Montasio Cheese Research Articles

Lacticaseibacillus casei as Anti-blowing Agents: Impact on the Evolution of Ripening and Sensory Profile of Montasio Cheese

AbstractRecently, the Lacticaseibacillus casei group strains have been gaining growing interest due to their potential to be used as secondary adjunct cultures in cheese. This work aimed to test autochthonous Lb. casei strains as anti-blowing agents and to evaluate their impact on the evolution of the ripening and the sensory profile of Montasio cheese. The cheesemaking trial included a control production without lysozyme (C1), a control with lysozyme (C2), and four experimental productions, each containing a different pool of autochthonous Lb. casei strains (EX1-4). Samples were taken during ripening, and physicochemical, microbiological, and sensory analyses were carried out. Lb. casei counts indicate that the selected strains survived the cheesemaking and maintained their viability of about 9 log cfu g−1 at the end of the ripening. Only EX3 showed a significant slowdown of the proteolytic index compared to controls over time. Furthermore, from the principal component analysis, it emerged that at the end of the 120-day-long ripening, C2 and the experimental samples were characterized by similar profiles of volatile compounds. The late-blowing defect (LBD) was observed exclusively in C1, whereas it was not detected in the control sample with lysozyme or in any experimental samples. These findings not only confirmed the efficacy of lysozyme in preventing LBD but also supported the effectiveness of the selected Lb. casei strains as anti-blowing agents with the ability to contribute to the final volatile profile without compromising the typicality of the product.

An integrated approach to explore the microbial biodiversity of natural milk cultures for cheesemaking

The use of natural milk culture (NMC) represents a key factor in PDO Montasio cheeses, contributing to its distinctive sensory profile. The complex microbial ecosystem of NMCs is the result of heat treatment and incubation conditions, which can vary considerably among different production plants. In this study, the microbiota of NMCs collected from 10 PDO Montasio cheese dairies was investigated employing colony counts and metagenomic analysis. Furthermore, residual sugars, organic acids, and volatile profiles were quantitatively investigated. Results showed that Streptococcus thermophilus was the dominant species in all NMCs, and a subdominant population made of other streptococci and L. salivarius was also present. The incubation temperature appeared to be the main driver of biodiversity in NMCs. Metagenomics allowed us to evidence the presence of minor species involving safety (e.g., Staph. aureus) as well as possible functional aspects (Next Generation Probiotics). Statistical analysis based on residual sugars, organic acids, and volatiles' content allowed to correlate the presence of specific microbial groups with metabolites of great technological and sensory relevance, which can contribute to giving value to the artisanal production procedures of NMCs and clarify their role in the creation of the characteristics of PDO Montasio cheese.

Effects of grazing cow diet on volatile compounds as well as physicochemical and sensory characteristics of 12-month-ripened Montasio cheese

The aim of this study was to evaluate the effects of pasture type and cow feeding supplementation level on a 12-mo-ripened Montasio protected designation of origin (PDO) cheese, which is one of the most important PDO cheeses produced in northeast Italy. Cheeses were characterized for volatile compounds, color, mechanical variables, and sensory descriptors. Pasture type significantly affected most of the instrumental variables considered and, as a consequence, sensory properties were affected as well. Cheeses from the pasture characterized by a nutrient-rich vegetation type were higher in protein and lower in fat content. Furthermore, such cheeses, evaluated by a sensory panel, were more intense in color with a more pungent and less cow-like odor, in agreement with what found through instrumental analyses. Supplementation level resulted in less pronounced effects, limited to volatile compounds and texture properties, which were not detected by sensory analysis. The characterization of the 12-mo ripened Montasio cheese reported here is an important step for the valorization of this PDO product.

Montasio cheese liking as affected by information about cows breed and rearing system.

23±2·2 points on Labelled Affective Magnitude scale, P>0·05), it was possible to identifying consumers' clusters with differential liking for the two types of Montasio PDO, that were characterised by different physico-chemical properties. Consumers express a high EL for ISMC (38±2·6 points) and even more for ALP-ISMC (61±2·5 points). The AL of ISMC (35±2·1 points) was similar and statistically not different from the EL (complete assimilation of information about breed). For ALP-ISMC the assimilation was complete for consumers (29%) who have expressed a positive PL for it, at least twice as much than ISMC. For the rest of consumers, both information and intrinsic properties play a significant role in the AL of the pasture-derived cheese.

