Marcelo Angelo Cirillo

Influência da secagem do pequi (Caryocar brasiliense Camb.) na qualidade do óleo extraído

Pequi (Caryocar brasiliense Camb) has stood out for being an oleaginous fruit rich in carotenoids. Drying is widely used technique in the oil extraction process using hexane, but the degradation of oil and carotenoids may occur. The objective of this study was to evaluate the influence of different drying methods (sun, air-circulated drier at 40 and 60 °C) and time (4 hours and up to constant weight) on the yield and quality of the oil extracted using hexane using a soxhlet apparatus. When the pequi pulp was dried up to 3% or even lower, more oil yield was obtained (52-59%, dry basis). The total carotenoids contents obtained were higher and the peroxide index was lower for the pulp dried at 40 °C in an air-circulated drier when compared to drying at 60 °C in an air-ventilated drier and to sun drying technique. These results indicate that drying in an air-circulated drier at 40 °C for 19 hours resulted in higher oil yields with less heat degradation.

Influences of convective and vacuum drying on the quality attributes of osmo-dried pequi (Caryocar brasiliense Camb.) slices

Pequi is a fruit from Brazilian Cerrado. Despite its ascorbic acid and carotenoid contents, consumption of pequi is restricted to its region of origin. The goal of this work was to study drying of pequi slices (convective or vacuum drying at 40°C and 60°C) preceded or not preceded by osmotic pretreatment (sucrose solution concentrations of 40% and 60%). It was found that osmotic dehydration pretreatment substantially decreased the moisture content, duration of the drying process, and the volumetric ratio of the dried product. However, it also promoted leaching of bioactive constituents, such as ascorbic acid and carotenoids. Vacuum and low temperature drying without osmotic pretreatment were preferable because the ascorbic acid and carotenoids were retained, rehydration coefficients were higher and there were minimal volume and color changes.

Optimization of the components of an energetic diet for Africanized bees through the modelling of mixtures

Summary The Africanized bee Apis mellifera in Brazil possess a migratory tendency when there is a lack of food, so for that reason, it is common for beekeepers to supply an energetic diet to encourage fixed apiculture. This often consists of sucrose inverted using lemon juice, as beekeepers in remote rural areas cannot obtain citric acid for this purpose. In order to determine the optimum composition for these energetic diets, it is necessary to carry out both laboratory and field studies, to evaluate different proportions among the components usually used by the beekeepers for this supplementary feed. For these experiments, an appropriate statistical methodology, for instance, using the modelling of mixtures, allows a reduction in the number of treatments necessary. The present work studied the optimization of the following components: water, sugar and lemon juice, used in an energetic diet to maximize the longevity of bees kept in the laboratory. Our results showed that the optimum mixture was 47.50% water, 46.25% granulated sugar together with 6.25% lemon juice.

Selecting A Probabilistic Model Applied To The Sensory Analysis Of Specialty Coffees Performed With Consumer

Sensory analysis of cafes assumes that a sensory panel is formed by trained panelists according to recommendations of the American Specialty Coffee Association. However, the choice that determines the preference of a coffee is routinely done through experimentation with consumers, in which largely presents no particular skill in terms of sensory characteristics. Upon this fact, this study aimed to conduct a study considering several probabilistic distributions belonging to the class of generalized extreme value, considering a sensory analysis applied to evaluation of four specialty coffees produced with different processes and at different altitudes in the mountain region of the Mantiqueira state of Minas Gerais. For this analysis, we considered a sensory panel trained to untrained consumers. It was found that the extreme value distribution was the best fit and the final note that the odds of a consumer to submit a maximum score was 9.0 points lower. Therefore, there is evidence to conclude that an efficient identification of specialty coffees produced in this region made by consumers requires more intensive training.

Desiccation sensitivity from different coffee seed phenological stages 1

Maturity stage and drying method are the factors that most influence coffee seed quality. The objective of this study was to assess the physiological quality and investigate the electrophoretic patterns of catalase and endo-s-mannanase enzymes and heat resistant proteins in coffee seeds harvested at different phenological stages and dried under different conditions. Physiological quality was assessed when the seeds had developed the green, greenish-yellow, cherry, overripe and dry stages after three treatments: no drying, conventional drying and fast drying. After each treatment, the physiological quality of the seeds was assessed using the germination test and electrophoretic patterns of heat resistant proteins and the activity of catalase and endo-s-mannanase enzymes. Seeds harvested at the cherry phenological stage had the best physiological quality, and the drying process reduced quality at the cherry, overripe and dry stages. This reduction was greater under the faster drying process, but at the greenish-yellow stage, seeds had better physiological quality after slow drying. Regarding the results from electrophoretic analysis, endo-s-mannanase and catalase activities increase as the ripeness stages advance; the activity of endo-s-mannanase is directly associated with the deterioration process; the expression of heat resistant proteins increases with maturation process and is associated with seed physiological quality.

