Estudo do comportamento da lipase comercial Lipozyme RM IM em reações de esterificação para obtenção de biodiesel

The aim of this work was to study monoalkyl ester synthesis catalyzed by immobilized lipase Lipozyme RM IM via the esterification reaction. Yields of over 90% were obtained with butanol in esterification reactions with oleic acid. In the reactions with deodorizer distillates of vegetable oils and butanol, the conversion obtained was greater than 80% after 2.5 h. For the esterification reaction of palm fatty acid deodorizer distillate (PFAD) and butanol, seven reuse cycles of Lipozyme RM IM were carried out and the final conversion was 42% lower than the initial conversion.

Traditional Chinese materia medica: a retrospect and prospect

For thousands of years, traditional medicine and remedies have been practed and used in the fight against disease in China. They have proved to be valuable and the distillate of vast historical experience based on field-tested human experiments, long-term observations and clinical trials. The Chinese people belive that traditional medicine is consistent with theirown culture. Endowed with a unique theoretical system and provided outstanding clinical results, traditional Chinese medicine continues to play an important role in helping the Chinese nation flourish. The recent study of traditional medicinal plants in Chine has given us confidence that what was recorded in ancient medical literature through empirical observations is indeed still coindicent with the concepts of modern chemistry, pharmacology and medicine. The task of revealing what is valid and efficacious should be retained, and what is mythic and invalid should be discarded in traditional Chinese medicine may require scientific research lasting for several generations. Therfore, multidisciplinary cooperation and international collaboration in this field would be essential. Systematic coordination of work in traditional medicine by word organizations, national governments, private foundations and individual scientists is a requisite as well.

Spittlebug impacts on sugarcane quality and ethanol production

The objective of this work was to evaluate the impacts of spittlebug (Mahanarva fimbriolata) attack on sugarcane quality and ethanol production. Technological and microbiological parameters of juice and fermentation process were evaluated in ten fermentation cycles and two harvest seasons. Treatments consisted of different spittlebug stalk damage levels: control, with 100% of apparently healthy stalks; medium, with 15% of damaged or dry stalks (DDS); high, with 30% of DDS; and very high, with 60% of DDS. Spittlebug attack caused significant losses in cane quality, reducing total soluble solids, sucrose content, total reducing sugars, and pH, and increasing total phenolic compounds, and total and volatile juice acidity. The fermentation process was also significantly affected, resulting in lower ethanol content in wine. There was an increase in acetaldehyde concentration in the distillate. The spittlebug attack caused negative impacts on sugarcane quality and fermentation process, and these impacts are stronger in late season harvests.

Identificação e quantificação do cristal violeta em aguardentes de mandioca (tiquira)

Tiquira is a traditional homemade alcoholic distillate produced in the Maranhão State (Brazil), gotten from cassava (Manihot esculenta, Crantz.). It can be normally found on street markets. Due to the addition of tangerine leaves, the original tiquira has a bluish color. Samples of this beverage were acquired in the local trade and analyzed from the spectroanalytical point of view. The results indicated that these drinks had been adulterated by the addition of crystal violet, a potencialy hazardous compound. The identification and quantification of crystal violet in 10 spiked samples was accomplished by UV-Vis spectrophotometry through the standard addition method. In order to verify the efficiency of the proposed method, experiments on the quantification and recovery were carried out and the results indicated a content of crystal violet in the 10-6 to 10-7 mol L-1 range.

Chemical profile of sugarcane spirits produced by double distillation methodologies in rectifying still

The objective of this study was to determine the chemical profile of sugarcane spirits produced by different double distillation methodologies in rectifying still. Fermented sugarcane juice was distilled in rectifying still according to three double distillation methodologies: the methodology used for cognac production; the methodology used for whisky production; and the 10-80-10 percentage composition methodology, referring to the volumes of head, heart and tail of the distillate fractions from the second distillation. For comparison purposes, a simple distilled spirit was also produced. The distillates were analyzed for concentrations of ethanol, copper, volatile acidity, furfural and hydroxymethylfurfural, aldehydes, esters, methanol and higher alcohols. The spirits were also evaluated on the sensory attributes of aroma, taste and preference. Compared to simple distillation, double distillation improved the chemical quality of the spirits, since it has reduced the concentrations of acids, aldehydes, esters, methanol, higher alcohols and, consequently, their coefficient of congeners. Regardless of the methodology employed, the double distillation improved the sensory quality of the spirits since they obtained higher sensory acceptance in relation to spirits produced by simple distillation. Among double distilled spirits, the one produced according to whisky methodology obtained the best scores from appraisers on the aroma and flavor parameters and it was also the most preferred.

Characterization and extraction of volatile compounds from pineapple (Ananas comosus L. Merril) processing residues

The aim of this study was to extract and identify volatile compounds from pineapple residues generated during concentrated juice processing. Distillates of pineapple residues were obtained using the following techniques: simple hydrodistillation and hydrodistillation by passing nitrogen gas. The volatile compounds present in the distillates were captured by the solid-phase microextraction technique. The volatile compounds were identified in a system of high resolution gas chromatography system coupled with mass spectrometry using a polyethylene glycol polar capillary column as stationary phase. The pineapple residues constituted mostly of esters (35%), followed by ketones (26%), alcohols (18%), aldehydes (9%), acids (3%) and other compounds (9%). Odor-active volatile compounds were mainly identified in the distillate obtained using hydrodistillation by passing nitrogen gas, namely decanal, ethyl octanoate, acetic acid, 1-hexanol, and ketones such as γ-hexalactone, γ-octalactone, δ-octalactone, γ-decalactone, and γ-dodecalactone. This suggests that the use of an inert gas and lower temperatures helped maintain higher amounts of flavor compounds. These data indicate that pineapple processing residue contained important volatile compounds which can be extracted and used as aroma enhancing products and have high potential for the production of value-added natural essences.