Mirabal Gallardo, Yaneris

Chilean agribusiness generates large quantities of by-products and they have been little studied. According to the literature they represent important sources of sugar, protein, lipid, micronutrient, fiber, and others that have a broad field of action. In this work, by-products (white and red grape seeds, peach stones, avocado seeds, olive pomace, and corn cob) of Chilean agribusiness are characterized chemically with a view to their functional and nutritional potential. They are analyzed following standardized methodology which revealed that byproducts are found to be a suitable source of protein (0.59-10.00 % on DW), fiber (33.85-71.93 % on DW), lipid (0.61-14.4 % on DW)), organic matter (77.34-99.87 % on DW), inulin (8.3-33 mg fructose/g dry sample), and a wide range of essential metals. They are rich in K, Ca, and Mg. Moreover, they have very good antioxidant capacity (FRAP, and DPPH), and total phenolics and flavonoids contents. In conclusion, Chilean agribusiness by-products are attractive potential sources of food products, which could be used for nutritional purposes, and for the development of technologies.

The present study shows porous activated carbon obtained from Chenopodium quinoa Willd and Quillaja saponaria and their use as potential adsorbents to remove three types of dyes from aqueous solutions. The adsorption results were compared with commercial charcoal to check their efficiency. All porous carbon materials were activated using carbon dioxide and steam and fully characterized. Moreover, the steam-activated samples exhibited a high total pore volume with a BET surface area of around 800 m2 g−1. Batch adsorption experiments showed that commercial charcoal is the charcoal that offered the best adsorption efficiency for tartrazine and sunset yellow FCF. However, in the case of crystal violet, all activated carbons obtained from Chenopodium quinoa Willd and Quillaja saponaria showed the best captures, outperforming commercial charcoal. Molecular dockings of the dyes on the commercial charcoal surface were performed using AutoDock Vina. The kinetic results of the three isotherm’s models for the present data follow the order: Langmuir~Freundlich > Temkin. © 2022 by the authors.

In this work, Aspergillus niger and Fusarium culmorum cell wall by-products were chosen as microbial sources for chitin and chitosan production. Both polysaccharides were characterized by FTIR and 13C-CPMAS NMR, but GPC analysis was only performed for chitosan. SEM-EDX analysis was performed to fungal chitosan loaded with metal ions. Chitosan extracted from both fungus had low to medium molecular weight (Mw) and degree of deacetylations (DD) ranging from 65.7-83.3%. Fungal chitosan samples were intended to be used for bioremediation applications. For this purpose, two independent absorption experiments regarding pesticide Dimethoate (DM) and heavy metal ions (Al(III), As(III), Cd(II), Cu(II), Mg(II), Mn(II), Pb(II), Zn(II), Fe(II)) in a complex mixture were carried out. An experimental design considering the solution pH, contact time and chitosan physicochemical properties (DD) were performed. The highest percentage of dimethoate pesticide and selected metal ions absorption was obtained with highest DD chitosan, the contact time of 24 h, pH 6 for metals and pH 4 for pesticide, repectively. Molecular dynamics simulation studies allowed to analyze at the molecular level the chitosan-DM interaction. A higher number of h-bonds were identified as the main interactions that stabilize the affinity of the chitosan-DM complexes. Based on our results, we suggest the use of a multipurpose fungal chitosan system for water bioremediation.

Coffee is one of the most consumed beverages worldwide. Its production generates a large amount of waste, and its use is of vital importance to prevent it from becoming a source of environmental pollution. Cuba is a country with a well-known coffee-growing tradition. Although coffee production has decreased, it is vitally important to use the waste generated in these productions to reduce environmental pollution. To know the possible use or application of coffee waste, it is necessary to know its composition. In this article, three Cuban Arabica coffee wastes (husk, parchment and spent coffee grounds) were characterized using chemical, physical and physicochemical methods. In the characterization of these wastes, SEM and EDX were used to determine their microscopic form and chemical composition. The Chesson–Datta method, ATR and TGA were used to determine whether these materials were lignocellulosic. Ash, pH and density of the waste were determined as characterization methods. The extractive content was determined and a phytochemical screening was performed to determine the groups of the secondary metabolites present.