Enzymes extracted from fruits like papaya, pineapple, kiwifruit and fig have uses as medicines, food-processing agents and dietary supplements.

Fruits contain enzymes

Fruits like papaya, kiwifruit, pineapple and figs all contain enzymes called proteases. Proteases speed up the breakdown of proteins.

Uses of fruit enzymes

Fruit enzymes that break down proteins have many potential uses. For example, papain, the protease enzyme from papaya, is used for tenderising meat, treating wounds, dietary supplements and removing particles from cold beers.

Plant

Protease

Uses

Papaya
(or pawpaw)

Papain

  • Meat tenderiser
  • Clarifying cold beers
  • Dietary supplement
  • Wound treatment
  • Treating jellyfish stings and insect bites
  • Clotting milk
  • Treating wool to prevent shrinkage

Kiwifruit

Actinidin

  • Dietary supplement

Pineapple

Bromelain

  • Dietary supplement
  • Wound treatment

Fig

Ficin

  • Deworming medicine

Kiwifruit enzyme may aid digestion

PhloeTM – a kiwifruit-based dietary supplement developed by New Zealand company Vital Foods and launched in 2007 – has proven benefits in regulating bowel movements with no side effects such as cramps or diarrhoea. It is commonly used in hospital wards for treating constipation.

 

Recent research undertaken at the Riddet Institute has confirmed that eating green kiwifruit with a protein-rich meal helps improve digestion of several food proteins. This confirms beliefs that have existed for some time – that enzymes in green kiwifruit can break down proteins for better absorption in the digestive process.

Other uses of kiwifruit enzymes

Over the last 10 years, scientists have shown that fruit enzymes may act as an insecticide, protecting the fruit from attack from insects. Researchers at Plant & Food Research have shown that the protease in kiwifruit can reduce insect growth and survival.

The kiwifruit ate my jelly!

Have you ever eaten a piece of pineapple or kiwifruit and felt a prickly sensation in your mouth? This is caused by proteases acting on the inside of your mouth. They can even cause an allergic reaction in some people.

Whilst fruit enzymes are good for breaking down meat proteins, they also digest other types of protein. For example, if you made a jelly and added some raw kiwifruit or raw pineapple, the protease enzymes will digest the gelatine and stop the jelly from setting properly.

Classroom experiment

You can try a simple experiment to look at the action of marinades. It could be used as an introduction to experiments with enzymatic digestion of proteins and as the basis for further experimentation.

Useful links

Plant & Food Research article about the effects of kiwifruit enzyme on insect growth and survival.

Read about research at Riddet Institute confirming that green kiwifruit extract enhances the digestion of a variety of food proteins more completely than digestive enzymes alone.

A news article about the results of clinical trials of a kiwifruit dietary supplement.

Find out more about kiwifruit dietary supplements on the Vital Foods website.

    Published 29 May 2012