Bananas are one of the most important crops worldwide. However, a large amount of residual lignocellulosic biomass is generated during its production and is currently undervalued. These residues have the potential to be used as feedstock in bio-based processes with a biorefinery approach. This work is based on the valorization of banana leaf and has the following objectives (i) to determine the effect of certain physical and environmental factors on the concentration of glucose present in banana leaf extract (BLE), using a statistical regression model; (ii) to obtain Bacterial Nanocellulose (BNC), using BLE (70% v/v) and kombucha tea as fermentation medium. In addition, the physicochemical properties of BNC were evaluated by X-ray diffraction (XRD), Fourier transform infrared (FTIR), and thermogravimetric analysis (TGA). The results indicate that storage time, location, leaf color, and petiole type are factors related to BLE concentration, which is reduced by approximately 28.82% and 64.32% during storage times of five days. Regarding BNC biosynthesis, the results indicate that the highest yield, 0.031 g/g, was obtained at 21 days. Furthermore, it was determined that the highest production rate was 0.11 gL−1h−1 at 11 days of fermentation. By FTIR, it was determined that the purification step with NaOH (3M) should be carried out for approximately two hours. This research supports the development of a circular bioeconomy around the banana value chain, as it presents a way of bioprocessing residual biomass that can be used to produce bioproducts.
Supercritical fluids’ extraction (SFE) and conventional solvent extraction (CSE) for defatting of quinoa flour as pretreatments to produce the quinoa protein hydrolysate (QPH) were studied. The objective was to extract the oil and separate the phenolic compounds (PC) and the defatted quinoa flour for subsequent quinoa protein extraction and enzymatic hydrolysis. The oil extraction yield (OEY), total flavonoid content (TFC), and QPH yield were compared. SuperPro Designer 9.0® software was used to estimate the cost of manufacturing (COM), productivity, and net present value (NPV) on laboratory and industrial scales. SFE allows higher OEY and separation of PC. The SFE oil showed a higher OEY (99.70%), higher antioxidant activity (34.28 mg GAE/100 g), higher QPH yield (197.12%), lower COM (US$ 90.10/kg), and higher NPV (US$ 205,006,000) as compared to CSE (with 77.59%, 160.52%, US$ 109.29/kg, and US$ 28,159,000, respectively). The sensitivity analysis showed that the sale of by-products improves the economic results: at the industrial scale, no significant differences were found, and both processes are economically feasible. However, results indicate that SFE allows the recovery of an oil and QPH of better nutritional quality and a high level of purity-free organic solvents for further health and nutraceutical uses.