Volatile compounds and sensory properties of Montasio cheese made from the milk of Simmental cows grazing on alpine pastures

The aim of this study was to analyze the volatile compounds, physicochemical characteristics, and sensory properties of Montasio, a semicooked pressed cheese, produced from the milk of the dual-purpose Italian Simmental cows grazing on alpine pastures. A total of 72 cows grazing on 2 pastures, which differed in botanical composition (nutrient-rich pasture vs. nutrient-poor pasture), received 2 different levels of supplementation (3.0 vs 1.5kg/head per day). The experimental cheeses were produced from whole, raw milk and ripened for 60 d. Sixty-one volatile compounds, including alcohols (11), aldehydes (6), ketones (10), lactones (2), esters (6), hydrocarbons (3), carboxylic acids (6), phenolic compounds (4), monoterpenes (7), sesquiterpenes (1), sulfur compounds (4), and amines (1), were detected. The main families in terms of relative weight appeared to be carboxylic acids, esters, and alcohols. A panel of trained assessors described the experimental cheeses as having an intense color; small and evenly distributed eyes; an intense odor and flavor of milk-sour, milk, and cow; and a tender and creamy texture. The pasture type affected the volatile fraction, particularly ketones, phenolic compounds, and terpenes, which are overall higher in nutrient-poor pastures. A slight effect on the sensory analyses, in particular the effect of the cow attribute on odor and flavor, was perceived by the panelists. The cheeses produced on nutrient-rich pasture had higher b* (yellowness) index. These results were consistent with the color evaluation of the sensory panel. In addition, the pasture affected some textural attributes (adhesivity, creaminess, and granules) as perceived by the panelists. Concentrate supplementation, which is required to meet the feeding requirements of grazing cows, had no clear effect on either the volatile compounds or the sensory properties of the cheeses. Thus, at least within levels of integration adopted, it is expected not to alter the organoleptic characteristics of this product.

Effect of rearing system (mountain pasture vs. indoor) of Simmental cows on milk composition and Montasio cheese characteristics

Dairy cattle in the Alps are traditionally maintained on high altitude pastures during summer. In recent decades, however, many farmers prefer to maintain the cows always indoor with a hay-based diet. Many authors have shown that the forage type is able to modify the characteristics of milk and cheese. Recently the product specification of PDO Montasio allowed differentiation between mountain cheeses and other products. Aim of this trial is to study the effect of rearing system on the characteristics of milk and cheese produced in this context. One hundred and twenty Simmental dairy cows were considered, 60 grazed on high altitude pasture, and 60 kept indoor and fed a hay-based diet. Cheese production was repeated in two periods (early July and late August) and ripened two and six months. Pasture-derived milk and cheese presented higher fat and lower protein content than hay-derived ones. Rearing systems also affected cheese colour. Textural parameters, hardness, gumminess and chewiness were found to be higher in pasture-derived cheese. In addition, it showed lower level of total saturated fatty acids, and higher level of mono and polyunsaturated fatty acids than hay-derived cheeses. Consumers perceived the difference of cheeses in terms of colour and holes, but they express a similar overall liking. More limited effects of period and ripening time were observed.

Identification of the Enterobacteriaceae in Montasio cheese and assessment of their amino acid decarboxylase activity

The aim of the study was to identify the species of Enterobacteriaceae present in Montasio cheese and to assess their potential to produce biogenic amines. Plate count methods and an Enterobacterial Repetitive Intergenic Consensus Polymerase Chain Reaction (ERIC-PCR) approach, combined with 16S rDNA sequencing, were used to investigate the Enterobacteriaceae community present during the cheesemaking and ripening of 6 batches of Montasio cheese. Additionally, the potential decarboxylation abilities of selected bacterial isolates were qualitatively and quantitatively assessed against tyrosine, histidine, ornithine and lysine. The most predominant species detected during cheese manufacturing and ripening were Enterobacter cloacae, Escherichia coli and Hafnia alvei. The non-limiting physico-chemical conditions (pH, NaCl% and a(w)) during ripening were probably the cause of the presence of detectable levels of Enterobacteriaceae up to 120 d of ripening. The HPLC test showed that cadaverine and putrescine were the amines produced in higher amounts by almost all isolates, indicating that the presence of these amines in cheese can be linked to the presence of high counts of Enterobacteriaceae. 44 isolates produced low amounts of histamine (<300 ppm), and four isolates produced more than 1000 ppm of this amine. Only 9 isolates, belonging to the species Citrobacter freundii, Esch. coli and Raoultella ornithinolytica, appeared to produce tyramine. These data provided new information regarding the decarboxylase activity of some Enterobacteriaceae species, including Pantoea agglomerans, Esch. fergusonii and R. ornithinolytica.

