Optimisation of pectin production from dragon fruit peels waste: drying, extraction and characterisation studies

Abstract

Reutilisation of agricultural wastes is a major challenge faced by the research community. The current study aimed to address this issue by recovering commercial pectin from dragon fruit peels by investigating the pretreatment and extraction process and their parameters. Optimum oven-drying temperature was identified at 45 °C with the highest pectin yield (6.27%) and the lowest ash content (8.34%). Investigation of the drying kinetics revealed Page's model as the best-suited model to the experimental data in terms of the highest R 2 (0.99685) and lowest RSME (0.0002). A three-factor, three-level Box-Behnken design was applied to optimise ultrasound-assisted pectin extraction for the parameters of time, temperature and solid-to-liquid ratio. Under the optimised condition of 32 min at 85 °C with a ratio of 1:30 g/ml, a maximum pectin yield (23.09%) was obtained as compared to the predicted value (22.84%). The extraction kinetics study showed the logarithmic model was the best-fitted model to represent pectin's extraction in terms of the highest R 2 (0.9384) and lowest RMSE (0.821). Degree of esterification of pectin pre-(36.36%) and post-optimisation (33.27%) characterised it as low methoxyl pectin. The ash content of pectin was reduced by 23.65% revealing that higher-purity pectin was extracted following optimisation. Comparison of the Fourier transform infrared spectra with commercialgrade pectin shows the extracted pectin from dragon fruit peels has high potential in food applications. The current study recommends waste dragon fruit peels as a sustainable alternative source for high-value pectin.

Supplementation of pitaya peel powder to cookie formulation: Effects of ratio of pitaya peel powder on the product quality, predicted glycemic index and antioxidant release during in vitro sequential digestion

“…In addition, there was evidence that amylase-catalysed starch hydrolysis may be affected due to the interaction between pectin and amylase [43]. Polygalacturonic acid, a pectin component of pitaya peel [44], might interact electrostatically with α-amylase and act as a non-competitive inhibitor of this enzyme [45]. Moreover, cookies incorporated with high PPP ratios contained more phenolic compounds which might reduce their glycemic index by the inhibition of α-amylase and/or α-glucosidase as well as the interactions between polyphenol and starch molecules [46].…”

Optimization and Characterization of Ultrasound-Assisted Pectin Extracted from Orange Waste

“…The extraction was carried out utilizing Chua [17], with modification in all runs, and 40 gm of the powdered sample was blended with pH of (2 3) citric acid solution in a 400 mL flask. It was then sonicated for (15 30min), in the range of 60 140W, ultrasound power, thereafter the mixture was maintained at a temperature of 25 0 C and percolated.…”

“…The esterification degree was decided based on the procedure adopted by Chua [17], with modification by utilizing Eq. ( 8).…”

Effects of high‐pressure pretreatment on acid extraction of pectin from pomelo peel

“…The DE of high methoxyl pectin (HMP) is higher than 50%, and that of low methoxyl pectin (LMP) is <50% (Duan et al, 2021). Currently, commercial pectin is mostly derived from apple pomace and citrus peel (Zhong et al, 2021); however, many other plants are reported to be good sources of pectin, including pomelo peel, sugar beets, and dragon fruit (Guo et al, 2016; Kazemi et al, 2019; Chua et al, 2020; Tocmo et al, 2020).…”