Green Extraction of Hodgsonia heteroclita Oilseed Cake Powder to Obtain Optimal Antioxidants and Health Benefits

Abstract

Most biowaste produced by domestic food preparation and food processing has no value, is difficult to manage, and is detrimental to the environment. Oil extraction from Hodgsonia heteroclita seeds produces large amounts of oilseed cake powder (OCP) as biowaste. The extraction of residual phytochemicals using simple and eco-friendly methods can increase the economic utility of OCP. This study optimized the extraction process for Hodgsonia heteroclita OCP using a Box-Behnken design and response surface methodology. The optimized extraction condition was 30 °C for 5 h in 50% (v/v) ethanol, giving a total phenolic content (TPC) of 414.23 mg of gallic acid equivalent/100 g dry weight (DW). Phytochemical profiles of OCP using liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ECI-MS/MS) identified 4-hydroxybenzoic acid and ferulic acid as the major compounds. Antioxidant activities and enzyme inhibitory activities toward the major enzymes involved in obesity (lipase), diabetes (α-amylase, α-glucosidase, and dipeptidyl peptidase IV (DPP IV)), Alzheimer's disease (acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and β-secretase-1 (BACE-1)), hypertension (angiotensin-converting enzyme, ACE), and genotoxicity were also investigated. Results showed that H. heteroclita OCP possessed antioxidant activity and potential inhibitory activities against BACE-1 and ACE, while also being genome-safe. A simple extraction method for H. heteroclita OCP was developed, demonstrating the enhanced value of its phytochemical and health-promoting qualities.

Keywords: agricultural waste; enzyme inhibition; genotoxicity; phenolics; response surface methodology; sustainability.

Figure 1

Experimentally measured total phenolic contents (TPCs) of H. heteroclita oilseed cake powder obtained from heat and enzymatic pretreatment (HEP-OCP) vs. predicted TPCs calculated from Equation (2). The different colors were corresponded to the color explained in Figure 2, in which the red color indicated high TPCs, while the blue color indicated low TPCs.

Figure 2

Response surface plots illustrating the interaction effects of temperature and ethanol concentration (A,B), time and ethanol concentration (C,D), and temperature and time (E,F) on total phenolic contents (TPCs) extracted from H. heteroclita oilseed cake powder obtained from heat and enzymatic pretreatment (HEP-OCP). Intermediate levels of TPCs are displayed as a green color, while high levels of TPCs are shown in the graph surface area as a red color and low levels as a blue color.