Effect of Salicylic Acid Treatment on Postharvest Yellowing and Nutritional Quality of Broccoli

Abstract

This study investigated the effect of salicylic acid (SA) treatment on preserving the color and nutritional quality of broccoli during postharvest cold storage. The results demonstrated that SA treatment significantly delayed the yellowing process, increased chlorophyll content, −a*/b* value, quantum yield (Fv/Fm), and fluorescence decline ratio (Rfd) and decreased L* value and yellowing index compared with untreated control. Meanwhile, the losses of glucoraphanin (GRA), glucobrassicin (GBS), sulforaphane (SFN), indole-3-methanol (I3C), and ascorbic acid (AsA) were obviously alleviated in the treated samples, and the accumulation of total phenols and total flavonoids was significantly increased. In addition, the total antioxidant capacity (T-AOC) of the treated samples was improved remarkably and the content of malondialdehyde (MDA) was significantly reduced. Multivariate statistical analysis visualized the distribution of sensory and nutritional variables in both groups of samples, further demonstrating that SA treatment was more effective in preserving GRA and AsA and effectively induced an improvement of the antioxidant capacity.

Keywords

• broccoli; postharvest; salicylic acid; glucosinolates; quality deterioration