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The aims of this proof of principle study were to compare two different chemometric approaches using a Bayesian method, Partial Least Square (PLS) and PLS-discriminant analysis (DA), for the prediction of the chemical composition and texture properties of the Grana Padano (GP) and Parmigiano Reggiano (PR) PDO cheeses by using NIR and Raman spectra and quantify their ability to distinguish between the two PDO and among their ripening periods. For each dairy chain consortium, 9 cheese samples from 3 dairy industries were collected for a total of 18 cheese samples. Three seasoning times were chosen for each dairy industry: 12, 20, and 36 months for GP and 12, 24, and 36 months for PR. A portable NIR instrument (spectral range: 950–1,650 nm) was used on 3 selected spots on the paste of each cheese sample, for a total of 54 spectra collected. An Alpha300 R confocal Raman microscope was used to collect 10 individual spectra for each cheese sample in each spot for a total of 540 Raman spectra collected. After the detection of eventual outliers, the spectra were also concatenated together (NIR + Raman). All the cheese samples were assessed in terms of chemical composition and texture properties following the official reference methods. A Bayesian approach and PLS-DA were applied to the NIR, Raman, and fused spectra to predict the PDO type and seasoning time. The PLS-DA reached the best performances, with 100% correctly identified PDO type using Raman only. The fusion of the data improved the results in 60% of the cases with the Bayesian and of 40% with the PLS-DA approach. A Bayesian approach and a PLS procedure were applied to the NIR, Raman, and fused spectra to predict the chemical composition of the cheese samples and their texture properties. In this case, the best performance in validation was reached with the Bayesian method on Raman spectra for fat (R2VAL = 0.74). The fusion of the data was not always helpful in improving the prediction accuracy. Given the limitations associated with our sample set, future studies will expand the sample size and incorporate diverse PDO cheeses.

ABSTRACT: Recognized worldwide for its history, flavor, and high nutritional quality, Grana Padano (GP) is one of the most traditional Italian raw-milk, hard-cooked, long-ripened cheese. Throughout GP manufacturing, some well-known and undesired bacterial species, such as clostridia, can proliferate and lead to spoilage defects that mischaracterize the final product; however, little is known about the development of late-blowing defects in hard cheese samples without clostridia. Therefore, in this study we aimed to use metataxonomic analysis to identify bacterial taxa associated with the development of late-blowing defect in GP samples. Furthermore, the presence of several heterofermentative lactobacilli species in defective zones were verified by primer-specific PCR assay. Considering α- and β-diversity analyses, no statistically significant differences were detected between cheese samples with and without blowing defect. Following taxonomic assignment, Lactobacillus and Streptococcus were the dominant genera, whereas clostridia-related taxa were not detected in any of the 20 analyzed samples. Using EdgeR, the genera Propionibacterium and Acinetobacter were found to be prevalently more abundant in samples categorized as having “big regular holes.” In samples with “small regular holes,” multiplex PCR amplification revealed differences in terms of Lactobacillus population composition, mainly obligate homofermentative lactobacilli, between defective and non-defective zones of the same cheese wheel. This study demonstrated that GP samples with blowing defects not caused by clostridial development share similar biodiversity indices with GP collected from control zones, but an imbalance of obligate homofermentative lactobacilli was noticed between samples, which requires further analysis to better comprehend the exact mechanism involved in this process.

