News Video | Policy | GPs | Hospitals | Medical | Mental Health | Welfare | Search

 


Altering Acid Levels In Fruit

Perfecting The Taste - Altering Acid Levels In Fruit


It's difficult to get the acidity level in fruit just right for the consumer, yet along with sweetness it has a major influence on flavour.

Once acid metabolism is fully understood, New Zealand growers will be better able to produce fruit that has the optimum taste. The average acid content of New Zealand mandarins is 1.2 percent but the ideal is approximately 1 percent.

HortResearch scientist Ken Marsh has been working alongside researchers in Florida to discover which enzymes control acidity in citrus, with the intention of using this research to create the optimum balance of sugar and acid in other fruit.

"If we understand acid metabolism, we will be able to target orchard processes, or even modify the growing environment, to effect appropriate enzymes and produce a better acid to sugar ratio."

Dr Marsh said initial research, although not conclusive, suggests the enzyme pyrophosphatase, present in all fruit, influences the acid to sugar ratio in horticulture crops.

In Florida the hot climate means oranges tend to lack acidity, whereas New Zealand suffers a related, yet different conundrum. "Our problem is that the colder climate means oranges often don't drop their acidity levels and can therefore have a sharp, tangy taste."

Because pyrophosphatase increases late in the season as fruit mature, it may play an important role in influencing their final acidity level, Dr Marsh said.

After measuring the activity of enzymes involved in the transport and accumulation of acid in different varieties of orange, Dr Marsh found low acid varieties had greater pyrophosphate levels than high acid varieties. "If we want to influence high acid varieties of orange, we need to look for ways to increase pyrophosphate activity."

Dr Marsh said he is interested in the acidity of all crops. The reason he began his research using citrus fruit is because they are easy to study. "This research [with citrus] will be used as a model system for continued work on the acid and sugar ratio of other fruit."

This most recent research grew from a project Dr Marsh worked on with another HortResearch scientist Annette Richardson where they looked at the influence of temperature on acid and sugar levels in mandarins. Words 356

For further information contact: Dr Ken Marsh, scientist Caleb Hulme-Moir, writer HortResearch Mt Albert HortResearch Palmerston North Tel: 09 815 4200, ext 7151 Tel: 06 351 7000, ext 7728 Fax: 09 815 4201 Fax: 06 354 6731 Email:kmarsh@hortresearch.co.nz Email:chulme-moir@hortresearch.co.nz


© Scoop Media

 
 
 
 
 
Culture Headlines | Health Headlines | Education Headlines

 

NZ On Air TV Funding: More Comedy Comes Out Of The Shadows

Paranormal Event Response Unit is a series conceived by Jemaine Clement and Taika Waititi as a TV spin-off from their highly acclaimed feature film What We Do In The Shadows. More>>

ALSO:

Mars News: Winners Announced For The 2016 Apra Silver Scroll Awards

Wellington singer-songwriter and internationally acclaimed musician Thomas Oliver has won the 2016 APRA Silver Scroll Award with his captivating love song ‘If I Move To Mars’. More>>

ALSO:

Scoop Review Of Books: Salt River Songs by Sam Hunt

Colin Hogg, a longtime comrade of Sam, writes in his Introduction that, ‘There is a lot of death in this collection of new poems by my friend Sam Hunt. It’s easier to count the poems here that don’t deal with the great destroyer than it is to point to the ones that do.’ More>>

Electronica: Restoring The World’s First Recorded Computer Music

University of Canterbury Distinguished Professor Jack Copeland and UC alumni and composer Jason Long have restored the earliest known recording of computer-generated music, created more than 65 years ago using programming techniques devised by Alan Turing. More>>

ALSO:

Scoop Review Of Books: Almost Getting Away With Murder

The Black Widow by Lee-Anne Cartier: Lee-Anne Cartier is the sister of the Christchurch man found to have been murdered by his wife, Helen Milner, after an initial assumption by police that his death, in 2009, was suicide. More>>

Howard Davis: Triple Echo - The Malevich/Reinhardt/Hotere Nexus

Howard Davis: The current juxtaposition of works by Ralph Hotere and Ad Reinhardt at Te Papa perfectly exemplifies Jean Michel Massing's preoccupation with the transmigration of imagery in a remarkable triple echo effect... More>>

Get More From Scoop

 
 

LATEST HEADLINES

 
 
 
 
Health
Search Scoop  
 
 
Powered by Vodafone
NZ independent news