With the advancement of food technology and increasing demand for readymade food, the need for food preservatives is at its peak. There is also a changing trend in food sweetening products and the days are gone when sucrose was the only sweetening product available in the market. Different types of carbohydrate based sweeteners are dominating the current market and have considerable applications both in food and pharmaceutical industries. Invert sugar syrup or inverted sugar syrup is the most popular among the artificial sweeteners, which is widely used in bakery, confectionery, fruit processing and other parts of food industry, as well as in pharmaceutical industry.
Invert syrup is an equimolecular mixture of glucose and fructose. The syrup is manufactured as the result of hydrolysis or inversion of the disaccharide sucrose molecule, which splits into glucose and fructose components. Invert sugar syrups are graded into different varieties based on the degree of inversion, resulting from the varied amount of heat, acid and enzyme applied. The two most common types of this product are medium invert and total invert. In medium invert sugar syrups, only half of the sucrose molecules are split into the component molecules, while the rest half remains in undisturbed state. In contrary, for the total invert syrup, all the sucrose molecules are split into the glucose and fructose components and no sucrose molecule is left intact. This golden yellow viscous liquid is also known as artificial honey, because of its composition, which is nearly the same as that of real honey, though lacking some of the wonderful ingredients present in the original one.
Invert syrups have many properties that facilitate preservation and hence these are widely used as preservatives for baked foods and other processed foods. It exhibits features like high osmotic pressure, increased humidity and better solubility compared to the regular sugar. The sugar crystals present in inverted sugar syrup are smaller in size than that of sucrose syrup, which dissolve much faster, thereby ensuring the smoother texture of the final products. Only 10-15% of invert syrup mixed with sucrose is sufficient for reducing the crystallisation and improving the shelf life of the product. This artificial sweetener is also good in retaining the moisture content, which helps in increasing the storage time or shelf-life of the product. This is 25% sweeter than regular sugar, hence ideal for preparing flavoured drinks or energy drinks. Lesser amount of invert sugars and blends can achieve the same sweetness level with lower carbohydrate content in food products. When heated, the inverted sugar syrup turns brown and its flavour is enhanced, which is ideal for making toffee and caramel products. This product can be stored easily up to 6-9 months after opening the bottle, though it is suggested to store within refrigerator for avoiding mould formation on it.
Apart from the extensive use in bakery and confectionery industries, invert sugar syrup is also used for making herbal cosmetics and energy drinks. This has usage in tobacco industry, and also for mounting small microscopic objects. Sugar syrup mounting medium is better than using sucrose only, as their slow crystallisation property does not ruin the preparation easily. The invert sugar syrup can be prepared either by acid hydrolysis method or through enzymatic inversion. The acid hydrolysis is comparatively older method and can leave impurities in the sugar mixture. The enzymatic inversion is achieved through using yeast derived enzyme called Invertase and leaves negligible amount of impurities in the syrup. It is always suggested to select invert syrup that is produced by enzyme inversion for achieving better results.