In 2006, in The Netherlands, an outbreak of Salmonella Typhimurium phage type 561 (STM DT7, corresponding to the rare DT7 in the international typing scheme) was detected, accumulating to over 200 ...cases. By telephone interviews, data were collected from all laboratory-confirmed cases. In addition, in August 2006, a case-control study was performed in a subset of cases. Environmental and microbiological investigation was performed on a suspected dairy farm. In the case-control study (51 cases, 105 matched controls), hard cheese purchased from a farm, specifically farm X, and from a market stall were found to be associated with infection. The dairy production room of farm X tested STM DT7-positive in August. However, it was only in November, after earlier unsuccessful attempts, that a low-level contamination was confirmed in the hard farmhouse cheese, triggering control measures. A timely and adequate response was hampered during this outbreak for several reasons. Measures for improvement in handling future similar incidents are discussed.
This reprint is dedicated to new insights into food fermentation. The goal of this reprint was to broaden the current knowledge on advanced approaches concerning food fermentation, gathering studies ...on conventional and unconventional food matrix fermentation, functional compounds obtained through fermentation, fermentations increasing quality and safety standards, as well as papers presenting innovative approaches shedding light on the microbial community that characterizes fermented foods.
The buffalo dairy sector is extending its boundaries to include new buffalo cheese productions beyond mozzarella, overcoming some barriers that make cheeses expensive and unsustainable. This study ...aimed to evaluate the effects of both the inclusion of green feed in the diet of Italian Mediterranean buffaloes and an innovative ripening system on buffalo cheese quality, providing solutions capable of guaranteeing the production of nutritionally competitive and sustainable products. For this purpose, chemical, rheological, and microbiological analyses were carried out on cheeses. Buffaloes were fed with or without the inclusion of green forage. Their milk was used to produce dry ricotta and semi-hard cheeses, ripened according to both respective traditional (MT) and innovative methods (MI); these are based on automatic adjustments of climatic recipe guided by the continuous control of pH. Green feed enhances the nutritional profile of the final products (high content of MUFAs and PUFAs). As far as the ripening method is concerned, to our knowledge, this is the first study that tests aging chambers, commonly used for meat, for the maturing of buffalo cheeses. Results pointed out the MI validity also in this field of application, as it shortens the ripening period without negatively compromising any of desirable physicochemical properties and the safety and hygiene of the final products. Conclusively, this research highlights the benefits of diets rich in green forage on productions and provides support for the ripening optimization of buffalo semi-hard cheeses.
Technological use of donkey milk in cheesemaking Niro, Serena; Fratianni, Alessandra; Colavita, Giampaolo ...
International journal of dairy technology,
August 2017, 2017-08-00, 20170801, Volume:
70, Issue:
3
Journal Article
Peer reviewed
The efficacy of donkey milk as an alternative to hen's egg white lysozyme in preventing cheese blowing during ripening of Italian Grana cheeses was tested. Indices of proteolysis and lipolysis did ...not differ between the different cheesemaking processes. All tested products showed good microbiological and sensorial quality.
The aim of this study was to explore diversity and dynamic of indigenous LAB strains associated with a long ripened hard cheese produced from raw milk and undefined natural starter such as PDO Grana ...Padano cheese. Samples of milk, curd, natural whey culture and cheeses (2nd, 6th, 9th and 13th months of ripening) were collected from 6 cheese factories in northern Italy. DNA was extracted from each sample and from 194 LAB isolates. tRNAAla-23S rDNA-RFLP was applied to identify isolates. Strain diversity was assessed by (GTG)5 rep-PCR and RAPD(P1)-PCR. Finally, culture-independent LH-PCR (V1–V2 16S-rDNA), was considered to explore structure and dynamic of the microbiota. Grana Padano LAB were represented mainly by Lactobacillus rhamnosus, Lactobacillus casei, Lactobacillus paracasei, Lactobacillus delbrueckii, Lactobacillus helveticus and Pediococcus acidilactici, while the structure and dynamic of microbiota at different localities was specific. The strength of this work is to have focused the study on isolates coming from more than one cheese factories rather than a high number of isolates from one unique production. We provided a valuable insight into inter and intraspecies diversity of typical LAB strains during ripening of traditional PDO Grana Padano, contributing to the understanding of specific microbial ecosystem of this cheese.
•Polyphasic molecular approach was applied to identify LAB associated with GP cheese.•CD approach revealed higher biodiversity.•CI approach provided better insight into population dynamic.•Lactobacillus rhamnosus was found to be the predominant isolate in cheese.•For the first time, Pediococcus acidilactici, was isolated from GP NWC.
The potential of mid-infrared and intrinsic fluorescence spectroscopies was investigated for determining the geographic origin of different hard cheeses. Mid-infrared (1700–1500
cm
−1 region), ...fluorescence emission spectra, following excitation at 250 and 290
nm, and fluorescence excitation spectra following emission at 410
nm were recorded directly on cheese samples. Twelve experimental hard cheeses were made using identical and controlled cheese-making conditions with milks originating from three different regions in Jura (France). The results of factorial discriminant analysis (FDA) performed on the fluorescence and mid-infrared spectra of the experimental cheeses showed a good discrimination of the cheeses.
