Cheese Dairy Research Articles

Segmentation of Parmigiano Reggiano dairies according to cheese-making technology and relationships with the aspect of the cheese curd surface at the moment of its extraction from the cheese vat

Parmigiano Reggiano cheese dairies develop specific cheese-making strategies to adapt the variable characteristics of raw, not standardized milk to the final goal of obtaining cheese consistent with the standard. Analyzing 1,175 cheese-making reports from 30 out of 383 dairies associated with the Parmigiano Reggiano Consortium in 2010 and 2011, 4 groups of Parmigiano Reggiano dairies using specific cheese-making technologies were discriminated by means of multiple linear discriminant analysis. Cheese makers manage cheese-making practices to obtain curd with different roughness properties, classified according to jargon words such as “rigata” and “giusta” or synonyms, because they believe that the roughness of the cheese curd surface immediately after the extraction from the vat is associated with different whey-draining properties and to the final outcome of the cheese. The aspect of the surfaces of the curds produced by the 4 groups of dairies was different according to the technology applied by each group. Cutting of the coagulum when it is still soft for a longer time and faster cooking of the cheese curd grains were associated with a less rough appearance of the surface of the curd, whereas under the opposite conditions, cutting the coagulum when it is firm for a shorter time, led to a curd with a rougher surface. These findings partially support the traditional feeling of Parmigiano Reggiano cheese makers, who consider the curd surface aspect one of the main drivers for their technological choices; to date, however, no data are provided about correlation between the aspect of the curd and the quality of the ripened cheese. If a sufficiently strong correlation could be demonstrated by the future development of the research, the operational effectiveness of Parmigiano Reggiano dairies will be able to largely benefit from the availability of sound and early process markers.

Transcriptomic clues to understand the growth of Lactobacillus rhamnosus in cheese

BackgroundLactobacillus rhamnosus is a non-starter lactic acid bacterium that plays a significant role during cheese ripening, leading to the formation of flavor. In long-ripened cheeses it persists throughout the whole time of ripening due to its capacity to adapt to changing environmental conditions. The versatile adaptability of L. rhamnosus to different ecosystems has been associated with the capacity to use non-conventional energy sources, regulating different metabolic pathways. However, the molecular mechanisms allowing the growth of L. rhamnosus in the cheese dairy environment are still poorly understood. The aim of the present study was to identify genes potentially contributing to the growth ability of L. rhamnosus PR1019 in cheese-like medium (CB) using a transcriptomic approach, based on cDNA-amplified fragment length polymorphism (cDNA-AFLP) and quantitative real-time reverse transcription-PCR (qPCR).ResultsUsing three primer combinations, a total of 89 and 98 transcript-derived fragments were obtained for L. rhamnosus PR1019 grown in commercial MRS medium and CB, respectively. The cDNA-AFLP results were validated on selected regulated genes by qPCR. In order to investigate the main adaptations to growth in a cheese-mimicking system, we focused on 20 transcripts over-expressed in CB with respect to MRS. It is worth noting the presence of transcripts involved in the degradation of pyruvate and ribose. Pyruvate is a intracellular metabolite that can be produced through different metabolic routes starting from the carbon sources present in cheese, and can be released in the cheese matrix with the starter lysis. Similarly the ribonucleosides released with starter lysis could deliver ribose that represents a fermentable carbohydrate in environments, such as cheese, where free carbohydrates are lacking.Both pyruvate degradation and ribose catabolism induce a metabolite flux toward acetate, coupled with ATP production via acetate kinase. Taking into account these considerations, we suggest that the energy produced through these pathways may concur to explain the great ability of L. rhamnosus PR1019 to grow on CB.ConclusionsBy a transcriptomic approach we identified a set of genes involved in alternative metabolic pathways in L. rhamnosus that could be responsible for L. rhamnosus growth in cheese during ripening.

Proteomic Analysis Shows That IndividualListeria monocytogenesStrains Use Different Strategies in Response to Gastric Stress

