Practical applications of gums and stabilisers in dairy Foods
Transcription
Practical applications of gums and stabilisers in dairy Foods
Practical applications of gums and stabilisers in dairy Foods Matt Golding & Lara Matia-Merino IFNHH Content • Definitions • Structure, type and function • Hydrocolloids as food additives – Examples of dairy applications – Synergistic aspects – Processing – Trouble shooting Functional Ingredients in Dairy Terminology: Hydrocolloids, Biopolymers cular-weight water-soluble polymers Types: Polysaccharides or Proteins (disordered or globular) surface-active stabilizing polymers Proteins: emulsification and foaming properties Polysaccharides: water-holding Some Hydrocolloids are used as emulsifying agents e.g., gum arabic, gelatin. Food Hydrocolloids High-molecular-weight hydrophilic biopolymers that can control microstructure, texture, flavour and shelf-life •Many polysaccharides extracted from plants , seaweeds, microbial sources (agar, carrageen, xanthan..) and gums (gellan, guar, acacia gum) and modified starch or cellulose (chemically or enzymatically) •Protein gelatin Hydrocolloids at a Glance Hydrocolloids as functional ingredients can be found in many foods Food Hydrocolloids Plant Animal Microbial Seaweed extracts Red (agar, carrageen..) Brown (alginates..) Gelatin Xanthan, dextran, curdlan, gellan, pullulan Exudates (gum arabic, tragacanth, gum karaya Seeds (locust bean gum, guar gum, tara gum..) Roots (konjac) Plant extracts (pectins, B-glucan) Cellulose derivatives Neutral Charged Guar gum, LBG, konjac, curdlan, MCC Pectin, alginate, PGA, carrageenan, xanthan, gellan, agar, gum arabic Structural assembly of polysaccharides www.nottingham.ac.uk/ncmh Hydrocolloids in one page Food Hydrocolloids: • Stabilizer – Maintains the homogeneous dispersion of two or more immiscible substances in a food. • Thickener – Increases the viscosity of the continuous phase. The size and structure of these large molecules (polysaccharides) create viscosity at fairly low concentrations (usually less than 1%) • Gelling agent – Forms a network gel by chain-chain, chain-solvent crosslinks Functionality in dairy products Thickening, gelling, water binding, emulsion stabilization, foam stabilization, milk protein stabilization, prevent syneresis, prevent of ice recrystallization STARCH, CMC, GUAR, LBG, PGA, XANTHAN Selecting a hydrocolloid PECTIN, CARRAGEENAN 1 WHAT IS THE GUM’S MAJOR FUNCTION? 1. THICKENING/VISCOSITY 3 START HERE 2. SUSPENSION OF PARTICULATES (YIELDPOINT) 3. GELLING 4. PROTEIN STABILIZING 4 2 pH OF FINAL PRODUCT XANTHAN, PGA BELOW ISOELECTRIC pH LM PECTIN CARRAGEENAN PECTIN AROUND ISOELECTRIC pH CMC ABOVE ISOELECTRIC pH CARRAGEENAN Gum types commonly found in dairy applications Applications of guar and LBG APPLICATION Ice Cream Cream cheese Baked goods Pastry fillings Soups, sauces and marinades Meringues • Excellent viscosifying properties • Good tolerance to salt and pH FUNCTION Ice crystal and Viscosity control. Fat mimetic. Speeds up coagulation, Improved moisture binding and texture. Improved yield and extension of shelf life. Viscosity and syneresis control. Viscosity control. Stabilisation and syneresis prevention. Carrageenan APPLICATION FUNCTION Chocolate milk Cocoa suspension and mouth feel. Improve succulence, yield and slice ability. Provides a transparent flexible glaze that eliminates syneresis. Gelling agent and syneresis control. Provides body and creaminess. Viscosity control, improves foam structure and body. Suspends insoluble materials, improves mouthfeel and helps stabilise emulsions. Suspends particulates, improves texture and mouth feel. Whey off protection. Texture modification. Viscosity control. Gelling agent and syneresis control. Gelling agent. Allows reduction in dairy protein levels. Cost reduction. Improves succulence and yield. Prevents shrinkage upon cooking Ham injection Nappage Hot fill Dairy dessert Instant mousse Applications of carrageenans Thickened milk drinks Oil free dressings Ice Cream & Sorbet Flans Processed cheese Ground meat emulsions Interactions with proteins • k-Carrageenan stabilizes milk k-casein products due to its