The orange juice challenge – we find out how visual cues can fool your taste buds

Orange juice samples

It’s January, time to look after ourselves, perhaps with a regular glass of orange juice. Research now shows that lots of environmental factors influence how we taste, and so, inspired by a piece of research published today in our journal Flavour, we decided to have a bit of fun in the office, and replicate an experiment all about tasty OJ.

The research by scientists at Nottingham and collaborators in Spain looked at whether the colour of orange juice affects our perception of sourness and sweetness. They added small amounts of red and green food colouring to orange juice so there were subtle changes, and used regular orange juice as a control to compare perception.

Click here to display content from YouTube.
Learn more in YouTube’s privacy policy.

We repeated part of the study in the BioMed Central offices where our staff came and tasted orange juice to see if their perception was changed by the colouring we had added. It’s not an exact replication of the study, but is something fun you can try at home, and it gave us a chance to think about how to set up an experiment like those we publish in Flavour. Take a look at the video above to see how we got on!

Testing orange juiceOur results are shown below, and although we haven’t run any statistical analysis of significance, there are some trends. We found people rated the green orange juice as more sour when compared to red. It’s thought that green is perceived as sour because unripe fruit is usually green, and sour, so the brain associates the two. We also found an effect for the red food colouring, which was perceived as sweeter, when compared to both the control and the green juice. Red fruit is sweet and so again the brain makes this association.

Interestingly, the study published in Flavour didn’t find an effect on sweetness from the red juice, but we may have added more food colouring! We also found the our staff really disliked the green juice, even though the only difference was the colour.

Test group

What they tested

How many people rated the juice as:

Favourite

Sweeter

Sourer

1

Control

21

14

14

Green

8

15

15

2

Red

16

18

12

Green

13

11

17

3

Red

13

16

10

Control

14

11

17

 

We’d like you to try this at home too, so why not download our protocol and give it a go? If you do, we’d love to hear how you got on – tweet us at @BiomedCentral, or post your photos on our Facebook page!

View the latest posts on the On Biology homepage

Comments