Evaluation of Nutritional Value and Shelf Life of Marigold with the Application of Spermidine, Citric acid and Proline

Edible flowers contain a variety of vitamins, carbohydrates and proteins and play an important role in the antioxidant activity and control of diseases. Marigold is also known as one of the most common edible flowers. The aim of this study was to investigate the improvement of nutritional value of Marigold flowers by spraying with spermidine, citric acid and proline.

This research was carried out in a completely randomized design with 14 treatments including two levels of spermidine, citric acid, proline (0, 50 and 100 mg/L) and postharvest shelf life (Start experiment, 5 and 10 days) in 3 replications. Each replication consists of 10 flowers. Foliar application was performed in three stages of six visible leaves, complete tillering and first bud emergence. The samples were stored at 4°C for post-harvest shelf life. Characteristics including biochemical and nutritional values were evaluated.

The results showed that, at the 10th day after harvest, the highest fresh and dry weight of flower, carotenoid, phenol, carbohydrate were detected in proline 100 mg/L sample, while the highest vitamin C, total antioxidant and postharvest life were observed in citric acid 100 mg/L sample and the highest flavonoid was determined in spermidine 100 mg/L sample and the highest protein was detected in proline 50 mg/L sample. All treatments showed significant differences at 1% and 5% level of control.

All treatments had significant effect on the measured variables, but the best improved characteristics were obtained at the concentration of 100 mg/L proline, citric acid and spermidine. The highest longevity was in citric acid 100 mg/L with 9.7 days and the lowest in control with 5.3 days.