charge interaction with the casein micelles (~200 nm diameter); their incorporation into the network preventing whey separation. • k-Carrageenan’s ability to complex with milk proteins leads to the formation of a weak thixotropic gel structure which will suspend cocoa in chocolate milk at 0.02% and form milk gels, such as flans, at 0.20%. • k- Carrageenan is also used as a binder in cooked meats, to firm sausages and as a thickener in toothpaste and puddings. Typical dairy dessert (neutral pH) Milk 81.5-83.0 wt% Sugar 8.0-12.0 wt% Skimmed milk powder Starch 1.8 wt% Carrageenan 0.15-0.25 wt% Flavour 0.025 wt% Colour 0.005 wt% 1.5-4.5 wt% Electrostatic interaction between k-casein and k-carrageenan has long been exploited for stabilizing dessert milk products. Xanthan gum Apparent viscosity (Pa.s) 100 0.5% xanthan 0.7% Guar gum 10 1 0.1 0.01 0.01 0.1 1 10 Shear rate (1/s) 100 1000 Xanthan – applications in food APPLICATION Oil - Water dressings Syrups and toppings Baked goods FUNCTION Emulsion stabilisation and viscosity control. Viscosity control and cocoa suspension. Prevents lump formation during kneading and improves dough homogeneity. Pastry fillings Viscosity and syneresis control. Soups, sauces and marinades Whipped creams & mousses Instant mixes Viscosity control. Air cell stabilisation. Rapid thickening, suspension and provides body Polysaccharide applications in ice cream • Interact with proteins (3D network) • Increase viscosity of the liquid mix • improve whippability • increase overrun, • reduce serum separation (wheying off) (Molecules binds the liquid (serum) as the ice cream starts to melt) • Contribute to body, texture, chewiness, creaminess, mouthfeel and eating quality (cold and warm-eating). • Reduce the rate of meltdown, reduce moisture migration • Shape retention on melting Locust bean gum (410) – stabilises ice crystals (forms cryogel), maintains quality on temperature cycling, promotes viscosity (0.05 – 0.3%) K-carrageenan (407) – promotes viscosity, stabilises mixes, prevents wheying off (0.02%) Guar gum (412) – promotes viscosity, thickness and body (0.05 – 0.2%) Xanthan (415) – cold hydrating viscosifier for soft-ice Stabiliser Locust bean gum Guar Carrageenan Alginate Agar Xanthan Recommended dispersal temp Dosage level E number (° C) (%) 410 412 407 401 406 415 80 20 - 80 >55 80 >90 ambient 0.05 - 0.3 0.05 - 0.3 0.02 - 0.15 0.1 - 0.5 0.1 - 0.5 0.1 – 0.3 Microcrystallinecellulose (MCC) – hydrolysed cellulose • MCC crystals do not dissolve in water, but the colloidal form hydrates to form thixotropic gels that can stabilize foams, replace fat, and control ice-crystal growth • Thixotropy– gels readily break down with shear; when the shear is removed, the gel will reform over time with minimal loss to viscosity. • Foam Stability– MCC network thickens the water phase between air cells and acts as a physical barrier to maintain the air cells in suspension. • Heat Stability – MCC is stable during heat processing, including baking, retorting, UHT processing and microwave heating with minimal loss in viscosity. • Shorten Textures– shorten textures or add body without creating a gummy or pasty texture cleaner mouthfeel and excellent flavor release. • Suspend Particles – the 3-D matrix is useful in suspending particulates e.g. calcium carbonate • Replace Fats and Oils – mimics the flow behaviour of oil emulsions •Control Ice Crystal Growth – the 3-dimensional matrix of colloidal MCC and the surface area of the microcrystals retards ice crystals growth during freeze/thaw cycles. Generally effective in maintaining the three phase system of water/fat/air. • Opacity – insoluble cellulose crystallites act as opacifiers and can add whiteness to products. Uses of MCC Application Function Fortified milk Long term suspension of insoluble material. Improves creaminess Improves creaminess and opacity. Reduces meltdown. Improves mouth feel, creaminess and opacity. Stabilises emulsion and improves cling. Improves cling, reduces fat absorption during frying and sogginess Long term Cocoa suspension and mouth feel. Stabilises foam structure and emulsion. Reduces boil-out, improves cling and opacity