Salinity Stress Ameliorates Pigments, Minerals, Polyphenolic Profiles, and Antiradical Capacity in Lalshak

Abstract

Previous studies have shown that salinity eustress enhances the nutritional and bioactive compounds and antiradical capacity (ARC) of vegetables and increases the food values for nourishing human diets. Amaranth is a salinity-resistant, rapidly grown C4 leafy vegetable with diverse variability and usage. It has a high possibility to enhance nutritional and bioactive compounds and ARC by the application of salinity eustress. Hence, the present study aimed to evaluate the effects of sodium chloride stress response in a selected Lalshak (A. gangeticus) genotype on minerals, ascorbic acid (AsA), Folin−Ciocalteu reducing capacity, beta-carotene (BC), total flavonoids (TF), pigments, polyphenolic profiles, and ARC. A high-yield, high-ARC genotype (LS6) was grown under conditions of 0, 25, 50, and 100 mM sodium chloride in four replicates following a block design with complete randomization. We recognized nine copious polyphenolic compounds in this accession for the first time. Minerals, Folin−Ciocalteu reducing capacity, AsA, BC, pigments, polyphenolic profiles, and ARC of Lalshak were augmented progressively in the order: 0 < 25 < 50 < 100 mM sodium chloride. At 50 mM and 100 mM salt concentrations, minerals, AsA, Folin−Ciocalteu reducing capacity, BC, TF, pigments, polyphenolic profiles, and ARC of Lalshak were much greater than those of the control. Lalshak could be used as valuable food for human diets as a potent antioxidant. Sodium chloride-enriched Lalshak provided outstanding quality to the final product in terms of minerals, AsA, Folin−Ciocalteu reducing capacity, BC, TF, pigments, polyphenolic profiles, and ARC. We can cultivate it as a promising alternative crop in salinity-prone areas of the world.

Keywords: ABTS+; DPPH; HPLC–UV; antiradical capacity; ascorbic acid; beta-carotene; color attributes and pigment; minerals; polyphenolic profiles; salinity stress.

Figure 1

Color attributes of Lalshak as influenced by salt stress (n = 6). L* = Lightness; a* = Redness/greenness; b* = Yellowness/blueness. Dissimilar letters in the bars varied significantly by Duncan’s Multiple Range Test (DMRT) (p < 0.01).

Figure 2

Pigments of Lalshak as influenced by salt stress (n = 6). Dissimilar letters in the bars varied significantly by DMRT (p < 0.01).

Figure 3

The salt-induced increment in color attributes and pigments (%) over control in Lalshak.

Figure 4

Macroelements (mg g⁻¹ DW) of Lalshak as influenced by salt stress (n = 6). Dissimilar letters in the bars varied significantly by DMRT (p < 0.01).

Figure 5

Microelements (µg g⁻¹ DW) of Lalshak as influenced by salt stress (n = 6). Dissimilar letters in the bars varied significantly by DMRT (p < 0.01).

Figure 6

Comparison of the salt-induced increment in mineral composition (%) over control in Lalshak.

Figure 7

Response of phytochemical composition of Lalshak under salt stress (n = 6). Dissimilar letters in the bars varied significantly by DMRT (p < 0.01).

Figure 8

Comparison of the salt-induced increment in phytochemical composition (%) over control in Lalshak.

Figure 9

Impact on polyphenolic compounds of Lalshak under salt stress (n = 6). Dissimilar letters in the bars varied significantly by DMRT (p < 0.01).

Figure 10

Comparison of the salt-induced increment in polyphenolic compounds (%) over control in Lalshak.

Figure 11

Impact on polyphenolic fractions of Lalshak under salt stress (n = 6). Dissimilar letters in the bars varied significantly by DMRT (p < 0.01).

Figure 12

Comparison of the salt-induced increment polyphenolic fractions (%) over control in Lalshak.