THE USE OF ONION PEEL EXTRACT TO INHIBIT THE THERMAL OXIDATION OF POLYETHYLENE

The paper studies experimentally the antioxidant activity of onion peel acetone extracts of three varieties (Albion F1, Kaba, Red Baron) in the inhibition process of polyethylene thermal oxidation. The onion varieties differ in the color of their surface scales (colorless (white onion), yellow-orange (yellow onion), red (red onion)) and in the antioxidant properties of their extracts: red onion> yellow onion >> white onion. The results correspond to the mass of the extracted substances. A different sequence of onion varieties has been obtained in terms of the inhibitory effectiveness of their extracts: yellow onion> red onion >> white onion. The comparison of the extracted onion peel extracts with the industrial antioxidant Irganox 1010 in terms of inhibitory efficiency has been carried out. The paper presents and analyzes the IR spectra of the extracts. An increase in the extraction time from 24 hours to 56 days leads to an increase in the antioxidant properties of the extracts of all three varieties, but an increase in the inhibition efficiency is noted only for Albion F1 onion peel extract. In Red Baron and Kaba varieties, the main part of biologically active substances with antioxidant action is extracted from the peel into acetone during the first days of extraction.

Investigation of the anti-hyperglycemic and antioxidant effects of wheat bread supplemented with onion peel extract and onion powder in diabetic rats

Aim Onion is one of the commonly cultivated and consumed vegetables rich in nutrients and phytochemicals. Various nutraceuticals are found in the outer fleshy layers and dry peel of onion which usually is treated as a common biowaste. Diabetes mellitus is a leading non communicable disease causing hyperglycemia and increased production of free radicals that potentially disrupts antioxidant enzymatic activity. Considering global consumption of wheat, the present study was designed to evaluate the anti-hyperglycemic and antioxidant effects of wheat bread supplemented with onion peel extract (OPE) or onion powder (OP) on diabetic rats. Methods In this study, ethanolic extract of onion peel and onion bulb were prepared separately. Male Sprague Dawley rats were divided into 6 groups (n = 7). Different regimens of supplemented wheat bread (OPE (1% and 3%) and OP (5% and 7%)) were given to diabetic rats for eight weeks, plain bread was used as the control. Blood glucose level, body weight and activities of SOD, CAT, GPx, GR, GSH and MDA in the liver and kidney tissues were evaluated. Statistical analysis was performed using SPSS Version (25) and Dunnett’s multiple comparison test. Results Bread supplemented with 1% and 3% onion peel extract and 7% onion powder significantly reduced blood glucose levels and MDA in the treated rats compared with the control group diabetic rats. Body weight of diabetic rats was reduced for control group, while onion supplemented diet improved the body weight of treated rats. Onion supplementation also brought significant improvement in antioxidant enzyme activities among the treated diabetic rats. Conclusion These findings suggested that onion supplementation is effective in lowering blood glucose and could potentially aid in protecting organs from oxidative stress.

The enhanced reduction of bromate by highly reactive and dispersive green nano-zerovalent iron (G-NZVI) synthesized with onion peel extract

In this study, novel green nano-zerovalent iron (G-NZVI) is synthesized for the first time using onion peel extract for the prevention of rapid surface oxidation and the enhancement of particle dispersibility with a high reductive capacity.