Production Of Artisanal Cheeses Research Articles

Environmental aspects of artisanal minas cheese production

Several studies have been conducted with the aim of improving the quality of artisanal Minas cheese, but substantial environmental impacts research is still lacking. This study aimed at identifying potential environment effects, due to the relative lack of this kind of subject. In loco verification was done in manufacturing process, water consumption and solid waste generated from the industrial process. The main environmental aspects observed were: effluents, cheese shavings, cardboard / plastic packaging and chemical products. The process of burning solid waste like cardboard and plastic is made on-site. The effluents generated by these industries are released into the soil in 100% of the cases, without technical criteria. There is an obvious need of establishing effluent treatment systems compatible with the economic reality of producers to minimize negative environmental impacts. Based on this study, could be observed the need for greater interaction between research institutions and small producers with their thirst for knowledge and a guideline for waste management, water use reduction and recycling/reuse considering the environmental as part of the process. The implementation of the project, allowed starting the interaction mentioned, but there are still a lot of hard work ahead.

Virulence factors and genetic variability of Staphylococcus aureus strains isolated from raw sheep's milk cheese

Contamination of dairy products with Staphylococcus aureus can be of animal or human origin. The host pathogen relationship is an important factor determining genetic polymorphism of the strains and their potential virulence. The aim of the present study was to carry out an extensive characterization of virulence factors and to study the genetic variability of S. aureus strains isolated from raw ewe's milk cheese. A total of 100 S. aureus strains isolated from cheese samples produced in 10 artisan cheese factories were analyzed for the presence of enterotoxins (sea-see) and enterotoxins-like genes (seh, sek, sel, sem, seo, sep), leukocidins, exfoliatins, haemolysins, toxic shock syndrome toxin 1 (TSST-1) and the accessory gene regulator alleles (agr). Strains were also typed using pulsed-field gel electrophoresis (PFGE). AMOVA analysis carried out on PFGE and PCR data showed that the major component explaining genetic distance between strains was the dairy of origin. Of the total isolates 81% had a pathogenicity profile ascribable to "animal" biovar while 16% could be related to "human" biovar. The biovar allowed to estimate the most likely origin of the contamination. Minimum inhibitory concentrations (MICs) of nine antimicrobial agents and the presence of the corresponding genes coding for antibiotic resistance was also investigated. 18 strains carrying blaZ gene showed resistance to ampicillin and penicillin and 6 strains carrying tetM gene were resistant to tetracycline. The presence of mecA gene and methicillin resistance, typical of strains of human origin, was never detected. The results obtained in the present study confirm that S. aureus contamination in artisan cheese production is mainly of animal origin.

Goat and sheep milk products in the United States (USA)

Goat and sheep milk represent only about 0.08% of the total annual milk production in the USA. Currently about 24% of the goat milk is used for fluid consumption. Approximately 75% of goat milk and 95% of the sheep milk produced is used in the production of cheeses. Predictive cheese yield formulas have been developed for both goat and sheep milk. To avoid competition from imported goat and sheep milk cheeses, U.S. processors are concentrating on production of specialty and artisanal cheeses. With a continued emphasis on the special qualities of goat and sheep milk, the market for goat and sheep milk products in the USA should continue to grow.

Characterization of Staphylococcus aureus strains isolated from raw milk utilized in small-scale artisan cheese production.

Staphylococcus aureus is an important agent of bacterial mastitis in milking animals and of foodborne intoxication in humans. The purpose of this study was to examine the genetic and phenotypic diversity, enterotoxigenicity, and antimicrobial resistance of S. aureus strains isolated from raw milk used for the production of artisan cheese in Vermont. Cross-tabulations revealed that the 16 ribotypes identified among the 90 milk isolates examined were typically associated with a specific animal species and that more than half of these ribotypes were unique to individual farms. In general, specific EcoRI ribotypes were commonly associated with specific phenotypical characteristics, including staphylococcal enterotoxin production or the lack thereof. Limited antimicrobial resistance was observed among the isolates, with resistance to ampicillin (12.51%) or penicillin (17.04%) most common. Two isolates of the same ribotype obtained from the same farm were resistant to oxacillin with 2% NaCl. More than half (52.22%) of isolates produced toxin, and 31 of the 32 isolates solely produced staphylococcal enterotoxin type C. Although these data demonstrate that S. aureus strains found in raw milk intended for artisan cheese manufacture are capable of enterotoxin production, staphylococcal enterotoxin C is not typically linked to foodborne illness. Because S. aureus is a common contaminant of cheese, an understanding of the ecology of this pathogen and of the antimicrobial susceptibility and toxigenicity of various strains will ultimately contribute to the development of control practices needed to enhance the safety of artisan and farmstead cheese production.

