Chemical, morphological, rheological and thermal properties of Solanum lycocarpum phosphorylated starches

Abstract

RESUMO Características químicas, morfológicas, reológicas e térmicas de amidos fosfatados da Frutado-lobo (Solanum lycocarpum)Em vista da necessidade de amidos com características específicas, é fundamental o estudo de amidos não convencionais e de suas modificações, de acordo com as exigências do mercado consumidor. O objetivo deste trabalho foi estudar as características físico-químicas de amidos nativo e fosfatado da S. lycocarpum. O amido foi fosfatado com tripolifosfato de sódio (de 5 a 11%), sob agitação. Determinaram-se a composição química, a morfologia, a densidade, a capacidade de ligação à água fria, o poder de inchamento e o índice de solubilidade, a turbidez e a sinerese, as propriedades reológicas e calorimétricas. Não se detectou fósforo na amostra nativa, porém, a fosfatação gerou amidos modificados com teores de fósforo de 0,015, 0,092 e 0,397%, que se caracterizaram por absorver maior quantidade de água, a frio e a quente. Os resultados reológicos mostraram a forte influência do teor de fósforo na viscosidade dos fosfatados, apresentando temperatura de empastamento menor e viscosidade de pico maior que as do amido nativo. A Chemical, morphological, rheological and thermal properties of Solanum lycocarpum phosphorylated starchesThe increasing need for starches with specific characteristics makes it important to study unconventional starches and their modifications in order to meet consumer demands. The aim of this work was to study physicochemical characteristics of native starch and phosphate starch of S. lycocarpum. Native starch was phosphated with sodium tripolyphosphate (5-11%) added with stirring. Chemical composition, morphology, density, binding ability to cold water, swelling power and solubility index, turbidity and syneresis, rheological and calorimetric properties were determined. Phosphorus was not detected in the native sample, but the phosphating process produced modified starches with phosphorus contents of 0.015, 0.092 and 0.397%, with the capacity of absorbing more water, either cold or hot. Rheological data showed the strong influence of phosphorus content on viscosity of phosphate starch, with lower pasting temperature and peak viscosity higher than those of native starch. Enthalpy was negatively correlated with the phosphorus content, requiring 9.7; 8.5; 8.1 and 6.4 kJ g -1 of energy for the transition from the amorphous to the crystalline state for the starch granules with phosphorus contents of 0; 0.015; 0.092 and 0.397%, respectively. Cluster analysis and principal component analysis showed that starches with 0.015 and 0.092% phosphorus have similar characteristics and are different from the others. Our results show that the characteristics of phosphate modified S. lycocarpum starch have optimal conditions to meet the demands of raw materials, which require greater consistency in stickiness, combined with low rates of retrogradation and syneresis.

Corn and Pinhão Starches Modified with Sodium Tripolyphosphate: Thermal, Pasting, Structural and Morphological Properties

“…The same tendency with respect to pasting temperature and peak viscosity was found by Ascheri [26] for STTP-modified Solanum lycocarpum starch. The authors pointed out that the increase in the viscosity peak is possibly due to the presence of intermolecular forces that strengthen the amorphous region of the starch granules.…”

“…In addition, possible differences found for the DS of the phosphate groups may be related to the conditions used during the modification, such as temperature, pH adjustment and concentration used . According to Ascheri et al, the phosphorus content is directly linked to the concentration of STPP used in phosphating. Besides that, the amount of water is also fundamental, since it favours the selectivity of the reaction between the reactants and the starch chains …”

Effect of Ball Milling Treatment on Thermal, Structural, and Morphological Properties of Phosphated Starches from Corn and Pinhão

“…As expected, the calculated ash content of phosphate starches was higher than that of native starch due to the incorporation of phosphorus . The ash content decreased after ball milling treatment.…”

“…As expected, the calculated ash content of phosphate starches was higher than that of native starch due to the incorporation of phosphorus. [1,36] The ash content decreased after ball milling treatment. These data corroborated the results of the WDXRF analysis (Table 1), whose phosphorus and sodium content was reduced after treatment.…”

Phosphorylated Starches: Preparation, Properties, Functionality, and Techno‐Applications

“…Ascheri et al. [ 72 ] prepared PS from S. lycocarpum using STPP (5–11%) added with stirring. The functional traits of PS had optimal properties to meet the demands of functional materials that require high consistency in stickiness, combined with low levels of retrogradation.…”