ABSTRACT
The flours obtained from peach palm by-products are rich in dietary fiber (62-71%) and they can be used as food ingredients. The aim of this work was to investigate the carbohydrate composition of the flours processed from the residual parts (stem and median sheath) of a hearts-of-palm industry. The flours were fractionated, based on their solubility, whose monomeric compounds were determined. The fraction containing mostly cellulose (S5) was the most abundant (26-28%), followed by the sum of fractions (S2, 53, S4) extracted with alkaline solutions (21-22%). The S1 fraction contained the highest percentage of uronic acids, which characterizes the presence of pectin. Xylose and arabinose were found in high proportion in S2 and S3 fractions. The S4 and S5 fractions, rich in glucose, were the main portion of the cell wall material and correspond to the insoluble fraction of the dietary fiber.
Subject(s)
Arecaceae/chemistry , Flour/analysis , Monosaccharides/chemistry , Polysaccharides/chemistry , Arabinose/analysis , Arabinose/isolation & purification , Arecaceae/metabolism , Cellulose/analysis , Chromatography, High Pressure Liquid , Chromatography, Ion Exchange , Dietary Fiber/analysis , Monosaccharides/analysis , Monosaccharides/isolation & purification , Plant Stems/chemistry , Plant Stems/metabolism , Polysaccharides/analysis , Polysaccharides/isolation & purification , Principal Component Analysis , Solubility , Uronic Acids/analysis , Uronic Acids/isolation & purification , Xylose/analysis , Xylose/isolation & purificationABSTRACT
O emprego do calor é uma alternativa utilizada com a finalidade de garantir a inocuidade, melhorar características sensoriais e aumentar a digestibilidade dos vegetais, tornando-os aptos ao consumo de crianças. No entanto, condições severas de calor podem alterar a sua composição nutricional. O objetivo deste trabalho foi avaliar o efeito do calor seco ou úmido, antes da moagem, na composição química de farinhas integrais de grãos de amaranto (Amaranthus cruentus). As farinhas foram produzidas de grãos integrais in natura (FIAI), tostados (FIAT), cozidos e secos (FIAC) e pipocados (FIAP). Os tratamentos térmicos aplicados aos grãos não afetaram os teores de minerais das farinhas, com exceção do Ca e Cu, mas elevaram os teores de lipídios (12 a 19%) e de fibra solúvel (18 a 35%) e reduziram de fibra insolúvel (5,8 a 8,5%) em comparação com à in natura. Os aminoácidos sulfurados foram os primeiros limitantes na FIAI, para idades de 1 a 10 anos e o pipocamento reduziu a qualidade aminoacídica do grão, que passou a ser limitante, também, em lisina para todas as idades. A tostagem e a cocção melhoraram o balanço aminoacídico das farinhas e os aminoácidos sulfurados deixaram de ser limitantes para maiores de três anos.
The use of heat is an alternative to ensure the safety, improve sensory characteristics and increase digestibility of vegetables, making them suitable for children consumption. However, severe heat conditions may alter its nutritional composition. The objective of this study was to evaluate the effect of dry or humid heat before milling in chemical composition of whole amaranth (Amaranthus cruentus) grain flours. The flours were produced from in nature whole grains (UGF), toasted (PGF), cooking and dried (CDF) and popping (PGF). The heat treatments applied to grains did not affect the mineral contents of the flour, with the exception of Cu and Ca. However, the treatment elevated the levels of lipids (12-19%) and soluble fiber (18-35%) and reduced the insoluble fiber (5.8-8.5%) of the flour when compared to in nature. The sulfur amino acids were first limiting in UGF, for 1-10 years old and the popping reduced the quality of the amino acids which has become limiting, too, in lysine, for all ages. The toasting and cooking improved the balance of amino acids of flours obtained and the sulfur amino acids ceased to be the limiting for children over three years.
ABSTRACT
This study investigated the enzymatic treatment of soy slurry using Viscozyme L to hydrolyze the carbohydrates. The optimum temperature of Viscozyme L action was 55 °C. The increase of glucose and galactose content in tofu (1.36 and 0.19 g/100 g, respectively) confirmed the Viscozyme activity on soy slurry when compared to the control. The treated tofu had more total phenolics than the control (173 and 161 mg gallic acid equivalents/100 g freeze-dried tofu, respectively) and higher antioxidant activity by the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt and 1,1-diphenyl-2-picryhydrazyl,2,2-diphenyl-1-picryhydrazyl radical tests. Total reducing sugar (glucose equivalents) content in treated tofu was approximately four times higher than that in the control under the optimum conditions (30 Fungal Beta-Glucanase units/10 g solids, 55 °C, 30 min). The tofus differed in the sensory analysis for soy odor and surface uniformity, but there was no preference for one over the other.
