Caracterización tecnológica, química, bioquímica y sensorial del queso de Valdeón con I.G.P. durante la maduración = Technological, chemical, biochemical and sensory characterization of Valdeón cheese with P.G.I. during ripening

234 p.Esta tesis doctoral surge con el objetivo principal de caracterizar la I.G.P. Queso de Valdeón estudiándose la influencia que tiene el tiempo de maduración, la estación de elaboración y el tratamiento térmico aplicado a la leche en la calidad final de esta variedad. Para ello, se elaboraron un total de 12 lotes, 8 de ellos a partir de leche pasterizada (2 en cada una de las estaciones del año) y 4 a partir de leche cruda en la Quesería Picos de Europa S.L. (Posada de Valdeón, León, España

Characteristics and proteolysis of a Spanish blue cheese made with raw or pasteurised milk

[EN] Valdeón cheese is a Spanish Protected Geographical Indication of blue-veined cheese produced on an industrial scale from raw or pasteurised cow and/or goat milk. The aim of this work was to evaluate the impact of pasteurisation on the microbiological, physicochemical and sensory characteristics of cheese. Cheeses made with raw milk showed higher counts of lactobacilli and enterococci, as well as lower values of pH and D-lactic acid and salt/moisture ratio. Cheeses made with pasteurised milk showed greater extent of proteolysis, higher concentration of free amino acids and lower concentration of biogenic amines. Pasteurisation produced more elastic and harder cheeses, but with a lower sensory profileSIJunta de Castilla y Leó

Changes in the Concentration and Profile of Free Fatty Acids during the Ripening of a Spanish Blue-Veined Cheese Made from Raw and Pasteurized Cow and Goat Milk

[EN]Blue-veined cheeses in general undergo a pronounced lipolysis. The aim of this work was to determine the evolution of free fatty acids (FFA) in Valdeón cheese during ripening, comparing cheeses made from raw and pasteurized milk. The effect of season on the evolution of FFA in pasteurized milk cheeses was also studied. Cheeses made with raw milk showed the highest concentrations of FFA, reaching values of 23,081.9 mg 100 g−1 dry matter at the end of ripening, compared to the values of cheeses made with pasteurized milk (7327.1 mg 100 g−1 dry matter), in both cases with a predominance of oleic and palmitic acids. However, pasteurization did not affect the FFA profile of the cheeses. Regarding the cheeses made with pasteurized milk in different seasons, the highest FFA concentration was reached in cheeses made in summer after 30 days of ripening. The season also influenced the FFA profile and thus the concentration of short-, medium- and long-chain fatty acids in relation to total FFA. There were no significant differences in sensory analysis between cheeses made from raw and pasteurized milk.SIThis work was supported by project L021A12-2 from Junta de Castilla y León

Peptidomic study of Spanish blue cheese (Valdeón) and changes after simulated gastrointestinal digestion

It is increasingly evident that digestion can affect the biological activity of cheese by the release of new active peptides from their precursors or, on the contrary, giving rise to fragments without activity. The characterization of the peptidome of a Spanish blue cheese, Valdeón, has been conducted before and after gastrointestinal digestion, and the digests have been compared to those obtained from pasteurized skimmed milk powder (SMP) using a bioinformatics platform. Peptidomic profiling of digests revealed several regions that are especially resistant to digestion (among them β-casein 60-93, 128-140, and 193-209). Some of them correspond to well-conserved regions between species (human, cow, sheep, and goat) and include peptide sequences with reported bioactivity. The great peptide homology found between both digests, cheese and SMP, suggests that the gastrointestinal digestion could bring closer the profile of products with different proteolytic state. Although most of the biologically active peptides found in cheese after digestion were also present in SMP digest, there were some exceptions that can be attributed to the absence of the relevant precursor peptide before digestion. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.Funded by: Consolider-Ingenio FUN-C-Food CSD 2007-063. Grant Number: AGL2011-24643 and Ministerio de Economía y Competitividad. Grant Number: L021A12-2.Peer Reviewe

Comparison of peptidomic studies of simulated gastrointestinal digests from Spanish cheeses

Resumen del póster presentado al 1st International Conference on Food Digestion celebrado en Cesena (Italia) del 19 al 21 de marzo de 2012.During cheese ripening, casein is hydrolyzed into a large variety of peptides by proteases and peptidases from milk, rennet, starter culture and secondary microbial flora. These peptides are characteristic of each cheese type and ripening time and are in part responsible of the typical and differentiating organoleptic characteristics of cheese. Some of these peptides are known to be partially resistant to digestion or they can act as precursors of the peptides that finally are absorbed. Different studies performed at our laboratory aimed the identification of the major peptides generated after two-step hydrolysis process that simulates gastrointestinal digestion of different Spanish cheeses. These include: Manchego cheese which is a hard or semi-hard variety made from ewe's milk; Serena cheese which is elaborated with ewe's milk and vegetal rennet; Tetilla cheese is made from bovine milk and animal rennet and a cheeses made from mixtures of caprine, ovine and bovine milk (Iberian and Valdeon cheeses). Therefore, the degree of proteolysis and the peptidic profile before simulated digestion was different and distinctive for each cheese type and ripening time. After digestion, the water soluble extracts were subjected to ultrafiltration through a 3000 Da membrane and the permeates were analyzed by HPLC coupled to tandem spectrometry. Many homologous sequences were found in the ultrafiltrates of the water soluble extracts although they were obtained from different cheese types. There are casein regions specially resistant to hydrolysis that were found in many of these studies such as, k¿-casein f(134-139) HLPLPL; k-casein f(47-52) DKIHPF; k-casein f(114-119) YPVEPF. Interestingly, some of the most often peptides found had been previously been reported with a given bioactivity as antihypertensive, opioid or with antiallergenic properties.Peer Reviewe

Técnicas de producción alfarera vaccea contrastadas a través de la arqueología experimental

Producción CientíficaLa maestría de los alfareros vacceos desvelada en algunas de sus claves gracias a la arqueología experimental