Present trends towards technologies and processes that increase the use of residues make starchy vegetal biomass an important alternative material in various applications due to starch's versatility, low cost and ease of use when its physicochemical properties are altered. Starch is increasingly used in many industrial applications and as a renewable energy resource. Starch can be modified to enhance its positive attributes and eliminate deficiencies in its native characteristics. In this article, the state of knowledge on conventional and unconventional starches and their properties, characteristics, modifications and applications are reviewed.

Bixin is the major carotenoid in the seed of the Annatto plant (Bixa orellana L.). The aim of this study was to obtain extracts containing bixin from seeds that had been partially defatted by supercritical fluid extraction. Pressurized liquid extraction (PLE) and lowpressure solvent extraction (LPSE) methods were used, and the effects of the solvent, temperature, pressure, solvent mass to feed mass (S/F) ratio and ultrasonication were evaluated for the global yield (X 0 (%)) and the bixin yield (BY(%)). Extraction conditions producing high yields of bixin were established for both the PLE and LPSE methods. Analysis of variance was used to examine the influence of the individual extraction variables in LPSE and PLE. For LPSE; significant effects were found for solvent, temperature, and the interactions of temperature with solvent and temperature with S/F. Solvent was the only variable that significantly affected X 0 (%) and BY(%), for PLE. While ultrasonication did not significantly affect X 0 (%) or BY(%), scanning electron microscopy analysis revealed structural changes in the vegetal matrix following this treatment.

Agricultural and agroindustrial residues are major sources of cellulose, hemicellulose, and starch that can be converted into bioactive compounds, such as oligosaccharides and monosaccharides, using various chemical and biological methods. These bioactive compounds can be used as raw materials by food, cosmetic and pharmaceutical industries, as well as in the production of intermediate products and the development of biomaterials by chemical industries. In Brazil, the major industrial residues, which are corn residues, soybean residues, sugarcane bagasse, palm and coconut fibers, and grape and tomato seeds, among others, are produced at a rate of approximately of 600 million tons per year. Thus, the utilization of these residues using sustainable technology is of great interest. Hydrothermal treatment is a green technology that includes autohydrolysis as well as subcritical and supercritical hydrolysis, in which water is used at high pressures and temperatures to recover polysaccharides from complex vegetal matrices. The hydrolytic mechanisms can be improved by changing the ionic product or the polarity and electrical conductivity of water in subcritical and supercritical states. These properties promote the selective dissolution of the starch, hemicellulose and cellulose in the residues. The conversion of starch and hemicellulose into oligosaccharides and monosaccharides is preferentially performed at temperatures of less than 200°C. In contrast, the conversion of cellulose into oligosaccharides is promoted at temperatures greater than 200°C, with the highest amount oligosaccharide formation occurring at close to the critical point. In this article, the main biomass components, the properties of water under subcritical and supercritical conditions, and the latest studies of polysaccharide conversion in biomasses using hydrothermal treatments are reviewed.

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Açai is considered a functional food, and in addition to being a source of energy and fiber, it is a valuable source of bioactive compounds such as anthocyanins, minerals and fatty acids. In the present work, antioxidant-rich extracts from açai pulp were obtained using pressurized liquid extraction (PLE). The effects of the independent variables, including solvent type (pure ethanol and ethanol/water (50:50 v/v)), citric acid (0 and 0.3%, w/w), pressure (20 and 80 bar) and temperature (30 and 60 °C) were evaluated using a full factorial design. The extraction was affected primarily by the solvent type and the citric acid percentage. The results indicate that the maximum overall yield (X 0 ) was 64 ± 9 (%, d.b.) when the process was performed using ethanol (99.5%) and citric acid (0.3% w/w). The maximum total anthocyanin content and anthocyanin recovered from the raw material were 7 ± 1 (mg anthocyanin/g extract, d.b.) and 11 ± 2 (%, d.b.), respectively.