Organoleptic Chemical Markers of Serpa PDO Cheese Specificity

Abstract

Serpa is a protected designation of origin cheese produced with a vegetable coagulant (Cynara cardunculus L.) and raw ovine milk. Despite the unique sensory profile of raw milk cheeses, numerous parameters influence their sensory properties and safety. To protect the Serpa cheese quality and contribute to unifying their distinctive features, some rheologic and physicochemical parameters of cheeses from four PDO producers, in distinct seasons and with different sensory scores, were monitored. The results suggested a high chemical diversity and variation according to the dairy, month and season, which corroborates the significant heterogeneity. However, a higher incidence of some compounds was found: a group of free amino acids (Glu, Ala, Leu, Val and Phe), lactic and acetic acids, some volatile fatty acids (e.g., iC4, iC5, C6 and C12) and esters (e.g., ethyl butanoate, decanoate and dodecanoate). Through the successive statistical analysis, 13 variables were selected as chemical markers of Serpa cheese specificity: C3, C4, iC5, C12, Tyr, Trp, Ile, 2-undecanone, ethyl isovalerate, moisture content on a fat-free basis, the nitrogen-fractions (maturation index and non-protein and total nitrogen ratio) and G’ 1 Hz. These sensory markers’ identification will be essential to guide the selection and development of an autochthonous starter culture to improve cheese quality and safety issues and maintain some of the Serpa authenticity.

Proteomics Parameters for Assessing Authenticity of Grated Grana Padano PDO Cheese: Results from a Three-Year Survey

“…The inoculation of adjunct cultures is rather common in industrial cheese manufacture to accelerate the ripening process; however, it has an impact on FAA composition [27]. Correlations existing between cheese microbiota and specific FAAs have been highlighted by several authors [28][29][30]. In a previous study, it was demonstrated that in GP cheeses intentionally contaminated with Clostridium tyrobutyricum, the main species responsible for the so called "late blowing" defect in hard cheeses, high contents of free R REVIEW 2 of 10 investigated approaches.…”

“…In these last cases, poor accuracy in grated cheese mixing before filling the packages can be hypothesized. Indeed, due to the lower water content in the outermost part of the cheese [26,30], grated rind normally contains fibrous particles that tend to separate from the rest of the mix. In a recent study of grated Parmigiano Reggiano cheese, the effect of using different grater types, i.e., drum grater or knife mill, was evaluated [40].…”

Impact of LAB from Serpa PDO Cheese in Cheese Models: Towards the Development of an Autochthonous Starter Culture

“…For FAA analysis, the Pico-Tag™ method [37] was used with some adjustments, as described by Araújo-Rodrigues et al [31]. In the first phase, deproteinization and FFA extraction were carried out, homogenizing each cheese model with perchloric acid (0.6 N; 1:10) in an Ultra-turrax ® (T18, IKA) for 2 min at 12,000 rpm.…”

“…Headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography and mass spectrometry (GC-MS) was used to determine the VFA present in cheese models according to the conditions described by Araújo-Rodrigues et al [31]. For the experiment, flasks of 20 mL (capped with a gastight seal) were used, adding 1 g of each cheese-like model and 10 µL of internal standard (50 mg L −1 of 3-octanol).…”

“…Other molecules also impact the final organoleptic profile and authenticity, including, for example, medium-chain fatty acids, esters, and peptides [28,29]. A screening of sensory, physical, and chemical parameters of Serpa cheeses produced in different seasons and by distinct producers was carried out by Araújo-Rodrigues et al [31].…”