Recognized worldwide for its history, flavor, and high nutritional quality, Grana Padano (GP) is one of the most traditional Italian raw-milk, hard-cooked, long-ripened cheese. Throughout GP manufacturing, some well-known and undesired bacterial species, such as clostridia, can proliferate and lead to spoilage defects that mischaracterize the final product; however, little is known about the development of late-blowing defects in hard cheese samples without clostridia. Therefore, in this study we aimed to use metataxonomic analysis to identify bacterial taxa associated with the development of late-blowing defect in GP samples. Furthermore, the presence of several heterofermentative lactobacilli species in defective zones were verified by primer-specific PCR assay. Considering α- and β-diversity analyses, no statistically significant differences were detected between cheese samples with and without blowing defect. Following taxonomic assignment, Lactobacillus and Streptococcus were the dominant genera, whereas clostridia-related taxa were not detected in any of the 20 analyzed samples. Using EdgeR, the genera Propionibacterium and Acinetobacter were found to be prevalently more abundant in samples categorized as having "big regular holes." In samples with "small regular holes," multiplex PCR amplification revealed differences in terms of Lactobacillus population composition, mainly obligate homofermentative lactobacilli, between defective and non-defective zones of the same cheese wheel. This study demonstrated that GP samples with blowing defects not caused by clostridial development share similar biodiversity indices with GP collected from control zones, but an imbalance of obligate homofermentative lactobacilli was noticed between samples, which requires further analysis to better comprehend the exact mechanism involved in this process. [ABSTRACT FROM AUTHOR]

Cheese is a worldwide produced and consumed commodity. There are many varieties of cheese from soft to hard, white to yellow, and fresh to aged after ripening. Especially, each category has its own producing technology. Many countries have labeled their most traditional cheese as Protective Designation of Origin (PDO). Moreover, several studies using advanced technologies, such as proteomics, have been performed to enhance labeling. In this review, broadly diffused and marketed, as well as Mediterranean countries' special interest in Mediterranean diet-related PDO cheeses have been chosen as a reference. The aim of this work was to highlight the use of proteomics methods to examine how cheese proteins and peptides rearrange after ripening and use of starters. Further, we aimed to examine what kind of proteins are produced. Finally, we focused on bioactive molecules in cheeses and distinction of the original product from its counterfeit. [ABSTRACT FROM AUTHOR]

Grana Padano (GP) and Parmigiano Reggiano (PR) are the two most important Italian PDO cheeses. To improve the environmental sustainability of their production, a Life Cycle Assessment (LCA) was completed on 84 dairy farms located in the province of Mantova (Northern Italy). In particular, 33 farms delivered milk for GP production, whereas 51 farms to dairies for PR production. In GP farms, maize silage represented 33.7% of total farmland and alfalfa represented 28.1%. While in PR farms, alfalfa represented 63.6% of total farmland. Fat and Protein Corrected Milk (FPCM) and Dairy Efficiency (DE, calculated as kg of produced FPCM per kg of DM intake) were different in the two production system: FPCM was 30.2 ± 4.32 kg/d in GP farms and 25.0 ± 4.71 kg/d in PR farms; DE was 1.35 ± 0.26 in GP farms, and 1.15 ± 0.22 in PR farms. Mitigation strategies to improve both environmental and economic sustainability were suggested focussing on forage crop production, milk production, herd management and off-farm purchased feed. From the preliminary results, there is evidence that improvements are needed. Climate Change (kg CO2 eq/kg FPCM) and Land Use (kg Carbon deficit/kg FPCM) were similar (1.38 ± 0.33 and 19.3 ± 7.08 for GP system; 1.46 ± 0.37 and 21.8 ± 11.4 for PR system). The most efficient farms in terms of milk production and DE generally showed the best environmental and economic sustainability, while the others show worse outcomes, mainly due to poor DE, livestock-management issues, feed purchase and ration composition.Highlights 84 farms producing milk for Grana Padano and Parmigiano Reggiano cheese were studied in the Province of Mantova. Life Cycle Assessment was used to quantify the environmental impacts of farms and statistical analysis was helpful to identify 6 clusters. Farm, animal and milk efficiencies were poor and mitigation strategies to improve the sustainability of milk production were suggested.