Ingestion of contaminated dairy products, in particular soft cheese, is one of the major routes of infection by the human pathogen Listeria monocytogenes. During cheese processing, this foodborne pathogen is exposed to sublethal acid and osmotic stress conditions, which may induce tolerance responses and influence subsequent survival in the gastric tract. The aim of the current study was to evaluate the impact on a L. monocytogenes cheese isolate (serotype 4b) and two cheese dairy isolates (T8, serotype 4b, isolated from vat; and A9, serotype 1/2b or 3b, isolated from shelf stand) of exposure to sublethal conditions of pH and salt (5.5 and 3.5% [w/v] NaCl) in a cheese-simulated medium and further challenge with gastric stress. The bacterial cells exposed to pH 7.0 and no added salt were considered non-adapted. Via two-dimensional gel electrophoresis (2-DE), the proteomes of cheese-simulated medium and gastric challenged Listeria cells were compared. All L. monocytogenes isolates were able to survive the high acidity of gastric fluid (pH 2.5), and no significant differences were observed between adapted and non-adapted cells. However, the analysis of the intracellular proteome profiles revealed a significant intra-strain variation in the protein arsenal used to respond to the adaptation in the cheese-based medium and to the gastric stress. In cheese-based medium, the three strains produced different stress proteins. All three strains showed a higher abundance of carbohydrate proteins, but there was no overlap between them. Exposure to the gastric fluid induced the production of a group of proteins in T8 adapted and non-adapted cells that had not been detected previously in the cheese-based proteome. No such response was shown by A9 and C882 strains. Taken together, this study evidences the proteome tools used by adapted and non-adapted cells to cope with the hostile microenvironment of the stomach.

Substrate removal kinetics in high-rate upflow anaerobic filters packed with low-density polyethylene media treating high-strength agro-food wastewaters

The process kinetics for two upflow anaerobic filters (UAFs) treating high strength fruit canning and cheese-dairy wastewaters as feed were investigated. The experimental unit consisted of a 10-L (effective volume) reactor filled with low-density polyethylene media. COD removal efficiencies of about 80% were recorded at the maximum OLRs of 19 and 17 g COD L−1 d−1 for the fruit canning and cheese-dairy wastewaters, respectively. Modified Stover–Kincannon and second-order kinetic models were applied to data obtained from the experimental studies in order to determine the substrate removal kinetics. According to Stover–Kincannon model, Umax and KB values were estimated as 109.9 and 109.7 g L−1 d−1 for fruit canning, and 53.5 and 49.7 g L−1 d−1 for cheese dairy wastewaters, respectively. The second order substrate removal rate k2(s) was found to be 5.0 and 1.93 d−1 respectively for fruit canning and cheese dairy wastewaters. As both these models gave high correlation coefficients (R2 = 98–99%), they could be used in predicting the behaviour or design of the UAF.

Anaerobic digestion of cheese dairy wastewater following chemical oxidation

As global cheese production has gradually increased there has been a proportional increase in the wastewater produced which poses serious environmental problems. Conventional anaerobic treatment processes are often used for dairy wastewaters. However, lipids inhibition and high suspended solids concentrations are the main operational problems for anaerobic digesters treating dairy wastewater. The performance of a pilot scale cheese production wastewater treatment plant that includes an oxidation pretreatment stage and a UASB (upflow anaerobic sludge blanket) reactor was investigated. Monitoring was performed during the start-up period, the fully operational period and the period following wastewater depletion. The data from this six month period are presented and evaluated. The mean composition of raw wastewater was: chemical oxygen demand (COD) 20,314 mg l −1 , total organic carbon (TOC) 7920 mg l −1 , total Kjeldahl nitrogen (TKN) 285 mg l −1 , total phosphate (TP) 85 mg l −1 , fats 1931 mg l −1 and pH 4. In the oxidation pretreatment stage fats presented a significant reduction that reached 80% and the sharp peaks of the all pollution parameters of the raw wastewater were adequately smoothed. The anaerobic digester performance was considered satisfactory, since the COD reduction >90%. A significant fraction of the input carbon was retained in the sludge bed as “absorbed” carbon and then hydrolysed slowly following first order kinetics with a hydrolysis rate constant of 0.0036 d −1 . The pilot plant operation showed that the proposed technology could be sustainable not only in terms of the treatment of cheese-dairy wastewater but for their energy utilisation as well. ► Fenton oxidation improved the biodegradability of the wastewater. ► Significant fats reduce was reported. ► The pollution parameters fluctuations were smoothed. ► The TOC reduction in the UASB was over 90%. ► The produced biogas had a high methane content.

Occurrence of Methicillin-Resistant <i>Staphylococcus aureus</i> in Cheese Produced in German Farm-Dairies

The aim of this study was to determine if raw milk cheese or cheese to be made out of heated milk, manufactured in small German cheese dairies might be a reservoir of contaminations with methicillin-resistant Staphylococcus aureus (MRSA). Due to predominantly manual handling during cheese making, recontaminations with Staphylococcus (S.) aureus or MRSA cannot be excluded. Commercial cheese products (n = 72) available in the region of Hanover(Lower Saxony) and dairy products offered via internet were analyzed with regard to the occurrence of S. aureus and MRSA. Thereof, two cheese samples, manufactured from pasteurized milk and two samples, produced from raw milk, were S. aureus positive with CFU/g between 1.0 × 101 and 7.0 × 101. MRSA was not detected. All analysed cheese samples could be considered safe for consuming.