EFEITO DE DIFERENTES ESTRUTURAS DE CORRELAÇÃO NOS ÂNGULOS FORMADOS ENTRE COMPONENTES PRINCIPAIS E INTERPRETÁVEIS EM AMOSTRAS COM PRESENÇA DE PONTOS DISCREPANTES

Analise de Componentes Principais (ACP) tem como objetivo descrever a estrutura de covariâncias de um vetor aleatorio utilizando combinacoes lineares das variaveis originais. Em algumas situacoes, os coeficientes dos Componentes Principais (CP) podem nao ser facilmente interpretados devido ao numero de variaveis ou presenca de pontos discrepantes. Assim foram introduzidos os Componentes Interpretaveis (CI), os quais sao avaliados atraves do ângulo formado entre os mesmos e os Componentes Principais. O presente trabalho tem como objetivo avaliar os efeitos de diferentes estruturas de correlacao via Simulacao de Monte Carlo e estatistica circular na distribuicao dos ângulos formados entre os componentes em amostras com e sem contaminacao. Foi verificado que as estruturas de correlacao atuam de forma diferente nos ângulos, sendo a estrutura de Simetria Composta a que apresenta menores medias angulares para os primeiros componentes em situacoes de maior coeficiente de correlacao. Foi verificado tambem que a contaminacao da amostra nao atua diretamente na magnitude dos valores esperados dos ângulos.

Modelos ridge em planejamentos de misturas: uma aplicação na extração da polpa de pequi

Mixture Models can be used in experimental situations involving areas related to food science and chemistry. Some problems of a statistical nature can be found, such as effects of multicollinearity that result in uncertainty in the optimization of a dependent variable. This study proposes the application of the ridge model adapted for mixture planning considering the Kronecker (K-model) and Scheffe (S-Model) methods applied to response surfaces. The method determined the proportions of hexane, acetone and alcohol proportions that resulted in the maximum response of percentage of extracted pequi (Caryocar brasiliense) pulp oil.

Estudo da não linearidade dos modelos de Oswin e Halsey aplicados na construção de isotermas

A study of Oswin and Halsey non linear models applied in the construction of isotherm curves Oswin and Halsey Regression models are used in food science to adjust isotherm curves in various applications. However, since they are nonlinear models, one can question its asymptotic proprieties which in turn are related to their capacity to become linear. The purpose of this study conducted via Monte Carlo simulation, considering as independent variable levels of water activity ( a w ) was on obtaining results from the properties of nonlinearity, by measuring the intrinsic (IN) and extrinsic curvature (PE) . Both models, when considering high values of a w behaved similarly, with promising results regarding the complexity of conver gence. The results of the PE showed that in all ranges of a w evaluated the models require a parameterizati on that can guarantee a behavior closer to that of an equivalent linear model.

Avaliação de métodos de estimação intervalar para funções lineares binomiais via bootstrap infinito

This work aimed to evaluate confidence intervals of different linear functions of binomial proportions base on Wald and Walds adjusted method using the infinity bootstrap technique. Several sample sizes (ni), binomial parameters (p) and number of coefficients of the linear functions were considered. One concluded through the probabilities of binomial population confidence covered intervals that the bootstrap generalization of adjusted Walds method was efficient for linear functions whose coefficients indicated a comparison of versus the others proportion (p=0.2) considering different sample sizes.

Analysis of defects in coffee beans compared to biplots for simultaneous tables

The demand for high quality coffee has become a consolidated criterion to achieve the best prices. Currently, cooperatives evaluate the coffee beans mainly through the particle size and the number of defects in the sample. This evaluation type generates counting data that originates contingency tables from different periods or groups involving the same variables in the row and column and there may be interest in knowing if two tables are related and how much are related. These are the so-called combined tables. Statistical analysis techniques normally employed do not include categorical data in the combined tables. The aim of this study was to evaluate the incidence of different types of defects in samples of large flat coffee beans in two different harvests through the construction of biplots. The decomposition theory in single simultaneous values of double entry contingency tables was used. The results of defect counting in beans of 24 coffee samples from southern Minas Gerais, Brazil, were evaluated in the 2014 and 2015 harvests. Moreover, the association among defect types, considered within different total defect proportions in the sample, was verified based on the percentage in 17/18 sieves. It was also evaluated the relative sums of squares from the similarity and dissimilarity among the harvests. It is concluded that the simultaneous analysis technique allows better visualizing the common behavior and alterations among different harvests, distinguishing the defect types associated with each harvest and among different proportions of large flat beans.