Effect of Agroecological Conditions on Biologically Active Compounds and Metabolome in Carrot.

Martin Koudela,Ales Krmela,Hana Chmelarova,Jana Hajslova,Vera Schulzova,Cenek Novotny

doi:10.3390/cells10040784

Abstract

Carrot serves as a source of health-beneficial phytochemicals for human diet whose content is affected by agroecological conditions. The effect of conventional, integrated and organic farming on ascorbic acid (AA) and α,β-carotene levels of new carrot cultivars Cortina F1 and Afalon F1 was investigated and their metabolomic profiles were measured by direct analysis in real time ion source coupled with a high-resolution mass spectrometer (DART-HRMS). Cortina and Afalon exhibited high levels of AA and total carotenes under all agroecological conditions tested that fluctuated in broad ranges of 215–539 and 173–456 mg AA.kg−1 dry biomass and 1069–2165 and 1683–2165 mg carotene.kg−1 dry biomass, respectively. The ratio of β- to α-carotene in both cultivars was about 1.3. The most important variable for the PCA and the partial least squares discriminant analysis (PLS-DA) models for ethyl acetate extracts measured in positive and negative ionization mode was 6-methoxymellein (6-MM). Total carotene content and 6-MM levels were higher in the organic carrot compared to the conventional one and were correlated with a higher level of spontaneous infection. Other important compounds identified were sitosterol, hexose and various organic acids including antioxidant ferulic and coumaric acids. The findings allow comparison of metabolomic profiles and the AA and carotene contents of both cultivars with those of other commercially used carrots.

Highlights

The carrot (Daucus carota L.) is an important vegetable plant produced worldwide, used in human nutrition, serving as an important source of phytochemicals with beneficial effects on human health, namely ascorbic acid (AA), phenolics, carotenes, and polyacethylenes [1]
The AA levels of 215–539 and 173–456 mg kg−1 dry weight measured in Cortina and Afalon cultivars in 2012 and 2013 in different production systems (Figure 1a,b,c) were higher than those of semi-late and late carrot cultivars reported by Bratu et al (2006) [55] and Matejková and Petríková (2010) [16] but comparable to the contents reported by Faisal et al (2017) [56] for winter-season grown carrots
Crop year factor was found to be dominant with respect to the contents of carotenes and metabolomic fingerprints measured by the DART-MS method

Summary

Introduction

The carrot (Daucus carota L.) is an important vegetable plant produced worldwide, used in human nutrition, serving as an important source of phytochemicals with beneficial effects on human health, namely ascorbic acid (AA), phenolics, carotenes, and polyacethylenes [1]. The genetic background is an important factor controlled by the producer that modifies the nutritional, sensory, and health-related properties of carrots [3,4,5]. Different carrot cultivars show a wide range of AA content ranging from 21 to 775 mg kg−1, dark orange carrots containing four times more AA than yellow, purple, and orange ones [6,7,8]. Carotene content decreases in the order of purple, orange, yellow, and white carrot varieties [11,12]. Fertilizer application and various biotic and abiotic stress factors including various elicitors influence the amount of phenolic compounds [19,20,21]

Methods

Results

Conclusion