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Why breed a red-fleshed apple?

A new apple cultivar with red skin and red flesh is being developed at Plant & Food Research. Discover how the idea came about and why it may appeal to consumers.

Apple germplasm collection orchard, New Zealand.

Apple germplasm collection

The apple germplasm collection at Plant & Food Research includes apples of all sizes, shapes and colours, including red-fleshed varieties.

Rights: The University of Waikato Te Whare Wānanga o Waikato

Plant & Food Research (PFR) is breeding a new apple cultivar that has red flesh. The red colouring of this new apple cultivar, with its possible health benefits and novelty value, is expected to have high consumer appeal.

How the red-flesh breeding programme began

The idea of breeding a new red-fleshed apple came out of a trip by a New Zealand scientist from HortResearch (now PFR) to central Asia in the 1990s. The scientist was part of an American research team that went to the wild apple forests of Kazakhstan to collect different apples and expand PFR’s collection of genetically diverse apple trees (germplasm collection). They found many apples with distinctive red flesh, but they weren’t good eating apples, so they decided to use these varieties to breed a tastier, more appealing red-fleshed apple for modern consumers.

Red flesh is healthy

The scientists at PFR were particularly interested in red-fleshed apples because of their possible health benefits. Apples are healthy anyway (they are high in vitamins and antioxidants and are associated with reduced risk of some diseases), but it’s possible that red-fleshed apples will be even healthier. This is because they contain higher levels of anthocyanins, the compounds that make their skin and flesh red, than white-fleshed apples.

Mix of berry fruits: raspberries, blueberries and blackberries

Fruits high in anthocyanins

The deep red and purple colouring of fruits such as berries indicates high levels of anthocyanins.

Rights: Raliand/123RF Ltd

Anthocyanins are members of a group of plant compounds (phytochemicals) known as polyphenols. In plants, anthocyanins act as antioxidants – they mop up the DNA-damaging free radicals that are released during photosynthesis, particularly during high light. This minimises damage to the plant’s DNA. Interestingly, anthocyanins probably have a different function in our bodies – they seem to work by upregulating our own antioxidant systems, rather than acting as antioxidants themselves. Learn more about polyphenols and their role in our diet.

Potential health benefits of red-fleshed apples

Red-fleshed apples may be healthier than white-fleshed ones. This is because anthocyanins (the plant antioxidants that give apple flesh and skin its colour) are present in large amounts in red-fleshed apples (a several hundred-fold increase in red flesh compared with white flesh). Here, Richard Espley of Plant & Food Research discusses recent research into the health benefits of anthocyanins and describes how anthocyanin concentration in apples is measured in the lab.

Questions to consider Would the antioxidant content of a new apple variety affect whether you bought it? What about its aesthetic appeal (such as red flesh colour)?

Rights: The University of Waikato

Forecasting the market

Before embarking on a breeding programme, PFR had to consider whether a red-fleshed apple would be something that consumers would want to buy and why. This is important because the breeding and commercialisation process is long and expensive. It can take 25–30 years from the beginning of the breeding programme until a new apple variety is available to buy.

Consumers are interested in health benefits in food, and they’re also attracted by novelty, so evidence of the health benefits of anthocyanins, together with the novelty and visual appeal of the red flesh colour, is a combination breeders predicted would appeal to consumers. This was confirmed by consumer research early in the breeding programme.

A consumer focus group discussing red-fleshed apples

A consumer focus group

Christina Bava discusses the red-fleshed apple with a consumer focus group to find out their response to the red flesh and how they might use such an apple.

Rights: The University of Waikato Te Whare Wānanga o Waikato

Novelty is also important to apple breeders and growers as it provides a point of difference from existing apple varieties, contributing to commercial success and sustainability of a new variety.

Ongoing input from sensory and consumer scientists will affect which apple is finally chosen as the cultivar for commercial purposes.

Useful links

Plant & Food Research scientists are analysing other dark-coloured fruits that are known to add additional benefits to consumers. Find out why sports people and those who seek a healthy lifestyle are interested in New Zealand blackcurrents.

This RNZ article describes another PFR research project: breeding a 'super' hybrid blueberry. The fruit combines the the taste and growing characteristics of blueberries with the colourful flesh of bilberries

New Zealand apples and blackcurrents are just two examples of foods with validated health benefits. The High-Value Nutrition National Science Challenge aims to help New Zealand industries develop a range of higher-value branded food products for export.

Published: 27 May 2011,Updated: 27 March 2018