A. Brief Introduction ofβ-Cyclodextrin
English Name: β-Cyclodextrin (CD, short for Cyclodextrin)
Molecular Weight: (C6H10O5)7
Molecular Weight: 1135.0
Physical and Chemical Properties: White crystalline powder, odorless, slightly sweet, soluble in water（1.8 g/100 ml，20℃）but hardly soluble in methanol and ethanol; melting point 290-305℃; inner diameter(molecular interspace) 0.7-0.8nm; optical activity [α]25D+165.5°. It is stable in the alkaline solution but when reacting with acids, hydrolysis will slowly take place. Its iodo-complex appears yellow and the crystalline shape looks like the plate.
Source and Preparation: It is made by depigmentation, crystallization and separation of gelatinized starch via the effects of Cyclodextrin-glycMyltransferase produced by microorganism.
B. Application of β-Cyclodextrin in Food
1. Stability of food and food ingredients,food additives
1).Resistance to volatilization, oxidation, and photo-thermal decomposition
The food-grade flavors such as rose oil, anethole and camphor are volatile and subject to oxidative decomposition of air and sunlight. The crystalline inclusion compound with CD strikingly slows down volatilization and oxidization, so is convenient for long-term storage and being kept in food.
The oil extracted from fragrance and spicy seasonings is usually unstable, so the inclusion compound with β-CD is used which also contains 8－13% sesame oil. In storage, volatilization, oxidization and thermal decomposition of the compound are greatly reduced, so the compound has favorable stabilizing function in food production. Therefore, it is widely in the production of various food and cans to keep fragrance and prevent spice from decomposition, leading to the color change such as staple food, pancake, cookies, pastry, fast food, seasoning paste and favoring powders.
2). Keeping Pigment
The natural pigment can act as food colorant and has no toxicity problems but is unstable due to the effects of light, heat, acid and alkaline. Therefore, β-CD can be used form the inclusion compound to maintain stability in carotenoid pigments, flavonoid pigments, riboflavin, carmine, chlorophyll and other natural pigments.
3). Moisture Proof and Heat Preservation
The inclusion compound of β-CD in 10 shares, soybean oil in 5 shares and water in 5 shares can mix with sugar particles in 300 shares to form dry powders and act as deliquescence resistance agent.
Whipped cream, stirring cream, mayonnaise and various kinds of edible oil can add β-CD to make the dispersing agent, which has water-retaining property and shape preserving function and also helps to delay drying and shape changes when spread on bread and cakes.
2. Eliminating Bad Smell and Bitter Taste
CD has a significant effect on eliminating bad smell and bitter taste in food.
1). Eliminating Bad Smells
Raw fish, salted fish, other processed seafood products, mutton, other kinds of meat, viscera, processed dairy products and soybean products can be processed with CD syrup to eliminate bad smell. CD can be added to the yeast extract, a food nutrition additive, avoiding the smell, improving the color and decreasing moisture absorbability. In addition, the inclusion compound of soybean lecithin and CD helps to eliminate uncomfortable smells and can also act as the health food additive.
2). Eliminating Bitter Taste
Butter has unique bad smell as well as poor dissolubility in mouth in the production of cold food such as ice cream, cold milk and ice sucker while the compound of 0.5-10% CD can mix with other ingredients to make cold food and the smell can be improved.
3. Emulsifying Property
The addition of β-CD into food such as beverages with high oil content, mayonnaise, flavoring oil, mixing cream, ice cream and coffee enables to form milky suspension with long-term stability.
When fatty acid, glycerol, glyceride and β-CD act as the emulsifying agent, added with other ingredients, they can form various kinds of processed liquid or paste fatty food with favorable emulsifying performance. With stable emulsifying state, the products can be stored for a month without change of quality. Besides, the fatty food with β-CD also has transparency as well as plasticity.
In the production of ice cream, oil and protein are used as substitutes to form emulsion with citric acid, but it doesn’t work well and the emulsifying state is very unstable during freezing process. However, the addition of CD helps to form disperse particles and to maintain emulsifying stability as well as the unique smell during freezing process.
β-CD itself has no preservative function but helps to protect preservatives for long-term effectiveness. The inclusion of β-CD and sorbic acid, dehydroacetic acid or other salts is more effective than the original compound.