Phenolic acids accumulation and their antioxidant potential in wheat cultivars under the reduced and optimal nitrogen levels

Marija Kovačević Babić¹,Daniela Horvat¹*,Dario Novoselović¹, Filip Horvat²,Krešimir Dvojković¹

¹Agricultural Institute Osijek, Južno predgrađe 17, 31000, Osijek, Croatia
²Croatian Agency for Agriculture and Food, Centre for Seed and Seedlings, Usorska 19, Brijest, 31000 Osijek, Croatia

ARTICLE INFO	ABSTRACT
TYPE: Original scientific paper https://doi.org/10.17508/CJFST.2024.16.2.03 PDF	Three common wheat cultivars (Triticum aestivum L.) were grown under the reduced and optimal nitrogen (N) levels during 2018/2019 vegetation season. In this study, phenolic compounds were analysed as soluble-free and insoluble-bound fractions, because the majority of them are found in cereals in these forms. Total phenolic content in both extracts (TPC) was determined using the Folin-Ciocalteu reagent, while the antioxidant activity (AOA) of phenolics was evaluated using the 2,2–diphenyl–1–picrylhydrazyl radical scavenging test. The composition and content of phenolic acids (PAs) was analysed by HPLC. On average, TPC and AOA values were several times higher in the insoluble–bound extract compared to the soluble–free one (163.2 mg GAE/100 g DM vs. 60.7 mg GAE/100 g DM, and 48.5% vs. 17.6%, respectively). Soluble–free PAs ranged from 4.0 mg/100 g DM (p–coumaric acid) to 4.6 mg/100 g DM (p–hydroxybenzoic acid), while insoluble–bound PAs content was much higher, ranging from 2.2 mg/100 g DM (caffeic acid) to 56.5 mg/100 g DM (ferulic acid). For phenolic extracts, TPC, AOA and almost all PAs content was higher under the reduced nitrogen levels. In general, insoluble–bound PAs were more susceptible to higher nitrogen supply than soluble-free ones. Although cultivars showed a similar response to increased nitrogen rate, considerable variability in their phenolic properties was observed.
*CORRESPONDENCE Daniela Horvat daniela.horvat@poljinos.hr
ARTICLE HISTORY Received:October 29, 2024 Accepted: November 26, 2024
CITATION Kovačević Babić M, Horvat D, Novoselović D, Horvat F, Dvojković K. Phenolic acids accumulation and their antioxidant potential in wheat cultivars under the reduced and optimal nitrogen levels. Croatian Journal of Food Science and Technology (2024) 16 (2) 209 – 217
COPYRIGHT: © 2024 by the author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY).
	KEYWORDS wholegrain wheat; nitrogen level; total phenolics; antioxidant activity; phenolic acids
	KEY CONTRIBUTION In the wholegrain samples, much higher content and antioxidant potential was found in the insoluble–bound phenolics compared to the soluble–free ones. The properties of dominant insoluble–bound phenolics were more affected by higher nitrogen. The most abundant phenolic acid was ferulic. Wheat grains are rich source of phenolic compounds with potential health benefits.