The aims of this proof of principle study were to compare two different chemometric approaches using a Bayesian method, Partial Least Square (PLS) and PLS-discriminant analysis (DA), for the prediction of the chemical composition and texture properties of the Grana Padano (GP) and Parmigiano Reggiano (PR) PDO cheeses by using NIR and Raman spectra and quantify their ability to distinguish between the two PDO and among their ripening periods. For each dairy chain consortium, 9 cheese samples from 3 dairy industries were collected for a total of 18 cheese samples. Three seasoning times were chosen for each dairy industry: 12, 20, and 36 months for GP and 12, 24, and 36 months for PR. A portable NIR instrument (spectral range: 950-1,650 nm) was used on 3 selected spots on the paste of each cheese sample, for a total of 54 spectra collected. An Alpha300 R confocal Raman microscope was used to collect 10 individual spectra for each cheese sample in each spot for a total of 540 Raman spectra collected. After the detection of eventual outliers, the spectra were also concatenated together (NIR + Raman). All the cheese samples were assessed in terms of chemical composition and texture properties following the official reference methods. A Bayesian approach and PLS-DA were applied to the NIR, Raman, and fused spectra to predict the PDO type and seasoning time. The PLS-DA reached the best performances, with 100% correctly identified PDO type using Raman only. The fusion of the data improved the results in 60% of the cases with the Bayesian and of 40% with the PLS-DA approach. A Bayesian approach and a PLS procedure were applied to the NIR, Raman, and fused spectra to predict the chemical composition of the cheese samples and their texture properties. In this case, the best performance in validation was reached with the Bayesian method on Raman spectra for fat (R2VAL = 0.74). The fusion of the data was not always helpful in improving the prediction accuracy. Given the limitations associated with our sample set, future studies will expand the sample size and incorporate diverse PDO cheeses., Competing Interests: PB co-author of this manuscript, is also administrator of GraiNit srl, which provided the portable NIR instrument. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Stocco, Gómez-Mascaraque, Deshwal, Sanchez, Molle, Pizzamiglio, Berzaghi, Gergov and Cipolat-Gotet.)

Milk characteristics in terms of volatile compounds can influence the subsequent product characteristics and can give indications about metabolism. These features can strongly depend on feeding and management. In this perspective, the screening of milk samples intended for Parmigiano-Reggiano and Grana Padano located in Northern Italy was performed, focusing on a panel of volatile molecules. The work was carried out on a total number of 25 bovine milk samples for the production of Parmigiano-Reggiano and Grana Padano. Milk samples were collected from May to September and analyzed for volatile molecules using headspace gas chromatography mass spectrometry. A range of several volatile molecule classes was considered (aldehydes, ketones, alcohols, carboxylic acids, esters, aromatic hydrocarbons, solforates). Results showed a significant influence of the month and destination of milk due to the time period and subsequent use in cheesemaking (Parmigiano-Reggiano and Grana Padano). Significant differences between months were observed for all volatiles. These preliminary results indicate differences between the two types of milk due to the period and destination. The study of volatile molecules in milk will give important information about the physiology of milk and the evolution of dairy products. These features must be extended and confirmed by the sensory analysis of milk and derived products, leading to a more complete characterization of milk biology and derived products. [ABSTRACT FROM AUTHOR]

Grana Padano (GP) and Parmigiano Reggiano (PR) are the two most important Italian PDO cheeses. To improve the environmental sustainability of their production, a Life Cycle Assessment (LCA) was completed on 84 dairy farms located in the province of Mantova (Northern Italy). In particular, 33 farms delivered milk for GP production, whereas 51 farms to dairies for PR production. In GP farms, maize silage represented 33.7% of total farmland and alfalfa represented 28.1%. While in PR farms, alfalfa represented 63.6% of total farmland. Fat and Protein Corrected Milk (FPCM) and Dairy Efficiency (DE, calculated as kg of produced FPCM per kg of DM intake) were different in the two production system: FPCM was 30.2 ± 4.32 kg/d in GP farms and 25.0 ± 4.71 kg/d in PR farms; DE was 1.35 ± 0.26 in GP farms, and 1.15 ± 0.22 in PR farms. Mitigation strategies to improve both environmental and economic sustainability were suggested focussing on forage crop production, milk production, herd management and off-farm purchased feed. From the preliminary results, there is evidence that improvements are needed. Climate Change (kg CO2 eq/kg FPCM) and Land Use (kg Carbon deficit/kg FPCM) were similar (1.38 ± 0.33 and 19.3 ± 7.08 for GP system; 1.46 ± 0.37 and 21.8 ± 11.4 for PR system). The most efficient farms in terms of milk production and DE generally showed the best environmental and economic sustainability, while the others show worse outcomes, mainly due to poor DE, livestock-management issues, feed purchase and ration composition. 84 farms producing milk for Grana Padano and Parmigiano Reggiano cheese were studied in the Province of Mantova. Life Cycle Assessment was used to quantify the environmental impacts of farms and statistical analysis was helpful to identify 6 clusters. Farm, animal and milk efficiencies were poor and mitigation strategies to improve the sustainability of milk production were suggested. [ABSTRACT FROM AUTHOR]