The Contribution of Dairy Products to Micronutrient Intakes in France

Objective: To assess the contribution of milk and dairy products to the intake of vitamins and minerals in the French population.Methods: Data from the French Individual National Food Consumption Survey 2 (2005–2007) carried out in a representative sample of French people aged 3 to 79 years were used for analysis.Results: Dairy products are strong contributors of calcium; iodine; phosphorus; potassium; zinc; vitamins B2, B12, B5, and D; and retinol. Of all dairy products, milk contributes the most to the intake of these nutrients in children, whereas in adults, cheese and ultra-fresh dairy products contribute equally.Conclusion: Dairy products are an important source of vitamins and minerals in the French population and help strongly to meet micronutrient recommendations for both children and adults.

The Contribution of Dairy Products to Micronutrient Intake in The Netherlands

Objective: To assess the contribution of dairy products to the intake of various vitamins and minerals in several life stages in the Dutch population.Method: Data from 3 Dutch Food Consumption Surveys and the Leiden Longevity Study were used to estimate the contribution of dairy products—as percentage of total intake—to the intake of iron, copper, selenium, zinc, calcium, folic acid, vitamin D, vitamin C, and vitamin B12.Results: In young children, dairy products contributed substantially to the intake of calcium (73%), selenium (21%), iron (8%), zinc (39%), copper (12%), folic acid (24%), vitamin C (18%), vitamin D (16%), and vitamin B12 (58%). Of all dairy products, milk contributed the most to the intake of these nutrients. In adults and elderly subjects, the contribution of dairy products to total micronutrient intake was 65%–68% for calcium, 18%–19% for selenium, 3%–4% for iron, 28%–31% for zinc, 6%–7% for copper, 17%–19% for folic acid, 10%–14% for vitamin C, 11%–16% for vitamin D, and 44%–46% for vitamin B12. Milk as well as cheese contributed the most to the intake of these nutrients.Conclusions: Dairy products are an important source of vitamins and minerals in the Dutch population. Dairy products, especially milk and cheese, contribute substantially to the intake of calcium, selenium, zinc, and vitamin B12.

Constructed wetlands are suitable to treat wastewater from Italian cheese productions

Two horizontal sub-surface flow constructed wetlands (h-SSF CW) were set-up and controlled to determine their efficiency in reducing the polluting load of wastewater from Parmigiano-Reggiano and Grana Padano cheese production. Besides, comparisons were made of biomass production and nutrient uptake of cattail (Typha latifolia) reaped at different stages. The average concentrations of the influent waters were about 250-320 mg/l TSS, 940-1060 mgO2/l COD, 600-700 mgO2/l BOD5, 35 mg/l TKN, 8-13 mg/l total P, 60-170 mg/l animal and vegetable fats and oils. The removal of COD, BOD5 and animal/vegetable fats and oils were above 95%, while resulted 60-65% for nitrogen and very different for phosphorus, varying from 75% in one CW to 20% in the other. Results demonstrated that h-SSF CW could help to solve the problem of the cost-effective disposal of cheese dairy wastewater, being a suitable treatment for reducing pollutants to values in conformance with Italian standards for discharge to a watercourse. Typha latifolia showed considerable biomass yield, though the N and P uptake was quite low if compared with nutrients inputs in CW (about 10%). There is the possibility to maximise biomass yield and nutrient uptake reaping cattail twice a year instead of only one time.

Lactobacillus sp. as probiotics for human health with special emphasis on colorectal cancer

Probiotics are live microorganisms when administered in adequate amount confer health benefit to the host. Extensive usage of probiotics in dairy as a starter in preparation of cheese and other dairy products has become popular in the recent past. The representatives of probiotics mainly include Lactic Acid bacteria such as Lactobacillus acidophilus, L. plantarum, L. johnsonii, L. gasseri, L. casei, L. rhamnosus and Bifidobacterium longum, B. breve, B. infantis, B. thermophillum, B. pseudolongum and others. A number of animal studies conducted by various research groups indicated that the probiotics possess potential anticancer effects. Colorectal cancer (CRC) is one of the most devastating diseases causing high morbidity and mortality among human in most of the urban, eastern and western parts of the world. Oral intake of large number of substances among human perhaps act as mutagenic compounds resulting in change of native microbiota of intestine and could induce cancer. In the present review, the beneficial effects of probiotics in reducing the risk of colorectal cancer (CRC) have been discussed drawing observations from an ongoing related research work in our laboratory. The present article also focuses to describe the beneficial applications of Lactobacillus spp. particularly in human.

