Vedecký časopis

Journal of Food and Nutrition Research
Online First Articles

Tóth, T. – Bystrická, J. – Tomáš, J. – Siekel, P. – Kovarovič, J. – Lenková, M.
Changes of phenolic and sulphur content in onion (Allium cepa L.) in relation to different levels of sulphur fertilization

Judita Bystrická, Department of Chemistry, Faculty of Biotechnology and Food Sciences, Slovak University of Agriculture in Nitra; Tr. Andreja Hlinku 2, 949 76 Nitra, Slovakia. Tel. +421 37 641 4353, e-mail: judita.bystricka@centrum.sk

Received 6 October 2017; 1st revised 23 January 2018; accepted 30 January 2018

Súhrn: This experiment evaluated the effects of different levels of sulphur fertilization on the quality of onions (Bingo, Boston, Red Matte, Karmen, White Solid and Diamant) and it was conducted as field experiment. Sulphur was added in amounts 0, 30.00, 40.00 and 50.00 kg·ha-1 respectively. In this work were studied for the content of total sulphur, total polyphenols and quercetin their antioxidant activity as well as the possible correlations between the qualitative parameters. Sulphur fertilization increased (P < 0.05) the sulphur, quercetin, total polyphenols content and the value of antioxidant activity in onion. Statistically significant highest contents of polyphenols as well as quercetin were recorded in red cultivars at sulphur dose 40.00 kg·ha-1. The highest contents of polyphenols were recorded in yellow cultivars at sulphur dose 50.00 kg·ha-1. White cultivars contained the lowest content of polyphenols as well as quercetin, but the highest values were recorded at the sulphur dose 40.00 kg·ha-1. The highest values of antioxidant activity were achieved in all cultivars at the level of sulphur 40.00 kg·ha-1, except cultivars Boston and Diamant.

Kľúčové slová: antioxidant activity; phenolic compounds; total sulphur