk by agitation and by beating air into the cream. Electron micrographs have been used to show the individual stages of buttergrain formation (ie, phase reversal from oil-in-water into water-in-oil):(1) building up foam from the skim milk, (2) adsorption of fat globules at the foam lamellae and (3) agglomeration of fat globules, (4) destabilization of the foam and mechanical clumping of the agglomerates to form butter grains. The microstructure of the butter grains as well as of the finished butter is characterized by a dispersion of water, air, fat crystals and fat globules in oil. By contrast, margarine has a more homogeneous structure. It does not contain globular fat. Thus the texture of butter tends to be solid, while that of margarine tends to be greasy. The consistency of butter can be influenced to a large extent by temperature treatment of the cream (physical cream ripening). A simple device has been developed for optimizing physical cream ripening which automatically records the melting and crystallization curves of the fat. Many raw material, process and machine specific parameters affect the efficiency of churing as well as the quality of butter, and many of these parameters exert an opposite effect. They therefore have to be set carefully so that they balance each other as required. Dosage of buttermilk and dried skim milk into the product stream has allowed the fat content of butter to be reduced to 60% and the water content to be increased to 36% without impairing product quality. This method has been developed further (Pasilac) for manufacturing a stable, long keeping half-fat and quarter-fat butter (the latter in only a few experiments so far). The structure of these products is not of the oil-in-water dispersion type. It could be characterized as a water-in-oil/fat dispersion, which contains an additional locally continuous aqueous phase. The Alfa buttermaking process (which was used during the 1950s and early 1960s) has recently been revived for the production of the Swedish mixed spread, Bregott, in order to minimize fat losses and to increase further maximum levels of oil inclusion in the blend. Blended spreads comprising milk fat (60­75%) + vegetable oil (25­40%) are no doubt more spreadable than butter at refrigerator temperature. However, they have proved to be too soft above 16­18°C. Therefore experiments have been undertaken to improve the consistency of blended spreads by using different milk fat fractions. In order to preserve the butter character artificial creams have been prepared and churned. The fat mixtures were emulsified in skim milk. Distilled unsaturated monoglycerides were added to the fat phase at different concentrations (0­2%) to make the emulsions sufficiently unstable at low temperatures. Beyond a certain monoglyceride concentration the emulsions could be churned successfully. However, below this critical concentration (which corresponds to roughly half of the mass required for covering all fat globules with monolayers) churning efficiency decreased significantly. Electron micrographs elucidate the mechanism of destabilizing the cream by monoglycerides. Electron micrographs also reveal the globular structure of the products thus obtained. Globular structures are known to cause the typical butter like mouth feel. The firmness/temperature curves of spreads obtained by churning adequately blended fat emulsions could be improved over those of butter (ie, flattened and shifted). In addition, the consistency, as in the case of ordinary butter, could equally be influenced by physical cream ripening.     

Characterisation of Macedonian white‐brined cheese: Effect of raw or heat‐treated caprine milk

This research analysed the use of raw and pasteurised milk in the production of Macedonian white caprine milk cheese. Pasteurisation resulted in a considerable decrease in the nitrogen fractions, urea‐polyacrylamide gel electrophoresis of caseins, peptide profiles and volatiles during the maturation period. Forty‐five volatile components were detected, including twelve acids, fourteen esters, six ketones, three alcohols, four terpenes and six other compounds. It was deduced that pasteurisation of milk for the manufacture of artisanal white‐brined cheese delayed the evolution of volatiles, which are related to the unique flavour of the cheese.     

A review of the microbiological hazards of dairy products made from raw milk

This review concentrates on information concerning microbiological hazards possibly present in raw milk dairy products, in particular cheese, butter, cream and buttermilk. The main microbiological hazards of raw milk cheeses (especially soft and fresh cheeses) are linked to Listeria monocytogenes, verocytotoxin-producing Escherichia coli (VTEC), Staphylococcus aureus, Salmonella and Campylobacter. L. monocytogenes, VTEC and S. aureus have been identified as microbiological hazards in raw milk butter and cream albeit to a lesser extent because of a reduced growth potential compared with cheese. In endemic areas, raw milk dairy products may also be contaminated with Brucella spp., Mycobacterium bovis and the tick-borne encephalitis virus (TBEV). Potential risks due to Coxiella burnetii and Mycobacterium avium subsp. paratuberculosis (MAP) are discussed. Pasteurisation ensures inactivation of vegetative pathogenic microorganisms, which increases the safety of products made thereof compared with dairy products made from raw milk. Several control measures from farm to fork are discussed.     

A BELGIAN SURVEY OF HYGIENE INDICATOR BACTERIA AND PATHOGENIC BACTERIA IN RAW MILK AND DIRECT MARKETING OF RAW MILK FARM PRODUCTS

To monitor the bacteriological quality of raw milk and raw milk farm products, 143 samples of raw farm milk and 100 samples of raw milk farm products, 64 butters, 9 yogurts, 16 cheeses, 7 ice creams and 4 fresh cheeses, produced in Belgium were examined for coliforms, β-glucuronidase positive Escherichia coli, verotoxin producing Escherichia coli O157 , Staphylococcus aureus, Salmonella spp. , Listeria spp. and Listeria monocytogenes. The results were compared with the threshold and maximum values of the EC directive 92/46/EC or the maximum values of the Belgian Order of Council from September 3, 2000. The presence of staphylococcal enterotoxins was investigated on samples with S. aureus counts higher than the legal threshold values mentioned in the EC directive or, if not regulated in the directive, higher than the maximum value mentioned in the Belgian Order of Council. The obtained results for the hygiene-indicators coliforms, β-glucuronidase positive E. coli and S. aureus in the raw milk samples were comparable with most other industrialized countries. Compared to a prevalence of 0.7% and 6.3% for, respectively , E. coli O157 and L. monocytogenes, no Salmonella was found in the 25 g raw milk farm samples. The isolated E. coli O157 strain was confirmed to be verotoxigenic; it was positive for VT2 , eaeA and hly A. In butter not only a prevalence of 18.7% for L. monocytogenes in 25 g was found but also the maximum values for the hygiene-indicators mentioned in the Belgian Order of Council were often exceeded. No significant difference was found between the count of hygiene-indicators and the presence of Listeria spp. as well in raw milk as in raw milk butter. The bacteriological quality of on-farm made raw milk butter suggest that suitable hygienic conditions are not always provided. One of the 7 ice cream samples contained L. monocytogenes in 25 g.