Effect of extrusion conditions on the physical properties of coconut rice-based extrudates

Abstract

Coconut meal is a by-product of coconut oil and coconut milk production. It is a rich source of dietary fiber which shows to have an important role in lowing the risk of various chronic diseases. Therefore, it is interesting to convert the coconut meal, previously recognized as a valueless by-product, into a nutritious food product. The aim of this work is to investigate the possibility of such conversion using a widely known extrusion method. The effect of extrusion variables, including the coconut meal content (0, 6, and 12 %), glutinous rice content (5, 10 and 15%) and screw speed of extruder (380, 400 and 420 rpm) were investigated on the properties of extruded products. Physical properties of the extrudates such as expansion ratio, density, water absorption index (WAI), water solubility index (WSI), crispness and moisture content were evaluated. Our study showed that the extrudates had expansion ratio of 2.30-2.78%, density of 0.55-0.76 g/cm3, WAI of 4.24-5.50 g/g, WSI of 21.51-33.37%, crispness of 16.87-27.73 kg.sec and moisture content of 6.76-8.27%. The regression models for true density, expansion ratio, crispness, WAI and WSI were derived and statistically significant (p<0.05).

The effects of feed moisture and dried coconut meal content on the physicochemical, functional, and sensory properties of gluten-free Riceberry rice flour-based extruded snacks

“…This finding is in agreement with those of Wang et al (2017), who explained that adding cherry pomace significantly decreased the WAI of snacks due to competition for water absorption between the pomace and starch. Earlier, Dumchaiyapoom et al (2019) found that WAI decreased with increased coconut meal in mixed rice and glutinous rice-based extrudates. Furthermore, it can be observed that the interaction had a significant (p ≤ 0.001) effect on the WAI.…”

“…Several by-products, such as pomace (Alam et al, 2016) and bagasse from fruits and vegetables (Navarro Cortez et al, 2016), bran, coat, and wasted grains from cereals (Fleischman et al, 2016;Unsaeng et al, 2019;Zhong et al, 2021), have been used in extruded snack applications. However, there have been only a few studies examining the use of coconut meal in extruded snacks (Khan et al, 2015;Dumchaiyapoom et al, 2019).…”

Pengaruh Penambahan Tepung Kacang Merah pada Grit Jagung dan Suhu Barrel Terhadap Sifat Fisik Ekstrudat

“…Rasio Ekspansi (ER) Pengukuran dilakukan dengan membandingkan diameter ekstrudat dengan diameter die (Dumchaiyapoom et al, 2019). Diameter ekstrudat diukur menggunakan kaliper.…”