The dairy sector is recognised as one of the most impacting agricultural activities. In Italy approximately 24% of cow's milk is destined to Grana Padano, a Protected Designation of Origin long ripening cheese. The Grana Padano production has increased by 10% in the last decade and approximately reached 183,000 t in 2015. Around 38% of this production is exported to Germany, US, France and to the rest of the world. This study evaluated the environmental impact of production of Grana Padano, through a “cradle to cheese factory gate” Life Cycle Assessment. The study involved an Italian cheese factory that produces about 3.6% of the total production of Grana Padano cheese and a group of 5 dairy farms, chosen among the farms that sold all milk produced to the cheese factory. The functional unit was 1 kg of Grana Padano cheese 12-month ripened. Environmental impacts of co-products: whey, cream, butter and buttermilk were also evaluated. Two sensitivity analyses were conducted: the first one had the aim to explore the effect of different allocation methods based on dry matter content, economic or nutritive value of cheese, respectively; the second one considered the variation of the impacts of milk production and its effect on cheese environmental impact. Milk production phase gave the most important contribution to the environmental impact of cheese, with a percentage of 93.5–99.6% depending on the impact category. Excluding milk production from the system boundary, milk transport and use of electricity were the main responsible of the environmental impact of cheese-making process. The climate change impact for the production of 1 kg Grana Padano was 10.3 kg of CO 2 eq, using a dry matter allocation method, while 16.9 and 15.2 kg of CO 2 eq adopting economic and nutritive value allocation methods, respectively. [ABSTRACT FROM AUTHOR]

Milk characteristics in terms of volatile compounds can influence the subsequent product characteristics and can give indications about metabolism. These features can strongly depend on feeding and management. In this perspective, the screening of milk samples intended for Parmigiano-Reggiano and Grana Padano located in Northern Italy was performed, focusing on a panel of volatile molecules. The work was carried out on a total number of 25 bovine milk samples for the production of Parmigiano-Reggiano and Grana Padano. Milk samples were collected from May to September and analyzed for volatile molecules using headspace gas chromatography mass spectrometry. A range of several volatile molecule classes was considered (aldehydes, ketones, alcohols, carboxylic acids, esters, aromatic hydrocarbons, solforates). Results showed a significant influence of the month and destination of milk due to the time period and subsequent use in cheesemaking (Parmigiano-Reggiano and Grana Padano). Significant differences between months were observed for all volatiles. These preliminary results indicate differences between the two types of milk due to the period and destination. The study of volatile molecules in milk will give important information about the physiology of milk and the evolution of dairy products. These features must be extended and confirmed by the sensory analysis of milk and derived products, leading to a more complete characterization of milk biology and derived products.

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. © 2016 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Os queijos de denominação geral de Grana (queijos duros), na Itália, apresentam renome mundial: o Grana Padano e o Parmigiano Reggiano. Ambos são elaborados com leite de vaca e possuem grande semelhança ente si, mas não se trata do mesmo queijo. O objetivo desse trabalho é apresentar uma revisão sobre os queijos Grana Italianos.

