Sugar Talk Sugar Talk
How is sugar used in the dairy industry?
Dairy products, which are worth £9.2 billion per year in the UK alone, rely on sugar for a multitude of functions, including enhancing taste, developing mouthfeel and extending shelf life. Here, we examine the important and varied functions that sugar performs in four main dairy products.
Why is sugar in milk?
When many consumers browse the back of a milk bottle, they are often surprised to find sugar listed within the nutritional content on the label. But in reality, this is rather unsurprising, simply because sugar naturally occurs in milk.
The sugar that naturally occurs in milk is called lactose – it is the main carbohydrate in milk and provides the slightly sweet taste that is present in plain, unsweetened milk. Naturally, it is easily broken down by the body and turned into glucose and galactose. The former gives us energy while the latter supports the central nervous system.
In fact, this insightful article by Dr. Michael Mosley explains exactly why cow’s milk is better for us than plant-based alternatives, citing it as “essential for brain development in babies and regulating mood and metabolism in adults.”
Feeding babies on milk is, of course, a basic part of human nature. That said, it can be more challenging getting children to drink milk once they have outgrown the toddler phase. One way that children can be encouraged to drink more milk is with flavoured milk, with popular flavours being strawberry, banana and chocolate. Indeed, studies have shown that children drink far less milk when flavoured is not available and are therefore less likely to meet their recommended calcium targets.
Flavoured milk on the production line.
Sugar plays an important role in the production of these flavoured milks. Homemade flavoured milk is typically made using straight sucrose (white sugar) as its neutral flavour allows the chocolate, strawberry or banana flavour to take centre stage. Branded flavoured milks produced on a larger commercial scale are usually made using straight sucrose and either invert sugar syrup or glucose syrup as these syrups are humectants that prolong the shelf life of the flavoured milk. Furthermore, both syrups are used in the powders that are mixed into milk to produce flavoured milk.
Adding flavour and developing texture in yoghurts
When bacteria ferment the lactose in milk into lactic acid, this, in turn, coagulates the proteins in the milk and naturally forms yoghurt. But pure sugars are also used in yoghurt production for a range of different purposes.
Crystalline sugars are used in fruit purées in fruit flavoured yoghurts to develop a sweet flavour and stabilise the purée by increasing the pH of the acidic fruit. This stabilisation extends the purée’s shelf life and enables it to be safely stored and transported before being added to the yoghurts at a different production facility. Watch this episode of the BBC’s ‘Inside the Factory’ to learn more about sugar’s role in the manufacture of fresh fruit yoghurts at Yeo Valley.
Depending on the manufacturer’s location, either beet sugar or cane sugar is used. In addition, ethical consumerism trends have led many manufacturers to prefer using organic sugar, with it acting as a natural sweetener and preserving agent to a standard unmatched by sweetener alternatives.
Sugar protects the component ingredients in fresh fruit yoghurts.
Drinkable yoghurts – that do not include real fruit or fruit compotes – often use liquid sugar to develop a smooth, pourable texture and mouthfeel.
Furthermore, an increase in demand for food ‘on the go’ has also seen many retailers stocking takeaway breakfasts in the form of yoghurt and fruit granola clusters, typically sold in two conjoined containers to avoid the yoghurt softening the cereal’s crunch. Sugar plays another important role here.
Partially inverted refiners syrup or golden syrup are used to combine the mixture of ingredients in premium granola, such as Dorset Cereals, which usually includes rolled oats and nuts, sometimes enhanced by the addition of freeze-dried fruit or puffed rice. The syrup acts as a binding agent to create clusters while adding a mellow and not overly sweet flavour.
Developing flavour in fresh custard
Custard is typically produced using milk, cream, eggs, and sugar – and the sugar constituent used depends greatly on where the product is stored. Pre-made custards stored in cool, dry places in tins or cartons and shelved as ‘dry food’ often use straight sucrose to add sweetness and act as humectant with other stabilising ingredients.
Fresh custards are kept refrigerated and, as they are fresher, typically come with a higher price tag and more prominent vanilla flavour. In addition to straight sucrose, these premium products are often also produced with demerara sugar because its mellow notes complement the subtle vanilla flavour.
Performing vital functions in ice creams
Ice cream is the dairy product in which sugar performs the most functions, with full invert sugar syrup being the most effective and widely used pure sugar of choice. It depresses the freezing point of the ice cream being produced and, as a result, prevents the formation of large ice crystals. This enables ice cream to have a smooth texture and mouthfeel while also making it easier to scoop.
Full invert improves scoopability.
Full invert sugar syrup also has a sweetness value approximately 40% higher than straight sucrose, which makes it the ideal sweetness enhancer for ice creams. This is especially true of ice cream flavours that we would normally associate with savoury flavours such as pistachio or coffee.
It seems that sugars perform vital functions and flavour enhancing roles in the production of dairy products, as well as occurring naturally.