The insolubility of ice cream is mainly related to two factors: anti-melting and shape-keeping. The purpose of anti-melting is to delay the melting time of ice cream, and the purpose of shape preservation is to make ice cream melt and keep its shape as much as possible.
Melting resistance refers to the tolerance of ice cream to room temperature. It will be affected by many conditions, such as sugar and fat in ice cream will affect its anti-melting. Generally speaking, the anti-melting effect of sugar is the most obvious. Compared with other sugar additives, sucrose is more conducive to maintaining good melting resistance of ice cream, while common small molecular sugar substances such as fructose and erythritol will weaken the melting resistance.
In addition, different kinds of oils added to ice cream will also greatly affect its anti-melting. Generally speaking, oils with high saturation and melting point, such as common thin cream and coconut oil, will significantly enhance the melting resistance of ice cream.
Conformal refers to the characteristics of ice cream to maintain its own shape and morphology in non-low temperature environment. The less water content, that is, the higher solid content, the better shape retention. The opposite of shape retention is the degree of expansion. Generally, the higher the swelling degree of ice cream, the softer the texture and the worse the shape retention.
These additives will affect the melting speed and degree of ice cream.
Additives in ice cream, such as emulsifier and thickener, will also affect its melting resistance and shape retention.
Emulsifier is mainly used to improve the uniformity and stability of ice cream raw materials. Common emulsifiers include whey protein and lecithin. We usually use the hydrophilic-lipophilic balance value (HLB value) to measure the emulsifying performance of emulsifier. The greater the HLB value, the stronger the hydrophilicity of emulsifier; The smaller the HLB value, the stronger the lipophilicity of emulsifier.
Generally speaking, the emulsifier in ice cream is like a pair of clenched hands, which can firmly grasp all kinds of tiny bubbles and fat particles in ice cream raw materials, effectively improve the melting resistance and shape retention of ice cream, and also provide a basic guarantee for its soft and smooth taste to a great extent.
Thickeners can make ice cream and its raw materials more viscous, so that melted ice cream can "try its best" to keep its original state. Ruan said that in general, thickeners added to ice cream can be divided into natural thickeners and synthetic thickeners.
Common natural thickeners are carrageenan, agar and gelatin, and common synthetic thickeners are carboxymethyl cellulose and casein. The main difference between them is that natural thickeners are generally extracted from plants containing polysaccharide viscous substances, while synthetic thickeners are chemically synthesized.
Thickener, as a highly hydrophilic polymer, can enhance the viscosity and thickness of ice cream when dissolved in water. At the same time, it will make the shape of ice cream more stable, and it is not easy to melt under the influence of external stimuli such as light.
According to the current national standards, emulsifiers and thickeners added in ice cream production should be used appropriately according to production needs.
In fact, whether it is emulsifier or thickener, regular enterprises generally do not add too much, because it is not cheap, and adding too much will affect the taste. In addition, excessive addition may also affect the production efficiency of enterprises. For example, if the thickener is added too much, the ice cream may stick to the ice cream on the production line, which will affect the subsequent operation.