Nesse trabalho foi estudada a produção do éster alifático octanoato de n-pentila por esterificação direta usando a enzima Lipozyme TL IM como catalisador, sendo esse éster usado como aroma na indústria de alimentos. Foi verificada a influência da concentração inicial de substratos na velocidade inicial da reação, sendo esta determinada através do consumo de ácido octanoico ao longo do tempo. Modelos cinéticos clássicos descritos na literatura não se ajustaram bem aos dados experimentais. A máxima velocidade da reação foi alcançada a 40 ºC. A enzima Lipozyme TL IM sofre inibição por substrato

In this work, the production of the aliphatic ester n-amyl octanoate by direct esterification using the enzyme Lipozyme TL IM as catalyst was studied. The influence of the initial concentration of the substrate on the initial rate of reaction was verified. The initial rate of the reaction was determined by the octanoic acid consumption over time. The kinetic models described in the literature did not fit to the experimental data. The maximum rate was reached at 40 ºC. Lipozyme TL IM was inhibited by the initial concentration of the substrate

O objetivo do presente estudo foi avaliar os compostos orgânicos voláteis produzidos por Sporidiobolus salmonicolor (CBS 2636) utilizando metil e etil ricinoleato, ácido ricinoleico e óleo de mamona como precursores. A análise dos compostos voláteis produzidos foi conduzida por Micro-Extração em Fase Sólida (MEFS). A técnica de planejamento experimental foi utilizada na avaliação das condições de extração, na qual se avaliaram a agitação (0-400 rpm), a temperatura (25-60 ºC), o tempo de extração (10-30 minutos) e o volume da amostra (2-3 mL). A identificação dos compostos foi realizada por Cromatografia a Gás com detecção por Espectrometria de Massas (CG/EM). As condições que resultaram na máxima extração foram: 60 ºC, 10 minutos de extração, sem agitação, volume de amostra de 2,0 mL e adição de solução de KCl saturada (1:10 v/v). Na bioprodução dos compostos voláteis, o efeito da agitação (120-200 rpm), da temperatura (23-33 ºC), do pH (4,0-8,0), da concentração do precursor (0,02 a 0,1%), da concentração de manitol (0 a 6%) e de asparagina (0 a 0,2%) foi avaliado. Na condição de 28 ºC, 160 rpm, pH 6,0 e com a adição de 0,02% de ácido ricinoleico ao meio, foi atingida a máxima produção dos compostos voláteis, identificados como: 1,4-butanodiol, 1,2,2-trimetilciclopropilamina, beta-ionona; 2,3-butanodiona, pentanal, tetradecano, 2-isononenal, 4-octen-3-ona, ácido propanoico e octadecano.

The aim of the present study was the assessment of volatile organic compounds produced by Sporidiobolus salmonicolor (CBS 2636) using methyl and ethyl ricinoleate, ricinoleic acid and castor oil as precursors. The analysis of the volatile organic compounds was carried out using Head Space Solid Phase Micro-Extraction (HS - SPME). Factorial experimental design was used for investigating extraction conditions, verifying stirring rate (0-400 rpm), temperature (25-60 ºC), extraction time (10-30 minutes), and sample volume (2-3 mL). The identification of volatile organic compounds was carried out by Gas Chromatography with Mass Spectrum Detector (GC/MSD). The conditions that resulted in maximum extraction were: 60 ºC, 10 minutes extraction, no stirring, sample volume of 2.0 mL, and addition of saturated KCl (1:10 v/v). In the bio-production of volatile organic compounds the effect of stirring rate (120-200 rpm), temperature (23-33 ºC), pH (4.0-8.0), precursor concentration (0.02-0.1%), mannitol (0-6%), and asparagine concentration (0-0.2%) was investigated. The bio-production at 28 ºC, 160 rpm, pH 6,0 and with the addition of 0.02% ricinoleic acid to the medium yielded the highest production of VOCs, identified as 1,4-butanediol, 1,2,2-trimethylciclopropilamine, beta-ionone; 2,3-butanodione, pentanal, tetradecane, 2-isononenal, 4-octen-3-one, propanoic acid, and octadecane.

Carotenoids are natural dyes synthesized by plants, algae and microorganisms. Application in many sectors can be found, as food dyeing and supplementation, pharmaceuticals, cosmetics and animal feed. Recent investigations have shown their ability to reduce the risks for many degenerative diseases like cancer, heart diseases, cataract and macular degeneration. An advantage of microbial carotenoids is the fact that the cultivation in controlled conditions is not dependent of climate, season or soil composition. In this review the advances in bio-production of carotenoids are presented, discussing the main factors that influence the microbial production of these dyes in different systems.

This work studied the pretreatment of sugarcane molasses (CM) and corn steep liquor (CS) for the production of carotenoids by Sporidiobolus salmonicolor (CBS 2636). The acid pretreatment removed less micronutrients than that with activated carbon and led to high removals of Cu and Mn. Reduction in optical density of the prepared medium and removal of glucose from it were 22% and 7% for CM and 95% and 38% for CS, respectively. Total carotenoids obtained with substrates pretreated with acids (541 mg/L) were higher than the results obtained when the medium was treated with activated carbon (208 mg/L).