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  • The Surplus Value of HS-SPME/GC on the Rapid Quality Assessment of Dairy Products, Particularly Cheese, by The Volatile Components Profile
    Publication . Paiva, Lisete; Baptista, José
    ABSTRACT: Food aroma is a sensory property produced by the interaction between chemical compounds and sensory receptors and, particularly, cheese aroma consumer perception is one of the foremost criteria for its preference and acceptance. Head-space solid phase microextraction gas chromatography (HS-SPME/GC) is commonly used for qualitative and quantitative analysis of volatile compounds in various food products, in which analytes are adsorbed directly on the stationary phase coated on the outer surface of fuse-silica, eliminates the needs for solvent-extraction and/or sophisticated apparatus, requires much less sample preparation and manipulation time per sample. Bearing all this in mind, the aim of the present study was to determine and to compare cheese aroma profiles, particularly from Azorean Region, influenced by climate, soil composition, seasons, different management, and feed practices, genetic modified cows, and probably different cheese-making technologies using HS-SPME/GC methodology. Significant differences were observed in levels of individual head-space volatiles in different cheese aroma samples.
    2023-08-11Periodical Open access Show more
  • Island spider origins show complex vertical stratification patterns in Macaronesia
    Publication . Costa, Ricardo; Cardoso, P.; Rigal, F.; Borges, Paulo A. V.
    1.Spiders are among the most diverse and yet threatened groups of arthropods in Macaronesia. Found in most habitat types, they occupy the vertical gradient of native forests from ground to canopy level. 2. We hypothesize that their vertical distribution is influenced by the colonization origin. As introduced species should arrive using shipping containers and similar means, they should mostly occupy the lower levels in the gradient, with potential negative effects on the indigenous epigean fauna. 3. Spiders were sampled from epigean to arboreal microhabitats (maximum height varying between 2 and 4 m) on 45 sites across five islands belonging to three archipelagos. The mean and range of vertical stratification were obtained for each captured species. These values were then compared between different colonization origins at Macaronesian and archipelagic levels. 4. Native non-endemic species were found at significantly higher vertical strata than both endemic and introduced species. Likewise, native non-endemics had a larger vertical range. These patterns were largely replicated across archipelagos, although there were exceptions. 5. Overall, introduced species do not seem to occur mostly at lower strata in the native forests of Macaronesia (at least in the studied vertical range) but seem to be vertically restricted in most settings with the exception of Madeira.
    2023-08-11Journal article Open access Show more