Encapsulation applications in probiotic dairy products and cheese technology

Encapsulation applications in probiotic dairy products and cheese technology

Concentrations and fate of sugars, proteins and lipids during domestic and agro-industrial aerobic treatment

This work investigates the composition and the fate of sugars, lipids, proteins, amino acids under aerobic conditions for 13 domestic and 4 agro-industrial wastewaters, sampled before and after treatment. The rates of aerobic degradation were moreover studied with a 21-day continuous aeration batch test. It is shown that the sum of the biochemical forms represented 50 to 85% of the total chemical oxygen demand (COD). Lipids represented the half of the identified COD; sugars and proteins correspond to a quarter of the identified COD. Aerobic processes provided an increase of the relative fractions for proteins, whereas the ones of lipids decreased and sugars fraction remains stable. For the wastewaters released from cheese dairy (lipid-rich) and slaughterhouses (protein/lipid-rich), the dissolved phase after biological treatment is composed of proteins whereas the particulate one is composed of lipids. After the 21-day test, the concentration in proteins was nearby 10 mg/L. The results should be used for operations of WWTP to detect when a dysfunction is about to occur. They can be used to predict the concentrations in the treated water when upgrading an existing municipal plant that will admit agro-industrial discharge.

What I Do Has to Be Great (Video)

A short documentary film that chronicles the life journey of Vermont dairy farmer and cheese maker John Putnam. The film explores a life-altering choice that is ultimately pitted against the sometimes-overbearing weight of societal expectation. Shot on location in rural Vermont.

Characterization of Staphylococcus strains collected throughout the production chain of a Ewe's milk cheese dairy plant

Characterization of Staphylococcus strains collected throughout the production chain of a Ewe's milk cheese dairy plant

Des souches locales aux ferments lactiques spécifiques: démarche de recherche-action sur l'activation et la gestion d'une ressource biotechnique

This study presents a research-action program carried out in Corsica with a group of cheese makers to develop specific starters. Based on the direct participation of the cheese makers, this study consisted in designing starters with lactic acid bacterial strains isolated from milks and cheeses of this group of cheese makers. This process modified an individually and empirically used resource, local strains, into a shared and collectively managed resource, specific starters. Patrimonial features of these strains and the direct participation of the cheese makers were determining factors in the collective management of this resource. These starters are now used daily. They represent a concrete way of meeting the new conditions present in cheese dairies, characterised by low levels of lactic acid bacteria in milk.

Chromosomal regions underlying noncoagulation of milk in Finnish Ayrshire cows.

About 10% of Finnish Ayrshire cows produce noncoagulating milk, i.e., milk that does not form a curd in a standard 30-min testing time and is thus a poor raw material for cheese dairies. This phenomenon is associated with peak and midlactation, but some cows produce noncoagulating milk persistently. A genomewide scan under a selective DNA pooling method was carried out to locate genomic regions associated with the noncoagulation of milk. On the basis of the hypothesis of the same historical mutation, we pooled the data across sires. Before testing pools for homogeneity, allele intensities were corrected for PCR artifacts, i.e., shadow bands and differential amplification. Results indicating association were verified using daughter design and selective genotyping within families. Data consisted of 18 sire families with 477 genotyped daughters in total, i.e., 12% of each tail of the milk coagulation ability. Data were analyzed using interval mapping under maximum-likelihood and nonparametric methods. BMS1126 on chromosome 2 and BMS1355 on chromosome 18 were associated with noncoagulation of milk across families on an experimentwise 0.1% significance level. By scanning gene databases, we found two potential candidate genes: LOC538897, a nonspecific serine/threonine kinase on chromosome 2, and SIAT4B, a sialyltransferase catalyzing the last step of glycosylation of kappa-casein on chromosome 18. Further studies to determine the role of the candidates in the noncoagulation of milk are clearly needed.

