No abstract

This research evaluated the effects of biosolid levels on yield and chemical composition of Mentha piperita L. essential oil. Mint plants were grown in a greenhouse in pots containing the equivalent to 0, 28, 56, and 112 t.ha-1 biosolid. Three evaluations were made at 90, 110, and 120 days after planting (DAP). The oil was extracted from the dry matter of shoots by hydrodistillation, and composition was determined by GC/MS. Oil production was slightly affected by the biosolid, increasing when plants were grown with 28 t.ha-1, a condition which did not result in quality improvement. Menthyl acetate was the component obtained at the highest percentage in all treatments. At 90 DAP, plants showed a higher percentage of menthol, the second-highest oil constituent, with a content of 42.3% in plants grown without biosolid. The presence of biosolid favored menthofuran formation. As with menthol, menthone decreased with plant development. Under these conditions, plant harvesting is recommended at 90 DAP, period in which the menthol level was higher. Since the production of biosolid is on the rise, a suitable destination must be given to it, and restrictions exist for its use in relation to the environment and plants. Thus, although cultivation with 28 t.ha-1 is within the limits allowed by law, such a rate, which increased oil yield, did not improve oil quality. Therefore, biosolid from the Barueri Station is not recommended for cultivation of this specie.

The supercritical fluid extraction of fatty acids and carotenoids from the microalgae Spirulina maxima with carbon dioxide was studied. The effects of pressure and temperature on the yield and chemical composition of the extracts were assessed. The experiments were conducted at temperatures of 20−70 °C and pressures of 15−180 bar. The solvent mass flow rate was 3.33 × 10-5 kg/s. Statistical analysis showed that neither the temperature nor the pressure significantly affected the total yield, but both the temperature and the pressure affected the extraction rate, and the effect of the temperature prevailed over that of the pressure. The extracts were rich in essential fatty acids and carotenes, and at 100 bar and 45 °C the extract contained no carotenes. Temperatures larger than 50 °C degraded the carotenes, as expected. The model of Goto et al. described the overall experimental extraction curves quite well.

Lippia alba (Verbenaceae) is a shrub whose essential oil has important biological, pharmacological, and aromatizing properties. To reach the sustained cultivation of new species with economic potential, the present study aimed to evaluate L. alba performance for fresh leaf matter (FM), leaf dry matter (DM), virus symptoms (VS -Cucumber mosaic virus, CMV), oil yield (OY), and oil chemical composition (OC), and to evaluate DM stability and adaptability. Ten genotypes of four chemical groups (chemotypes) were evaluated in six experiments designed as randomized blocks with two plants per plot, over the whole State of São Paulo, Brazil. A 2.0 × 0.4 × 1.6 m spacing was used in Monte Alegre do Sul and Pindorama, while a 1.0 × 0.4 × 0.6 m spacing was used in Campinas, where four experiments were established under different irrigation and fertilization conditions. The genotype effect was significant (p < 0.05) for all traits evaluated, with high leaf productivity of IAC-16 (citral chemotype), best OY means in the linalool and limonene/carvone chemotypes, and susceptibility of the latter chemotype to CMV. The genotype performance oscillations in the six environments were significant for FM and DM, and despite their significance for phytochemical traits (OY and OC), they were of low magnitude. No qualitative variation was detected for OC. The IAC-2 (linalool) and IAC-13 (limonene/carvone) genotypes showed high stability and wide adaptability, and are recommended to establish initial cultivations of this species. This research also indicated genetic sources to start Lippia alba genetic breeding programs. IAC-1 to IAC-4 (linalool), IAC-9 to IAC-11 (myrcene/ camphor), IAC-13 and IAC-14 (limonene/carvone), and IAC-16 (citral). Plants were selected based on differences in plant morphology, oil yield, and the relative proportions of substances in the oil. Six experiments were carried out in three regions of the State of São Paulo (SP), Brazil, in a randomized block design, with four replicates and two plants (clones) per plot. Four experiments were installed in Campinas (22°31' S, 47°02' W, 680 m), representing four environments (E1 -with both fertilization and irrigation; E2 -with fertilization but no irrigation; E3 -no fertilization but with irrigation; E4 -no fertilization nor irrigation). As to fertilization, two sidedressing applications of the 04-14-08 (N, P 2 O 5 , K 2 O) fertilizer were made, and a drip irrigation system was used. A row spacing of 1.0 m was adopted in these four experiments (environments), with 0.4 m between clones and 0.6 m between plots. The other two experiments were carried out in Monte Alegre do Sul (22°24' S, 46°24' W, 760 m) (E5) and Pindorama (21°06' S, 48°32' W, 534 m) (E6), with a row spacing of 2 m, 0.4 m between clones, and 1.6 m between plots, under a sprinkler irrigation system.

