Impact of Extending Hard-Cheese Ripening: A Multiparameter Characterization of Parmigiano Reggiano Cheese Ripened up to 50 Months

Abstract

Extending ripening of hard cheeses well beyond the traditional ripening period is becoming increasingly popular, although little is known about the actual evolution of their characteristics. The present work aimed at investigating selected traits of Parmigiano Reggiano cheese ripened for 12, 18, 24, 30, 40 and 50 months. Two cheeses per each ripening period were sampled. Although moisture constantly decreased and was close to 25% in 50-month cheeses, with a parallel increase in cheese hardness, several biochemical changes occurred involving the activity of both native and microbial enzymes. Capillary electrophoresis demonstrated degradation of αs1- and β-casein, indicating residual activity of both chymosin and plasmin. Similarly, continuous release of free amino acids supported the activity of peptidases deriving from lysed bacterial cells. Volatile flavor compounds, such as short-chain fatty acids and some derived ketones, alcohols and esters, evaluated by gas chromatography with solid-phase micro-extraction, accumulated as well. Cheese microstructure was characterized by free fat trapped in irregularly shaped areas within a protein network, with native fat globules being no longer visible. This study showed for the first time that numerous biochemical and structural variations still occur in a hard cheese at up to 50 months of aging, proving that the ripening extension deserves to be highlighted to the consumer and may justify a premium price.

Ripening of Nostrano Valtrompia PDO Cheese in Different Storage Conditions: Influence on Chemical, Physical and Sensory Properties

“…In general, L* values were in line [51] or lower [47,49] with those reported for Parmigiano Reggiano cheese ripened up to 50 months; by considering other PDO ripened Italian cheeses such as Montasio and Asiago cheeses, L* a* b* values were comparable, with the exception of b* values in the case of Asiago, which were lower [23,24,52].…”

“…An increase in the lightness index L* during ripening time is an interesting finding for a long-ripened cheese type, as previous studies performed on various ripened cheeses reported a decrease of this parameter during ripening [ 23 , 24 , 37 , 46 , 47 ], that can be due to an increase in the hydration of proteins and a reduction of light scattering related to free water [ 48 ]. On the other hand, Sberveglieri et al [ 49 ] recently reported an increase in the L* index of Parmigiano Reggiano cheese during a 36-month period.…”

Evolution of VOC and Sensory Characteristics of Stracciatella Cheese as Affected by Different Preservatives

“…The fastest way to analyze these compounds is using SPME-GC/MS (Solid Phase Micro Extraction-Gas Chromatography/Mass Spectrometry). It is widely used among researchers for milk and dairy products [ 11 , 12 , 13 , 14 , 15 ] and other foods [ 16 , 17 , 18 ]. It is used also in the flavoromics approach [ 19 , 20 ], because it is capable of ppb detection level for a wide range of molecular weight.…”

Evaluating the Authenticity of the Raw-Milk Cheese Fontina (PDO) with Respect to Similar Cheeses

“…The degradation of casein fractions was evaluated by capillary zone electrophoresis (CZE) using a P/ACE TM MDQplus equipment (AB Sciex, Milan, Italy) and a hydrophilically coated capillary column DB-WAX126-7012 (50 cm length, 50 µm i.d., 0.05 µm coating, 100 × 800 µm slit opening) (Agilent Technologies, Milan, Italy). The analytical conditions were those described by D’Incecco et al [ 14 ]. Briefly, 1 g of grated cheese was added with 10 mL of sample buffer, kept at room temperature for 4 h, then diluted 1:5 with the same buffer and filtered with a 0.22 µm PVDF membrane filter (Merck, Milan, Italy) immediately before analysis.…”

“…Peak area ratios were calculated between selected casein breakdown fragments and the corresponding parent casein fractions. In particular, the ratios αs1-I-CN/αs1-CN and Σγ-CN/Σβ-CN described by D’Incecco et al [ 14 ] were considered as indicators of the primary proteolysis of αs1- and β-casein fractions, respectively.…”