RESUMO
Baked foams made with plantain flour (PF) and sugarcane fiber (SF) were characterized by calorimetric, mechanical, physicochemical and structural techniques in order to assess the results induced by different sugarcane concentrations and fiber size on the structure of baked foams. The addition of SF to the baked samples increased their hydrophobic properties. Thermal conductivity (TC) decreased when the concentration of SF was 10 g and 7.5 g in the baked foams. The density of the biodegradable baked foams (BBFs) decreased with decreasing concentrations of SF, observing an inverse behavior in water vapor permeability (WVP) and solubility properties. The mechanical properties of the baked foams were more influenced by the concentration of SF than by the size of SF, obtained from different sieves. The scanning electron microscopy cross-sectional images of the BBFs showed that the size of SF affected the size and number of the internal cells in the BBFs.
RESUMO
The objective of this study was to evaluate the effects of starch source and amylose content on the expansion ratio, density, and texture of expanded extrudates, as well as to investigate the structural and molecular changes that occur in starch granules as a function of extrusion. The starches employed were rice starches (8%, 20%, and 32% amylose), carioca bean starch (35% amylose), and Hylon V® corn starch (55% amylose). The extrudates from rice starches containing 20% and 32% amylose exhibited the highest expansion ratio, while, extrudates from Hylon V® corn starch containing 55% amylose exhibited the lowest expansion ratio. The hardness values of the extrudates with 55% amylose were twice those of the extrudates with 20%, 32%, and 35% amylose. An additional finding was that although the amylopectin promoted the expansion of the gelatinized starch matrix, it failed to strengthen and sustain the walls of the extrudate bubbles during expansion.
Assuntos
Amilopectina/análise , Amilose/análise , Fabaceae/química , Oryza/química , Amido/química , Zea mays/química , Análise de Alimentos , Gelatina/química , Estrutura MolecularRESUMO
Jabuticaba (Myrciaria cauliflora. Mart) is a highly perishable fruit native to Brazil, which is consumed both fresh and industrially processed in the form of juices, jams, wines and distilled liqueurs. This processing generates a large amount of waste by-products, which represent approximately 50% of the fruit weight. The by-products are of interest for obtaining valuable bioactive compounds that could be used as nutraceuticals or functional ingredients. In this study, fermented and non-fermented jabuticaba pomaces were studied regarding their hydrophilic and lipophilic compounds, as well as their antioxidant properties, including: soluble sugars, organic acids and tocopherols (using high performance liquid chromatography coupled to refraction index, diode array and fluorescence detector, respectively); phenolics and anthocyanins, (using liquid chromatography coupled to diode array detection, and mass spectrometry with electrospray ionization); and fatty acids (using gas-liquid chromatography with flame ionization detection). The analytical data demonstrated that jabuticaba pomaces are a rich source of bioactive compounds such as tocopherols, polyunsaturated fatty acids and phenolic compounds (namely hydrolyzable tannins and anthocyanins) with antioxidant potential. Therefore, jabuticaba pomace may have good potential as a functional ingredient in the fabrication of human foods and animal feed.