Enzymatic extraction of pectin from passion fruit peel (Passiflora edulis f. flavicarpa) at laboratory and bench scale

•An enzymatic process for extracting pectin from passion fruit peel was developed.•Enzymatic extraction of pectin generated higher yields than chemical extraction.•Enzymatic extraction of pectin showed similar yield but lower rate at bench scale.•Passion fruit pectin has similar characteristics as commercial citrus pectin.

Passion fruit peel, a waste product from the fruit processing industry, was used as feedstock for pectin extraction. For this purpose, a novel process was developed at flask scale using a crude extract of the fungal enzyme protopectinase-SE. The enzymatic pectin extraction was compared with the classic chemical extraction and scaled-up to 7 L stirred tank bioreactor. Pectin yields (measured as galacturonic acid) of 17-26 g/100 g of dry peel were achieved with the enzymatic extraction, which were 6-40% higher than that obtained with the traditional chemical extraction method. Effect of agitation speed, enzyme loading, pH, and temperature were evaluated, and all factors but agitation speed had a significant effect on the pectin yield. Best yields were obtained using 30 U/mL of protopectinase-SE loading at pH 3.0 and 37 °C. Scale-up to bench scale (7 L bioreactor) was successful using Reynolds or Froude number as scale-up criteria, achieving similar yields to those obtained in flasks, but with a slightly lower extraction rate. Enzymatic extracted passion fruit pectin had a galacturonic acid content of 85 g/100 g and a degree of esterification of 68%, similar to commercial citrus pectin.