Design, Development and Performance Evaluation of an Abrasion Peeling Machine for Ambarella (<em>Spondias dulcis</em>) fruits

Abstract

Ambarella (Spondias dulcis) is one of the newest exotic fruits to gain popularity since it has been used to produce various processed food in Sri Lanka. The fruit pulp of Ambarella is the primary entity used to process food. Thus, peeling at the preliminary processing stage is required to obtain fruit pulp. Currently, it has been done manually using hand tools, which takes a lot of time and labour costs. In addition, no technical solution has been developed for the small and medium food processing industry. Consequently, a continuous type, rotary abrasion peeling cum washing peeler was fabricated as a solution for Ambarella peeling to satisfy food processing at micro, small and medium enterprises (MSMEs). The machine consists of an abrasion drum where a fibre brush roller and water spraying unit are incorporated. While the drum spins, peeling is performed by a combination of abrasion surface, brush roller and water. The comparative machine performance was evaluated to find the best suited horizontal drum angle for peeling of Large and Miniature fruit types of Ambarella and compared with the manual knife peeling method. The best suited horizontal drum angle and rpm for mechanical Ambarella peeling were 10° and 75 rpm respectively. At this point, the machine capacity was 102 kg/h, with 49% peeling efficiency regardless of Ambarella fruit types. Moreover, the new peeling machine showed significantly higher (22-fold) mechanical peeling capacity in comparison to knife peeling (p &lt; 0.05). However, machine peeling efficiency was significantly lower than manual knife peeling (p &lt; 0.05). Furthermore, the material loss was less than 5%. The costs of peeling the Ambarella by machine and manual process were 2.00 LKR/kg and 40.00 LKR/kg, respectively. Machine peeling necessitates 19 times less labour than manual peeling. Based on the machine capacity, it is appropriate for MSMEs. However, further improvements are needed to enhance the Ambarella peeling efficiency.