Freeze–Thaw Pre-Treatment of Cassava Tubers to Improve Efficiency of Mechanical Peeling

Barati Barati,Romuli Romuli,Latif Latif,Müller Müller

doi:10.3390/app9142856

Abstract

The effect of a freeze–thaw pre-treatment (FTP) on the peeling process of cassava tubers was investigated in this study. The length and weight of the cassava tubers varied from 200 to 280 mm and 500 to 900 g, respectively. A prototype abrasive cassava peeling machine was used. The operational parameters were the rotational speed of the brushes (550–1150 rpm), peeling time (1–5 min), thawing temperature (50–90 °C), and incubation time of the thawing treatment (0–120 s). Response surface methodology was applied to optimize FTP to improve the peeling process of cassava tubers. Peeled surface area and peel loss were measured as the responses. Results revealed that the peeled surface area and peel loss were significantly influenced by the rotational speed of the brushes, peeling time, and the incubation time of the thawing treatment (p < 0.05). Under optimal peeling conditions, with a rotational speed of 1000 rpm, a peeling time of 3.4 min, a thawing temperature of 59 °C, and an incubation time of 90 s, the peeled surface and the peel loss were approximately 99.5 and 19%, respectively. The results show that the use of FTP can improve cassava peeling by softening the peels and increasing the peeled surface area.

Highlights

Cassava, one of the staple foods in tropical and sub-tropical lands, has gained attention due to its capability to provide food security in recent decades [1,2,3]
The results showed that increasing the rotational speed of the brushes, the peeling time and incubation time positively affected the peel loss
The most efficient process conditions for an optimum peeling process were found to be a rotational brush speed of 1000 rpm, a peeling time of 3.4 min, thawing temperature of 59 ◦ C, and an incubation time of 90 s, which resulted in a peeled surface area of 99.5% and a peel loss of 19%

Summary

Introduction

One of the staple foods in tropical and sub-tropical lands, has gained attention due to its capability to provide food security in recent decades [1,2,3]. Fresh cassava tubers do not have a long shelf-life due to their high moisture content [4]. Cassava tubers are usually processed to obtain various relatively shelf-stable products [5]. Peeling is an essential step in cassava processing, which includes removing the corky periderm and cortex from the tubers. Either for industrial or domestic use, is still a major challenge in cassava processing. It is traditionally done by hand or by mechanical, thermal, or chemical methods [6]. Each method of peeling presents its own advantages and disadvantages

Objectives

Methods

Results

Conclusion