Hanne K. Ludvigsen has been Global Product & Application Manager for Dairy & Ice Cream at Palsgaard’s Danish headquarters since 1995. She holds an M.Sc in Chemical Engineering from the Technical University of Denmark and a Graduate Diploma in Business Administration from Aarhus University. She has more than 25 years of experience of working in the food industry including R&D, product development and product management. Her email is firstname.lastname@example.org.
Less saturated fat, same rich experience for ice cream
Living a healthy lifestyle is becoming increasingly important for consumers. But they still like to enjoy an occasional sweet treat. From America to China, across Europe and beyond, ice cream continues to be popular. Americans, for example, consume more than 10.4 litres of the delicious treat per capita each year. And countries like Finland and New Zealand consume 12.9 and 23 litres per capita, respectively.
These days, to maintain a healthy lifestyle and still enjoy indulgent foods, all consumers need to do is choose products with more wholesome profiles. However, just being healthier isn't enough. Healthy products must also have high-quality sensory and storage properties for consumers to view them as suitable alternatives.
The secret lies in the tweaking of recipes and determining the perfect blend of stabilisers and emulsifiers to deliver a satisfying treat to discerning consumers.
Ice cream has changed
Traditionally, ice cream is made from dairy cream. Nowadays, however, vegetable fat types that typically contain 80 – 90% saturated fat are a common ingredient — and it’s exactly this type of food ingredient nutritionists have been warning us to avoid for some time.
Fat is, of course, a vital source of energy. So, it shouldn’t be entirely excluded from diets — our bodies need fat to absorb vitamins and minerals, and to structure cell membranes. When it comes to general health, however, some fats are certainly better than others. For example, nutritionists consider mono- and polyunsaturated fats to be good, while saturated fats, and especially fats containing trans-fatty acids, are generally not considered to be very healthy.
Consequently, due to its well-documented contribution to disease (primarily cardiovascular), health authorities in many countries recommend that consumers decrease the amount of saturated fat in their diets. In fact, FAO (Food and Agriculture Organisation of the United Nations) and WHO (World Health Organisation) recommend its consumption should be restricted to a maximum of 10% of daily energy intake.
Stable shelf life
Saturated fat has long been an important ingredient in ice cream production. It contributes not only to that wonderful, creamy texture but, together with milk proteins and emulsifiers, it is also a primary structuring ingredient. In other words, it holds the ice cream’s essential structure together. Ice cream is, effectively, frozen foam, so its stability is crucial to maintaining taste and texture quality throughout its shelf life.
Reducing the level of saturated fatty acids in the fat used when making ice cream will, other factors being equal, compromise the ice cream’s structure, mouth-feel and stability. This is because there is less crystalline fat available for building structure.
Making ice cream
During mix production, proteins cover the fat globule surface, but during ageing, they are displaced by an emulsifier, destabilising the fat globule membrane formed during homogenisation.
Such destabilisation is necessary for the agglomeration and coalescence of fat globules when whipping (and freezing) the mix. During the whipping and freezing process, from the fat globule membrane, the emulsifier facilitates the formation of a three-dimensional structure of fat crystals around air cells. This stabilises air bubbles in the ice cream and produces a smooth and creamy texture. It also influences the ice cream’s melting behaviour and heat-shock stability.
However, as already mentioned, when the level of saturated fat is reduced, there is less crystalline fat available for structure building. This calls for adjustments in the recipe — especially in the composition of the emulsifier— that are necessary to ensure good structure and storage stability.
Emulsifiers in ice cream
The most common emulsifiers used in ice cream are mono- and diglycerides (MDG), which are produced from vegetable fats. Mono- and diglycerides can be further esterified into, for example, lactic acid esters of mono- and diglycerides (LACTEM).
Compared with MDG, LACTEMs are more hydrophilic and are relatively uncommon in ice cream production. However, in combination with MDG, LACTEMs have a significant influence on foam stability and texture. Manufacturers can utilise this fact to produce ice cream with lower levels of saturated fat. As always, in ice cream production, stabilisers are added together with the emulsifier. The stabilisers are then hydrated and dispersed during the water phase. This reduces the amount of free water in the ice cream, which lessens the risk of ice crystals growing and improves the ice cream’s sensory properties.
Better health ahead
With much of today’s ice cream containing 80 – 90% saturated fat, and lifestyle diseases on the rise, the task is very clear: Manufacturers must change their products to protect both consumers and their own business viability in markets that are turning to healthier alternatives.