Recensione

Bibliografia__________________________________________________________________________

Crippa G, Zabzuni D, Bravi E, Piva G, De Noni I, Bighi E, Rossi F. Randomized, double blind placebo-controlled pilot study of the antihypertensive effects of Grana Padano D.O.P. cheese consumption in mild - moderate hypertensive subjects. Eur Rev Med Pharmacol Sci. 2018 Nov;22(21):7573-7581. doi: 10.26355/eurrev_201811_16299. 

Abstract. Objective: Grana Padano, an Italian protected designation of origin (PDO) semi-fat cheese, undergoes a long ripening period during which the proteolysis carried out by natural starter lactic acid bacteria releases peptides having sustained angiotensin-converting enzyme (ACE)-inhibitory activity. The length (generally 3-8 amino acid residues) and the sequence of these peptides are responsible for their ability to elicit ACE-inhibitory activity. The aim of this study has been the evaluation of the effect of a daily dietary supplement consisting in a small amount (30 g/day) of Grana Padano cheese, in terms of the lowering of the blood pressure (BP) of mild-moderate hypertensive subjects. Patients and methods: Thirty mild-moderate hypertensive patients, with BP values not on target (> 140 and/or > 90 mmHg) after at least 3 months of stable treatment were considered in this randomized, double-blind placebo-controlled cross-over study. All patients randomly received a dietary integration (30 g/day) of Grana Padano cheese or a placebo (made from flavored grated bread mixed with fats and salts in concentrations equal to those of the cheese). BP was evaluated at baseline and at the end of the active and placebo treatments (2 months each) by: - Office BP (OBP); - Automated Office BP (AOBP) using the BpTRU®, an automated oscillometric device that provides the average of multiple (n=6) blood pressure measurements; - Ambulatory Blood Pressure (ABP) 24 hour monitoring. Results: Dietary integration with Grana Padano cheese resulted in a significant decrease in Office, Automated Office and Ambulatory BP. The mean decrease (vs. placebo) for 24-hour ABP was -3.5 mmHg for systolic and -2.4 mmHg for diastolic BP (p = 0.0063 and p = 0.0065, respectively). Conclusions: Daily dietary integration with 30 g of Grana Padano DOP cheese effectively reduces BP and may help mild-to-moderate hypertensive patients to reach a target BP.

Neviani E. The Natural Whey Starter Used in the Production of Grana Padano and Parmigiano Reggiano PDO Cheeses: A Complex Microbial Community. Microorganisms. 2024 Nov 27;12(12):2443. doi: 10.3390/microorganisms12122443. 

Abstract. Natural whey starter (NWS) is an undefined complex culture used in the production of Grana Padano and Parmigiano Reggiano PDO cheeses. The aim of this review is to discuss, in light of the latest research results, the role of NWS as a primary player in the cheese-making process, considering the microbial community scenario. NWS is traditionally produced by fermenting part of the whey collected at the end of a previous cheese-making process. The method used to produce NWS, based on the back-slopping principle, favors the selection of a microbiota composed mainly of thermophilic lactic acid bacteria. This method of preparation induces the survival of several different species and biotypes. The presence of such a mixture of strains facilitates the development of a natural starter characterized by a remarkable ability to adapt to non-standardized cheese-making parameters. NWS is a microbial community whose activity is not simply the result of the sum of the activities of individual microorganisms, but rather the activity of the community as a whole, in which each individual bacterial cell responds to the presence of the others. According to this traditional protocol, the NWS becomes the 'microbiological bond' between cheeses over time.

Summer A, Formaggioni P, Franceschi P, Di Frangia F, Righi F, Malacarne M. Cheese as Functional Food: The Example of Parmigiano Reggiano and Grana Padano. Food Technol Biotechnol. 2017 Sep;55(3):277-289. doi: 10.17113/ftb.55.03.17.5233. 

Abstract. Italian hard cooked types of cheese, like Parmigiano Reggiano and Grana Padano, are characterised by positive nutritional qualities. In fact, they contain substances that have particular biological activities, and therefore they can be fully considered, according to the definition given by the European Unit, as 'functional' foods. This short review concisely describes these components and the beneficial effects related to their activities. The description of the biologically active components has been organised in the following paragraphs: protein and peptides, fat and lipids, carbohydrates and prebiotics, probiotic bacteria, vitamins, mineral salts, and components of dairy products active in disease prevention. In particular, several known bioactive peptides were found in Parmigiano Reggiano cheese samples: for example, phosphopeptides, which are known for their mineral-binding capacity and vehiculation activity, peptides with immunomodulatory activity, and angiotensin-converting enzyme-inhibitory peptides with anti-hypertensive effects. Among lipids, the role of conjugated linoleic acid and other fatty acids present in these cheese types was taken into consideration. The presence of oligosaccharides with prebiotic properties and probiotic bacteria was also described. Finally, particular emphasis was given to highly available calcium and its impact on bone health.

Giraffa G. The Microbiota of Grana Padano Cheese. A Review. Foods. 2021 Oct 29;10(11):2632. doi: 10.3390/foods10112632. 

