Influence of Various Chemical Pre- Treatments And Drying Methods On Value Addition Of Marigold (Tagetes erecta L.)

The current study was carried out with the objective of determining the most effective pre-drying preservative treatments and the best drying method for marigold flowers. The flowers of marigold cv. Pusa Narangi Gainda were subjected to four different chemical pre-drying treatments, comprising of P0 (control), P1 (2% citric acid), P2 (10% MgCl2), P3(1:3 glycerol: water), and five different drying techniques, viz., D0 (air drying), D1 (silica gel + hot air oven), D2 (silica gel + microwave oven), D3 (Borax + hot air oven) and D4 (Borax + microwave oven). Results revealed that the maximum dry flower weight (1.55 g), minimum percent moisture loss (78.89 %), maximum dry flower diameter (4.64 cm), lowest diameter reduction (1.38 cm), minimum drying time (77.66 h), maximum score for color (2.82), texture (2.64), shape (3.60), non-shattering of petals (3.84) and overall acceptability (3.62) were achieved after pre-drying treatment with 1: 3 glycerol: water. Silica gel embedded flowers dried in a hot air oven resulted in less reduction in diameter (1.14 cm) and the maximum score for color (4.00), texture (4.10), shape (4.23), non-shattering of petals (4.18) and overall acceptability (4.55). Among the interaction effect, pre-treatment of glycerol: water (1: 3) and drying method (silica gel + hot air oven) showed the least amount of diameter reduction (0.97cm) and maximum scores for color (4.30), texture (4.50), shape (4.50), non-shattering of petals (4.50) and overall acceptability (4.80). Flowers dried in a microwave oven with either of the desiccant used took the least time to dry recording 0.16h. Air-dried flowers without embedding recorded the least dry flower weight (0.74g), maximum percent moisture loss (90.14%), minimum dry flower diameter (3.10cm), and largest diameter reduction (2.94cm). However, air drying took the longest drying time (352.33 h) and also yielded unacceptable dried flowers with minimum scores for color (1.20), texture (1.28), shape (1.93), and overall acceptability (2.30).