Rice Bran-Based Bioplastics: Effects of Biopolymer Fractions on Their Mechanical, Functional and Microstructural Properties

Abstract

Rice bran is an underutilized by-product of rice production, containing proteins, lipids and carbohydrates (mainly starches). Proteins and starches have been previously used to produce rice bran-based bioplastics, providing a high-added-value by-product, while contributing to the development of biobased, biodegradable bioplastics. However, rice bran contains oil (18–22%), which can have a detrimental effect on bioplastic properties. Its extraction could be convenient, since rice bran oil is becoming increasingly attractive due to its variety of applications in the food, pharmacy and cosmetic industries. In this way, the aim of this work was to analyze the effect of the different components of rice bran on the final properties of the bioplastics. Rice bran refining was carried out by extracting the oil and fiber fractions, and the effects of these two procedures on the final properties were addressed with mechanical, functional and microstructural measures. Results revealed that defatted rice bran produced bioplastics with higher viscoelastic moduli and better tensile behavior while decreasing the water uptake capacity and the soluble matter loss of the samples. However, no significant improvements were observed for systems produced from fiber-free rice bran. The microstructures observed in the SEM micrographs matched the obtained results, supporting the conclusions drawn.

Valorization of Honduran Agro-Food Waste to Produce Bioplastics

“…The rest of the unidentified components were assumed to be fibers present in the composition of these fruits. These fibers could serve as filler reinforcing the bioplastics [ 45 ].…”

Turning Food Protein Waste into Sustainable Technologies

“…In addition, rice bran can be processed by injection molding, and the properties of the resulting bioplastics can be tuned by the processing conditions and the addition of plasticizers, as well as by the blend components and the pretreatments of the byproduct. In fact, defatted rice bran results in bioplastics with higher viscoelastic moduli and higher performance compared to untreated bran, whereas, in contrast, lipids provide a plasticizing effect …”

“…In fact, defatted rice bran results in bioplastics with higher viscoelastic moduli and higher performance compared to untreated bran, whereas, in contrast, lipids provide a plasticizing effect. 543 5.1.6. Bioplastics from Denatured Proteins.…”

“…Because of the low solubility of these proteins, however, they first require complicated protein extraction and purification processes, , and also the use of potentially harmful solvents and additives for the production of biomaterials. To overcome these limitations, a few authors focused on valorizing protein-rich rice byproducts, such as rice bran − and rice wine meal, avoiding expensive pretreatments and extraction processes, and used them as building blocks or as additives to develop edible films ,, and composite bioplastics. − ,,,, For instance, the addition of rice bran microparticles into starch films allows improvement of their mechanical properties and water stability . In addition, rice bran can be processed by injection molding, and the properties of the resulting bioplastics can be tuned by the processing conditions and the addition of plasticizers, as well as by the blend components and the pretreatments of the byproduct.…”

Utilization and Evaluation of Rice Bran and Rice Bran Wax as a Tablet Lubricant

“…Several studies have reported on the use of rice bran as an ingredient in animal feed and in human food products, such as cereals, bread, and snacks [ 16 ]. It has also been studied for its potential use in various industrial applications, such as in the production of biofuels, bioplastics, and nutraceuticals [ 17 , 18 , 19 ]. The use of rice starch as a pharmaceutical excipient has long been established.…”