Low fat Ice Cream Low fat salad dressings Batters & Breadings Chocolate milk Whipped toppings Bake-stable fillings Hydrocolloids in other dairy products Fermented (Cultured) Dairy Products • • • • • • Butter Milk Cottage Cheese Cream Cheese Sour Cream Yogurt Processed cheese Cream cheese Ingredient % Pectin, starches, modified starches, carrageenan, pectin, LBG, gelatin • Fat, protein replacement • Texture enhancement • Stabilisation 1-Dry blend salt + LGB 2-Mixture is added to fresh cream cheese with agitation 3-Pasteurization 4-Hot fill containers, fridge Salt 0.8 Locust bean gum 0.2 Standard fresh cream cheese 99.00 LBG is used to prevent syneresis throughout its shelf life Pectin • Gelling (Jam, Jelly, confectionary….) • Viscosity (beverage, fruit preparations, culinary…..) • Protein stabilisation (acidified protein drinks, heat treated beverages….) • Syneresis control (yoghurt, desserts, mousse…) • Health benefits (fiber source, cancer prevention…) Applications of pectins APPLICATION FUNCTION Jams, Jellies and Marmalades Formation of a gel network. Bake-stable fruit preparations Formation of a Bakestable gel network. Soft drinks Stabilising turbidity in soft drinks. Yoghurt drinks Protective colloid. Dietary fibre enrichment Positive effect on serum cholesterol level. Fruit jelly confectionery Formation of a gel network. Pectin • HM Pectin ≥ 50% DE • LM Pectin < 50% DE • LMA Pectin Polymer of partially methylated galacturonic acid (31% DE) (degree of esterification) and (17% DA) degree of amidation • • HMP casein dispersion stabilizer (yoghurt or milk/fruit juice drinks) LMP gelling of milk or dessert products (~0.6 ̶ 0.9%) by interaction with calcium. Low sugar/acid products Low Methoxyl versus High Methoxyl pectin Gelation of LM pectin Gelation of HM pectin Ca+2 Tend to gel in the presence of calcium, so it will gel with Ca+2 in milk Tend to gel at low pH and in the presence of high [sugar] Used in yoghurt/dairy dessert Used in jams and AMDs Acid Milk Drinks (AMDs) Formulations • Fruit milk drinks • Yoghurt drinks • Butter milk ―Acidified protein liquid system with stability and viscosity similar to natural milk‖ • Whey drinks They are composed of: • Kefir an acid dairy phase (fermented base) or a neutral base (milk, soy-milk, etc) with an acidic medium (fruit phase: pulp, fruit concentrate, etc) which can be flavoured. sugars and stabilizers are added HM Pectin in Acid Milk Drinks Pectin + Casein Interaction AMDs need addition of stabilizer: (HM Pectin) The optimum pH range for interaction between HM pectin and casein is 3.6 to 4.2 1- No pectin • Casein micelles lose stability towards the pI 4.6 and they aggregate, below pH 4.6 they are slightly positive 2- Low pectin concentration (< 0.2%) • Pectin is still negatively charged at pH 4.0 • Pectin cover casein micelles from around pH 5.0 and neutralise casein positive net charge • Bridging flocculation and instability AMDs need addition of stabilizer: (HM Pectin) 3-Pectin critical concentration • Casein micelles are fully covered by pectin • charge of dispersed particles slightly negative • solution viscosity is minimum 4- High pectin concentration • additional concentration of pectin is responsible for viscosity increase •Weak gel is formed with casein particle as nodal point •Steric stabilization of the beverage What matters for thickening Polysaccharide thickeners • The most efficient thickeners are; • • • • Linear (e.g. cellulose derivatives) High molecular mass (e.g. alginate) Charged (e.g pectin) Rigid (e.g. xanthan) • However – non ionic polysaccharides are less sensitive to salt and pH What matters for gelling Factor Range of values Example Serving temperature Cold (5 ºC and below) Chilled Room temp (about 20 ºC) Kitchen temp Hot (50 ºC and above) Serve hot Clear/transparent Aspics, dessert jellies Opaque Custards, mousses Alkaline (>8) Egg whites Neutral (6–8) Most vegetables and meats Mildly acidic (3–6) Fruit juices, purees Very acidic (<3) Lemon juice, vinegars Thermo-reversible Melts with heat and resets when chilled Thermo-irreversible Sets with heat and does not melt Hysteresis Melts and sets at different temperatures Ions are