5 Industries found rice useful as an ingredient

Rice is one of the largest sectors in the food industry. It has long been established as a commodity but is gaining interest in the modified starch category. Starches are a necessity in today’s processed food industry. Many non-food sectors also use starches. The list can go on and on. Among them, five industries top the list. These are food and beverage, paper, cosmetics and personal care, pharmaceuticals, and pet food.

Table of Content

What is rice starch, and how is it made?

Rice grain contains 12% water, 75 to 80% starch, and 7% protein; the rest are lipids, vitamins, and minerals. Industrial rice starches are the pure form obtained by isolating the starch from the protein and the lipid. The aim is to reduce the protein content to less than 0.5%.

As most rice proteins are alkaline soluble. So, the extraction can be done by alkaline digestion. It can be of two types; alkaline steeping or alkaline enzymatic digestion. The process involves the following steps;

• Mix rice flour with an alkali (NaOH) or an alkali plus a protease enzyme.
• Allow protein to digest.
• Centrifuge the solution to separate the solid layer of starch from the liquid layer of digested protein.
• Drain or filter out the liquid layer.
• Wash the solid layer with water, centrifuge, and filter again.
• Add water and HCL to the solid layer. It will neutralize the alkali.
• Repeat the centrifuge, filtration, and water-washing step.
• The end product looks like a starch cake.
• Pass it through a dryer.

Alkaline digestion is an effective method, and it can yield up to 73 to 85% starch, 0.07 to 0.42% residual protein, and 0.07 to 2.6% damaged starch.

Use of rice starch in the Food & Beverage Industry

Rice starches can be divided into two categories; Regular rice starch and sticky rice starch. One starch is different from another in terms of composition. The composition has a greater impact on the type of gel the rice starch can form. Regular rice starch can gel faster due to higher amylose. But also lose its stability much earlier. The sticky rice starch contains high amylopectin, creating a more stable gel.

Regular rice starch is used;

• As a binder in confectionery, dairy, infant foods, processed meat, soups, sauces, puddings, and custards.
• As a dusting agent in confectionary like jelly.

Sticky rice starch;

• Acts as a binder in canned, infant, and ready-to-eat food.
• It acts as a crisp enhancer in cereals and extruded snacks.
• It gives a fat-like mouthfeel, so it found its use as a fat mimetic in dairy, pastries, sauces, soups, and processed meats.
• Useful in frozen food like low-fat ice cream and non-fat sausages for their high stability gel and mouthfeel. Usually, frozen products undergo freezing and thawing many a time. They need highly stable starches to avoid texture loss.

Use of rice starch in the Paper Industry

Starches are crucial for making a paper. It improves the paper’s bursting, tearing, tensile, and folding qualities. It can be used as a beater additive or a wet-end additive. To understand the role of these two additives, we must check the process first.

The process

• The raw material can vary from sawdust to waste paper.
• The process starts with pulping and bleaching of raw material. It helps to separate and clean the fiber.
• Then comes the beating and refining of the fiber. Adding starch as a beater additive can reduce the refining time at this stage.
• From this point onwards, the paper pulp becomes white.
• Once the beating is completed, the wet-end process starts.
• In the wet end, the pulp is mixed with a lot of fillers like clay and calcium carbonate, and other additives.
• Pulp turned into a thin fiber slurry of water, pulp, and additives.
• This slurry first passes through a wire mesh to form a thin screen. Then it is compressed to form a denser layer.
• It passes through a dryer conveyor and calendar section to make the surface smooth and glossy.

Its Role in Cosmetic Industry

Starches have wide use in the cosmetic industry. Starting from absorption to adsorption, it has many roles to play. The uses can be listed as follows;

Powder loose or compacts;

• It is effective as a replacement for talc and mica.
• The starch absorbs the sebum on the skin.
• It improves the stability of the compressed powder.

Lipstick, rouges, and pencils;

• In such an application, starch helps in the even distribution of color.

Emulsions;

• The starches bind with water to form a water-starch phase. Further adheres to the oil phase resulting in a stable emulsion. 
• It reduces the stickiness of the cream.
• It makes the cream easy to spread on the skin.
• The starch absorbs the oil on the skin and gives it a matt look.

There are four types of starches in use. These are potato, tapioca, corn, and rice starch. But rice starch is finer, with a particle size of 3 to 8 microns. It makes the starch highly absorptive. So, it is more effective than other starches.

Use in Pharmaceuticals

The tablets or capsules need substances to hold the active component or the medicine. This substance is a combination of various components. Starches are one of these. It has many roles to play. It acts as;

• Excipient; It stabilizes or provides bulk to the components that hold the medicine. It acts as a bulking agent, filler, or diluent.
• Disintegrant; It helps to release the medicine in a tablet when it comes in contact with a moist environment.
• Glidant; It helps to improve the flowability of the powder.
• Binders; It helps in increasing cohesion in compressed tablets.

Corn and potato starches are mainly used, but wheat and especially rice starches are gaining attention. Rice starches have many benefits; the one derived from sticky rice starch is like Bora rice. Study shows that it can effectively replace the gelatin in paracetamol as a binder. It is also found to be a great disintegrant or drug-releasing agent.

Use in Pet food

Most of the Pet foods in the market are made by extrusion. For this, it needs a good amount of starches. These starches play various roles in forming a pallet or extruded product of any form. It acts as a binder and texturizer, helps expand, and improves taste. All these properties are directly related to the gelatinization of starches. The starches with stable gels provide better expansion and look.

Though the non-food sector contributes a certain percentage towards rice starch consumption, most of it goes to the Food Industry.