Effect of Biostimulants and Storage on Discoloration Potential of Carrot

Abstract

The application of biostimulants to prevent stress-related losses and increase productivity is becoming an increasingly common practice. A study was carried out to determine the effect of the type and methods of biostimulant application and long-term storage on the content of antioxidant compounds determining the processes of the enzymatic browning of carrot roots. The natural seaweed biostimulant Kelpak and synthetic Asahi were applied as part of the study. A quality assessment of carrot roots was carried out directly after harvest and after six months of storage in air at a temperature of 1 °C and a relative humidity of 95%. A single application of Kelpak seaweed extract in the four-leaf phase (2 or 3 dm3 ha−1) proved to be the most effective for reducing oxidative darkening processes (by 33.5%). The oxidative potential was most strongly dependent on the anthocyanin (r = −0.477) and chlorogenic acid (r = −0.474) contents. The concentration of polyphenols (r = 0.836; r = 0.719) and flavonoids (r = 0.671; r = 0.729) had the greatest effect on the antioxidant capacity (FRAP and ABTS respectively). It was observed that pectin, polyphenol, chlorogenic acid, flavonoid and anthocyanin concentrations tended to increase after a single application of Kelpak in a dose of 2 dm3 ha−1. A long-term storage period had a stronger effect on the increase in the oxidation potential than on the antioxidant capacity FRAP value.

Biostimulants Improve Bulb Yield, Concomitantly Affecting the Total Phenolics, Flavonoids, and Antioxidant Capacity of Onion (Allium cepa)

“…The application of BT1 significantly increased flavonoid content in 2021 and 2022. Similar results have been documented in onions, carrots (Daucus carota), and beans (Phaseolus vulgaris) following SWE application [4,75,76]. This can be explained by the fact that SWE enhances the expression of genes involved in the synthesis of enzymes participating in the phenylpropanoid pathway, a process essential for flavonoid synthesis [18].…”

Biostimulants Affect Differently Biomass and Antioxidant Status of Onion (Allium cepa) Depending on Production Method

“…Synthesized flavonoids play a crucial role in contributing to the defense against stresses such as pathogens, wounding, and UV light damage [54]. The favorable impact of SWE has been observed in carrots and beans [15,16]. Bulbs treated with T2 had significantly higher flavonoid content than the control.…”

“…However, in research conducted by Francke et al [14], biostimulants with SWE did not significantly affect shallots (Allium cepa Aggregatum group). Concerning quality, in previous experiments with beans (Phaseolus vulgaris) and carrots (Daucus carota) SWE-based biostimulants significantly increased the content of antioxidant compounds such as flavonoids and anthocyanins [15,16]. In the case of lettuce (Lactuca sativa), there was an increase in phenol content in the presence of arbuscular mycorrhiza (Glomus mossae) [17].…”

Effect of Botanical Extracts on the Growth and Nutritional Quality of Field-Grown White Head Cabbage (Brassica oleracea var. capitata)

“…Phenolic compounds (e.g., carotenoids, anthocyanins, and flavonoids) have important health-related features and exhibit anticancer and antioxidant activities [ 102 , 103 ]. The increase in the antioxidant activity measured using a FRAP assay can be assigned to the activation of crucial enzymes connected with the homeostasis of cellular antioxidants and the improved absorption of the elements participating in the synthesis of amino acids [ 104 ].…”