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 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.
Trentingrana is a Protected Designation of Origin (PDO) hard cheese manufactured in the valleys of Trento province (eastern Italian Alps) by several small cooperative dairies linked in a consortium. ...Nine months after production, wheels are delivered to a shared facility, ripened up to 18 mo, and assessed by a panel of 8 experts for 7 sensory attributes; namely, external aspect, rind thickness, paste color, texture, odor, taste, and aroma. The evaluation takes place every 2 mo on wheels sampled within each dairy. Based on the results of the assessment, dairies receive a price premium or penalty depending on a quality index, which is the weighted sum of the scores attributed to each sampled wheel. Sensory scores and quality index of 652 wheels representing 11 dairies and 10 yr of production were analyzed using a model that included fixed effects of dairy, year, and season of production, and first-order interactions between them. The coefficients of determination ranged from 0.50 (texture) to 0.66 (aroma). All factors significantly affected the studied traits, with the exception of interactions between dairy and season of production for texture and external aspect, and between year and season of production for odor. Dairy was the most important source of variation for visually assessed traits (external aspect, rind thickness, paste color, and texture) and for quality index, whereas year of production was the most important for flavor attributes (odor, taste, and aroma). The latter traits were always highly correlated among them and with the quality index, whereas correlations among visually assessed attributes, between them and flavor attributes, and between them and the quality index were more erratic. The sensory evaluation performed by the panel of experts has proven to be a useful tool to define the quality index and address the payment system of Trentingrana cheese, but it has some limitations in correctly describing the sensory profile of cheese and identifying specific defects and possible remedies.
The genera
Propionibacterium and
Bifidobacterium are clustered in the class
Actinobacteria and form the anaerobic branch of coryneform bacteria. The dairy propionibacteria comprising four species
P. ...freudenreichii,
P. acidipropionici,
P. jensenii and
P. thoenii are industrially important as starter cultures in hard-cheese ripening and recently also as protective bio-preservatives and probiotics. These four species are considered as safe whereas cutaneous
Propionibacterium species (also named “acnes group") are pathogens. In contrast, bifidobacteria in fermented dairy products and milk powder are exclusively used as probiotics; selected strains of several species (out of more than thirty) contribute to this task. It has been only rarely found that commensal bifidobacteria have been connected with certain dental and other infections. Consequently, only one single species,
Bifidobacterium dentium, is recognized as pathogenic. Genome sequence analysis of
Bifidobacterium longum and molecular biological analysis of other probiotic strains confirmed so far the absence of virulence and pathogenecity factors. However, tetracycline resistance genes
tet(W), although probably not easy transferable, were found in
Bifidobacterium strains, also in
Bifidobacterium animalis subsp.
lactis, the worldwide most used industrial strain. Conclusively, strains from the
Propionibacterium and
Bifidobacterium species in dairy food generally represent so far no health hazards.
The distribution of mould species was examined at several points of the processing chain in a Manchego cheese plant and associated dairy farms. Geotrichum and Fusarium were the genera most frequently ...isolated from milk samples as well as in cheeses ripened for one month, evidencing a direct transfer from raw milk. Conversely, the mycobiota of long‐ripened cheeses consisted mainly of Penicillium species, which gained entry to the cheese through the air of ripening rooms. This study contributes to the understanding of the dynamics of fungal populations in semihard and hard cheeses, highlighting that airborne transfer from the stables could have a direct impact on their quality.
Late blowing on semihard and hard cheese may have an important economic effect on dairy production. Many studies have attempted to prevent this defect by physical treatment, the use of additives, and ...the use of bacteriocins. In this paper, we look at the effect of jenny milk as an inhibitor of blowing caused by clostridia and coliforms in ewe cheese making. Bulk ewe and jenny milk samples were collected in the morning by mechanical milking and were refrigerated at 4°C. On the collected samples, the count of somatic cells, coliforms, Clostridium butyricum, and Escherichia coli were determined. The bulk raw milk was divided in two 45-L vats: vat 1 was used as a control, whereas 0.5L of jenny milk was added to vat 2. Four semihard cheeses, weighing about 2kg each, were made from each vat. Cheese making was replicated twice. After a ripening period of 60 d, the count of coliforms and of C. butyricum was determined. In the treated group, a significant inhibition of coliform bacteria was observed. The addition of jenny milk in cheese making may prove to be a useful and innovative approach for the inhibition of spore-forming clostridia strains.
