Optimization of Pretreatment for Prevention of Enzymatic Browning of Fresh-Cut Lotus (Nelumbo nucifera) Root Slices

Abstract

The experiments were carried out optimized the chemical concentration as pre-treatments prior to drying of fresh-cut lotus root slices. The lotus root slices were pretreated by chemicals with Potassium metabisulphite (0.1, 0.2, and 0.3 % (w/v)), sodium bicarbonate (2, 4, and 6 % (w/v)), and ascorbic acid (0.5, 1 and 1.5 % (w/v)). The quality parameters of lotus root slices were taken as color parameters such as lightness (L*), redness (a*), and (b*) along with the browning index. The best treatment was decided based on the browning index. The experimental results indicated that the color parameters of fresh-cut lotus root slices and chemicals deteriorate over the time span of 0h to 5h. Besides that, chemically treated samples were improved over the fresh-cut lotus root slices. The lightness (L*), redness (a*), and yellowness (b*) of 0.30% potassium metabisulphite samples varies from 136 to 116, 1.17 to 248, and 2.87 to 5.34 for a period of time 0h to 5h, respectively. Which is the lowest as compared to all other samples. The browning index pre-treated samples was much lower than samples without treatment. The browning index increased with elapsed time and highly increase in untreated (fresh-cut lotus root slices) samples than pre-treated samples (chemicals treated). The optimized browning index was minimum (1.498 to 4.963) for 0.3 % KMS as compared to 5.337 to 16.02 and 2.73 to 9.227 for 6 % (w/v) sodium bicarbonate and 1.5 % (w/v) ascorbic acid solutions, respectively.