Placing the Taste of Vermont Cheese

This essay considers two ways in which farmstead cheesemakers in Vermont are translating the term “terroir” in order to convey the instrumental as well as gustatory values of their artisanal products. In the first, familiar from European systems of geographical indication, terroir calls attention to the material qualities of a locale that may carry through to the taste of a handmade cheese. But in the second, terroir talk offers a more prescriptive reading of the “taste of place” to encourage rural economic revitalization through artisan cheese production. What coalesces in Vermont farmstead cheese as the taste of place reflects, above all, cheesemakers’ entrepreneurial creativity and commitment to making a living by working the land.

Bacterial communities associated with the production of artisanal Istrian cheese

In this work we report on the main bacterial microflora typical for fermentation and ripening of traditional Istrian cheese. Samples from milk as well as Istrian cheese were analyzed during the ripening process by using culture independent molecular fingerprinting methods as well as culture based approaches. Our results indicate changes in bacterial diversity pattern during the ripening process. Differences in bacterial diversity at the same ripening stage among different farms investigated were comparably low. Sequence analysis of the most prominent bands of denaturing gradient gel electrophoresis fingerprints revealed dominance of Lactococcus lactis subs. lactis in all samples and a strong presence of Enterococcus spp. which was also confirmed by plate count analysis.

Microbiological quality of raw milk used for small-scale artisan cheese production in Vermont: Effect of farm characteristics and practices

This study 1) evaluated the overall milk quality and prevalence of 4 target pathogens (Listeria monocytogenes, Staphylococcus aureus, Salmonella spp., and Escherichia coli O157:H7) in raw milk used for small-scale artisan cheesemaking and 2) examined specific farm characteristics and practices and their effect on bacterial and somatic cell counts (SCC). Raw milk samples were collected weekly from 21 artisan cheese operations (6 organic) in the state of Vermont that manufactured raw-milk cheese from cow (12), goat (5), or sheep (4) milk during the summer of 2008. Individual samples were examined for standard plate counts (SPC), coliform counts (CC), and SCC. Samples were also screened for target pathogens both quantitatively and qualitatively by direct plating and PCR. Overall, 86% of samples had SPC <10,000cfu/mL, with 42% <1,000cfu/mL. Additionally, 68% of samples tested were within pasteurized milk standards for coliform bacteria under the United States’ Grade A Pasteurized Milk Ordinance at <10cfu/mL. Log10 SPC and CC did not differ significantly among species. Similarly, method of sample delivery (shipped or picked up), farm type (organic or conventional), and duration of milking (year-round or seasonal) did not have significant effects on farm aggregated mean log10 SPC, CC, or SCC. Strong positive correlations were observed between herd size and mean log10 SPC and between log10 SPC and CC as well as SCC when data from all animal species were combined. Although SCC for cow milk were significantly lower than those for goat and sheep milk, 98, 71, and 92% of cow, sheep, and goat milk samples, respectively, were within the compliance limits of the United States’ Grade A Pasteurized Milk Ordinance for SCC. Fourteen of the 21 farms (67%) were positive for Staph. aureus, detected in 38% of samples at an average level of 20cfu/mL. Neither L. monocytogenes, E. coli O157:H7, or Salmonella spp. were detected or recovered from any of the 101 samples tested. Our results indicate that the majority of raw milk produced for small-scale artisan cheesemaking was of high microbiological quality with no detectable target pathogens despite the repeat sampling of farms. These data will help to inform risk assessments that evaluate the microbiological safety of artisan and farmstead cheeses, particularly those manufactured from raw milk.

