Evaluation of the Effect of Blanching and Drying Temperature on the Colour, Browning and Phenolic Compounds of Dried Ripe Plantain

The aim of this study was to evaluate the effects of blanching and drying temperature on colour parameters, browning parameters and total phenolic compounds of ripe plantain. To this end, various treatments were applied to slices of plantain of the Corne 1 variety at the yellow ripening stage with spots. The parameters L, a*, b*, browning index and rate, total polyphenol content and antioxidant activity were then determined. The results showed significant differences between the samples. Treatments C2 (control pulp dried at 45℃), T1 (pulp blanched and dried at 45℃), C2 (control pulp dried at 50℃) and T2 (pulp blanched and dried at 50℃) recorded values of 32.79, 27.93, 30.60 and 29.87 respectively for the L parameter. For parameter a*, the values were 3.94 for control C1, 2.12 for treatment T1, 4.27 for control C2 and 2.71 for treatment T2. The b* parameter recorded values of 7.06, 5.58, 7.80 and 6.26 for C1, T1, C2 and T2 respectively. The browning index was 30.75 for C1, 27.15 for T1, 38.74 for C2 and 29.40 for T2. The browning rates obtained were 0.03 for control C1, 0.18 for treatment T1, 0.23 for control C2 and 0.62 for treatment T2. Treatments C1, T1, C2 and T2 obtained 59.32, 55.35, 69.33 and 65.58 respectively for total polyphenol content. Blanching and drying had a significant impact on colour intensity, redness, yellowness, browning index, total polyphenols and antioxidant activity. However, blanching and drying had a significant impact, characterised by a decrease in colour parameters and phenolic compounds, but also by an increase in browning rate.