Effect of Pretreatment and Drying Methods on the Quality of Anchote (Coccinia abyssinica (Lam.)) Flour

Abstract

Reduction of postharvest losses through improved technique is studied in this work. Pretreatment and drying, in particular, are important methods for using various tuber-based food items to produce intermediate products that increase economic benefit and availability with a longer shelf life in the production and consumption communities. This study was conducted to evaluate the effect of pretreatment and drying methods on the proximate composition and physical and functional properties of flour developed from anchote. The treated anchote flour was prepared using hot distilled water for blanching and potassium metabisulphite solution and drying methods (sun, solar, and oven). The obtained data were statistically analyzed using SAS software at $P<0.05$ . Accordingly, the untreated and sun-dried anchote had greater moisture content (10.34%) than the chemically treated and oven-dried anchote (8.71%). The samples treated with potassium metabisulphite and the solar-drying methods have higher protein content (4.02%) than the blanched and sun-dried samples (3.14%). Samples treated with blanching and solar drying have lower ash content (3.96%) than samples treated with potassium metabisulphite and dried (4.89%). The highest fiber content was recorded for samples treated with blanching and oven-drying methods, with a rating of 4.71%. Sun-dried samples had an increased fat content (1.14%) compared to blanch with all drying methods (0.72%). The untreated and sun-dried flour had lower carbohydrate content (80.95%) than blanched and oven-dried (83.03%). The potassium-metabisulphite-treated and oven-dried samples rated 2.66% with the highest water absorption value. The blanched and oven-dried samples had the lowest oil absorption capacity of 1.71%, a significantly different value from the highest value of 1.98% for the potassium-metabisulphite-treated and solar-dried samples. Oven-dried samples had higher swelling power than solar- and sun-drying methods. The anchote samples treated by blanching methods and dried in the oven had the highest solubility rating of 43.84% and the lowest value of 38.8% for control and sun-dried samples. The sun-dried anchote flour had the highest dispersibility value, which is significantly different from both the oven-dried and solar-dried versions. Along with that, the untreated samples had significantly lower dispersibility values than the potassium-metabisulphite-treated and blanched flour samples. The proximate values of anchote flour were significantly affected by pretreatment and drying methods. Additionally, the main and interactive effect of pretreatment and drying methods influenced the water absorption capacity, oil absorption capacity, swelling power, solubility, and dispersibility significantly. Further research is required to improve flour properties and characterize pasting properties to assess the suitability of the starch for different industrial inputs.