Claudio Lima de Aguiar

Structural and physicochemical characteristics of starch from sugar cane and sweet sorghum stalks.

The starch present in sugar cane and sorghum juice has been considered a problem to the sugar industry. The objective of this work was to study the structural and physicochemical characteristics of the starch present in sugar cane and sweet sorghum. Sugar cane and sweet sorghum starches presented small granules (maximum 5.9 and 7.9 μm), A-type diffraction pattern, high degree of relative crystallinity (44.4 and 42.0%), and low amylose content (17.5 and 16.4%), respectively. Sugar cane starch presented more uniformity in granule shape and size, more homogeneity in amylose chain length, higher number of long lateral chains of amylopectin, and higher susceptibility to enzymatic digestion. Besides being in higher amount in the juice, sweet sorghum starch presented lower values for thermal properties of gelatinization, as well as higher swelling factor, which can cause more problems during processing. Additional studies are needed to evaluate the variety and maturity influence on these properties.

Residual biomass potential of commercial and pre-commercial sugarcane cultivars

Sugarcane (Saccharum spp.) is an efficient and sustainable alternative for energy generation compared to non-renewable sources. Currently, during the mechanized harvest process, the straw left in the field can be used in part for the second generation ethanol and increasing the electric energy production. Thus, this study aimed to provide information on the potential for residual biomass cultivars of sugarcane cropping system. This study provides the following information: yield of straw, depending on the calculated leaf area index and the number of tillers per linear meter; primary energy production of several sugarcane genotypes; contribution of dry tops and leaves; biomass yield; and evaluation of fiber, cellulose, hemicellulose and lignin. Preliminary results obtained by researchers of the State of Sao Paulo, Brazil, and reCviews related studies are presented. The results suggest that the production of sugarcane straw content varies according to the cultivars; the greater mass of sugarcane straw is in the top leaves and that the potential for the crude energy production of sugarcane per area unit can be increased using fiber-rich species or species that produce more straw. The straw indexes was shown to be a good indicator and allow the estimation of straw volumes generated in a sugarcane crop. The cellulose, hemicellulose and lignin composition in sugarcane is distinct among varieties. Therefore, it is possible to develop distinct biomass materials for energy production and for the development of sugarcane mills using biochemical processes and thermal routes.

Physiological development of cagaita (Eugenia dysenterica).

It was evaluated the physiological aspects of the cagaita (Eugenia dysenterica) development, from anthesis to ripening. The fruits have been subjected to physical and chemical analysis during the fruit life cycle. The total fruit development comprised 37days. There was a steady increase in the total mass of the fruits and significant increase in transverse and longitudinal diameter, adjusting the double sigmoidal behavior in response to changes in the time. From the 23rd DAA, it was observed the beginning of loss of firmness, increase in total and soluble pectin content and a decrease in starch content. It occurred degradation of total chlorophyll and unmasking of carotenoids from 31st days after anthesis. A decrease in pH and, therefore, increase in acidity, low soluble solids content. The sucrose content was extremely low during the cycle. At the end of development, the respiratory and ethylene production peak was observed, suggesting climacteric behavior.

Criegee mechanism as a safe pathway of color reduction in sugarcane juice by ozonation

The production of crystal sugar is based on sugarcane juice clarification through sulphitation, that is, heat treatment with sulfur dioxide. The use of ozonation as an alternative to sulphitation aims to eliminate the disadvantageous presence of residual sulfite in crystal sugar. Both treatments are used to reduce color of sugarcane juice. The objective of this work was to evaluate two process parameters (temperature and pH) to reduce gallic acid, a low molecular weight pigment (MW 170gmol-1) widely found in sugarcane. Gallic acid was used as a model compound in sucrose solutions. The results showed that degradation of gallic acid was favored from pH 7.0 to 7.82 and temperature values between 50 and 70°C. The reaction mechanism was proposed for gallic acid degradation by ozone based on Criegee mechanism. Ozonation was an efficient method to reduce the potential low molecular weight pigment present in the sugarcane.

Metabolomics and Agriculture: What Can Be Done?

The importance of Brazil as a producer and exporter of food and feed will continuously increase. Despite the recent economic and political problems in Brazil, the scientific field is expanding. ABSTRACT The importance of Brazil as a producer and exporter of food and feed will continuously increase. Despite the recent economic and political problems in Brazil, the scientific field is expanding. Cutting-edge technology has only recently become available in the country, and we can now also join efforts with the global community to tackle global challenges. Using metabolomics based on mass spectrometry approaches to understand system-wide metabolism and metabolic pathways can have a significant impact in the society. With the recent development of a platform for organization and sharing of tandem mass spectrometry data, the global community can now work with complex biological samples. In this Perspective, we aim to describe how challenges and problems in global and local agriculture can be addressed using metabolomics based on mass spectrometry strategies.