Automatic milking systems in the Protected Designation of Origin Montasio cheese production chain: Effects on milk and cheese quality

Montasio cheese is a typical Italian semi-hard, semi-cooked cheese produced in northeastern Italy from unpasteurized (raw or thermised) cow milk. The Protected Designation of Origin label regulations for Montasio cheese require that local milk be used from twice-daily milking. The number of farms milking with automatic milking systems (AMS) has increased rapidly in the last few years in the Montasio production area. The objective of this study was to evaluate the effects of a variation in milking frequency, associated with the adoption of an automatic milking system, on milk quality and on the specific characteristics of Montasio cheese. Fourteen farms were chosen, all located in the Montasio production area, with an average herd size of 60 (Simmental, Holstein-Friesian, and Brown Swiss breeds). In 7 experimental farms, the cows were milked 3 times per day with an AMS, whereas in the other 7 control farms, cows were milked twice daily in conventional milking parlors (CMP). The study showed that the main components, the hygienic quality, and the cheese-making features of milk were not affected by the milking system adopted. In fact, the control and experimental milks did not reveal a statistically significant difference in fat, protein, and lactose contents; in the casein index; or in the HPLC profiles of casein and whey protein fractions. Milk from farms that used an AMS always showed somatic cell counts and total bacterial counts below the legal limits imposed by European Union regulations for raw milk. Finally, bulk milk clotting characteristics (clotting time, curd firmness, and time to curd firmness of 20mm) did not differ between milk from AMS and milk from CMP. Montasio cheese was made from milk collected from the 2 groups of farms milking either with AMS or with CMP. Three different cheese-making trials were performed during the year at different times. As expected, considering the results of the milk analysis, the moisture, fat, and protein contents of the experimental and control cheeses were comparable. The milking system was not seen to significantly affect the biochemical processes associated with ripening. In fact, all cheeses showed a normal proteolysis trend and a characteristic volatile compound profile during aging. Therefore, the milking system does not appear to modify the distinctive characteristics of this cheese that remain dependent on the area and methodology of production.

Characterization by solid-phase microextraction-gas chromatography of the volatile profile of protected designation of origin Montasio cheese during ripening

Montasio is a typical protected designation of origin (PDO) Italian semi-hard and semi-cooked cheese produced in northeast Italy from raw or thermized cow’s milk. The PDO label implies that the product has distinctive characteristics that are connected to traditional production methods. The aim of this work was to precisely characterize the volatile fraction of this Italian cheese. The volatile profile can be considered a fingerprint because the flavor of a cheese variety is the result of a specific balance between the volatile compounds produced during the ripening process. Analysis of the volatile profile of Montasio cheese was performed by solid-phase microextraction–gas chromatography. Six cheesemaking trials were performed, each in a different dairy located within the Montasio cheese production area. Cheeses were analyzed at 5 stages of ripening (60, 90, 170, 300, and 365 d). Only 11 compounds were identified and measured: 5 fatty acids, 3 alcohols, 2 ketones, and 1 ester. The limited number of volatile compounds measured in the headspace of the Montasio cheese is probably due to the specific making process of this cheese, which affects evolution of the microflora and the biochemical processes of ripening. The total volatile fraction profile progressively increased from 60 to 170 d, after which time it remained almost steady. The most important contributors were found to be ethanol, short-chain fatty acids (C2 to C6), diacetyl, and ethyl hexanoate. Ethanol and short-chain fatty acids increased up to 170 d, diacetyl increased up to 300 d and then declined, and ethyl hexanoate increased until the final stage.

