Hydrocolloids and its application in coating

NARESH KUMAR MEHTAPhD SCHOLAR

A hydrocolloid is defined as a colloid system wherein the colloid particles are dispersed in water.

One of most extensively used additive in the food industry

Hydrocolloids are high molecular weight hydrophilic biopolymer used as functional ingredient in the foods

Sources of hydrocolloids

Basically it is a polysaccharide• Plants- starch (Tapioca, Barley, rice )• Sea weeds (carageenan)• Microbes (xanthan gum)• Plant exudates (gum, gum Arabic)• Modified biopolymer made by chemical

treatment of cellulose

Hydrocolloids as additive in food Industry

•Starch•Agar•Pectin•Alginates•Carrageenan•Guar gum•Gum Arabic•Xanthan gum•Cellulose derivatives-CMC

properties

• Have neutral taste and utilized in small quantities• edible and Non toxic

• They provides an unctuous body to fat reduced products• Biocompatibility, non polluting, low cost

• Enhance the bulk of the product while improving many functional properties

• Barrier properties

starch

Source-corn, wheat, barley, potato and tapiocaIt is polymer of amylose and amylopectin (25:75)

Gelatinization temperature is 55-75 ⁰C

Use Of Starch- Sausage, battered And Breaded Products, noodles

Pectin

•It is polymer of galacturonic acid•Main source –peels of apple (15%) and citrus fruits (30%)•It is good gelling and solidifying agent•Uses-jem and jellies

Sodium Alginate

•Sodium alginate is an anionic polysaccharide •extracted principally from the giant kelp Macrocystis pyrifera as alginic acid and neutralized to the sodium salt.• It is soluble in hot or cold water and gives somewhat hazy solutions of neutral pH.

Guar Gum

Guar gum is a nonionicsource- endosperm of legume Cyamopsis tetragonolobusIt gives neutral pH Solution in cold water

Xanthan Gum•Xanthan gum is an anionic polysaccharide derived from the fermentation of the plant bacteria Xanthomonas compestris

•It is soluble in hot or cold water and gives visually hazy, neutral pH solutions

Carrageenan

•Carrageenan is an anionic polysaccharide •extracted principally from the red seaweed Chondrus crispus•Carrageenan is available in sodium, potassium, magnesium,calcium and mixed cation forms•Carrageenan solutions are typically clear, and of alkaline ph

Gum Arabic (Acacia)• Gum arabic is an anionic polysaccharide collected as the dried exudate from The acacia tree (Acacia senegal)• it is soluble in hot or cold water and gives clear solutions of neutral to acidic pH.

Hydrocolloids as additives

Polysaccharides and proteins are food hydrocolloids with an important role in the structure, stability and functional properties of several processed foods.

Protein carbohydrate interactions determine the functional properties in foods where proteins are the major ingredients, such as meat and fish processed products.

•Fish Protein solublised by salt and water forms a continuous matrix•Some additive can be entrapped within this matrix filling the gel and exerting their functional effect in restructured products by1. Influencing the formation of continuous surimi gel

matrix during thermal inducing gelation2. Modifying the viscosity, mobility and other properties

of the liquid phase3. Influencing the appearance and texture of the gel i.e.

particle size distribution, rheological properties and relative volume fraction of the gel.

Suggested mechanism for induced changes in protein due to hydrocolloids

Properties Food HydrocolloidBinding properties

sausages starch

Bulking agent Diatic food α-cellulose

Crystallization inhibitors

ice-cream Sodium alginates

Clarifying agent Beer, wine Ising glass

Clouding agent Fruit juices Gum arabic

emulsifier chocolates alginates

Encapsulating agent

capsule Gum ,gelatin

Gelling agent paste carrageen

Foam stabilizer Beer, myonnaise CMC

Hydrocolloids utilised in food Industry

Experimental set up

• Double filleted oil sardines were taken in the study

• Chitosan dip treatment was given at rate of 1 % and 2 % for 10 minutes and one control was performed.

• Fillets were kept in HDPE boxes and 1-2 ⁰C temperature was maintained with ice during whole storage study.

L is lightness, a-redness b-yelloness

conclusion

• Chitosan treatment was found to be effective in reducing spoilage and extending the self life of the fillets.

• It also helps to maintain good WHC, reduce drip loss and textural qualities

• A self life of 8 and 10 days was observed for 1 and 2 % chitosan treated samples respectively compare to 5 days for control.

Thank you