Polyphenols from different agricultural residues: extraction, identification and their antioxidant properties

Abstract

Agricultural residues like sugarcane bagasse (SCB), corn husk (CH), peanut husk (PNH), coffee cherry husk (CCH), rice bran (RB) and wheat bran (WB) are low-value byproducts of agriculture. They have been shown to contain significant levels of phenolic compounds with demonstrated antioxidant properties. In this study, the effects of two types of solvent extraction methods: solid-liquid extraction (SLE) and hot water extraction on the recovery of phenolic compounds from agricultural residues were investigated to optimize the extraction conditions based on total phenolic content (TPC), total tannin content (TTC) and total flavonoids content (TFC). Methanol (50 %) was found to be the most efficient solvent for the extraction of phenolics with higher DPPH, nitric oxide radical scavenging and reducing power activity, followed by ethanol and water. The phenolic compounds of methanolic extracts (50 %) were determined by reverse phase high performance liquid chromatography; in addition gallic acid became the major phenolic acid present in all the agricultural residues whereas ferulic acid, epicatechin, catechin, quercitin and kampferol present in lesser amounts. The present investigation suggested that agricultural residues are potent antioxidants. The overall results of this research demonstrated the potential of agricultural residues to be an abundant source of natural antioxidants suitable for further development into dietary supplements and various food additives.

Chemical composition, antioxidant, antibacterial, and tyrosinase inhibition activity of extracts from Newhall navel orange (Citrus sinensis Osbeck cv. Newhall) peel

“…Total polyphenol content was determined spectrophotometrically with Folin-Ciocalteu reagent. 27 Briefly, extract solution in methanol (20 μL) or methanol solvent (blank control, 20 μL), distilled water (60 μL), and Folin-Ciocalteu reagent (15 μL, prediluted by distilled water at a 1:1 ratio) were sequentially added to a 96-well plate and mixed well by smoothly shaking for 180 s. Four minutes later, 75 μL Na 2 CO 3 aqueous solution (2% w/v) was added, followed by slightly shaking for 180 s. After statically standing for 15 min, the absorbance was then measured at 750 nm by a microplate reader. Total phenolic content was calculated from the linear calibration curve of gallic acid which was constructed by series concentrations of gallic acid versus the corresponding absorbance.…”

Optimization of the antioxidant and antimicrobial response of the combined effect of nisin and avocado byproducts

“…The extraction process of agroindustrial byproducts generates phytochemicals that can be applied as functional food compounds, colorants, flavors, antioxidants, and stabilizers, among others (Rold an, S anchez-Moreno, de Ancos, & Cano, 2008;Silva et al, 2014;Vijayalaxmi, Jayalakshmi, & Sreeramulu, 2014). In addition, the use of these waste materials would help reduce the generated environmental impact and contribute to a cost reduction in the industry.…”

Identification of food preservative, stress relief compounds by GC–MS and HR-LC/Q-TOF/MS; evaluation of antioxidant activity of Acalypha indica leaves methanolic extract (in vitro) and polyphenolic fraction (in vivo)

“…Phenols, flavonoids and saponins are having large spectrum of biological importance such as antioxidant, anti-inflammatory, anti-cancer, anti-ulcer, effect on neuronal diseases and cardio vascular diseases, etc. (Gulcin et al 2004;Piacente et al 2005;Vijayalaxmi et al 2015). Based on the biological importance of phenols, flavonoids and saponins of the plants, which are also observed rich in phytochemical screening parameter in this study, we attempted to estimate those phytochemicals quantitatively in MEAIL.…”