Comparison of culture-dependent and -independent methods for bacterial community monitoring during Montasio cheese manufacturing

The microbial community in milk is of great importance in the manufacture of traditional cheeses produced using raw milk and natural cultures. During milk curdling and cheese ripening, complex interactions occur in the microbial community, and accurate identification of the microorganisms involved provides essential information for understanding their role in these processes and in flavor production. Recent improvements in molecular biological methods have led to their application to food matrices, and thereby opened new perspectives for the study of microbial communities in fermented foods. In this study, a description of microbial community composition during the manufacture and ripening of Montasio cheese was provided. A combined approach using culture-dependent and -independent methods was applied. Culture-dependent identification was compared with 16S clone libraries sequencing data obtained from both DNA and reverse-transcribed RNA (cDNA) amplification and real-time quantitative PCR (qPCR) assays developed to detect and quantify specific bacterial species/genera ( Streptococcus thermophilus, Lactobacillus casei, Pediococcus pentosaceus, Enterococcus spp., Pseudomonas spp.). S. thermophilus was the predominant LAB species throughout the entire ripening period of Montasio cheese. The culture-independent method demonstrates the relevant presence of Pseudomonas spp. and Lactococcus piscium at the beginning of ripening. The culture-dependent approach and the two culture-independent approaches produced complementary information, together generating a general view of cheese microbial ecology.

Effect of κ-casein B relative content in bulk milk κ-casein on Montasio, Asiago, and Caciotta cheese yield using milk of similar protein composition

The aim of this study was to investigate the effect exerted by the relative content of κ-casein (κ-CN) B in bulk milk κ-CN on coagulation properties and cheese yield of 3 Italian cheese varieties (Montasio, Asiago, and Caciotta). Twenty-four cheese-making experiments were carried out in 2 industrial and 1 small-scale dairy plant. Detailed protein composition of bulk milk of 380 herds providing milk to these dairies was analyzed by reversed-phase HPLC. To obtain 2 experimental milks differing in the relative content of κ-CN B in κ-CN, herds were selected on the basis of bulk milk protein composition and relative content of κ-CN genetic variants. Milk was collected and processed separately for the 2 groups of selected herds. A difference of 20% in the relative content of κ-CN B in κ-CN was obtained for the 2 experimental milks for Montasio and a difference of 15% for Asiago and Caciotta. The 2 experimental milks were of similar protein and CN content, casein number, pH, CN composition, and β-CN genetic composition. For each cheese-making trial, amounts of milk, ranging from 2,000 to 6,000kg, were manufactured. Each vat contained milk collected at least from 4 dairy herds. Cheese yield after brining and at the end of the aging was recorded. Milk with a greater proportion of κ-CN B in κ-CN (HIGHB) exhibited similar coagulation properties and greater cheese yield compared with milk with a lower proportion of κ-CN B in κ-CN (LOWB). The increased cheese yield observed for HIGHB when manufacturing Montasio cheese was ascribed to a greater fat content compared with LOWB. The probability of HIGHB giving a cheese yield 5% greater than that of LOWB ranged from 51 to 67% for Montasio cheese, but was less than 21% for Asiago and Caciotta cheeses. Variation in relative content of κ-CN B in κ-CN content did not relevantly affect industrial cheese yield when milks of similar CN composition were processed. An indirect effect due to the increased κ-CN content of κ-CN B milk is thought to explain the favorable effects of κ-CN B on cheese yield reported in the literature.

Evaluation of amino acid-decarboxylative microbiota throughout the ripening of an Italian PDO cheese produced using different manufacturing practices

To investigate the presence of biogenic amines (BAs) in Montasio cheese produced by using different cheese manufacturing practices. Three batches of Montasio cheese were made in the following way: batch A using raw milk and natural milk culture, batch B with thermized milk and natural milk culture and batch C with thermized milk and natural milk culture added of a commercial starter culture. During 120 days of ripening analyses were performed for microbial counts and BA content; indeed, the potential to produce BAs was screened in lactic acid bacteria and Enterobacteriaceae isolates. At the end of ripening, the total BA contents of cheeses from batches A, B and C were 166.3, 207.3 and 29.8 mg kg(-1), respectively. Amino acid decarboxylase activity was widespread among isolates. The BA content of Montasio cheese from the three batches was below the threshold proposed as potentially toxic. The highest BA content was found in cheese produced using thermized milk and natural milk culture; therefore, the thermal treatment of milk was not enough by itself to reduce the counts of decarboxylase-positive bacteria in cheese. The use of selected starters guaranteed a low BA content in Montasio cheese. The study of the effects of some technological processes on the incidence of decarboxylative microbiota in 'protected denomination of origin' cheeses could provide useful information on the hygienic risk related to their production.