Recebido em 21/9/05; aceito em 17/7/06; publicado na web em 19/1/07 VOLATILE COMPOUNDS PROFILE AND FLAVOR ANALYSIS OF YERBA MATE (Ilex paraguariensis) BEVERAGES. Volatile compounds from green and roasted yerba mate were analyzed by gas chromatography/mass spectrometry and the flavor profile from yerba mate beverages was determined by descriptive quantitative analyses. The main compounds tentatively identified in green mate were linalool, α-terpineol and trans-linalool oxide and in roasted mate were (E,Z)-2,4-heptadienal isomers and 5-methylfurfural. Green mate infusion was qualified as having bitter taste and aroma as well as green grass aroma while roasted mate was defined as having a smooth, slightly burnt aroma. The relationship between the tentatively identified compounds and flavor must be determined by olfatometric analysis.Keywords: yerba mate; volatile compounds; flavor. INTRODUÇÃOUma das questões fundamentais para a área de alimentos é a relação entre a qualidade percebida pelo consumidor e a presença de compostos responsáveis por seu sabor e aroma, parâmetros essenciais da qualidade de alimentos. Esta abordagem impacta diretamente na indústria, através da definição de índices que se relacionam com a qualidade e, portanto, com o valor agregado do produto 1 . No caso de infusões, como as de Camellia sinensis (chá verde, oolong e chá preto), o sabor determina a qualidade do produto e seu preço de mercado, evidenciando a importância do conhecimento das rotas bioquímicas de geração dos compostos voláteis, que são em grande parte responsáveis pelo aroma, durante o processamento [2][3][4][5][6][7] . As lipases presentes nas folhas liberam ácidos graxos insaturados das membranas celulares que, por sua vez, sofrem outras reações de degradação originando compostos voláteis indesejáveis para este produto, como trans-2-hexenal. A degradação de carotenóides leva à formação de compostos responsáveis pelo aroma doce e agradá-vel. A conversão de β-caroteno em β-ionona e outros compostos com ionona substituinte e/ou seus produtos de oxidação, bem como a conversão de outros carotenóides em linalol, aldeídos terpênicos e cetonas já foram relatadas e são dependentes da concentração e do tipo de carotenóide presente nas folhas, bem como da presença de antioxidantes, notadamente os polifenóis. Os aminoácidos originam aldeídos que podem ser oxidados a ácidos carboxílicos ou reduzidos a álcoois. A fenilalanina, por ex., sofre desaminação para originar o fenilacetaldeído, composto com aroma floral [1][2][3][4]6 .A caracterização da qualidade sensorial de chás depende dos compostos voláteis que dão origem a índices de qualidade, como o VFC ("Volatile Flavor Compounds") e o índice de terpenos ("terpene index") 1 . Os chás considerados mais aromáticos apresentam maiores teores de linalol e seus óxidos e baixos teores de hexanal 3,4,8 . A erva-mate é uma planta originária da América do Sul, consumida habitualmente na Argentina, Paraguai, Uruguai e Brasil. Das folhas secas desta planta produz-se o tererê e o chimarrão (bebidas à ba...