Estrella Fernández-García

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AIMS To study the effect of Enterobacteriaceae strains of dairy origin on caseins under cheese manufacture and ripening conditions. METHODS AND RESULTS Strains belonging to the genera Enterobacter, Escherichia, Hafnia and Serratia were isolated from fresh raw milk cheeses. Residual caseins in cheeses made from milk individually inoculated with 10 strains(More)
Production of volatile compounds by seven Pseudomonas strains belonging to six different species, Ps. brenneri, Ps. graminis, Ps. libanensis, Ps. lundensis, Ps. putida, and Ps. rhodesiae, was investigated, with the aim of elucidating their possible contribution to the volatile profile of cheese. Laboratory-scale cheeses were made from pasteurized milk of(More)
Volatile compounds produced in cheese by five Pseudomonas fragi strains isolated from 1-day-old raw milk cheeses were investigated. Each strain was representative of a different biochemical group of isolates of identical phenotypic characteristics, according to identification with API 20 NE strips. The five strains were ascribed to the species P. fragi(More)
The formation of volatile compounds in fresh cheese by 10 Enterobacteriaceae strains of dairy origin (4 Hafnia alvei, 2 Serratia liquefaciens, 1 Enterobacter cloacae, 1 Enterobacter sakazakii, and 2 Escherichia coli strains) was investigated. Small cheeses were made from pasteurized cow's milk separately inoculated with 1-3 x 10(3) CFU/ml of each of the(More)
An automatic purge and trap apparatus, coupled to a GC-MS was used to study the seasonal variability of the volatile fraction of raw milk Manchego cheese. Both season and dairy significantly affected abundance of most volatile compounds. Most aldehydes, methyl ketones, n-alcohols, and secondary alcohols reached significantly higher concentrations in spring(More)
Hispánico cheese is manufactured in Spain from a mixture of cow and ewe milk. Production of ewe milk varies throughout the year, with a peak in spring and a valley in summer and autumn. To overcome this seasonal shortage, curd from spring ewe milk may be frozen and used for cheese manufacture some months later. In the present work, ewe milk curds pressed(More)
The production of volatile compounds by wild strains of Lactococcus lactis used as starter cultures and their effect on the sensory characteristics of ewes' raw milk cheese were investigated. Sixteen vats of cheese were manufactured and ripened for 120 d in two experiments, each of them duplicated. In the first experiment, milk was inoculated with different(More)
Two proteinases, a neutral proteinase from Bacillus subtilis and a cysteine proteinase from Micrococcus sp., were used to accelerate the ripening process of raw cow's milk Hispánico cheese, a semihard variety. Two levels (0.1% and 1%) of a commercial starter culture containing Lactococcus lactis subsp. lactis and L. lactis subsp. cremoris were added for(More)
Nisin, free or incorporated in calcium alginate microparticles, was added to pasteurized milk (80% cows' and 20% ewes' milk) used for the manufacture of Hispánico cheese with a mesophilic starter and a thermophilic adjunct culture of high aminopeptidase activity. Addition of nisin incorporated in microparticles promoted early lysis of thermophilic adjunct(More)
The effect of high pressure treatment (400MPa, 10min at 12°C) on the volatile profile of Spanish dry-fermented sausage 'salchichón', packaged with or without aluminium foil in a multilayer polymeric bag, was investigated. The analysis of the volatile fraction was carried out by dynamic headspace extraction coupled to gas chromatography-mass spectrometry.(More)