How to sweeten strawberries without adding calories
I, along with other researchers at the University of Florida studied over 30 varieties of strawberries to find out that it’s not just sugar that makes them sweet. We’ve identified a few chemicals that make strawberries sweeter without having to add more sugar.
Our interaction with the thousands of chemicals we encounter every day is what gives us our sense of smell. When we smell a flower or drink lemon juice, we interact with these chemicals. They are volatiles, chemicals that diffuse into the air and are responsible for scent and flavour. The use of volatiles to increase sweetness perception without sugar has a wide-ranging effect on food chemistry. They can also be used as breeding targets for improved strawberry flavour and other fruits.
Ingredients are key
The sense of smell allows humans to make a chemical inventory in their mouth. We classify these chemicals as savoury (salty), bitter, sweet, and sour when we consume. The smell enhances the flavours. When we eat or drink, volatile chemicals are forced into the nasal cavity when we exhale. This path is known as the “retronasal”.
Different areas of the brain receive sensory information in different ways. There is a certain overlap between taste and smell. In the case of taste and smell, there is some overlap. The integration of retronasal and taste is what gives us our sense of flavour.
The genetic differences between strawberry varieties creates different flavors through the levels of acids, sugars and volatile chemicals. Today, there are thousands of different strawberry varieties. This genetic diversity is largely the result of over 250 years of breeding.
We wanted to determine how consumers perceive the different strawberry flavours. We might be able to find the ingredient that results in a strawberry which is more preferred. Over the course of two years we tested and cultivated over 30 different genetic strawberry varieties.
We measured the different types of volatile chemical, sugars, and other chemicals present in each strawberry type. We then asked 100 consumers for their sensory and hedonistic properties. Our results were published in the PLOS One journal.
How to make strawberries sweeter without sugar
It is not surprising that total sugar content was the best predictor of sweetness intensity. We were, however, surprised to find that only a few of the 300 potential volatiles contributed to the intensity in strawberries’ taste.
Linalool is a volatile that has been found to have a strong association with the intensity of strawberry flavour. It can also be found in blueberries and orange blossoms. Mesifuran is another volatile strongly associated with strawberry flavor and has been the focus of strawberry research for some time.
The study’s best finding was the identification of specific strawberry volatiles that contribute to sweetness perception independent of sugar content in the fruit. In the past, these sweetening volatiles such as 1-penten-3-1 were overlooked.
In our research, we have identified the individual volatile chemicals that enhance strawberry sweetness and flavour intensity without sugar. The effects occur in a retronasal rather than an orthonasal way. In the brain, retronasal taste and smell are integrated. Certain volatile chemicals can influence sweetness perception.
The University of Florida is using these findings to create more flavourful, sweeter strawberry varieties. By screening volatile chemicals, strawberry breeders can make sure that new varieties are the most delicious for consumers. The identification of the genes responsible for the quantity or presence of volatiles can also be used to develop molecular marks, which is a form of genetic testing. In the future, the Wimbledon strawberry tart may not require extra sugar.
