CJW-Gums+&+Stabilizers

Hydrocolloids are among the most widely use ingredients in the food industry Functions: Factors affecting gum properties Gelation of Hydrocolloids **Pectin** High Methoxy Pectin (HMP) Low Methoxy Pectin (LMP) Typical pectin uses: Jams,jellies and preserves, Stabilizer and in fermented/directly acidified dairy products. LM pectin gels are heat reversible
 * __Gums and Stabilizers__**
 * A range of polysaccharides and proteins
 * Also known as gums and stabilizers
 * Thickening agents
 * Gelling or texturizing agent
 * Stabilization of emulsions
 * Suspension of particulates
 * Control of crystallization
 * Encapsulation
 * Formation of film
 * Molecular weight
 * Monosaccharide composition ( building block
 * Type of side chains
 * Number of side chains
 * Distribution of side chains
 * Some hydrocolloids form gel on heating/ cooling; some require the presence of cations
 * Others will form gel under acidic pH + high sugar concentration – High Methoxyl Pectin; Some require alkaline pH
 * Thermoreversible gelling agents. Eg gelatin, agar, K-carrageenan, L-carrageenan, LM pectin, Gellan gum, Methy cellulose, Hydropropylmethyl cellulose (HPMC)
 * Thermally irreversible gelling agents Eg alginate, starch, konjac, HM pectin
 * Derived from the peel of citrus fruits
 * Natural form : protopectin (insoluble)
 * Chain of polygalacturonic acid- partially esterified as methyl esters
 * Commercial high methoxy pectin: DE 58% to 75%
 * To form gel, TSS must range between 55-85% and pH 2.8-3.8
 * Classified into ultrarapid/ rapid set (DE as high as 77)-used in jams & slow set (DE ~58)-used for very acid fruits to avoid premature gelation
 * Setting time 1-3min to >1h
 * Not heat reversible
 * DE <50%, Two sub group: Conventional low methoxyl pectin (LMP) and amidated low methoxyl pectin (ALMP)
 * Form gels in the presence of Ca 2+
 * LMP less Ca2+ reactive than ALMP=> used as a thickening agent in yoghurt fruit.
 * ALMP very Ca2+ reactive => assist gelation in low-sugar fruit
 * Gelation of LM Pectin based on “egg-box” model


 * Carrageenan **
 * Highly refined extract of seaweed from the rhodophyta family
 * 3 types of carrageenan:
 * 1. Kappa (K-carrageenan)
 * 2. Lambda (ɻ-carrageenan)
 * 3. Lota (ɩ-carrageenan)
 * Commercial carrageenans are not pure but contain vary amount of the other types
 * Kappa and lota- carrageenan have the ability to form thermoreversible gels upon cooling of hot aqueous solutions containing various cations; lambda-carrageenan does not form a gel (only act as thickening agent)

**Alginate**
 * Derived brown seaweed ( Laminaria hyperborean)
 * Made up of blocks of D-mannuronic acid (M-block) & L-guluronic (G-block)
 * Ratio of M:G & MW of polymer determine the solution and gelling properties of alginate
 * Can form gel in cold water in the presence of Ca ion, the gel is thermo-irreversible
 * Applications:
 * 1. Provide stabilizing effect in frozen products
 * 2. Act as thickener & stabilizer in beverage
 * 3. Propylene glycol alginate esterified form of alginate has emulsification property commonly used as stabilizer in emulsions


 * Gum Arabic **
 * =gum acacia- the oldest & best known
 * Sap exuded from various species of Acacia trees
 * Polysaccharide contain galactose, rhamnose, arabinopyranose, arabinofuranose, glucoronic acid
 * Contain small amount of protein, calcium, magnesium & potassium
 * Dissolve easily in hot/cold water
 * Least viscous & most soluble of all the hydrocolloids
 * Uses:
 * 1. Confectionery products – to retard sugar crystallization and promote emulsification
 * 2. Encapsulation agent
 * 3. Promote stabilization of foam in beer
 * 4. Emulsifier and stabilizer in soft drink emulsion

**Locust bean gum (LBG)**
 * Come from seed of the leguminose Ceratonia siliqua
 * Galactomannan gums
 * Insoluble in cold water & must be heated to dissolve
 * Does not form a gel by itself- gel when combined with xanthan gum
 * Non-ionic-stable over pH 3.5-11.0
 * Primary functions: thickening, stabilization of emulsions, inhibition of syneresis

**Guar Gum**
 * A linear chain of mannose with single galactose units attached as side chains
 * More highly substituted than LBG
 * Nongelling- used primarily as a viscosity builder, stabilizer & water binder
 * Stable from pH 4-10

