Hydrogen incorporation into solvents can improve the extraction of phenolics, flavonoids, anthocyanins, and antioxidants: A case-study using red beetroot

Abstract

Different methods are used for extracting phytochemicals from plant produce. Some ‎methods require sophisticated and expensive instruments, while others need multiple steps ‎and specialist equipment, leading to an increase in energy, solvents, cost, and time. Here, the effect of incorporating hydrogen (H2) into solvents (that is water, ethanol, ‎methanol) on the extraction of flavonoids (TFC), phenolics (TPC), anthocyanins ‎‎(TAC), and antioxidants (DPPH and ABTS), as well as the extraction yield from red ‎beetroot, were evaluated. The biggest extraction yield was with the use of H2-rich ‎methanol (HRM) (24.32%). Incorporating H2 into water, ethanol, and methanol ‎led to a significant increase in TPC by 77.34%, 39.02% and 89.07%, in the TFC by ‎‎43.30%, 50.5% and 88.87%, in the TAC by 92.62%, 199.5% and 257.41%. DPPH ‎scavenging activity increased by 6.49%, 7.05% and 12.15%, and ABTS scavenging ‎activity by 3.93%, 9.82% and 15.05%, respectively. The extraction of individual ‎phenolic compounds, using various solvents, were different for each compound ‎investigated, with HPLC analysis showing that the levels of some phenolics increased ‎when H2 was incorporated into the solvents. ‎This method, i.e., addition of H2 gas, is ‎suggested as a relatively cheap and practical method for increasing the extraction of ‎phytochemicals using an eco-friendly method.