Blanching effect on physicochemical and functional properties of flours processed from peeled and unpeeled white‐fleshed sweet potato Algerian cultivar

Louiza Belkacemi

doi:10.1590/fst.86821

Abstract

White sweet potato has high potential for flour production whose using in food preparations depends on its functional characteristics which in turn depend on variety, pretreatment methods and processing steps. This study investigated the effect of unpeeling and blanching on the chemical composition and functional properties of flour produced from white fleshed sweet potato Algerian cultivar. Sweet potato tubers were divided into two batches: a manually peeled batch and the unpeeled one, which were trimmed and soaked in water during 15 min. Each batch was then divided into two equal parts: one part was blanched in water at 100 °C for 5 min, the second part remained non-blanched. All samples were dried at 60 °C during 24 hours. The flours were analyzed for proximate composition, polyphenol and tannin content, and functional properties. Flour processed from unpeeling sweet potato exhibited higher (p < 0.001) lipid, starch, fiber, polyphenol and tannin content. Blanching decreased significantly polyphenols about 39% and 30% and tannins about 48% and 63%, respectively in unpeeled and peeled blanched SP-based flours. Finally, combination of both unpeeling and blanching increased water absorption capacity, swelling power, water solubility, emulsifying capacity of sweet potato flour which are interesting as properties in various food products.

Highlights

IntroductionSweet potato (SP) is utilized in various forms in different parts of the world
It is established that the unpeeled sweet potato tubers produced flour with a better nutritional composition and functional properties
Polyphenols and tannins were well-preserved in flours from unpeeled sweet potato which is useful in the human diet, especially that their content was nutritionally acceptable

Summary

Introduction

Sweet potato (SP) is utilized in various forms in different parts of the world It is consumed as raw, boiled, fried, steamed or further processed into various foods such as snacks, frozen and canned foods (Dereje et al, 2020). The preference is to store fresh sweet potato tubers in a cool store (Krochmal-Marczak et al, 2020) with controlled air relative humidity (85 to 95%) (Sugri et al, 2017). These conditions could only be fulfilled with advanced, expensive and workforce consuming equipment (Ndangui et al, 2014). It can be used to improve food products by enhancing color, flavor, natural sweetness and supplementing with nutrients (Ahmed et al, 2011)

Methods

Results

Conclusion