Effect of pulsed electric field parameters on the alkaline extraction of valuable compounds from perilla seed meal and optimization by central composite design approach

Abstract

Perilla seed meal (PSM) is the by-product of the oil extraction industry and a potential source of bioactive compounds. Pulsed electric field, a non-thermal technology, can be used to recover heat labile bioactive compounds from plant materials such as perilla seed meal. This study found that pulsed electric field (PEF) assisted alkaline extraction influenced the protein content and antioxidant activity of perilla seed meal (PSM). Among all PEF parameters, electric field strength (EFS) and pulse width (PW) were found to be the most significant as judged by F-value. Consequently, a central composite rotatable experimental design was applied to investigate the effect of electric field strength (EFS) and pulse width against protein content, antioxidant activity, and total phenolic content (TPC) of PEF treated PSM extract. Compared to conventional alkaline extraction, an increase in the yield of protein content by 10.58%, antioxidant activity by 7.48%, and total phenolic content by 21.59% was recorded at the optimal values of electric field strength (4 kV/cm) and pulse width (120 µs). Moreover, Karl pearson correlational analysis revealed a strong relationship (linear, R2=0.963) between antioxidant activity and total phenolic content. The validation was done at 95% confidence level for which the predicted values were compared with the actual experimental values, and the means were found to be insignificantly different from each other (p > 0.05). Industrial relevanceNon-thermal extraction techniques such as pulsed electric field used in this study can be used for the recovery of valuable compounds from the food materials especially heat sensitive compounds. PEF treatment increased the extractability of the water-soluble compounds from the perilla seed meal (PSM) samples and increased the recovery of valuable compounds from PSM while maintaining the nutritional and functional viability. Hence, this technology is having the potential to be used as assistant technology for the extraction of heat sensitive components from the plant cells which may find its applications in neutraceutical and pharmaceutical industries.