Biorefinery methods for extraction of oil and protein from rubber seed

Miao Yang,Wenlei Zhu,Hui Cao

doi:10.1186/s40643-021-00386-2

Miao Yang, Wenlei Zhu + Show 1 more

Open Access

https://doi.org/10.1186/s40643-021-00386-2

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Abstract

Rubber seeds are a by-product of rubber production and are rich in oil and protein. Upgrading of rubber seeds to produce proteins, oils and feedstock can generate additional revenue for rubber production and reduce waste. The present study investigates the effects of different pre-treatments and extraction methods to determine the optimal methods to produce oil and protein from rubber seed kernels. Mechanical expulsion using a screw press and solvent extraction using n-hexane were employed for oil separation. The highest oil recovery efficiency of 95.12% was obtained using rubber seed meal that was pre-dried at 105 ℃. The sequential water–alkaline treatment was ideal for achieving high protein recovery while reducing the protein denaturation that can result from high operating temperatures and organic solvent contact. Over 90% of the total protein from rubber seed kernels could be recovered. Separating oil from kernels using hexane followed by protein extraction from the meals by enzymatic treatment provides a suitable method for comprehensive utilization of rubber seeds.

Highlights

Rubber seeds are an abundant by-product in rubber plantations, with annual production between 136–2000 kg/ hectare (Zhu et al 2014); only 25% of rubber seeds are used for seeding and the residual 75% are wasted (Indonesian Directorate Generale of Plantation 2010)
This study focused on finding the optimal methods to produce oil and protein from rubber seed kernels
Our study revealed that the efficiency of extracting oil and protein from rubber seed kernels varies significantly depending on the pre-treatment and extraction methods

Summary

Introduction

Rubber seeds are an abundant by-product in rubber plantations, with annual production between 136–2000 kg/ hectare (Zhu et al 2014); only 25% of rubber seeds are used for seeding and the residual 75% are wasted (Indonesian Directorate Generale of Plantation 2010). This study focused on finding the optimal methods to produce oil and protein from rubber seed kernels. Rubber seed oil is an potential product that is currently getting more attention as an alternative feedstock for biodiesel production (Sai Bharadwaj et al 2019; Samart et al 2019). Separation and use of all fractions to Mechanical pressing and solvent extraction are two common methods to separate oil from oil seeds. Mechanical pressing includes hydraulic pressing and screw pressing, both of which are suitable for separating oil from kernel seeds (Gao et al 2018; Santoso et al 2014). Lee et al (2013) demonstrated that supercritical carbon dioxide extraction can be used to separate rubber seed oil, but the equipment is expensive and the oil recovery is relatively low, so it is not suitable for industrial production. Studies on rubber seed protein extraction are limited. Studies on rubber seed protein extraction are limited. Widyarani et al (2014) reported a maximum protein recovery of 71% obtained by alkaline extraction and assessed a one-step combined oil and protein extraction using an aqueous enzymatic method, which produced a

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