Microbiological characterization of artisanal Montasio cheese: analysis of its indigenous lactic acid bacteria

The aim of this study was to investigate the dynamics of the microflora during Montasio cheese ripening, with specific reference to some characteristics of biotechnological interest. Nine batches of Montasio cheese produced in different plants were analyzed. Streptococcus thermophilus was the predominant species throughout the whole ripening period of Montasio cheese. Enterococci were also frequently present. This microbial group resulted probably from milk, and its proportion decreased rapidly during ripening. The most acidifying microbial species was S. thermophilus, while the most proteolytic strains belonged to the genera Enterococcus. A high degree of phenotypic diversity occurred within the microbial species.

Formation of Biogenic Amines in a Typical Semihard Italian Cheese

Given that the concentration of biogenic amines in cheeses depends on variety, age, and type of microflora, a study was undertaken to investigate the formation of these compounds during the ripening of a typical semihard Italian cheese. Tryptamine, phenylethylamine, putrescine, cadaverine, histamine, and tyramine contents were calculated in 30 samples of Montasio cheese characterized by different levels of proteolysis. Histamine and tyramine were the major amines. Tryptamine and phenylethylamine concentrations were very low at all ripening periods. Putrescine and cadaverine were present only in samples with anomalous fermentation processes. The relationship between the total amine content and the proteolytic maturation coefficient was calculated; however, even for higher levels of proteolysis, the biogenic amine content in Montasio cheese was below the level considered potentially toxic.

Free amino acids and water-soluble nitrogen as ripening indices in Montasio cheese

Summary - Traditionally, in semi-hard and hard cheeses the development of proteolysis is followed by the increase of water-soluble nitrogen (SN) as a percentage of total nitrogen (TN), but the characterisation of proteolysis for each particular cheese must con sider ail the processes that lead to the formation of peptides, free amino acids and products of their catabolism. In Montasio cheese, a considerable variability in the SN values and the amino acid profiles of cheeses at the same stage of ripening was recorded. This variability was probably due to the different traditional technologies adopted. Therefore, no chemometric model could be set up to evaluate the typical nature of Montasio cheese. On the other han d, a relationship between the total free amino acid content and the SNrrN ratio was demonstrated and it was found that certain amino acids cou Id be used as an index for determining the level of proteolysis reached by the Montasio chee se. proteolysis / free amino acid / total nitrogen / water-soluble nitrogen / Montasio cheese

The influence of Lactobacillus plantarum culture inoculation on the fate of Staphylococcus aureus and Salmonella typhimurium in Montasio cheese

The growth and survival of Staphylococcus aureus and Salmonella typhimurium were investigated during the manufacturing and ripening of raw milk Montasio cheese. Initial inoculated populations in the cheese milk were about 10 5 cfu/ml for S. aureus and 10 6 cfu/ml for S. typhimurium. Samples of curds and cheeses were taken during manufacturing and storage and analysed for pH and microbial populations. S. aureus increased slightly in number during the early period ripening and attained a population of about 10 6 cfu/ml during the remaining period of storage. S. typhimurium decreased during cheesemaking and storage but persisted through 90 days. The addition of the Lactobacillus plantarum culture (0.2% v/v) produced a marked reduction in populations ofthe test strains in 10 days of storage. Enterotoxin A was not detected in Montasio cheese even with a S. aureus population of 1.1 × 10 7 cfu/ml. L. plantarum strains were also tested by the spot method and the associative growth approach for their antagonistic activity against S. aureus and S. typhimurium. The compound excreted by L. plantarum was active only toward S. aureus. Furthermore, its activity was destroyed by protease treatment. These results indicated that while the growth of S. typhimurium is reduced by the acid production, S. aureus inhibition can be ascribed to bacteriocin production.

Activity of proteolytic enzymes during Provolone and Montasio cheese ripening

Summary Acid and neutral protease, aminopeptidase, carboxypeptidase and acid phosphatase activities during Provolone and Montasio cheese ripening have been evaluated. The levels of acid and neutral protease activities have nearly an alike trend in Provolone and Montasio cheese samples. The former remains constant, while the latter increases. The aminopeptidase activity in Provolone cheese increases du ring the ageing from 15 to 105 days and it successively decreases. The carboxypeptidase activity shows a continuous decrease in Provolone . cheese and it disappeared in Montasio cheese. Finally, the values of acid phosphatase activity decline during the ripening of two cheses.