Maria Arias

The Maillard reaction during the ripening of Manchego cheese

The Maillard reaction was studied in semi-industrial Manchego cheese during ripening, through measurement of furosine and galactose. An accumulation of galactose was observed during the initial period of ripening, probably due to the inability of Streptococcus thermophilus to metabolise galactose. However, a considerable decrease in galactose content and increase in furosine amount were found after 15 days of ripening. No further formation of furosine was observed after 45 days. This fact could be attributable to the exhaustion of galactose due to its participation in Maillard reaction and/or its utilisation by the microorganisms Lactococcus and Lactobacillus. Furosine seems to be a useful indicator of the Maillard reaction during ripening of Manchego cheese.

The genus Bursaphelenchus Fuchs (Nematoda: Aphelenchida) in north-west Spain.

As a consequence of the report of pine wood nematode (Bursaphelenchus xylophilus) in the Setubal peninsula (Portugal), nematodes of the genus Bursaphelenchus and the vector insect were studied in pine forests, timber industries and entry points for imported timber in Galicia (north-west Spain). The aim of this paper was to contribute to the establishment of the necessary measures to prevent the introduction of B. xylophilus into Spain. Sampling, nematode extraction and identification were carried out according to the EU norm. From collections made in 1999-2002, a total of 2612 samples were studied. Bursaphelenchus eggersi, B. mucronatus and B. sexdentati were found, as well as Monochamus galloprovincialis, a vector cerambycid beetle. Bursaphelenchus xylophilus was not isolated. Morphometric characteristics and geographic distribution of the species are provided and the risk of introducing B. xylophilus to Spain assessed.

Survey of the Furosine Content in Cheeses Marketed in Spain

The furosine content in 53 samples of different cheese types (fresh, ripened with molds, artisanal hard-pressed, industrial hard-pressed, and processed) marketed in Spain was analyzed. The lowest furosine values were observed in artisanal hard-pressed cheeses (4.8 to 10.2 mg per 100 g of protein) and ripened with molds cheeses (4.2 to 12.8 mg per 100 g of protein). Industrial hard-pressed cheeses showed furosine values between 3.5 and 43.8 mg per 100 g of protein. Differences between samples may be attributed to the heat-treatment intensity given to cheese milk and to cheesemaking conditions. The highest contents of furosine were observed in processed cheeses (20 to 366.6 mg per 100 g of protein). A wide range of furosine content was found in fresh cheeses (17.9 to 73.6 mg per 100 g of protein), which could be due to the different amounts of dried milk added during the manufacture of cheeses.

Trichodoridae (Nematoda: Triplonchida) in Spain

A revision has been made of the Trichodoridae family in Spain. Seventy records were determined or confirmed. Reports of Paratrichodorus cf. acutus (one record) and 24 of Trichodorus species were not confirmed and those of eight species were regarded as erroneous. Thirteen species have been found in Spain, five belonging to the genus Paratrichodorus (P.anemones, P.hispanus, P.minor, P.pachydermus, P.teres) and eight to Trichodorus (T. beirensis, T. cylindricus, T. giennensis, T. lusitanicus, T. primitivus, T. similis, T. sparsus, T. viruliferus). P.minor and P.teres appeared in the Canary Islands. No trichodorids have been reported on the Balearic Islands. T.lusitanicus is a new species for Spain and 33 records are new.

Potential Insect Vectors of Bursaphelenchus spp. (Nematoda: Parasitaphelenchidae) in Spanish Pine Forests

Potential insect vectors of Bursaphelenchus xylophilus (PWN) were studied. Pathways of introduction of PWN from Portugal to Europe, through Spain, were determined and traps were located in pine stands sites along the pathways. 19 Cerambycidae, 12 Scolytidae, 12 Buprestidae and 10 Curculionidae species have been found. Trapped insects were examined for the presence of nematodes under their elytra. Nematodes were found on Arhopalus ferus, Spondylis buprestoides, Hylastes ater, Hylurgus lingniperda, Orthotomicus erosus, Pityogenes bidentatus, Tomicus piniperda, Hylobius abietis and Pissodes validirrostris specimens. Monochamus galloprovincialis was the most important insect species, representing a risk for the introduction of the PWN in Spanish pine forests; Cerambycidae and Curculionidae species, were taken into account because they have been reported as vectors of other Bursaphelenchus spp.

Distribution of Xiphinema pyrenaicum Dalmasso, 1969 with notes on X. aceri Chizhov, Tiev & Turkina, 1986 (nematoda: Longidoridae)

A study of the distribution and morphometric characteristics of Xiphinema pyrenaicum and X. aceri was done because of their presence and distribution in Spain. More than 50 populations of X. pyrenaicum were studied and one population of X. aceri, of which the latter included the four juvenile stages not previously described. The study revealed both species to be typical of Mediterranean environments, X. pyrenaicum being widespread in the circum-mediterranean basin.