Microwave‐assisted extraction of bioactive compounds fromAraucaria angustifoliabracts followed by encapsulation

Abstract

The aqueous extract of Araucaria angustifolia bracts was obtained by microwave‐assisted extraction and encapsulated by spray‐drying and freeze‐drying using pectin/hydrolyzed collagen (PEC‐HC) and polydextrose/partially hydrolyzed guar gum (PD‐PHGG) dispersions, added to the extract in the proportions of 0.25:0.75:9 and 0.5:0.5:9 (wt/wt/wt), respectively. The powders encapsulated with the PD‐PHGG mixture by spray‐drying and freeze‐drying showed the highest retention rates for total phenolic compounds (80.57% and 89.94%) and solubility (98.00 and 97.69 g 100 g−1), respectively. The scanning electron microscopy (SEM) images presented spherical forms on the spray‐dried powders, while the freeze‐dried powders exhibited irregular forms. The results obtained by FTIR suggested that the encapsulation occurred in all samples by physical interactions, whereas the thermogravimetric analysis showed that the PEC‐HC powders demonstrated greater thermal stability. Accelerated storage tests indicated that the PD‐PHGG freeze‐dried powders had lower decrease in the antioxidant capacity. Practical applications The industrial use of Araucaria angustifolia bracts (sterile seeds) is currently considered a type of waste. However, the bracts present bioactive compounds, including condensed tannins, considered among phenolic compounds, the most important natural antioxidants. The phenolic compounds of the bracts were extracted by microwave, using exclusively water as a solvent. The application of green technologies is an interesting alternative for the food industry since the use of organic solvents is completely replaced, as well shorter exposure times to high temperatures are obtained and, consequently, lower energy expenditure and lower antioxidant capacity loss. For the encapsulation of phenolic compounds, dietary fibers and protein were used as wall materials, which resulted in a powder containing natural antioxidants, fibers, and essential amino acids, which can be applied in several food formulations.

Regenerative food innovation delivering foods for the future: a viewpoint on how science and technology can aid food sustainability and nutritional well‐being in the food industry

“…The findings clearly indicated that combining microwave and ultrasound technologies aided recovery of food components whilst reducing energy consumption. Dorneles & Noreña (2020) also used microwave technology, but this time as extraction aids for phenolic compounds to aid effective recovery in a more environmentally friendly process. Other researchers have investigated the role of non‐thermal technologies in extraction of bioactive ingredients and food preservation techniques to ensure the safety and quality of foods (Ali et al ., 2021).…”

Biopolymer nanoparticles: a strategy to enhance stability, bioavailability, and biological effects of phenolic compounds as functional ingredients

“…In this sense, biopolymers are preferred because of their physicochemical characteristics and biocompatibility with the human body, including polysaccharides, proteins, whey protein, and mucilage from different sources. 5,44,47,48 Nanotechnology involves various strategies using different materials at nanoscale dimensions to fabricate devices widely employed in the electronic and food industries, as well as in the pharmaceutical and biomedical fields. Nano-carrier systems have shown many advantages in the encapsulation of phenolic compounds, such as uniform morphology, high encapsulation efficiency, increased solubility, thermal and storage stability, as well as improved bioactivity.…”

“…Likewise, various wall materials can be used to protect these bioactive components and control their release at the target site. In this sense, biopolymers are preferred because of their physicochemical characteristics and biocompatibility with the human body, including polysaccharides, proteins, whey protein, and mucilage from different sources 5,44,47,48 …”

Optimization of Pinhão Extract Encapsulation by Solid Dispersion and Application to Cookies as a Bioactive Ingredient

“…The encapsulation of pinhão extracts has been proposed by a few authors as follows. Dorneles and Noreña (2020) used hydrolyzed pectin/collagen and partially hydrolyzed polydextrose/ guar gum as encapsulating agents. The authors obtained microparticles by spray-drying and also by lyophilization, resulting in improved stability of antioxidant capacity during storage.…”