Extraction of Phenolic Compounds from Palm Oil Processing Residues and Their Application as Antioxidants

Abstract

The side streams derived from the palm oil production process, namely palm kernel cake, palm pressed fibre, palm kernel shells and empty fruit bunches, were evaluated as sources of phenolic compounds. Among these streams, kernel cake had the highest total phenolic content (in mg of gallic acid equivalents (GAE) per g of dry sample) with a value of 5.19, whereas the empty fruit bunches had the lowest value (1.79). The extraction time and liquid-to-solid ratio were investigated to optimize the phenolic extraction. Kernel cake exhibited the highest total phenolic content (5.35 mg/g) with a liquid-to-solid ratio of 40:1 during 20 min of extraction. The main phenolic compounds of the extracts deriving from all byproduct streams were also identified and quantified with HPLC-DAD. Pyrogallol, 4-hydroxybenzoic acid, gallic acid and ferulic acid were the main compounds found in kernel cake extracts. Empty fruit bunch and pressed fibre extracts were also rich in 4-hydroxybenzoic acid, while pyrogallol was the predominant compound in kernel shell extracts. All extracts showed antioxidant activity as it was indicated from the results of DPPH analysis and subsequently tested in sunflower oil aiming to prolong its shelf life. The addition of 0.8 % kernel cake extract increased the induction time of sunflower oil more than 50 %. According to the results obtained in this study, kernel cake extracts could be considered as a value-added co-product with a potential application as antioxidants in the food industry.

Comparative study of polyphenolic compound extraction from empty palm fruit bunches and sugarcane pulp

“…Distilled water and 70% methanol provided best total phenolic content, followed by ethanol. Although the total phenolic concentration results obtained here were still somewhat lower compared to those reported by Tsouko et al. (2019) , they paralleled those reported by Ulewicz-Magulska and Wesolowski (2019) .…”

“…Instead of disposing of agricultural waste it could, however, serve as a valuable resource for polyphenolic compounds with antioxidant properties ( Tsouko et al., 2019 ). Phenolic acids, flavonoids, and anthocyanins are produced by plants as a protective mechanism to counteract biotic and abiotic factors.…”

“…In addition to the choice of the solvent, the method of extraction plays an important role. Several methods, such as maceration ( Vianney et al., 2018 ), ultrasound assisted extraction (UAE) ( Filho et al., 2021 ; Tsouko et al., 2019 ), and Soxhlet or reflux extraction ( Shi et al., 2021 ; Li et al., 2013 ; Han and May, 2012 ) can also be employed. In general, extraction condition, such as temperature and time plays a role on the stability of the extracted compounds, yield, and efficiency of the processes ( Lameirao et al., 2020 ).…”

Bioactive Phenolic Compounds From Agri-Food Wastes: An Update on Green and Sustainable Extraction Methodologies

“…The olive oil industry also generates high amounts of byproducts, which are particularly rich in lignans, secoiridoids, and especially hydroxytyrosol, which is one of the most bioactive phenolic compounds present in nature, endowed with anti-inflammatory and antiplatelet properties (12,(28)(29)(30)32) (Figure 1). Soybean (33) and palm oil (34) byproducts have been also described as a valuable source of polyphenols.…”

Zero-Emission of Palm Oil Mill Effluent Final Discharge Promoted Bacterial Biodiversity Rebound in the Receiving Water System

“…Alcaligenaceae are known as the phenolic and aromatic compounds degraders [59]. Their growth was enhanced after the addition of POME final discharge [15] containing phenolic compounds from the palm oil fruit processing [60]. However, their presence was still detectable in the system at a low composition even after the implementation of zeroemission of POME final discharge, perhaps due to the remaining phenolic and aromatic compounds in the sample.…”