Effect of autochthonous starter cultures in the production of "Paio", a traditional Portuguese dry- cured sausage

Traditional dry-cured sausages are highly appreciated in Mediterranean countries. The aim of the present study was to evaluate the effect of different starter cultures in the sausages Alentejano pig meat was used to prepare drycured sausages in a local factory. Staphylococcus xylosus, Lactobacillus sakei and a yeast strain were inoculated at a concentration of 106 cfu/g meat batter both in separate and in mixed culture. Three independent batches with two replicates per treatment were produced. Samples were collected throughout the ripening process. pH and aw were determined according to the ISO standards. Microbiological counts of total mesophiles, total psycrotrophs, anaerobes, coagulase-negative staphylococci (CNS), lactic acid bacteria (LAB), enterobacteria, yeasts and moulds and Listeria monocytogenes were done according to the respective ISO standards, as well as detection of Salmonella spp. Biogenic amines quantification was performed by HPLC as described by Roseiro et al. (1). The treatment with L. sakei alone was the most effective in reducing the contamination level both with Salmonella spp. and L. monocytogenes, however this effect seems to be lost in the mixed cultures. The presence of the yeast strain seems to increase the levels of phenylethylamine and histamine. The contents in cadaverine, putrescine and tyramine were generally lower in the inoculated sausages. Regarding tyramine, the treatments with L. sakei showed significantly lower values. No significant differences between treatments were observed for both spermine and spermidine.

Irrigation management with remote sensing: Evaluating irrigation requirement for maize under Mediterranean climate condition

tWater use control methods and water resources planning are of high priority. In irrigated agriculture, theright way to save water is to increase water use efficiency through better management. The present workvalidates procedures and methodologies using remote sensing to determine the water availability in thesoil at each moment, giving the opportunity for the application of the water depth strictly necessaryto optimise crop growth (optimum irrigation timing and irrigation amount). The analysis is applied tothe Irrigation District of Divor, Évora, using 7 experimental plots, which are areas irrigated by centre-pivot systems, cultivated to maize. Data were determined from images of the cultivated surface obtainedby satellite and integrated with atmosphere and crop parameters to calculate biophysical indicatorsand indices of water stress in the vegetation—Normalized Difference Vegetation Index (NDVI), Kc, andKcb. Therefore, evapotranspiration (ETc) was estimated and used to calculate crop water requirement,together with the opportunity and the amount of irrigation water to allocate. Although remote sensingdata available from satellite imagery presented some practical constraints, the study could contribute tothe validation of a new methodology that can be used for irrigation management of a large irrigated area,easier and at lower costs than the traditional FAO recommended crop coefficients method. The remotesensing based methodology can also contribute to significant saves of irrigation water.

EFFECT OF SALT REDUCTION ON THE SAFETY AND STABILITY OF TRADITIONAL BLOOD DRY-CURED SAUSAGES

Health issues such as cardiovascular disease are often due to dietary habits. Thus, meat industry needs to reduce salt in their products. However, production of low-salt content dry-cured not affected. The current study evaluated the effect of salt reduction from 6% to 3% in two Portuguese traditional blood dry-cured sausages. Physicochemical and microbiological parameters, biogenic amines content, fatty acids profile, texture profile analyses and sensory panel evaluations were considered. Differences due to salt reduction were noticeable in a faint increase in water activity, which slightly favoured microbial growth, with the highest yeasts numbers found in 6% salt sausages. Total biogenic amines content ranged from 224.72 to 1302.81 mg kg-1 dry matter, with higher amounts, particularly of cadaverine, histamine and tyramine, in low-salt products. Still, histamine significant differences were observed due to salt content. However, texture profile analysis revealed that low-salt products showed lower resilience and cohesiveness, even though no textural changes were observed by the panellists. Nevertheless, low-salt sausages were clearly preferred. Still, taking the safety of these traditional meat products into account, the results obtained for pH, aw and biogenic amines, have shown that a reduction in salt content should be accompanied by complementary safety measures, such as the use of starter cultures to minimise microbiological and chemical risks.