Rice bran pellets drying with hot air and infrared light.

Rice Bran Revolution: How Hot Air & Infrared Drying Can Boost Nutrition

Elliot Brynn in Tech & Innovation December 2025 • 4 min read.

"Unlock the secrets of rice bran pellet drying with HA-IR technology for superior oil content and reduced free fatty acids."

Rice bran, a valuable byproduct of rice milling, is crucial for rice bran oil production. Typically comprising 8-10% of the whole grain weight, it undergoes steam cooking and extrusion to form rice bran pellets, which stabilizes the material by deactivating enzymes and creating a porous structure.

However, these pellets are naturally high in moisture, making them prone to lipid oxidation and unsuitable for immediate oil extraction. Traditional hot air drying, while effective, is time-consuming and energy-intensive.

Innovative drying methods, such as infrared (IR) drying, are gaining traction as potential alternatives. This research investigates the use of hot air-assisted infrared (HA-IR) drying to optimize the drying process and improve the quality of rice bran pellets, focusing on key factors such as drying characteristics, oil content, and free fatty acid (FFA) levels.

HA-IR Drying: A Game Changer for Rice Bran Pellets

Rice bran pellets drying with hot air and infrared light.

The study explored the effects of combining hot air and infrared (HA-IR) drying on rice bran pellets. By varying the intensity of infrared radiation (750 – 3750 W/m²) and the temperature of the hot air (40 – 80°C), researchers aimed to pinpoint the optimal conditions for drying. The goal was to reduce moisture content from 0.18 to 0.08 g water/g dry matter efficiently.

The results highlighted significant improvements in drying speed and efficiency. The maximum drying rate (DR) ranged from 0.0030 to 0.0165 g water/g dry matter per minute, while drying time was drastically reduced to between 8 and 54 minutes. Key findings include:

Faster Drying: Higher IR intensity and air temperature led to faster drying rates and shorter drying times.
Enhanced Moisture Diffusion: Effective moisture diffusivity (Deff) values ranged from 0.3103×10-7 to 2.7603×10-7 m²/s, indicating efficient moisture removal.
Superior Oil Quality: HA-IR dried pellets exhibited higher oil content and lower FFA content compared to commercially dried samples.
Controllable Oil Content: IR intensity primarily influenced oil content, while both IR intensity and air temperature affected FFA levels.

These findings suggest that HA-IR drying not only accelerates the drying process but also preserves and enhances the quality of rice bran pellets, making it a superior alternative to traditional methods.

The Future of Rice Bran Processing

The implications of this research are significant for the rice bran oil industry. By adopting HA-IR drying, producers can achieve faster processing times, reduced energy consumption, and improved product quality.

Consumers also benefit from this enhanced process. Higher oil content translates to better nutritional value, while lower FFA levels ensure a fresher, more stable product. This aligns perfectly with the growing demand for healthier, naturally processed foods.

HA-IR drying represents a step forward in sustainable and efficient food processing, paving the way for future innovations in the agricultural sector.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1051/matecconf/201819203040, Alternate LINK

Title: Effect Of Hot Air Assisted Infrared Drying On Drying Characteristics And Quality Of Rice Bran Pellets

Subject: General Medicine

Journal: MATEC Web of Conferences

Publisher: EDP Sciences

Authors: Sahachart Sansak, Jiraporn Sripinyowanich Jongyingcharoen

Published: 2018-01-01

Everything You Need To Know

What is rice bran, and why is it important?

Rice bran is a valuable byproduct of rice milling, making up roughly 8-10% of the whole grain. It's crucial for producing rice bran oil. The material undergoes steam cooking and extrusion to form rice bran pellets to stabilize the material. These pellets, however, have high moisture content, making them prone to lipid oxidation and unsuitable for immediate oil extraction. This context explains the necessity of the HA-IR drying process to prepare rice bran pellets.

What is HA-IR drying, and how does it work?

HA-IR drying is a method that combines hot air and infrared radiation to dry rice bran pellets. The research shows that varying the intensity of infrared radiation (750 – 3750 W/m²) and the temperature of the hot air (40 – 80°C) can optimize the drying process. The primary goal is to reduce the moisture content from 0.18 to 0.08 g water/g dry matter, improving the quality of the rice bran pellets for oil extraction. This method allows for faster drying, better oil content, and lower free fatty acid (FFA) levels compared to traditional methods.

What are the main benefits of using HA-IR drying for rice bran pellets?

The study's key findings indicate that HA-IR drying results in faster drying rates and shorter drying times due to higher IR intensity and air temperature. It also enhances moisture diffusion, indicated by effective moisture diffusivity (Deff) values. Moreover, HA-IR dried pellets exhibit higher oil content and lower FFA content compared to commercially dried samples. IR intensity mainly affects oil content, whereas both IR intensity and air temperature influence FFA levels. These findings showcase the superiority of HA-IR drying.

Why is it important to reduce Free Fatty Acid (FFA) levels in rice bran pellets?

Free Fatty Acids (FFAs) are undesirable compounds that can negatively affect the quality and shelf life of rice bran oil. Traditional drying methods can lead to increased FFA levels due to the prolonged exposure to heat and moisture. HA-IR drying helps reduce FFA levels because of its faster drying times and controlled conditions, preventing excessive lipid oxidation. This control is critical for maintaining the quality and value of the rice bran oil produced.

What is the significance of HA-IR drying for the rice bran oil industry?

By adopting HA-IR drying, the rice bran oil industry can benefit from faster processing times, reduced energy consumption, and improved product quality. This innovative drying method leads to higher oil content and lower FFA levels in rice bran pellets, which enhances the overall quality and marketability of the oil. These improvements have the potential to create more efficient and sustainable practices within the industry, resulting in better products for consumers.