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L'articolo analizza l'evolzione della redditività delle produzioni di formaggi gana DOP (Grana Padano e Parmigiano-Reggiano) con riferimento ai risultati dei caseifici cooperativi mantovani nel corso degli ultimi due decenni.

Monitoring L. helveticus strain dynamics in natural whey starters is of great interest at the industrial level due to the key role that this bacterial population plays in Grana Padano cheese production. In this study, we aimed to develop a PCR-Denaturing Gradient Gel Electrophoresis (PCR-DGGE) assay based on the slpH locus, in parallel with performing culture-dependent analysis of whey samples using optimized media to maximize the number of isolated strains. We designed new primers targeting the slpH locus to amplify a gene region that would be suitable for PCR-DGGE analysis and discriminating strains. Our results confirmed that the developed PCR-DGGE method was rapid and reliable for monitoring the L. helveticus population in whey starter cultures. All sequences of bands detected in the PCR-DGGE profiles from whey samples showed high similarity to S-layer genes of L. helveticus, and perfectly matched with the slpH locus sequences of dominant strains. Overall, our findings indicated that the target region of the slpH locus was sufficiently heterologous to discriminate L. helveticus strains, and that our PCR-DGGE analysis provided a more accurate picture of the population composition of whey starters compared to culture-dependent techniques that often fail to isolate the most abundant strains.

BACKGROUND: Considering that water availability for agricultural needs is being restricted, an alternative to corn in animal nutrition should be explored in the Po Valley. The present study aimed to evaluate the effects of either a partial (Trial I) or a total (Trial II) corn silage substitution with barley silage in dairy cows' diet on milk yield and composition, its coagulation properties, cheese yield and the sensorial profile of 16-month-aged Grana Padano cheese. RESULTS: A partial or a total substitution of corn silage with barley silage had no effect on milk yield. Milk fat content in Trial I and milk urea content in both trials were higher with barley silage based diets than in corn silage based diets. No effects were observed concerning the lactodinamographic profile for milk aptitude to cheese-making, cheese yield and its organoleptic traits between feed treatments in Trials I and II. In both trials, hardness, friability and solubility scores were generally lower than reference values, whereas deformability, elasticity and stickiness scores were generally higher than reference values. CONCLUSION: A partial or a total substitution of corn silage with barley silage in diets for dairy cows did not induce any negative effects on animal performance, nor on milk-quality traits, cheese quality and yield.

Breve intervento volto a sintetizzare criticamente quanto già scritto sulla storia antica e recente di due dei formaggi più conosciuti e apprezzati in Italia

Milk coagulation properties are used to evaluate the cheesemaking aptitude of milk samples. No international standard procedure exists, although laboratories often mimic the production of a full-fat fresh cheese for milk coagulation properties. Questions have arisen about the predictability of such a procedure for different types of cheese production. The aim of this study was to establish a procedure mimicking the production conditions of a long-ripened hard cheese, taking Protected Designation of Origin Grana Padano as a case study. With respect to the traditional conditions (standard procedure; SP), the Grana Padano procedure (GP) modifications were the use of standardized milk, coagulation lower temperature, previous milk acidification, lysozyme addition, and rennet type. Each modification was tested in turn versus the SP and also all together in the GP. Another 3 tests were carried out: SP on naturally creamed milk, SP with double the quantity of rennet, and a simplified GP on a full-fat milk sample. The 10 procedures were tested on 2 subsamples with 2 replicates each and were repeated using individual milk samples from 15 dual-purpose Simmental cows in 4 sessions for a total of 600 tests. Two Formagraph instruments (Foss Electric A/S, Hillerød, Denmark) measuring curd firmness every 15 s were used, prolonging test duration to 60. min to obtain 5 traditional single-point milk coagulation properties and 3 parameters of the curd firming model using all 240 points recorded for each replicate. The 8 traits of each replicate were analyzed according to a mixed model with fixed effects of 4 sessions, 10 treatments, 2 instruments, and 16. microvats, and random effects of 15 animals and 300 subsamples. Compared with the SP, the coagulation and curd firming was slowed by low temperature and was accelerated by acidification and by adding a double amount of rennet; natural creaming, fat standardization, and rennet with 5% pepsin affected only some traits, whereas lysozyme

Late blowing is still a significant problem in hard cheeses, including Grana Padano (GP), a DOP Italian cheese known worldwide. The main cause of this phenomenon is attributable to butyric Clostridia, gram-positive, spore former bacteria residing in soil that can be included in silages, pass through cows intestine and finally contaminate milk for cheese production, being durable to pasteurisation. In this study, a fingerprinting of Clostridia population in Grana Padano cheese was performed. Moreover, the direct quantification of Clostridium tyrobutyricum in cheese opens the way to further applications such as the analysis of milk contamination, setting in this way a valid and rapid molecular tool to assess milk quality

Il Grana Padano, così come le altre grandi Dop casearie italiane, si è retto per decenni su una ambiguità, che lo vede considerato una specialità quanto a tecniche produttive, caratteri qualitativi, area d'origine ecc. ma che, dal punto di vista quantitativo, ne fa necessariamente un prodotto di massa. Su qesta ambivalenza si è retta una va,orizzazione de la tte italiano nettamente superiore alla media. Oggi in un mutato contesto di mercato appare necessaria l'elaborazione di una nuova strategia organizzativa e commerciale.

CLA levels and fatty acid composition were measured to compare the fat composition in organic bulk milk, destined to the production of Grana Padano cheese, with those produced by conventional system. All analysed organic samples were characterized by higher annual means of CLA, vaccenic acid (TVA) and linolenic acid (LNA) in comparison with conventional samples (with P<005). Nevertheless, no particular effect of the production technology was seen on the CLA content. The animal diet appears to be the factor which has the highest effect on the CLA concentration in milk and milk products and an organic diet based on fresh or dried forage, that is rich in CLA precursory fatty acids, may improve the yield of fatty acids with beneficial effects on health.