Optimization of pea (Pisum sativum) seeds hydropriming by application of response surface methodology

Abstract

Evaluation of selected parameters viz. initial germination percentage (IGP), soaking duration (SD), process temperature (T), rotation speed (rpm) and air flow rate (AFR) was performed in this research investigation for hydropriming of Pea (Pisum sativum) seeds. Three seed lots having difference in their moisture content (14.94 to 28.04% d.b) and germination percentage (60 to 80%) were selected in this study. Procured seed lots were subjected to variable duration of accelerated aging (40±1°C, 100% RH) to attain necessary seed lots for experimental run. Response surface methodology (Box–Behnken design) with five factors and three level combination was adopted and the independent variables are, germination percentage (80, 70, 60), soaking duration, (45, 60, 75 min), temperature (20, 25, 30°C), rotation speed, (320, 340, 360 rpm) and air flow rate (0.411, 0.548, 0.685 m3/min). Second order polynomial equation was fitted for analyzing the experimental data and data was also subjected to analysis of variance (ANOVA) as a part of regression analysis. Process responses which were selected to evaluate the effect of hydropriming were moisture content after hydropriming (MC), final germination percentage (FGP), seedling length (SL), seedling dry weight (SDW), vigour indices (VI-I and VI-II) and electrical conductivity (EC). Regression analysis suggested that models were significant for all process responses and using numerical optimization technique, the optimal solution found was 75% IGP, 55 min SD, 20°C temperature, 320 rpm and 0.50 m3/min AFR. Values predicted by model were found to be at par with the results of a confirmation experiment carried out at optimum conditions.