In a second step, 25 Gruyère Protected Denomination of Origin (PDO) cheeses manufactured at different altitudes in Switzerland, i.e., 11 Gruyère PDO cheeses from the lowlands (<800
m), eight Gruyère PDO cheeses from the highlands (1100–1500
m) and six L’Etivaz PDO cheeses (1500–1850
m) were analysed. Only 80% of correct classification was obtained by applying FDA to the mid-infrared spectra of the investigated cheeses. A better classification (100%) was achieved based on the fluorescence spectra. Front-face fluorescence spectroscopy appeared to be rapid, low cost and efficient for the geographic determination of Gruyère cheeses.
Trentingrana (or Grana Trentino) is a Protected Designation of Origin hard cheese produced in the eastern Italian Alps by small cooperative dairy factories. To obtain the certification of quality, ...wheels are evaluated at 9±1 mo of ripening and those classified as first quality are revaluated at 18±1 mo. Traditionally, the assessment is based on 2 sensory features: namely, the external aspect of the wheel and the internal texture; the latter is evaluated through the sound produced by beating the wheel with a special hammer. Traits considered in the study were the percentage of first-quality wheels of total wheels examined at 9±1 (QW9mo) and 18±1 (QW18mo) mo of ripening, and their combination i.e., the percentage of first-quality wheels at 18±1 mo of ripening of the number of wheels evaluated at 9±1 mo (QWtot). The experimental unit was the batch of 2 mo of production of each of 10 cooperative dairy factories from 2002 to 2008. Data were analyzed with a model that included fixed effects of dairy factory, year and season of production, and interactions between dairy factory and year, and dairy factory and season. The coefficients of determination of the models were 0.57, 0.68, and 0.67 for QW9mo, QW18mo, and QWtot, respectively. All factors significantly influenced the traits, with dairy factory being the most important source of variation, followed by season and year of production. Remarkable differences were found between the best and the worst dairy factory for QW9mo (11.5%), QW18mo (21.1%), and QWtot (25.6%). The first 4 yr of production had a negative effect on the percentage of wheels labeled as first quality and QWtot decreased from 74 to 64%; nevertheless, a complete recovery was detected in the following years. The season of production strongly influenced the studied traits with the best results in spring and summer, and the worst in autumn and winter. Compared with average, the 3 best dairy factories were smaller, with smaller associated farms, and showed lower variation across years and seasons of production. Results support the relevance of routinely assessing and monitoring the quality of Trentingrana cheese.
Reggianito is a typical variety of grana-type hard cheese produced in Argentina. It is the most exported and due to its organoleptic characteristics is very appreciated by the consumers. The ...objective of this study was to characterise the global composition, lipolysis, proteolysis and volatile compound profiles of commercial Reggianito cheeses from different dairy plants.
Statistical differences (
P
⩽
0.05) in some physicochemical parameters, nitrogen fractions and FFA levels among commercial brands were detected. The volatile profiles were studied by SPME–GC–MS/FID. A total of 53 compounds were identified, the majority belonging to the groups of ketones, alcohols, acids, esters and aldehydes. All these compounds have been reported in Italian grana-type cheeses. Visualization of the analytical results was performed by principal component analysis. This analysis clustered cheese samples according to dairy plants. This fact could be, among other factors, consequences of differences in technologies and ripening time of different manufacturers.
The fraudulent addition of plant oils during the manufacturing of hard cheeses is a real issue for the dairy industry. Considering the importance of monitoring adulterations of genuine cheeses, the ...potential of fluorescence spectroscopy for the detection of cheese adulteration with plant oils was investigated. Synchronous fluorescence spectra were collected within the range of 240 to 700 nm with different wavelength intervals. The lowest detection limits of adulteration, 3.0 and 4.4%, respectively, were observed for the application of wavelength intervals of 60 and 80 nm. Multiple linear regression models were used to calculate the level of adulteration, with the lowest root mean square error of prediction and root mean square error of cross validation equalling 1.5 and 1.8%, respectively, for the measurement acquired at the wavelength interval of 60 nm. Lower classification errors were obtained for the successive projections algorithm-linear discriminant analysis (SPA–LDA) rather than for the principal component analysis (PCA)–LDA method. The lowest classification error rates equalled 3.8% (∆λ = 10 and 30 nm) and 0.0% (∆λ = 60 nm) for the PCA–LDA and SPA–LDA classification methods, respectively. The applied technique is useful for detecting the addition of plant fat to hard cheese.
The microbiota of Protected Designation of Origin (PDO) cheeses plays an essential role in defining their quality and typicity and could be applied to protect these products from counterfeiting. To ...study the possible role of cheese microbiota in distinguishing Grana Padano (GP) cheese from generical hard cheeses (HC), the microbial structure of 119 GP cheese samples was studied by DNA metabarcoding and DNA metafingerprinting and compared with 49 samples of generical hard cheeses taken from retail. DNA metabarcoding highlighted the presence, as dominant taxa, of
,
,
,
,
spp., and
spp. in both GP cheese and HC. Differential multivariate statistical analysis of metataxonomic and metafingerprinting data highlighted significant differences in the Shannon index, bacterial composition, and species abundance within both dominant and subdominant taxa between the two cheese groups. A supervised Neural Network (NN) classification tool, trained by metagenotypic data, was implemented, allowing to correctly classify GP cheese and HC samples. Further implementation and validation to increase the robustness and improve the predictive capacity of the NN classifier will be needed. Nonetheless, the proposed tool opens interesting perspectives in helping protection and valorization of GP and other PDO cheeses.
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