Clarificação de caldo de cana-de-açúcar por peróxido de hidrogênio: efeito da presença de dextrana

The quality of crystal sugar is directly associated with the quality of the sugarcane (Saccharum s.p.) delivered to the mills and to the efficiency of the industrial process. Dextran is considered to be a quality parameter of the raw material, since its presence indicates the sugarcane suffered deterioration between the cutting and processing steps. During processing of the juice, dextran can interfere in the process efficiency. In the clarification step, the main objective of sulphiting is to promote a reduction in the ICUMSA colour of the sugarcane juice. The ICUMSA colour is the most important parameter for the classification of commercial sugar in Brazil and the lower the ICUMSA colour the whiter the sugar. Hydrogen peroxide (H2O2) has been studied as a possible clarifying agent to replace sulphite in the clarification of sugarcane juice, since sulphite has some contraindications for human respiratory health. The objective of the present work was to determine the impact of the presence of dextran on the efficiency of the reduction in ICUMSA colour of sugarcane juice by peroxidation. During peroxidation, the temperature and pH significantly influenced the reduction in ICUMSA colour of the juice, increases in temperature, increases in the dose of hydrogen peroxide and decreases in the pH, all leading to decreases in ICUMSA colour. The values for dextran used (up to 1,000 ppm) showed no significant influence on the colour of sugarcane juice, however they showed significant interactions with other parameters.

Caracterização química de extratos etanólicos de própolis com atividade inibitória do crescimento de estafilococos isolados de mastite bovina

A mastite e uma doenca multifatorial de grande importância para a pecuaria e a industria do leite, acarretando serios prejuizos economicos decorrentes da diminuicao da secrecao lactea ou da perda total desta capacidade. O trabalho teve como objetivo avaliar a atividade antimicrobiana dos extratos etanolicos de propolis coletadas de regiao de Mata Atlântica da Bahia e Alagoas contra bacterias do genero estafilococos isoladas de mastite bovina. Conclui-se que houve diferenca na atividade inibitoria contra os microrganismos Staphylococcus aureus e Staphylococcus sp. analisados neste estudo, sendo o maior potencial encontrado na amostra de propolis do tipo-6 contra uma cepa de S. aureus (Sa-2) com cerca de 75% da atividade inibitoria do controle-positivo (gentamicina).

Spittlebugs produce foam as a thermoregulatory adaptation

Insects have evolved multiple mechanisms to adapt to variations in environmental temperatures, including postural control of solar input, variations in diurnal activity, external morphological structures and selecting/generating microhabitats. Foam produced by Mahanarva fimbriolata nymphs (also known as root spittlebugs) was found to aid in creating a constant thermal microhabitat despite environmental temperature fluctuations. The temperature within the foam was found to be similar to that of soil during the day and remained constant despite fluctuating external temperatures. In chemically analysing the composition of the foam, palmitic and stearic acids, carbohydrates and proteins were detected. These substances have previously been shown to act as a surfactant to stabilize and modulate foams. Since the immature ancestor of the spittlebug developed below ground, it is speculated that the foam may function as an ‘extension’ of the soil and, thus, may have enabled the spittlebug to emerge from the soil and adopt an epigean lifestyle.

Sugarcane Juice Clarification by Hydrogen Peroxide: Predictions with Artificial Neural Networks

Abstract: Hydrogen peroxide has been studied as an alternative for sulfur in the white sugar industry. Sulfur has been associated to allergic diseases, mainly asthma. In this study, artificial neural network (ANN) models are proposed to predict the effects of different variables (peroxidation time, temperature, pH, H2O2 dosage, and initial °Brix) on sugarcane juice color removal and sucrose content. Experimental results and the ANN models revealed that temperature showed the greatest influence on the decrease of juice color; nevertheless, the effect of temperature depended on pH: at pH<;5.0 a decrease in juice absorbance was observed at temperatures close to 38u2006°C, whereas in the pH range of 5.0–6.3, absorbance decreased only at about 50–62u2006°C, regardless of the amount of hydrogen peroxide used. On the other hand, the remaining sucrose content after peroxidation was influenced by the initial °Brix and by pH.

Sugarcane cells as origin of acid beverage floc in cane sugar

Brazil stands out as the largest producer of crystal sugar in the world, exporting much of its production to the soft drinks industry. However, the chemical composition of sugar may contain numerous compounds that promote the formation of acid beverage flocs (ABF), reducing product acceptance. This study aimed to identify the chemical composition of ABF using different analytical techniques. We could observe the ABF are formed by several chemical classes. Regarding the histochemical analysis, we observed the presence of cellular sugarcane tissues, which are not fully removed in sugarcane processing. Mineral compounds, such as silicon, were found in great amounts by the Scanning electron microscopy and energy dispersive system (SEM/EDS) analysis. The mass spectrometry, high resolution mass by Q-ToF analysis and MALDI-MS allowed identification of compounds, such as p-hydroxybenzaldehyde, vanillin, triacontanoic acid, hexadecanoic acid, octadecanoic acid and n-octacosanoic acid, in the ABF composition. These compounds are widely found in vegetable tissues, confirming that the ABF are formed by tiny particles of plant cells of sugar cane.