June 16, 2024

Starch Derivatives: An overview of the important modified starches

Starch Modification- Methods and Impact

Starches are commonly modified to alter their functionality and properties. There are various chemical, physical, and enzymatic methods used for starch modification. Some common methods include acetylation, hydroxypropylation, and cross-linking. Each method impacts the starch differently.

Acetylation involves treating starch with acetic anhydride which adds acetate groups to the starch polymer. Starch Derivatives  This process increases the stability of starch against heating and cooling. Acetylated starches have increased resistance to retrogradation. They are often used as thickening and stabilizing agents in foods.

Hydroxypropylation substitutes hydroxypropyl groups for some of the hydroxyl groups on starch. This process increases the stability of starch granules against heating and cooling. It also improves the viscosity of starch solutions. Hydroxypropylated starches find applications as thickeners, stabilizers, binders, coatings and fatigue-resist agents.

Cross-linking develops covalent linkages between adjacent starch polymers through the addition of chemicals like phosphorus oxychloride or sodium trimetaphosphate. This process enhances the properties of resistant starch and the stability of starch granules during processing. Cross-linked starches have reduced tendency to swell. They are used as stabilizers, thickeners and fat substitutes.

Resistant Starch

Resistant starch is the fraction of starch that escapes digestion in the small intestine and reaches the large intestine as a carbohydrate. It has been classified into four types based on the physical state and structure causing its resistance to digestion:

– Type 1 (RS1) – Physically inaccessible starch found in whole grains, seeds and legumes. Its granular structure prevents digestive enzyme access.

– Type 2 (RS2) – Native starch granule structure like raw banana, potato, high-amylose maize. Its crystalline structure resists digestion.

– Type 3 (RS3) – Retrograded amylose from cooked and cooled foods. Its double helices structure is tightly packed and indigestible.

– Type 4 (RS4) – Chemically modified starches by esterification, cross-linking or hydroxypropylation. It has altered structure resisting digestion.

Resistant starches contribute dietary fiber in foods and have many health benefits like improved glycemic and insulin response, prebiotic effect and reduced risk of colon cancer.

Specialty Starches

Some common types of specialty starches include:

– Dextrins – Produced by hydrolyzing gelatinized starch with acid. Used as binders, thickeners and extenders.

– Maltodextrins – Produced by hydrolyzing starch, usually corn starch. Used as low-sweetener bulking and filling agents.

– Cyclodextrins – Formed through enzymatic processing of starch. Have a doughnut shaped ring structure trapping guest molecules. Used for encapsulation applications.

– Octenyl succinic esters – Starch modified by octenyl succinic anhydride esterification. Has emulsifying properties and improve stability of foods.

– Carboxymethyl starch – Starch reacted with monochloroacetic acid giving carboxymethyl functional groups along polymer chain. Used as stabilizers, thickeners, emulsifiers.

Specialty starches play an important role in various industries like food, pharmaceuticals, animal feed, construction due to their tailored functional properties.

Starch Derivatives in Food Applications

Modified starches are widely used as additives in the food industry mainly as thickeners, stabilizers, emulsifiers, binders and extenders. Some popular applications include:

– Soups, sauces, gravies – Provide smooth consistency and prevent separation.

– Bakery fillings – Act as fat replacers improving mouthfeel and texture.

– Processed meats – Improve water binding capacity, slicing properties and reduce fat content.

– Dressings, condiments – Contribute desirable mouthfeel, lubricity and stability against acid or salt conditions.

– Baked goods – Contribute crumb softness, moisture retention reducing staling and improving shelf life.

– Beverages – Provide desired viscosity, prevent sedimentation and improve suspension of particulates.

– Confectionery – Prolong shelf life, act as lubricants during processing and improve texture.

With tailored functional properties, modified starches can help manufacturers formulate healthier and convenient foods while meeting consumer demands for natural clean label products. Their applications continue to grow in the food industry.

Starch Derivatives in Non-Food Applications

In addition to foods, modified starches have important roles in various non-food applications:

– Paper manufacturing – Used as binders, coating agents and strength enhancers in paper production.

– Textiles – Provide improved strength, absorbency and easier ironing as sizing agents for fabrics, garments and home furnishings.

– Pharmaceuticals – Act as disintegrants, binders and controlled release excipients in drug delivery systems.

– Construction – Contribute strength and adhesive properties in dry mortars, concrete masonry units, plasterboards and road construction.

– Mining and drilling – Aid the formulation of bentonite-based drilling muds thickening systems. Prevent settling and thinning at high temperatures.

– Oil recovery – Help recover more oil through water flooding processes when used as thickeners in injected waters.

*Note:
1.Source: Coherent Market Insights, Public sources, Desk research
2.We have leveraged AI tools to mine information and compile it