In this study, the relationship between the dynamics of the growth and lysis of lactic acid bacteria in Grana Padano cheese and the formation of the volatile flavor compounds during cheese ripening was investigated. The microbial dynamics of Grana Padano cheeses that were produced in two different dairies were followed during ripening. The total and cultivable lactic microflora, community composition as determined by length heterogeneity-PCR (LH-PCR), and extent of bacterial lysis using an intracellular enzymatic activity assay were compared among cheeses after 2, 6 and 13 months of ripening in two dairies. The evolution of whole and lysed microbiota was different between the two dairies. In dairy 2, the number of total cells was higher than that in dairy 1 in all samples, and the number of cells that lysed during ripening was lower. In addition, at the beginning of ripening (2 months), the community structure of the cheese from dairy 2 was more complex and was composed of starter lactic acid bacteria ( Lactobacillus helveticus and Lactobacillus delbrueckii ) and NSLAB, possibly arising from raw milk, including Lactobacillus rhamnosus / Lactobacillus casei and Pediococcus acidilactici . On the other hand, the cheese from dairy 1 that ripened for 2 months was mainly composed of the SLAB L. helveticus and L. delbrueckii. An evaluation of the free-DNA fraction through LH-PCR identified those species that had a high degree of lysis. Data on the dynamics of bacterial growth and lysis were evaluated with respect to the volatile profile and the organic acid content of the two cheeses after 13 months of ripening, producing very different results. Cheese from dairy 1 showed a higher content of free fatty acids, particularly those deriving from milk fat lipolysis, benzaldehyde and organic acids, such as pGlu and citric. In contrast, cheese from dairy 2 had a greater amount of ketones, alcohols, hydrocarbons, acetic acid and propionic acid. Based on these results, we can conclude that in the first cheese, the intracellular enzymes that were released from lysis were mainly involved in aroma formation, whereas in the second cheese, the greater complexity of volatile compounds may be associated with its more complex microbial composition caused from SLAB lysis and NSLAB (mainly L. rhamnosus / L. casei ) growth during ripening. [ABSTRACT FROM AUTHOR]

This study investigated the stress factors that affect the content and the spatial distribution of Clostridium spores in Grana Padano (GP) wheels and in GP samples purchased from the market. The cheeses analyzed were produced adding lysozyme to prevent late blowing defects (LBD). The highest NaCl amount was detected in the external part (5.2 ± 0.6%) while a lower level was observed in the core (2.8 ± 0.3%). The clostridial community differed in cheeses with different ripening times along with pH and salt changes that occur slowly over time. The spore level in the core (0.24 ± 0.19 and 0.16 ± 0.14 MPN/g after 11 and 20 months of ripening) was significantly lower than in the peripheral zones (0.48 ± 0.26 and 0.45 ± 0.31 MPN/g). Moreover, in the wheels aged 11 months, the presence of C. tyrobutyricum was higher in the areas with the lowest salt content, while after 20 months of ripening when a homogeneous concentration of salt and pH within the wheel occurred, C. sporogenes was the prevalent species. Our results showed that in the GP wheels changes in the presence of clostridia responsible for LBD still occur until the salt content in the center of cheeses is higher than threshold NaCl needed to inhibit spore germination. • Spore level in the core portion of the cheese was significantly lower. • Salt gradient within the cheese matrix affects the spatial distribution of Clostridum species. • C. tyrobutyricum and C. sporogenes are the most able to withstand adverse conditions. • C. tyrobutyricum content increases with the decrease of the NaCl concentration. • C. sporogenes was the prevalent species in internal and external areas. [ABSTRACT FROM AUTHOR]

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 addition affected none. Combination of all modifications tended to compensate for each of their effects, resulting in similar average patterns between GP and SP. Modifications to repeatability were found for all traits with the exception of 2. The ability of the SP to predict GP, tested through correlations between procedures, was not very high. Whereas SP is used for both research and in the dairy industry, better results for Grana Padano cheesemaking can only be achieved by adopting specific, more complex, and labor-intensive procedures at the research level or, possibly, by specific calibrations through Fourier-transform infrared spectroscopy at the industry level. [ABSTRACT FROM AUTHOR]

