Polissacarídeos extraídos da gabiroba (Campomanesia xanthocarpa Berg): propriedades químicas e perfil reológico

Abstract

Resumo:A Campomanesia xanthocarpa Berg (Myrtaceae) é uma frutífera nativa brasileira, com ampla distribuição natural na região Sul. Embora apresente frutificação abundante, produza frutos com características sensoriais e nutricionais atrativas, esses não são coletados e se perdem nos campos. Neste trabalho, a polpa do fruto sem semente (1500 g) foi triturada em etanol / água na proporção de 1:4 (v/v), refluxada por 15 minutos em temperatura de ebulição. O resíduo obtido foi submetido a extrações sequenciais. As extrações foram otimizadas utilizando um planejamento fatorial 2 2 , tendo como variáveis a concentração do ácido cítrico (0,5 e 5%) e a temperatura (50 e 100 °C). Os polissacarídeos provenientes de diferentes extrações foram caracterizados quanto à composição química e perfil reológico. Os altos teores de ácidos urônicos, arabinose e galactose detectados em todas as frações, indicam que estas são constituídas por polissacarídeos pécticos. Os polissacarídeos extraídos da polpa da gabiroba apresentaram um comportamento pseudoplástico. Todas as frações apresentaram como característica resistência frente às variações de temperatura. Quando submetidas a ciclos de aquecimento e posterior resfriamento estes géis retornam à sua estrutura original. Palavras-chave: Pectina, reologia, composição química. Polysaccharide Isolated From Gabiroba (Campomanesia xanthocarpa Berg): Chemical Properties and Rheology ProfileAbstract: The Campomanesia xanthocarpa Berg (Myrtaceae) is a Brazilian native fruit, widely abundant in the Southern region. Despite their large fructification, in addition to nutritional and attractive sensory characteristics, these fruits are not collected, being lost in the fields. In this work, the fruit pulp without seed (1500 g) was crushed in ethanol/water at a ratio of 1:4 (v/v), refluxed for 15 minutes at boiling temperature. The residue obtained was subjected to sequential extractions. The extractions were optimized using a factorial design 2 2 , with the concentration of citric acid (0.5 and 5%) and temperature (50 and 100 °C) as variables. The polysaccharides were characterized according to their chemical composition and rheological profile. The high concentrations of uronic acids, arabinose and galactose, detected in all fractions, indicate that they consist of pectin. The results showed that the extraction method was efficient for fractionation of pectin from different areas of the cell wall. The polysaccharides extracted from the fruit pulp of gabiroba showed a pseudoplastic behavior. All the fractions were resistant to temperature variations. When these gels are heated up and cooled down, they adopt their original structure. Keywords: Pectin, rheology, chemical composition. IntroduçãoPectinas são heteropolissacarideos complexos encontrados na parede celular primária e nas camadas intercelulares dos vegetais. Estão associadas aos polissacarídeos estruturais, contribuindo para adesão entre as células e para a resistência mecânica da parede celular [1] . Estruturalmente, as pectinas são consti...

Pectina: da matéria-prima ao produto final

“…Estudos de pesquisadores do Brasil com resultados relacionados à pectina foram conduzidos na gabiroba [64][65][66] , amorapreta [67,68] , morango e framboesa [68] , pequi [69] , abacaxi [70] , casca de maracujá [54,71,72] , goiaba [73] , maçã [33,34,38,[74][75][76] .…”

Characterization of biopolymers and soy protein isolate-high-methoxyl pectin complex

“…The soy protein isolate (SPI) contains at least 90% protein; it is thus virtually free from lipids and carbohydrates [2] . Pectin, probably the most complex natural macromolecule, is the most common stabilizer used in protein-based acidic beverages, positively contributing to the final product's taste, stability, and texture, even if it is added in small amounts [3][4][5] . Although pectins are part of the majority of plant tissues, the number of commercial sources used is very limited [4] .…”

“…Pectin, probably the most complex natural macromolecule, is the most common stabilizer used in protein-based acidic beverages, positively contributing to the final product's taste, stability, and texture, even if it is added in small amounts [3][4][5] . Although pectins are part of the majority of plant tissues, the number of commercial sources used is very limited [4] . The mainly polysaccharide used is derived from citric fruit and classified regarding the degree of esterification in: high-methoxyl pectins, when a half or more carboxyl groups are esterified, and low-methoxyl pectins, when less than a half the carboxyl groups are esterified [6] .…”

Physicochemical characterization of fruits of <i>Campomanesia guazumifolia</i> (Cambess.) O. Berg (Myrtaceae)

“…In similar studies, contents of 5.89, 5.7, and 0.72% of pectin in dry mass were reported for gabiroba, guava and araçá-do-campo, respectively. In addition, 0.258% was reported for gabiroba-do-cerrado, the latter being evaluated in fresh mass content (Santos, Petkowicz, Haminiuk, & Cândido, 2010;Abreu, Santos, Abreu, Corrêa, & Lima, 2012;Morzelle et al, 2015).…”