Abstract. Grana Padano (GP) is the most appreciated and marketed cheese with Protected Designation of Origin in the world. The use of raw milk, the addition of undefined cultures (defined as 'sieroinnesto naturale'), the peculiar manufacturing proces, and the long ripening make the cheese microbiota play a decisive role in defining the quality and the organoleptic properties of the product. The knowledge on the microbial diversity associated with GP has been the subject, in recent years, of several studies aimed at understanding its composition and characteristics in order, on the one hand, to improve its technological performances and, on the other hand, to indirectly enhance the nutritional quality of the product. This review aims to briefly illustrate the main available knowledge on the composition and properties of the GP microbiota, inferred from dozens of studies carried out by both classical microbiology techniques and metagenomic analysis. The paper will essentially, but not exclusively, be focused on the lactic acid bacteria (LAB) derived from starter (SLAB) and the non-starter bacteria, both lactic (NSLAB) and non-lactic, of milk origin.

Zago M, Rossetti L, Bardelli T, Carminati D, Nazzicari N, Giraffa G. Bacterial Community of Grana Padano PDO Cheese and Generical Hard Cheeses: DNA Metabarcoding and DNA Metafingerprinting Analysis to Assess Similarities and Differences. Foods. 2021 Aug 7;10(8):1826. doi: 10.3390/foods10081826. 

Abstract. 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 Lacticaseibacillus rhamnosus, Lactobacillus helveticus, Streptococcus thermophilus, Limosilactobacillus fermentum, Lactobacillus delbrueckii, Lactobacillus spp., and Lactococcus 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.

Rossetti L, Fornasari ME, Gatti M, Lazzi C, Neviani E, Giraffa G. Grana Padano cheese whey starters: microbial composition and strain distribution. Int J Food Microbiol. 2008 Sep 30;127(1-2):168-71. doi: 10.1016/j.ijfoodmicro.2008.06.005. 

Abstract. The aim of this work was to evaluate the species composition and the genotypic strain heterogeneity of dominant lactic acid bacteria (LAB) isolated from whey starter cultures used to manufacture Grana Padano cheese. Twenty-four Grana Padano cheese whey starters collected from dairies located over a wide geographic production area in the north of Italy were analyzed. Total thermophilic LAB streptococci and lactobacilli were quantified by agar plate counting. Population structure of the dominant and metabolically active LAB species present in the starters was profiled by reverse transcriptase, length heterogeneity-PCR (RT-LH-PCR), a culture-independent technique successfully applied to study whey starter ecosystems. The dominant bacterial species were Lactobacillus helveticus, Lactobacillus delbrueckii subsp. lactis, Streptococcus thermophilus, and Lactobacillus fermentum. Diversity in the species composition allowed the whey cultures to be grouped into four main typologies, the one containing L. helveticus, L. delbrueckii subsp. lactis, and S. thermophilus being the most frequent one (45% of the cultures analyzed), followed by that containing only the two lactobacilli (40%). Only a minor fraction of the cultures contained L. helveticus alone (4%) or all the four LAB species (11%). Five hundred and twelve strains were isolated from the 24 cultures and identified by M13-PCR fingerprinting coupled with 16S rRNA gene sequencing. Most of the strains were L. helveticus (190 strains; 37% of the total), L delbrueckii subsp. lactis (90 strains; 18%) and S. thermophilus (215 strains; 42%). This result was in good agreement with the qualitative whey starter composition observed by RT-LH-PCR. M13-PCR fingerprinting indicated a markedly low infra-species diversity, i.e. the same biotypes were often found in more than one culture. The distribution of the biotypes into the different cultures was mainly dairy plant-specific rather than correlated with the different production areas.

Ferranti P, Barone F, Chianese L, Addeo F, Scaloni A, Pellegrino L, Resmini P. Phosphopeptides from Grana Padano cheese: nature, origin and changes during ripening. J Dairy Res. 1997 Nov;64(4):601-15. doi: 10.1017/s0022029997002392. 

Abstract. Casein phosphopeptides (CPP) which develop in Grana Padano cheese at different ages were isolated by precipitation with Ba2+ and analysed by HPLC. Profiles were complex throughout the period between 4 and 38 months. CPP in a cheese sample 14 months old were identified by a combination of fast atom bombardment-mass spectrometry and Edman degradation. They were found to consist of a mixture of components derived from three parent peptides, beta-CNf(7-28)4P, alpha s1-CNf(61-79)4P and alpha s2-CNf(7-21)4P. In total, 45 phosphopeptides were identified: 24 from beta-CN, 16 from alpha s1-CN and 5 from alpha s2-CN. The presence of aminopeptidase activity during cheese ripening was deduced from the presence of a number of CPP of different lengths with the loss of one or more residues from the N-terminus. The longest had C-terminal lysine and seemed to be progressively hydrolysed by carboxypeptidases A and B to shorter peptides. CPP in cheese appeared to be shortened plasmin-mediated products. Moreover, those most resistant to further hydrolysis contained at least three closely located phosphoserine residues. The anticariogenic activity of CPP is also discussed.