An electronic tongue taste evaluation : identification of goat milk adulteration with bovine milk

An electronic tongue with 36 cross-sensibility sensors was built allowing a successful recognition of the five basic taste standards, showing high sensibility to acid, salty and umami taste substances and lower performance to bitter and sweet tastes. The taste recognition capability was afterwards tested in the detection of goat milk adulteration with bovine milk, which is a problem for the dairy industry. This new methodology is an alternative to the classical analyticalmethods used to detect caprine milk adulterations with bovine milk, being a simpler, faster and economical procedure. The different signal profiles recorded by the e-tongue device together with linear discriminant analysis allowed the implementation of a model that could distinguish between rawskim milk groups (goat, cowand goat/cow) with an overall sensibility and specificity of 97% and 93%, respectively. Furthermore, cross-validation showed that the modelwas able to correct classify unknown milk samples with a sensibility and specificity of 87% and 70%, respectively. Additionally, the model robustness was confirmed since it correctly or incorrectly classified milk samples with, respectively, higher and lower probabilities than those that could be expected by chance.Financial support received from FCT, Lisbon, under research projects POCI/QUI/58706/2004 and PPCDT/QUI/58076/2004, is gratefully acknowledged

Utilização de biossólido no crescimento inicial de mudas de aroeira (Schinus terebynthifolius Raddi) Utilization of sewage sludge in the seedling growth of aroeira (Schinus terebynthifolius Raddi) seedlings

Objetivou-se avaliar o uso do biossólido como componente do substrato para crescimento inicial de mudas de aroeira. Os substratos foram compostos de amostras de Neossolo Quartzarênico e de Latossolo Vermelho-Amarelo coletadas na profundidade de 0,2 a 0,5 m, acrescidos do biossólido produzido pela Estação de Tratamento de Esgoto (ETE) de Serrania, MG, nas seguintes proporções de solo:biossólido (%): 100:0; 80:20; 60:40; 40:60; e 20:80, sem a utilização de fertilização mineral. Após 30 dias da semeadura, foi feito o desbaste deixando-se uma planta por tubete, e, no final do período de 60 dias, as mudas foram coletadas para a determinação da massa seca da parte aérea (MSPA), das raízes (MSR) e total (MST), diâmetro de colo (D), altura das plantas (H), área foliar (A), relação altura da parte aérea com diâmetro do colo (H/D) e peso da massa seca da parte aérea com peso da massa seca da raiz (MSPA/MSR). O biossólido melhorou a fertilidade dos substratos, aumentando os teores de P, K, Ca, Mg, soma de bases, CTC, matéria orgânica e teores de micronutrientes, fato que proporcionou aumento no D, A, MSPA, MSR, MST, H, MSPA/MSR das mudas de aroeira, sendo que esses efeitos variaram de acordo com as proporções de biossólido empregadas. O crescimento máximo das mudas foi obtido com a proporção de 63:37, tanto para Neossolo Quartzarênico quanto Latossolo Vermelho-Amarelo. A concentração de metais pesados em todos os substratos ficou abaixo dos limites estabelecidos pela CETESB.<br>This work aimed to evaluate sewage sludge as substrate component for aroeira seedling growth. Substrates were composed of soil samples collected at 0.2-0.5 m depth from a Quartzarenic Neosol or from a Red-Yellow Latosol, with sewage sludge produced by the Sewage Treatment Station (Estação de Tratamento de Esgoto - ETE) located in Serrania, Minas Gerais, in five proportions: 100:0; 80:20; 60:40; 40:60 and 20:80, being all without mineral fertilizers. Thirty days after sowing, thinning was carried out to one plant per pot. Aroeira growth after 60 days was evaluated by shoot and root dry weight, total dry matter, stem diameter, plant height, leaf area, shoot height/stem and diameter shoot/root ratio. Amendments with sewage sludge increased substrate fertility as indicated by P, K, Ca, Mg concentrations, CEC and SB values, organic matter and micronutrient contents, which promoted growth of stem diameter, plant height, shoot and root dry weight, total dry matter, leaf area, and shoot/root ratio in aroeira seedlings . The effect of sewage sludge on aroeira seedlings growth varied according to the different proportions of sewage sludge. Maximum growth was obtained with the proportion 37% of sewage sludge + 63% of Quartzarenic Neosol or Red-Yellow Latosol. Heavy metal concentration in all substrates was below the limits allowed by CETESB