what is an emulsifier
(1) Emulsion: heterogenous system of at least one immiscible liquid dispersed in the form of small droplets in another liquid (margarine/butter: water in oil; mayonnaise/ice cream: oil in water; chocolate milk; solid particles in a liquid)
(2) Emulsifier: surface active (surface: air-liquid; interface: liquid-liquid or solid-liquid) agent which aids in the formation of an emulsion and increases the stability of an emulsion
water in oil example
butter
oil in water example
salad dressing
oil in water and air in water example
ice cream
function of emulsifiers 4
(1) to assist the formation and stabilization of emulsions by reducing the interfacial/surface tension at the oil-water/liquid-air interface
(2) to alter the functionality of other food components (e.g. staling resistance in bakery goods)
(3) Reduce stickiness in a food product (e.g. peanut butter)
(4) To modify the crystallization of lipids (e.g. inhibition of chocolate bloom)
what is the main emulsifier used in the food industry
made of what 3 compounds
is it considered a food additive
lecithin/phospholipids (ionic emulsifier(s); www.americanlecithin.com)
- by-product of soybean oil extraction (soybeans: 1-3% phospholipid content comprised of phosphatidyl choline, phosphatidyl ethanolamine and phosphatidyl inositiol)
pH changes the state—protonate negative charges to become neutral
-counter-ions
lecithin/phospholipids (ionic emulsifier)
- a value added product (co-product stream) from eggs (2-3% phospholipids), canola, corn and sunflower - has GRAS status - no ADI (GMP) - food additive designation in Canada—even though it’s naturally present in foods
mono- and diacylglycerols (non-ionic emulsifiers)—
produced by what 2 compounds reacting together
is it a food aditive
exist in nature, but when do chemically, changes it up a lot
- produced chemically via the reaction of glycerol with triacylglycerols (TAG) in the presence of a catalyst (sodium methoxide) or by enzymatic reaction of TAG with lipase
- GRAS status (used in foods since 1930) and no ADI - food additive designation in Canada 3. 3 billion dollars spend on emulsifiers in world each year - mono is more hydrophilic than diacylglycerol - chain length of f.a.—longer it is, more hydrophobic
Sorbitan fatty acid esters (polysorbates, tweens)
how is it produced is it amphiphilic
is it ionic?
- produced chemically by heating sorbitol in the presence of ethylene oxide + catalyst + either stearic or oleic acid
- amphiphilic and non-ionic
- approved for specific food use at specified levels (e.g. baked goods [< 0.5%], ice cream, coffee whiteners [0.0175%])
are synthetic emulsifiers toxic
- animal studies (rats, mice, dogs): 7, 12, and 29 g/kg of bwt
no cmta- animal studies: 1.5% (total diet), three generation studies
no fertility or reproductive disorders - human studies: 26 g/day for three weeks no observed acute or chronic effects
- LD50 for polysorbates: 30g/kg bwt (single oral dose level)
- ADI: 0.25-25 mg/kg bwt (JECFA)
- animal studies: 1.5% (total diet), three generation studies
- emulsifiers and irritable bowel syndrome (IBS) Polysorbate 80 (Tween 80) and carboxymethylcelluose (CMC) , bulking/filler promoted colitis and IBS in mice—IBS increased recently (biochem markers show this is true), correlated with consumption of emulsifiers
- levels used: 1.0% by wt in drinking water for 12-weeks (actual amount ingested was not reported); also ran the same experiments with 1.0%, 0.5% and 0.1% in rodent chow (actual amounts ingested were not reported) authors report that these levels matched those used in the food industry ?
- genetic strain of mice used were, “highly sensitive to any change in gut microbiota” and “prone to metabolic syndrome”
- in chow fed mice inflammation was observed @1.0% with much lower inflammation observed @0.5% levels and results @0.1% were not significantly different from the control (rodent chow with no emulsifer added)
- colitis incidence in drinking water control @12 weeks ~50% of mice population
- conclusion: “broad use of emulsifying agents might be contributing to an increase in societal incidence of metabolic syndrome and other chronic inflammatory diseases”
Biosurfactants
definition
(1) Glycolipid surfactants
risk
(1) Glycolipid surfactants
- lipids covalently linked to
carbohydrates (e.g. rhamnose)
(Pseudomonas)
Risk: antimicrobial activity
-antimicrobial resistance develop
biosurfactants
lipopeptide surfactants
what is it?
- lipids covalently linked to
peptides (Pseudomonas,
Bacillus and Lactobacillus) - surfactin: (Bacillus subtilis)
Leu-Leu-Asp-Val-Leu-Leu-Glu
(risk: antimicrobial activity)
Biosurfactants
(3) oligosaccharide/polysaccharide-lipd surfactants
where is it used?
- adjuvant activity (increases the
activity of certain pharmaceuticals;
reduces dental plaque formation)
-used in oil extraction (tar sands)
The future
saponins
where is it extracted from
- Q-Naturale®
- isolated from the bark of the
Quillaja saponaria Molina tree (Chile) - approved for use as a foaming agent in carbonated and non-carbonated beverages: Canada/USA/EU (2010) and has GRAS status (application for broader [eg. Ice cream] emulsifer use has been submitted by Ingredion™ [National Starch Co., Canada])
