Effect of Particle Size on Physical Properties of Rambutan Seed Powder

Abstract

Rambutan seed powder is derived from the crushing of dried seed of rambutan (Nephelium lappaceum L.) and it is promisingly used as an incorporating powder into food product. However, there is limited information on the effects of particle size on the handling and processing of rambutan seed powder in the industry. Therefore, a study was performed to determine the effects of particle sizes on physical properties of rambutan seeds powder. The physical properties measured moisture content, bulk and tapped density, as well as flowability characteristics. In this work, the powders were classified based on their mean diameter (d50) that ranged between less than 250 μm, between 250 μm and 750 μm and more than 750 μm. The fine rambutan seed powder (RSP) with particle 250 μm to 750 μm exhibited the best powder characteristics as it holds lowest moisture content, 5.42% and fair and passable flow properties, with Hausner ratio of 1.26 ± 1.20. The results indicated a significant impact of particle size on the cohesivity, where smaller particle size tended to decrease flowability and caused caking and agglomeration, which led to undesirable quality of food product.