**Xanthan Gum**
 * Polysaccharides produced from fermentation of CHO substrate with Xanthomonas campestris
 * Completely soluble in cold water & produce high viscosity at low conc.
 * Excellent stability to heat & pH
 * Pseudoplastic
 * Use for its thickening, suspending & stabilizing effects

**Cellulose Derivatives**
 * Alkaline treatment convert cellulose into an ether
 * Examples: carboxymethylcellulose (CMC), hydroxypropylmethylcellulose (HPMC)
 * Clear solution & stable over pH4-10
 * Use for thickening, suspending, stabilizing & modify flow characteristics
 * Methylcellulose (MC) & HPMC gel when heated & return to their original liquid viscosities when cooled.
 * Use in fried foods- barrier to oil absorption, stop loss of moisture & improve adhesion of batter

**Properties and Application of Gelatin in Food Products** What is Gelatin?
 * Natural foodstuff
 * Raw materials: skin (pigskin and hide split) and bone taken from slaughtered animals
 * Collagen contained is the starting material used for manufacture of gelatin
 * Amino acid contents: Glycine 33%, Hydroxyproline & Proline 22%, and other 17 amino acid 45%
 * Composition of edible gelatin: 84-90% Protein, 8-12% Water and 2-4% Mineral Salts
 * Contain no fat or CHO, no purine or cholesterol and free of all preservatives.

Source and Production of Gelatin **Type A:** derived from acid processed materials, e.g porkskin
 * Ø pI at pH 8.0-9.0
 * 1.
 * 2. Place in extraction kettles and hydrolyzed with successive portions of hot water.
 * 3. Filter and evaporate the dilute solution
 * 4. Chill the concentrated solutions to a gel
 * 5. Carefully dry with filtered and conditioned air in drying tunnels/ continuous dryers
 * 6. End product: solid containing ~10% moisture.
 * 7. Test for grade and quality

**Type B:** derived from alkaline or lime processed materials, e.g cattle or calf hides and ossein
 * Ø pI in the range 4.8-5.5
 * 1. Calf skin or hide trimmings, wash and treat with lime for 1-3months
 * 2. Limed skins are wash and neutralized with dilute acid.
 * 3. Transfer to kettles and heat with successive portions of hot water
 * 4. Partial hydrolysis of the collagen occurs, result in extracts which are dilute solutions of gelatin
 * 5. Continue Similar to Type A


 * Ossein gelatin (Type B):
 * 1. Degreased, hard bones, wash and leach with repeated portions of dilute HCl
 * (Acid reacts with mineral contents of the bone, removed in the acid solution, left ossein)
 * 2. Dry for storage or lime immediately.
 * 3. Follow the procedure outlined for the production of gelatin from calf skin

**Gelling Power** **Functional Properties of Gelatin** Note: temperature, salt content and pH are taken into account. Advantages Disadvantages **Fish Skin Gelatin** a) Normal gel strength ü Has a normal hydroxyproline content ü Made from fish from warmer water ü Not necessary from fresh water
 * Most important property of gelatin: Its ability to form gels in a thermoreversible way
 * Gelling power is determined by the bloom value - à the measurement of firmness of a standard gel under precisely determined conditions
 * Bloom value of commercially edible gelatin: 80 – 280
 * Advantages of high-bloom gelatins
 * Higher melting and solidification points
 * More rapid solidification and setting times in the final product
 * Lower amount needed
 * Lighter color
 * Better odor and taste
 * Which depending on factors of:
 * Concentration of the gelatin solution
 * Temperature
 * Gelling time and gelling temperature
 * Thermal pre-treatment and duration of treatment
 * pH of the solution
 * salt content
 * Gel formation
 * Water binding
 * Texturising
 * Thickening
 * Emulsion formation and stabilization
 * Foam formation and stabilization
 * Film formation
 * Adhesion / cohesion
 * Protective colloidal function
 * Forms thermally reversible gels with water
 * Gel melting temperature is below body temperature
 * Gives unique organoleptic properties and flavor release
 * Derived from animal hide and bone: Problems regarding kosher and Halal status and also vegetarians

b) Low or no gel strength ü Has a low hydroxyproline content ü Produced from cold water species ü Used to emulsify vitamin A before spray drying to give another type of microencapsulated product using gelatin

**Safety** ü Generally Regarded as Safe (GRAS) ü Joint Expert Commission on Food Addictives (JECFA) placed no limit on the use of gelatin in 1970