required Calcium to set alginate Slow and long-lasting High-fat gels and starches Fast and short-lived Gelatins, pectins, gellans Opacity pH Setting Flavour release What matters for gelling Factor Range of values Example Mouthfeel Creamy Cream sauces Sticky Syrups Slippery Noodles Soft, rubbery Hard-boiled egg white, High-acyl gellans Medium Aspics, gelatins Stiff, brittle Low-acyl gellans, agar gels Liquid when sheared Fluid gels Soft gel Gelatin gels Stiff gel Páte de fruit Very stiff gel Gummy bears Dried gels Films Elasticity Stiffness Origin Hydrocolloid-polysacch. Example Note From fruits High-methoxyl pectin Fruit jellies Low-methoxyl pectin Low-sugar pate de fruit Fruit pectin gels set in the presence of high sugar concentration or calcium Agar Yôkan, hot savory gels Forms firm brittle gels with almost any liquid Alginate Spherification Gels in the presence of calcium Carrageenan (kappa, iota) Eggless custards, yoghurt and dairy gels Gels best in dairy solutions Aloe Vera Dairy gels Mastic Dondurma (Turkish ice cream) Gum arabic or acacia gum Chewing gum Gum tragacanth Sugar craft Forms malleable gels with cooked sugar Locust bean gum Dairy gels Makes elastic gels with xanthan gum From seaweed From plant sap or resins From plant seeds Guar gum From microorganisms Cellulose gums High and Low-acyl gellan High= elastic, opaque Low= brittle, cleasr xanthan Elastic gels with LBG Hydroxypropyl methylcellulose Onion rings, gel noodles Methylcellulose Custards, baked goods.. Forms elastic gels Gels at low concentrations; can add unpleasant flavours Combination of hydrocolloids • Mixtures of hydrocolloids may act synergically to increase viscosity or antagonistically to reduce it. Some reasons: • Optimisation of cost of final product • Development of new texture • Improvement of sensorial properties • Low fat foods • Reduction of syneresis • Stabilisation of emulsions • Control ice crystals formation • replacement of gelatine Synergistic gelation - occurs when two hydrocolloids are combined 1. LBG and xanthan • e.g. LBG (non-gelling) and xanthan gum (weak gel). • If LBG and xanthan at sufficient concentration, heated to 70 C (158 F), and allowed to cool, a rubbery but rigid gel results. • As little as one part LBG in 500 parts xanthan (or vice versa) creates a gel if their total concentration in water is 0.5—1%. • Similarly, xanthan gum and Tara gum gel when combined. 2. Agar and alginate • Agar has less gel strength in the presence of sodium alginate or (to a lesser extent) gum karaya. 3. Agar and LBG • Agar has more gel strength in the presence of LBG or (to a lesser extent) cellulose gum. 4. LBG and K-carrageenan • LBG greatly modifies the texture of a K-carrageenan gel, making it more elastic with a higher break strength, less brittle, and less prone to syneresis. 5. Alginate and Pectin • High-methoxy pectins are only able to form gels at high sugar solids levels within a narrow pH range. When a sodium alginate is included, gel formation takes place at low solids and below pH 3.8 the gel is reversible, a property used commercially in jelly topping. • The alginate-pectin synergism is one of very few interactions for alginate with other hydrocolloids, and so far the only one of commercial value. • The gel temperature of the algin—pectin gel mixture increases as the system’s pH is lowered. Synergism Kappa carrageenan and LBG Synergism xanthan gum and LBG Hydrocolloid Dispersion Method 1. Dry blend (e.g. approx. 5 parts sugar with 1 part hydrocolloid) 2. Disperse in oil (non-solvent) 3. High shear mixing (e.g. using a Silverson mixer) 4. Mixing equipment (e.g. triblender) Silverson High Shear Mixer Gum arabic (emulsifier + stabilizer) C C C P C = hydrophilic carbohydrate blocks (ca. 2 105 Da) P = hydrophobic protein backbone P ‘Wattle blossom’ model of Acacia C C (E414) senegal in aqueous solution — a natural protein–polysaccharide conjugate emulsifier C C P oil C P Adsorbed at the oil–water interface In soft drinks, instability known known as NECK RING Problem solving Problem solving Problem solving Acknowledgments Mr. Rod Bennett Dr. Sung Je Lee Dupont Nutrition & Health A.P. Kelvin Goh Hawkins-Watts