My watch list  

Sourness & Scurvy

The Chemistry of a Lemon


© Compound Interest

Sourness & Scurvy

It seems like a good time to look at the chemistry of the humble lemon, and the compounds that give it its sour taste. Of course, citric acid is already well known – it even has its own E number (E330). However, a couple of other acid compounds are also contributors towards the chemical make up of a lemon.

One of these is malic acid, a compound that also has its own E number (E296). Citric acid is present in much higher quantities than malic acid and is the main contributor to the lemon’s sour taste; however, malic acid is present in around 5% of the concentration of citric acid. It is also found in apples and cherries, and responsible for aspects of their flavour.

Another acid present in lemons, and one with which citric acid is occasionally confused, is ascorbic acid, or vitamin C. The vitamin C levels in a lemon, at around 50 milligrams per 100 grams, are on a par with those of an orange, and significantly higher than those in a lime (~29mg/100g). This last fact in particular is one that the British Navy discovered belatedly to their detriment in the early 1900s.

  • teeth
  • scurvy
  • collagen
  • lemons
  • vitamin C
More about Compound Interest
  • Infographics

    2018’s biggest science stories

    As we head into 2019, it’s time to take a look back at some of the biggest science news stories over the past year. This year’s science news featured water on Mars, the effects of e-cigarettes, new types of isomerism and bonding, and more! 2018 saw a number of significant discoveries in sci ... more

    Unleashing our immune systems against cancer

    The first of the 2018 Nobel Prizes is awarded. The 2018 Nobel Prize in Physiology or Medicine was awarded to James P. Allison and Tasuku Honjo for their discovery of cancer therapy by stimulating the immune system to attack tumour cells. This graphic takes a look at the prize-winning research. more

    The creation of tools made from laser light

    After the Nobel Prize for Physiology or Medicine has been awarded, it is physics' turn. The 2018 Nobel Prize in Physics was awarded to Arthur Ashkin, Gérard Morou and Donna Strickland for their pioneering innovations in the field of laser physics. Strickland is only the third woman to recei ... more

Your browser is not current. Microsoft Internet Explorer 6.0 does not support some functions on Chemie.DE