Separation and concentration of natural antioxidants from the rape of olives

Abstract

Polyphenols were extracted from the rape of Israeli olive oil using hexane, acetone and ethanol in a simple sequential procedure yielding three fractions (A,B,C). Fraction A (extracted with hexane) contained few polyphenols (0.05%), while Fraction B (extracted with acetone) and Fraction C (extracted with ethanol) contained about 5% polyphenols each. Fractions B and C were also found to contain the highest ortho‐di‐phenol concentration (about 3%). The addition of purified Fraction B at a level of 100 ppm to refined olive or soybean oils partially inhibited the oxidative deterioration when the oils were stored in the dark at 100 C.

Evaluation of antioxidant capacity of some fruit and vegetable foods: efficiency of extraction of a sequence of solvents

“…water and acetone) was lower than the effective content. This is probably due to the lower pH value of methanol, obtained by the acidification with formic acid in the specific extraction procedure,22 which could have favoured the phenolic acid extraction, as previously reported 26. Finally, the amount of anthocyanins in the water extract was double that obtained with methanol, probably owing to the high polarity of these compounds.…”

Integral utilisation of barley husk for the production of food additives

“…These chemical antioxidants have been questioned because of their toxicity and safety. Thus, compounds with strong antioxidant properties have been identified in plants, and special attention has been devoted to the extraction of this type of compounds from residual sources such as peanut hulls, 12 -14 buckwheat hulls, 14 oat groats and hulls, 15 barley, 16 -18 barley leaves, 19,20 red grape pomade peels 21 or grape seeds, 22 potato peel waste, 23 olive rape, 24 barks 25 and corn bran hemicellulose fragments after acid hydrolysis. 26 This study deals with the chemical-biotechnological processing of barley husk obtained after the brewing process in order to carry out a complete use of the three fractions: cellulose, hemicelluloses and lignin.…”

Optimization of Phytosterols Recovery from Soybean Oil Deodorizer Distillate

“…Preparing high-purity concentrates of phytosterols and tocopherols involves a series of physical and chemical treatment steps. Several studies have been conducted to recover phytosterols and tocopherols from deodorization distillate, such as crystallization [5,18], solvent extraction [6], supercritical fluids extraction [7,8], supercritical extraction with a multistage countercurrent column [9], transesterification to form methyl esters followed by fractional distillation [10], neutralization and washing [11], membrane separation [12], enzymatic esterification [13,14], and batch adsorption [15]. Phytosterols cannot be removed by molecular distillation because their molecular weights and volatilities are similar to those of tocopherols [16].…”