The manuscript focuses on the valorisation of citrus fruit waste for production of pectin using PolyE-IL-1 catalyst. The catalyst offers several advantages, including high yield, easy catalyst separation, and recyclability. The intensified process provides 30 % pectin yield at a temperature of 95 °C within 90 minutes in a batch mode of operation. Thus, the present process has implications for waste reduction and the production of valuable products from citrus waste by-products.

Abstract

Citrus fruit waste is a potential source for valorisation into pectin. In present manuscript a PolyE-IL-1 as an efficient acid catalyst has been integrated for fractionation of pectin from citrus fruit waste. The use of PolyE-IL-1 catalyst has specific advantages in term of high yield, ease of catalyst separation, recycle and reuse etc. The process optimization study was conducted to check the influence of catalyst concentration, temperature, time and substrate concentration etc., to obtain maximum yield of pectin. The intensified process yields 30 % pectin at 95 °C in 90 min in batch mode of operation. Moreover, batch reactor, ultrasound batch reactor and microwave batch reactor were compared to observe the influence of the mode of reactor operation. Various citrus waste feedstock (Orange, Sweet lime and Lemon) was tested and maximum yield of (32.52 %) pectin was obtained from Lemon peels. The catalyst recyclability study showed consistency in pectin yield (30 %) for five consecutive recycle runs. Thus, the use of an easily recyclable PolyE-IL-1 catalyst provides an efficient route to produce pectin from citrus fruit peel waste.