October 29, 2015 – Researchers have explored a wide variety of natural, label-friendly emulsifiers & surfactants.
“Unfortunately, industry faces significant hurdles to commercialization for some of these products. Current natural emulsifiers will probably never match traditional emulsifiers for performance, and some novel emulsifiers may be clean label but may not be appealing to consumers,” said Professor Peter J. Wilde, Ph.D., Institute of Food Research.
All emulsifiers contain a hydrophobic or fatty acid component which likes the oil phase, and a hydrophilic or polar head which likes the water phase. Emulsifiers are ranked on an HLB scale from 1-20. A rating of 1 is given to a very oil-soluble or hydrophobic emulsifier, while a rating of 20 indicates a very water-soluble or hydrophilic emulsifier. Traditional natural food emulsifiers include egg yolk and soy lecithin, both rich in phospholipids.
Bile salts, which are currently found in dietary supplements, are excellent emulsifiers and may have potential for food use.
Synthetic emulsifiers include mono- and diglycerides, which are derived from naturally occurring fatty acids that have been processed to control HLB and functionality, and also esters of monoglycerides. Polysorbates and sucrose esters are synthetic ingredients
with a large polar head group, making them very effective surfactants, said Wilde.
Food products where emulsification is important include mayonnaise, margarine, chocolate, bread, meats, ice cream and whipping cream. Wilde gave numerous examples of potential natural emulsifiers and surfactants.
• Quillaja extract, derived from the bark of the soapbark, is rich in saponin, a natural surfactant.
• Bile salts, typically derived from ox bile and sold as dietary supplements, show potential as food emulsifiers.
• Lipoproteins are natural oil bodies in plants and animal tissues, such as egg yolk, soy or sunflower. When concentrated, they create highly stable and energy-efficient emulsifiers.
• Chloroplasts are plant membranes that are packed with galactolipids. These are good emulsifiers; can inhibit fat digestion; and have been linked with foam stability in bread. Unfortunately, they are difficult to process.
• Hydrophobins are secreted by filamentous fungi and form a strong film on the surface of a bubble. They can provide excellent long-term stability of bubbles in ice cream and are
responsible for gushing in beer.
• Cuckoospit froth, an incredibly stable foam secreted by froghopper insects, is a natural glycoprotein, but is not necessarily label-friendly.
• Tannins derived from grape seed and apple show emulsifying and antioxidant properties.
• Lactic acid bacteria, such as Lactobacillus pentosus, produce efficient biosurfactants and bioemulsifiers.
• Dairy proteins, including both whey protein and casein protein, contain hydrophobic and hydrophilic groups. They form an elastic interface and find use as whipping agents.
• Hydrophobins are a group of proteins that can create elastic interfaces which improve mouthfeel in low-fat products and create the sensory perception of a higher-fat product.
• Natural carbohydrates, such as gum Arabic and sugar beet pectin, have both protein and carbohydrate components and are popular for stabilizing flavor oils.
• Small starch granules, such as quinoa and rice, can be modified to form stable emulsions. These rely on a process called Pickering stabilization to create stable droplets.
There is significant potential in process modification, enzymes and bacteria to alter the functionality of some clean label alternatives. One approach is to modify the natural molecules that already exist in the food. For example, lipid bodies in pumpkin seed are already in emulsified form, and industry is looking at ways to exploit these oil bodies in situ. Another approach is to use processing aids, such as lipases which alter the lipid profile of natural grains, thus improving crumb structure in baked products. Many of these novel ingredients and approaches show strong promise for commercialization
.Peter Wilde, Ph.D., Institute for Food Research, www.ifr.ac.uk, peter.wilde@ifr.ac.uk, +44 (0) 1603 255 000
October 29, 2015–Global Food Forums, Inc. — The following is an excerpt from the “2015 Clean Label Magazine.”
