Sugar performs a variety of functions in food products, in addition to providing a sweet taste and flavour. Sugar is used as a preservative, in products such as jams and jellies, and acts to inhibit the growth of microorganisms. Sugar is used in baked goods, like cakes, to hold moisture and prevent the staleness that occurs when these foods dry out. In canned fruits and vegetables, sugar enhances the texture and colours. Sugar is also used to prevent large ice crystals from forming in frozen sweet mixtures, like ice cream, and to support fermentation in products containing yeast, such as bread. In these roles and others, sugar is an important and versatile food ingredient.
Preserves and Jams
Sugar is commonly used as a preservative in jams and jellies, and enhances the colour and flavour of various fruits. Sugars attract water, which acts to inhibit the growth of micro organisms that can cause food to spoil. The addition of sugars to jams and jellies is also essential to the gelling process, to obtain the desired consistency and firmness.
Sugar is used in baked goods, like cakes for example, to hold moisture and prevent staleness. It also helps tenderize bakery products and provide a source of nourishment for the growth of yeast, which helps the leavening process (e.g. breads to rise). The browning reaction that sugar undergoes when exposed to heat adds flavour, and contributes to the appearance of colour that can be seen on bakery foods such as the crusts of bread and the browning of cookies.
See the many roles of sugar in a Genoise Cake with Buttercream Icing in this video with Chef Claire Tansey:
Canning and Freezing
Sugars are added to canned fruits and vegetables to improve flavour, enhance texture and preserve natural colours. Sugars are also used to slow the freezing process, and prevent large ice crystals from forming in frozen sweet mixtures, such as ice cream. Large ice crystals can create a gritty texture, while the formation of smaller ice crystals results in a smoother product, providing a more desirable texture. Sugars also increase the thickness of frozen desserts, imparting a thick, creamy texture in the mouth.
In this video, Chef Claire Tansey demonstrates the functions sugar plays in Quick-Pickled Carrots:
Sugar (sucrose) is the primary ingredient in a wide variety of candies, largely due to its solubility. In its simplest form, candy is made by dissolving sugar in water, and heating the solution. As the temperature rises, more sugar can dissolve. The solution is boiled until no more sugar will dissolve (a supersaturated solution). As the solution continues to boil, the water evaporates, making the solution more concentrated. When the solution cools, the sugar’s solubility decreases and the sugar crystallizes out of solution. The type of candy that is being made (and its desired consistency) determines the degree of sugar concentration, and the extent to which sugar particles are recrystallized.
Sugars are added to beverages to provide both sweetness and body (otherwise known as “mouthfeel”). Sugars are also important in the brewing and wine-making industry. Sugars or other carbohydrates (except lactose) can be used to produce alcohols by fermentation. During fermentation, yeast feeds on sugars and produces bubbles of carbon dioxide, water and alcohol.
Sugar is a key ingredient in the preparation of custards, puddings, and sauces. These food products depend on sugar to perform a number of functions, in addition to its role as a sweetener. In custards, sugars help to breakdown proteins in egg (whites) so that they are more evenly dispersed in the liquid mixture. This permits the egg mixture to thicken slowly, mixing with the other ingredients, resulting in a smoother consistency.
Sugar helps to prevent lumping and thicken sauces and puddings by separating the starch molecules of the flour (or other thickening ingredient such as cornstarch). This allows for a more desirable consistency.
In non sweet foods such as salad dressings, condiments and sauces, sugars enhance flavours and balance the natural acidity of tomato and vinegar based products. This is because sugars are easily broken down by weak acids.
Watch Chef Claire Tansey use sugar to create a Caramel Sauce for Salmon with Puy Lentils in this video:
In these roles and others, sugar is an important and versatile food ingredient. For more important functions sugar plays beyond sweetness:
Non-Food Uses of Sugar
Sugar also has some surprising non-food uses:
Sugar is involved in the fermentation process to make products containing alcohol, such as wine
Sugar slows the setting of cement and glues
Sugar is an ingredient in printers' inks