Hot air drying and quality powder of three, red-skinned, white-skinned and yellow-skinned, onion varieties (Alium cepa L.)

Anamaria Pop, Georgiana Petruț, Sevastiţa Muste, Adriana Păucean, Simona Man, Simona Chiş, Liana Salanță, Romina Vlaic

Volume 24, Issue 3;
Pages: 207-210; 2018
ISSN: 2069-0053 (print) (former ISSN: 1453-1399), Agroprint;
ISSN (online): 2068-9551
Food dehydration is one of the oldest unit operations used by the food processing industry. Onion (Allium cepa) have been widely reported to possess a significant antioxidant activity which has been ascribed to allicin, a known scavenger of peroxyl radicals. The onion contains a number of quercitin, isorhamnetin, and kaempferol conjugates and, indeed, is one of the major sources of flavonols in European diet. The study aim was to evaluate the quality of onion powder obtained by dehydration of three different varieties (white, yellow and red onion) by evaluating the polyphenol content and antioxidant activity. The onion raw materials were purchased from the food market (local farmers from Cluj-Napoca).Three onions varieties were chosen (white, yellow and red). After preliminary cleaning, peeling, slicing and chopping, onions were dehydrated at 70–60 °C in a Hot Air Dryer Machine, the temperature being reduced as the moisture content decreases. Total phenolics content was assesed by Folin-Ciocalteu spectrophotometric method using a UV-VIS spectro photometer.The radical scaveging activity (RSA%) was assesed by DPPH spectophotometric methods. The highest content of total polyphenols was recorded in the red onion powder extract 1086.71 (mg.GAE/100g sample), followed by the yellow onion powder extract 667.87(mg.GAE/100g sample) and then the white onion powder extract 353.18(mg.GAE/100g sample). Regarding the antioxidant activity, the scavenging efficiency of onion powder extracts against the DPPH radical was the strongest due to their high polyphenol content. According to these results it is recommended to use red onion powder as a basic ingredient in the preparation of different spice mixtures or in the simple use in different culinary preparations.
300645-Timisoara, Calea Aradului 119, Romania
Tel: +40-256-277423
Fax: +40-256-277326
Copyright © 2022 Journal of Agroalimentary Processes and Technologies