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Recebido em 26/2/04; aceito em 30/7/04; publicado na web em 12/11/04 DEGRADATION OF BTXs BY ADVANCED OXIDATIVE PROCESSES. In this study the efficiency of advanced oxidative processes (AOPs) were investigated toward the degradation of aqueous solutions containing benzene, toluene and xylenes (BTX). The results indicated that BTX can be effectively oxidized by the UV-A-assisted photo-Fenton process. The treatment permits almost total degradation of BTX and removal of more than 80% of the phenolyc intermediates at reaction times of about 30 min. Preliminary investigations using solar light suggest a good potentiality of the process for the treatment of large volumes of aqueous samples containing these polluting species.Keywords: BTXs; advanced oxidation processes; remediation. INTRODUÇÃOA contaminação de solos e águas subterrâneas por compostos orgânicos voláteis tem sido destaque nas últimas décadas, principalmente em função da freqüência com que episódios de contaminação são verificados e da gravidade com que o meio ambiente é afetado. Embora os grandes vazamentos acidentais de petróleo sejam preocupantes e ocupem grande espaço na mídia, estima-se que a principal fonte de contaminação por estas espécies seja devida a pequenos e contínuos vazamentos de combustível em postos de distribuição 1 , favorecidos pelo envelhecimento dos taques de estocagem.No Brasil existem cerca de 27.000 postos de combustíveis, muitos dos quais operando em condições de risco. Em razão deste fato, o potencial poluente desta atividade mostra-se bastante elevado, o que faz com que a contaminação de aqüíferos seja apenas uma questão de tempo 2 . A preocupação relacionada com o potencial de contaminação de águas subterrâneas vem crescendo em diversas cidades, principalmente São Paulo, Curitiba e Joinville. Estudos realizados pela prefeitura de Joinville em 65 postos da cidade revelaram que somente um dos postos examinados não apresentava problemas de vazamento que redundasse em contaminação do lençol freático 3 .O potencial poluente da gasolina está diretamente relacionado com os hidrocarbonetos aromáticos de maior solubilidade em água, isto é, benzeno, tolueno e xilenos (BTXs). Dentre estes, o benzeno mostrase especialmente tóxico, podendo provocar câncer quando em condições de exposição crônica, principalmente devido à absorção por via respiratória 4 . Além disso, a gasolina comercializada em nosso país é aditivada com cerca de 20 a 25% de etanol, fator que aumenta consideravelmente a solubilidade destes poluentes e, conseqüentemente, a sua migração em corpos d'água 5 . Adicionalmente, estudos recentes têm demonstrado que a biodegradação do etanol consome rapidamente todos os aceptores de elétrons disponíveis no meio, o que faz com que a biodegradação dos BTXs seja drasticamente afetada 6 . Em função destes antecedentes, a busca de novas alternativas para a remediação de águas contaminadas mostra-se absolutamente essencial.Nos últimos anos, os processos oxidativos avançados (POAs) têm aparecido como uma excelente alternativa para o tratame...

This study aims to evaluate the aromatic profile of fermented apple, obtained by the action of strains of Hanseniaspora uvarum and Hanseniaspora guilliermondii using two methods of analysis: static headspace and solid phase microextraction (SPME). The results obtained confirm that the strains of the Hanseniaspora genus contributed positively to the aroma profile of fermented apple, producing considerable amounts of esters and higher alcohols. In comparing the methods of analysis of aromatic compounds using headspace and SPME, it was verified that by using the headspace method it was possible to capture amounts that were up to 16 times greater than the value of the volatile compounds obtained by SPME. However, when using SPME, 5 times more compounds were obtained than when using headspace. Even so, in the conditions of this study it was noted that headspace was more efficient in the extraction of the aromatics of fermented apple when taking into consideration the cost effectiveness of both methods.

