Valorization of lotus byproduct (Receptaculum Nelumbinis) under green extraction condition

Food waste including byproducts has been growing with increasing food and its products consumption, leading to various environmental problems. Considering valorization, the food waste could be converted into useful byproducts. Receptaculum Nelumbinis, a lotus byproduct, was considered to contain higher level of phenolic compounds. This study was designed to extract valuable phenolic compounds from Receptaculum Nelumbinis considering three independent factors i.e., extraction time, temperature and glycerol concentration. The viscosity of solvent was also estimated during experiment and analysis of phenolic compounds was conducted using UPLC-Triple-TOF/MS method. Results showed that under optimum condition the extraction yield as total polyphenol content (Y-Tp) was found to be 62.32 +/- 1.25 mg GAE g(-1) dw, which was close to the model predicted value. Moreover, the extraction capacity of glycerol was significantly negatively correlated with viscosity. Under optimized extraction condition a total of seventeen phenolic compounds, including catechin, procyanidin, hyperoside, isoquercitrin and quercetin were recorded. These results indicated glycerol could effectively extract phenolic compounds from Receptaculum Nelumbinis and thus could be an ideal solvent for environmental-friendly extraction process of phenolic compounds. Moreover, the valorization of lotus byproduct into nutraceutically valuable compounds could also be considered as economically viable solution and further could be useful for industrial applications. (C) 2019 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.