Physical and Thermal Properties of Averrhoa bilimbi L.: Mass Modelling for Postharvest Processing
La Choviya Hawa, Lita Puspita Rizka Perdana*, Ubaidillah Ubaidillah, Mochamad Bagus Hermanto, Nabila Intan Milania

Department of Biosystems Engineering, Faculty of Agricultural Technology, Universitas Brawijaya, Malang, Indonesia
*litapuspita[at]ub.ac.id

Abstract

Averrhoa bilimbi L. of family oxalidaceae, widely cultivated throughout tropical countries. The chemical constituents of A. bilimbi have been identified include citric acid, vitamins A, B, and C, as well as phenolic compounds, flavonoids, saponins, tannins, anthocyanins, and triterpenoids. Due to its high acid content, A. bilimbi can be used as a food flavoring. However, the potential of A. bilimbi have never been well developed, causes the moisture content which reaches more than 90%. This makes it highly susceptible to postharvest quality degradation. Therefore, drying is postharvest technique, thereby extend its shelf life and quality. This study quantified the physical and thermal properties of A. bilimbi to aid in the design of processing equipment. The fruits principal dimensions averaged 47.1 mm in length, 24.0 mm in width, and 23.0 mm in thickness. The mass ranged from 5.8 to 39.7 g, with volumes between 4.5 and 40.5 cm3. The average geometric and equivalent diameters were 29.6 mm, and the fruit had an ellipsoid shape. A. bilimbi has relatively high thermal conductivity (0.610 J.ms C). Four empirical models, i.e. linear, quadratic, power, and S-curve, were evaluated to predict fruit mass using physical attributes. The multivariate quadratic model with principal dimensions (LWT) provided the highest R2 value for mass prediction. These findings offer a scientific basis for designing grading, sorting, and processing equipment, and for developing postharvest and derivative products.

Keywords: Averrhoa bilimbi L.-physical properties-thermal properties-mass modelling-regression

Topic: Agricultural and bioprocess engineering