THE EFFECT OF ADJUNCT CULTURES ON SOME CHEMICAL AND BIOCHEMICAL PROPERTIES OF WHITE-BRINED CHEESE

ABSTRACT The influence of different adjunct cultures on some of the chemical and biochemical properties of white-brined cheese was investigated. Four batches of cheese were produced: C, with no added adjuncts, containing only cheese culture (Lactococcus lactis ssp. lactis plus Lc. lactis ssp. cremoris); CY, containing C culture plus yogurt culture (Streptococcus thermophilus + Lb. delbrueckii ssp. bulgaricus); CH, containing C culture plus Lactobacillus helveticus; and CYH, containing all of them. Analyses were carried out on days 2, 30, 60 and 90 of ripening. It was found that the addition of different adjunct starters to the cheese influenced (P < 0.01) the chemical composition significantly, except salt contents (P > 0.05). Total solids, protein, fat and pH values were higher in C cheese than the others. On the other hand, titratable acidity of C and CY cheeses was lower than that of CH and CYH cheeses. Although the lipolysis (acid degree value), water-soluble nitrogen (WSN) and trichloroacetic acid-soluble nitrogen (TCA-SN) values of cheeses were affected significantly (P < 0.01) from these treatments, no significant differences exist (P > 0.05) among phosphotungstic acid-soluble nitrogen values. Cheeses made with CYH culture had the highest lipolysis, WSN and TCA-SN. Degradation rates of αs1- and β-casein were higher in CYH cheese followed by CY, CH and C cheeses. Also, breakdown products of casein were higher in CY, CH and CYH cheeses compared with the control cheese. The amounts ofαs1- and β-caseins of all cheese samples decreased continuously during the ripening period, while the amounts of αs1-I casein and other breakdown products increased. PRACTICAL APPLICATIONS Starter cultures contribute to cheese sensory quality with their peptidase activity. In artisanal cheese production, the cheese is made without the deliberate addition of a starter culture relying on the indigenous flora of the milk for ripening. Recently, mesophilic and/or thermophilic starter cultures were used in the manufacture of Turkish white-brined cheese. Little information on using adjunct culture in white cheese has been reported and may provide information to improve the process and ripening by enhancing the quality of the final product while preserving its typical nature. Adjunct cultures can accelerate flavor development or contribute additional flavors to cheese as it ages and control bitterness in aged cheeses, depending on the fermentation process and adjunct type. They can also accelerate cheese ripening, which may allow substantial cost savings for the cheese industry.

A survey on biotechnological potential and safety of the novel Enterococcus species of dairy origin, E. italicus

The biotechnological and safety properties of the novel enterococcal species of dairy origin, Enterococcus italicus, were investigated. The strains of the species showed technological characteristics related to their use as adjunct cultures in the production of artisanal cheeses. They were susceptible or poorly resistant to several clinical relevant antibiotics. Moreover, E. italicus strains were associated with low virulence profiles, as verified by screening for the presence of 33 different genes encoding antibiotic resistance and known virulence factors in the genus Enterococcus. From the data obtained, we deduce that the presence of E. italicus strains in cheeses results in a low health risk and that within the species new safe adjunct cultures for the dairy industry could be found.

Microbiological characterization of artisanal Raschera PDO cheese: Analysis of its indigenous lactic acid bacteria

The aim of this research was to study the bacterial populations involved in the production of artisanal Raschera PDO cheese (Italian Maritime Alps, northwest Italy) in order to collect preliminary knowledge on indigenous lactic acid bacteria (LAB). A total of 21 samples of Raschera PDO cheese, collected from six dairy farms located in the production area, were submitted to microbiological analysis. LAB were randomly isolated from M17 agar, MRS agar and KAA plates and identified by combining PCR 16S–23S rRNA gene spacer analysis, species-specific primers and 16S rRNA gene sequencing. Biodiversity of Lactococcus lactis subsp. lactis isolates was investigated by RAPD-PCR. LAB microflora showed the highest count values among all microbial groups targeted. They reached counts of 10 9 colony forming unit (cfu)/g in cheese samples after 3 days of salting and 15 days of ripening. Yeast population also showed considerable count values, while enterococci and coagulase-negative cocci (CNC) did not overcome 10 7 cfu/g. L. lactis subsp. lactis was the species most frequently isolated from Raschera PDO samples at all different production stages while in aged cheeses Lactobacillus paracasei was frequently isolated. RAPD-PCR highlighted that isolates of L. lactis subsp. lactis isolated from Raschera PDO were highly homogeneous.

Yeasts from Water Buffalo Mozzarella, a traditional cheese of the Mediterranean area

Countries of the Mediterranean area are characterized by production of artisanal cheeses, obtained from goat, sheep, cow and buffalo raw milk. The numbers and species of yeasts in the different cheeses are variable, but some species are more frequently detected than others. Kluyveromyces marxianus, K. lactis with their anamorph, Candida kefir, Debaryomyces hansenii and C. famata, C. colliculosa and C. catenulata are dominant species in several cheeses. However, Saccharomyces cerevisiae is often detected in pasta filata cheeses, such as Water Buffalo Mozzarella (WBM) or Cacio Cavallo Podolico. Recently, a comprehensive study of yeasts isolated from Mozzarella cheese produced in Basilicata (Southern Italy) has been carried out. The study has focused on lactose and/or galactose fermenting species ( Kluyveromyces and Saccharomyces) to evaluate their role on the functional and sensory properties of the product. End products in milk were evaluated and the biodiversity in terms of production of sulphur dioxide, higher alcohols, ethyl acetate, and acetaldehyde was studied. In particular, S. cerevisiae strains from Water Buffalo Mozzarella cheese, compared to strains isolated from different habitats, such as wine, exhibited considerable difference in the production of some volatile compounds. The diversity observed could be related to the particular microhabitat of S. cerevisiae occurring in whey cheese of water buffalo milk.