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Near-infrared reflectance spectroscopy (NIRS) with partial least squares regression (PLSR) was used to determine levels of fat, protein and moisture in ricotta cheese without complex sample preparation. Spectra of 19 conventional and low-fat ricotta samples from different manufacturers were collected in duplicate, with 33 of the 38 spectra used as a calibration set and the remaining 5 spectra used as an external validation set. The best results were obtained by processing the spectral region between 1,100 and 2,500 nm. Multivariate models with six latent variables (LVs) showed good prediction capability for fat and protein determinations, with average relative errors (Er) of 6.37 % and 5.95 %, respectively. For moisture, a more robust model was obtained with 4 LVs, showing better prevision capacity and Er of 1.91 %.

Ciênc. Tecnol. Aliment., Campinas, 25(4): 672-676, out.-dez. 2005 672 -���������� ����������A tendência mundial ao consumo de produtos naturais, como sucos de frutas cítricas, tem contribuído para estimular o aumento da produção de citros no Brasil, que levou o país à liderança mundial na exportação de suco de laranja concentrado [5].Além da laranja, outros citros são utilizados para a fabricação de sucos naturais e concentrados como limão rosa (Citrus limonia) e o limão siciliano (Citrus limon). O limão rosa, conhecido como limão cravo, é extensamente cultivado em pomares e viveiros, pois induz a maturação precoce das SUMMARYChARACTERIzATION OF RANGPUR LIME (Citrus limonia Osbeck) AND "SICILIAN" LEMON (Citrus limon) SEED OILS, AN AGROINDUSTRIAL WASTE. The purpose of this study was to characterize the oil extracted from rangpur lime and "Sicilian" lemon seeds. Iodine, peroxide values, as well as free fatty acid percent (FFA%) expressed as oleic acid were accomplished. The thermal gravimetric analysis, TG; differential thermal gravimetric, DTG; differential scanning calorimetry analysis, DSC; infrared and ultraviolet spectroscopic and gas chromatographic analysis were also determined. In the rangpur lime seed oil, the following fatty acids, as methyl esters were identified: caprilic (0,90%), palmitic (21,40%), stearic (2,60%), oleic (21,20%), linoleic (43,00%), linolenic (7,60%) and araquidic (0,20%) and in the Sicilian lemon seed oil: caprilic (1,00%), myristic (0,10%), palmitic (19,60%), stearic (3,00%), oleic (28,60%), linoleic (34,40%), linolenic (10,00%) and araquidic (0,20%). The results indicate that both oils present thermal stability until 250ºC, as well as analogous chemical composition and high contents of unsaturated fatty acids (UFA, 71,80 and 73,00%). With the fatty acid composition, it was possible to determine the triacylglycerol composition of both oils. The results indicated that the oils show characteristics analogous to the edible oils with good quality.

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Heating drying processes may cause undesirable changes in tomato composition and loss of quality, mainly in bioactive components. The objective of the study was to evaluate the effects of oven drying, heated air flow, and freeze‐drying on blanched and unblanched tomatoes. This allows choosing drying conditions with less undesirable changes. The contents of sugar, citric acid, ascorbic acid, lycopene, β‐carotene, and total phenolic compounds, and 5‐hydroxy‐2‐furaldehyde (HMF) formation were evaluated. Results revealed that samples with lower sugar content also showed higher level of HMF. The heated air flow lead to low HMF formation, low reduction of sugar and a higher concentration of lycopene, β‐carotene, phenolics, and ascorbic acid. Freeze drying lead to low levels of carotenes in the end product. In conclusion, fractions of lycopene, β‐carotene, phenolics were increased by blanching, and losses of sugars, HMF, ascorbic acid were related to blanching. Practical applications The actual applications of this research are to evaluate the behavior of bioactive components in tomatoes that underwent different drying methods. Different processing parameters may lead to undesirable changes in composition of tomatoes and cause loss of quality in dried products. The potential applications are to evaluate which parameters are capable to maintain the higher quality levels in the end product.