Virulence of Listeria monocytogenes isolated from the cheese dairy environment, other foods and clinical cases

The virulence potential of 51 Listeria monocytogenes isolates, including strains from cheese, cheese production environments and from human cases of listeriosis, was evaluated in this study. The isolates were used to infect HT-29 cell monolayers in an in vitro test of virulence, based on a plaque-forming assay (PFA). Fifteen selected isolates were used for subcutaneous footpad inoculation in mice and subsequent recovery of the bacterium from the spleen 3 days after inoculation. In the PFA, two isolates from milk (serovar 1/2a) were not significantly different (P<0.05) from the low-virulence strain (442) used as reference. Thirty-three isolates were not significantly different (P<0.05) from the virulent strain (EGDe) used as reference. Nine isolates were significantly more virulent (highly virulent) than the EGDe strain and seven isolates were significantly less virulent. The nine highly virulent isolates were either from humans (four), from cheese dairy environments (two isolates of a strain were found persistently in two dairies), from cheese (one), from milk (one) and the reference strain for serovar 1/2b (CECT 936). The two milk isolates with low virulence in the PFA were found to be virulent in mice. In conclusion, all the isolates from food and food-related environments were potentially virulent or highly virulent. These results stress the risk of listeriosis associated with the consumption of cheese contaminated with L. monocytogenes, and once more emphasize the importance of good manufacturing practices (GMPs) together with sanitation standard operating procedures (SSOPs) throughout the food chain.

Relationship between westernization of dietary habits and mortality from breast and ovarian cancers in Japan.

To clarify the relationship between the westernization of dietary habits and the changes of mortality from breast and ovarian cancers in Japan, correlation analyses were performed using data from the Vital Statistics and National Nutritional Survey Reports. With increasing population size of the areas, the age-adjusted death rates (AADRs) for both types of cancer increased together with the per capita intakes of fat, animal protein and western-style foods such as butter & margarine, cheese, ham & sausage and dairy products. The association of the AADRs with the population size was strong after the age group of 45-54 years in breast cancer, and became stronger as the age increased in ovarian cancer. The association of the AADRs with western-style foods was also observed in the correlation analyses among the 12 geographical districts in Japan. From chronological correlation analyses, the correlation coefficients for some nutrients and foods in breast cancer were highest when the "time-lag" between the foods/nutrients intake and the cancer mortality was assumed to be around 10 years. The results of the present study suggest that an increase of western-style fat-rich foods such as butter & margarine, cheese, bread and ham & sausage among Japanese might be associated with the recent increase of AADRs for breast cancer and ovarian cancers in Japan.

Importance of Brucella melitensis for food safety

Brucellosis is an infectious disease caused by members of the Brucella spp. Various species of Brucella spp. infect different animals including cattle, sheep, goats, pigs, dogs, sea mammals and a variety of other animals. Infection of humans occurs directly via contact with infected animals or through animal products, in particular unpasteurised milk, cream, cheese and other dairy products. The incidence of brucellosis in humans in the Balkan and Mediterranean countries has not shown any declining tendency in previous decades. Preventive measures for keeping the food chain safe are recommended.

THE ECONOMIC CONDITIONS OF AGRICULTURE IN THE NEW MEMBER STATES

The common agricultural policy (CAP) is one of the most developed policy areas in the EU and the preparations for its implementation represent a considerable challenge for the NMS. The CAP was criticised for supporting agricultural specialization and intensification which has negative impacts on the environment. On the other hand, it is also a key policy tool because the farmers provide the delivery of public goods, e.g. via agro-environment schemes. The implementation of the CAP will generally improve the situation of agriculture in the NMS as compared to the situation of the countries without membership and under domestic policies. The CAP in combination with the size of the Single Market provides more stable and slightly higher prices as compared to what the domestic policies of the individual Accession Countries can secure for the years to come. The EU-27 will exhibit a higher degree of competitiveness across production regions and will thus lead to different patterns of production. The new Member States will find growing markets, e.g. for poultry products and feed grains, in the old Member States, and expand production. By contrast, old Member States will benefit from the expansion of the markets for fresh dairy products, cheese and pork in the NMS. The economic comparative method was used to compare macroeconomic indices of EU -15 countries and of new Member Countries. On this base, some conclusions were drawn, conclusions regarding their position in the agricultural sector of European Union. There were used data published by European Commission and reports on development of the new Member States. The structure of the paper points out some key policy questions that provide an insight into the relationship between agriculture and development in the NMS: What are the characteristics of agriculture in NMS-12 in terms of farm structure, management, production and associated biodiversity and how do these compare to agriculture in the EU-15? What are the recent agricultural trends and their underlying drivers? How do these agricultural changes affect the environment and what are the main concerns? Our analysis suggests that: improving the functioning of capital asset, insurance, and credit markets; investing in human capital, relevant to managing farm business; and taking steps to help improve the asset endowments and food security of the poorer segments of the rural population, would enable rural households to set aside resources in various activities according to their comparative advantage.