Do oranges taste like orange or oranges? The answer
Scientists have discovered how oranges get their distinctive flavour.
Oranges becoming more infected with disease so scientists are attempting to recreate their distinct flavour.
Citrus greening disease, also known as huanglongbing (HLB), has slowly devastated the production of citrus fruits around the world.
Oranges have been particularly affected.
But as the flavour orange has become a staple to our diets, researchers from the US Horticultural Research Laboratory in Florida are on course to create hybrids that are tolerant to the disease but also retain the signature flavour.
The researchers analysed 179 juice samples from different citruses, such as oranges (Citrus sinensis), mandarins (Citrus reticulata), trifoliate oranges (Citrus trifoliata) and their hybrids.
And to be further in good hands, trained citrus testers also taste-tested the samples.
The analysis revealed that 26 compounds are responsive to the distinct orange taste, with several of these compounds being a type of chemical called esters. This seemed to be the key to distinguishing the tastes of oranges and mandarins.
The team then conducted a genetic analysis of the fruits and found a gene responsible for the synthesis of all seven esters, which they called C. sinensis alcohol acyltransferase 1.
By being able to pinpoint the esters’ master gene, the researcher could make something known as a DNA marker for it – a tool that is used as a quality check for the genetic presence of a desirable trait.
Citrus Greening Disease: the lowdown
- Citrus Greening, also known as huanglongbing (HLB), is one of the most destructive diseases of citrus trees
- Once a tree is affected there is no control or cure, and affected trees will bear bitter fruit, which is unsuitable for sale or to juice
- The disease is passed on through the Asian citrus psyllid, a little bug that originates in Asia but now has been across the US, South America and Africa
- It poses no threat to humans or animals but destroys all types of citrus trees, including orange, grapefruit, lemon and lime
This, in turn, would help screen seedlings that have the desired favours of oranges at an early stage, rather than waiting for the plant to mature.
‘Our work will greatly accelerate the breeding of orange-like hybrids,’ said Dr Anne Plotto, a co-author of the study.
‘With the aid of the DNA marker for orange flavour, seedlings can be screened at an early stage, long before they produce fruits, and orange flavour can be more rapidly recovered with fewer generations of backcrossing.’
For us, that means we don’t need to give up our morning glass of orange juice.