Abstract: Grana Padano (GP) is a Protected Designation of Origin cheese made with raw milk and natural whey culture (NWC) that is characterised by a long ripening period. In this study, six GP productions were considered in order to evaluate the trend of microbial dynamics and compare lactic acid bacteria (LAB) population levels in cheeses during the entire cheese-making process. To reach this goal, for each GP production, samples of vat raw milk, NWC and cheeses at 48h, 2, 6, 9 and 13 months were subjected to plate counts and direct counts by fluorescence microscopy, as well as amplicon length heterogeneity-PCR (LH-PCR). Statistical analysis was applied to the results and ecological indices were estimated. It was demonstrated that the LAB able to grow in the cheese-environment conditions could arise from both raw milk and NWC. Starter lactobacilli (SLAB) from NWC were the main species present during acidification, and non-starter LAB (NSLAB), mainly from milk but also from NWC, were able to grow after brining and they dominated during ripening. The peak areas of LH-PCR profiles were used to determine ecological indices during manufacture and ripening. Among cheese ecosystems with different ageing times, diversity, Evenness and Richness were different, with highest bacterial growth and diversity occurring in cheese ripening at 2 months. At this time point, which seemed to be a crucial moment for GP microbial evolution, cell lysis of both SLAB and NSLAB was also observed. Sampling modality and statistical analysis gave greater significance to the results used to describe the microbiological characteristics of a cheese recognised worldwide. [Copyright &y& Elsevier]

The aim of this study was to assess the effect of chemical composition, coagulation properties, pH, and titratable acidity (TA, SH°/50 ml) of vat milk on Grana Padano cheese yield (CY) under field conditions. Twelve cheese-making sessions were carried out from February to December 2009 in a dairy cooperative of Grana Padano Consortium (Italy), for a total of 96 vats of milk processed. For each vat, samples of raw milk were collected and analysed for quality traits (fat, protein, and casein contents), pH, TA, and milk coagulation properties (MCP), measured as rennet coagulation time (RCT, min), curd-firming time (k20, min), and curd firmness (a30, mm). Cheese yield was expressed as kilograms of cheese per 100 kg milk transformed, and was measured after 2 d of drainage. Fat, protein, and casein contents were positively and strongly correlated with CY (coefficients of correlation, r = 0·72, 0·88, and 0·84, respectively; P < 0·001). Coagulation properties were moderately and significantly (P < 0·001) related to CY: milk that coagulated earlier and had stronger a30 was associated to greater CY. Cheese yield was analysed with a model that accounted for fixed effects of cheese-making day, fat and protein content, TA, and a30. Significance was found for all the effects (P < 0·05). Milk characterised by high values of a30 resulted in higher CY than milk with low values of a30, indicating that MCP could be used as indicators of cheese-making efficiency. Future research should investigate the relationships between MCP and quality of cheese, and explore the feasibility of including MCP in multiple component milk pricing system for Grana Padano cheese production. [ABSTRACT FROM PUBLISHER]

Twenty-one natural whey starters, collected from dairy factories located in six provinces of the Grana Padano production area, were characterized. Basic techniques, such as acidity evaluation and microbial plate count, together with more complex methods such as the Live/Dead BacLight™ bacterial viability kit, have been used. Seven parameters, including pH, Soxhlet Henkel degrees, microbial plate count in Man Rogosa Sharpe medium and Whey Agar medium, together with count of total, viable and non-viable cells, have been adopted to produce sunray plots. One plot for each natural whey starter sample was obtained by characterizing the status of the microbial culture and compared with three natural whey starters prepared in the laboratory. In this way, a sunray trace is suggested to define the traits of a good natural whey starter. Another multivariate technique, principal component analysis, was applied, and it should be possible to conclude that, for this particular dataset composed of 24 objects and 7 variables, PCA allowed the highlighting of the good and bad samples, while sunray plots, even if remaining only a descriptive and explorative analysis, allowed the better visualizing of the differences among all the samples. [ABSTRACT FROM AUTHOR]

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. The curds and Grana Padano cheeses were also analysed to evaluate the effects of the production technology on the CLA content. 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<0.05). 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. [ABSTRACT FROM AUTHOR]

