Extrusion Not Only Stabilizes Rice Bran – It Makes It Better
In previous blogs, we’ve discussed how high shear, dry extrusion from Insta-Pro Intl can be used to stabilize rice bran.
As Mayette Ramos, Sales Director for SE Asia, wrote about this topic in her blog post:
“During the rice milling process, the enzyme in the rice bran is activated which causes a rapid degradation of oil in the rice bran into free fatty acids and glycerin. This affects the shelf life & stability of rice bran as it becomes rancid. Insta-Pro technology will stabilize rice bran and prolong shelf life. Immediately after milling process rice bran must be extruded at the appropriate temperature. The high shear dry extrusion process has been proven to inactivate the enzymes thus preventing rancidity.”
Rancid oils have terrible odors and taste characteristics. Often, unstabilized, degraded rice bran will be rejected and, if consumed, it may reduce animal performance.
This is important because rice bran contains notable quantities of nutrients. While amounts will vary, rice bran typically contains greater than 10% protein and an oil content that approaches 20%. So, extrusion of this valuable protein and energy can deactivate enzymes and preserve for longer-term storage.
But, can extrusion do more than preservation? Can extrusion improve the feeding value of rice bran?
We can pull from published data to answer this question. In addition to other experiments, the researchers determined the effect of pelleting and extrusion on digestibility of various parameters in rice bran fed to broilers. Recall that digestibility is an important measure of ingredient quality and gives information on the usefulness of nutrients to support growth performance. A higher digestible value (%) means that more of the nutrients in rice bran are available to support muscle protein deposition, weight gain, etc. The digestibility results are shown below.
You can plainly see that extruded rice bran has improved digestibility. Given that broilers have well-defined nutrient requirements for amino acids in protein, fatty acids in oil, and energy from the ingredients in a complete diet; extruded rice bran will better help to meet these requirements when it’s included as an ingredient in a complete diet. Also, dry matter digestibility, a measure of the digestibility of everything besides moisture was improved, which means that with extruded rice bran, less waste will be produced.
Pelleted, fresh, and rancid rice brans all had lower digestibility values. It’s interesting that fresh and “rancid” produced very similar results. The researchers did not indicate how long the rice bran sat around to become “rancid” and the data given in the paper (% free fatty acids) indicated that what they were calling “rancid” was not much different than fresh rice bran. As non-extruded rice bran is stored it will continue to degrade and further reduce its digestibility performance from fresh rice bran.
In conclusion, rice bran should be extruded to not only preserve it, but also, to enhance it. Considering how much rice is produced around the world, and how much animal production is expected to increase, contact us about how our process works great for stabilizing and improving rice bran.