Selected strains of mesophilic lactobacilli with key enzymatic activities may be employed to intensify or diversify cheese flavor during ripening. Among enzymes of interest, aminotransferases are ...most important, as they are involved in the first step of amino acid (AA) catabolism. In previous studies, Lactobacillus paracasei I90 has been shown to increase both the secondary proteolysis in soft and semihard cheeses and the production of volatile compounds in minisoft cheeses. In this work, its potential for the formation of volatile compounds derived from AA catabolism was assessed by solid-phase microextraction coupled to GC-FID/MS in a hard-cooked cheese model, consisting of a cheese extract sterilized by filtration. Lb. paracasei I90 showed aminotransferase activity towards all the AAs studied (branched-chain AAs, aromatic AAs, aspartic acid, and methionine). The highest levels were observed for aspartic acid, followed by branched-chain AAs and tryptophane. Among the volatile compounds derived from AAs, 2-methylbutanal, 3-methylbutanal, diacetyl, 3-methyl1-butanol, acetic, and 3-methylbutanoic acids were detected at higher level in extracts inoculated with Lb. paracasei I90 than in controls. It was concluded that the production of volatile compounds by Lb. paracasei I90 in a hard cheese model was consistent with its main aminotransferase activities, making this strain a good candidate for enhancing flavor in hard cheeses.
Caseinophosphopeptides (CPPs) are bioactive peptides originating from proteolysis of caseins, the main proteins of milk. In this study, the generation of CCPs during Beaufort cheese making and by in ...vitro simulated gastro-intestinal hydrolysis using pepsin and pancreatin were assessed using selective precipitation and liquid chromatography–electrospray ionisation tandem mass spectrometry. Seventy-two water-soluble CPPs, mainly originating from β-casein, were identified in Beaufort cheese, while 79 CPPs, mainly generated from α
s1-caseins, were obtained from enzymatic hydrolysates. Most of the peptides generated by the action of digestive enzymes were monophosphorylated; however, 17 out of the 23 polyphosphorylated CPPs identified from digested Beaufort cheese still contained the characteristic cluster sequence Ser(P)-Ser(P)-Ser(P)-Glu-Glu, providing calcium-binding properties to CPPs. The content of CPPs in Beaufort cheese before and after the action of digestive enzymes was estimated to be 230 and 275 mg per 100 g of fresh cheese, respectively. The action of proteolytic digestive enzymes on CPPs is discussed.
The angiotensin-converting enzyme (ACE) inhibitory activity and the concentration of the 2 ACE-inhibiting tripeptides Val-Pro-Pro (VPP) and Ile-Pro-Pro (IPP) were studied during cheese ripening in 7 ...Swiss cheese varieties. The semi-hard cheeses Tilsiter, Appenzeller 1/4 fat, Tête de Moine, and Vacherin fribourgeois and the extra-hard and hard cheeses Berner Hobelkäse, Le Gruyère, and Emmentaler were investigated. Three loaves of each variety manufactured in different cheese factories were purchased at the beginning of commercial ripeness and investigated at constant intervals until the end of the usual sale period. Good agreement was found between ACE-inhibitory activity and the total concentration of VPP and IPP at advanced ripening stages. In most of the investigated varieties ACE-inhibitory activity and the concentration of the 2 tripeptides initially increased during the study period. A decline in the concentration of VPP and IPP was obtained toward the end of the investigated period for Tilsiter and Gruyère. The ratio of VPP/IPP decreased during ripening in all varieties with the exception of Emmentaler. However, large variations were observed among the cheese varieties as well as the individual loaves of the same variety. Chemical characterization of the investigated cheeses revealed that qualitative differences in the proteolysis pattern, not quantitative differences in the degree of proteolysis, are responsible for the observed variations in the concentrations of VPP and IPP. The presence of Lactobacillus helveticus in the starter culture was associated with elevated concentrations of VPP and IPP. The results of the present study show that concentrations of VPP and IPP above 100mg/kg are attainable in semi-hard cheese varieties after ripening periods of about 4 to 7 mo and that stable concentrations of the 2 antihypertensive tripeptides can be expected over several weeks of cheese ripening.
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