Aims: The aim of this work was to study the viability and cultivability of microbial populations of different natural whey starters and to evaluate their resistance to thermal treatments (such as exposure to high or low temperatures). Methods and Results: Twenty-three natural whey starters for Grana Padano cheese were investigated and subsequently pH measurement, plate count agar using Man-Rogasa-Sharpe (MRS) pH 5·4 agar and whey agar medium (WAM) were performed using these samples. LIVE/DEAD® BacLightTM bacterial viability kit was used. Total count and viability of all the 23 samples were high and similar to each other (CV 20%). However, the cultivable population was lower in terms of cfu ml−1 and number of cells per millilitre than the viable fraction and highly variable, although its count value was higher in WAM than in MRS pH 5·4. The heating (60°C for 5 min and 54°C for 1 h) and freezing (−20 and −80°C) treatments affected the cultivability and viability of the microbial population. Conclusions: This study demonstrated the effectiveness of LIVE/DEAD® BacLightTM bacterial viability kit, which has already been used to evaluate bacterial populations, in investigating microbial viability in a complex ecosystem such as a natural whey starter. Significance and Impact of the Study: The aim of this study was to quantify the presence of damaged nonviable bacterial cells in natural whey starters. The Thoma Glass is a useful method to obtain fluorescence microscopy counts to evaluate the technological performance of natural whey starters. [ABSTRACT FROM AUTHOR]

c. andrighetto, g. marcazzan and a. lombardi. 2004. This work was carried out in order to evaluate the microbial diversity of whey cultures collected from different Grana Padano cheese plants in Veneto region (north-east Italy) by means of RAPD-PCR and Temporal Temperature Gradient Gel Electrophoresis (TTGE) analysis. Lactobacillus helveticus was the dominant species among isolated thermophilic lactobacilli. RAPD-PCR with primers M13 and D8635 resulted a suitable method for typing Lact. helveticus at strain level. Thirteen different Lact. helveticus biotypes were detected in the seven whey cultures studied with one biotype present in all the whey cultures. Besides Lact. helveticus, Lact. delbrueckii subsp. lactis was the main microbial species detected by TTGE. RAPD-PCR resulted very useful in studying Lact. helveticus biodiversity; furthermore, TTGE analysis allowed to detect the dominant thermophilic microflora characteristic of Grana Padano cheese whey cultures. By the combined used of RAPD-PCR and TTGE it could be possible to follow the behaviour in strain or species composition of whey cultures during time. [ABSTRACT FROM AUTHOR]

A processed cheese using Grana Padano and Mozzarella cheese shavings with the addition of microencapsulated chia oil and inulin was studied. After the study of microencapsulation of chia oil, 4 processed cheeses were formulated and chemically, microbiologically and sensorially analyzed. The efficiency of microencapsulation of chia oil using ionic gelation was 94.4% with the 3:1 oil:alginate ratio, with a low solubility in water (0.04%) and a particle size of ~195 μm. The formulation with inulin had a 36% fat reduction, with no sensorial differences compared to the standard formulation. Microencapsulation was able to mask the oil taste when compared to the formulation of inulin and microcapsules of chia oil and the formulation of inulin and free-chia oil. The use of Grana Padano, inulin and encapsulated chia oil gave a product with reduced fat content and high acceptability. • An alternative process for obtaining processed cheese was developed. • Processed cheese with inulin had up to 36% less fat. • Chia oil showed thermal stability when microencapsulated. • Addition of chia oil allowed the replacement of saturated by polyunsaturated fat. [ABSTRACT FROM AUTHOR]

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. • Monitoring L. helveticus strain dynamics in natural starters is of interest because it has a key role in cheese production. • Compared to culture-dependent methods, PCR-DGGE method enabled easier evaluation of whey starters in terms of biodiversity. • The region of the slpH locus selected for PCR-DGGE analysis was heterogeneous enough to discriminate L. helveticus strains. • The PCR-DGGE assay is rapid, robust and could be a valid method for monitoring shifts in strain composition. [ABSTRACT FROM AUTHOR]