Nu­tri­tion

If you be­lieve fruit fi­bre float­ing in a glass of fresh juice makes it any less sug­ary, you’re mis­taken.

New Zealand Listener - - CONTENTS - By Jen­nifer Bow­den

If you be­lieve fruit fi­bre float­ing in a glass of fresh juice makes it any less sug­ary, you’re mis­taken.

Ques­tion:

In a past col­umn on sugar in fruit ver­sus juice, you noted that the sugar in fruit is en­cap­su­lated by the cell wall. I pre­sume in the process of mak­ing juice, the cells are bro­ken. So if fruit juice con­tains pulp, does this mean the in­tegrity of the cells is main­tained? Or is the act of squeez­ing an or­ange suf­fi­cient to dis­rupt the cell walls?

An­swer:

It’s a mod­ern conundrum – al­though plant­based di­ets are rec­om­mended for good health, not all plant-based foods are healthy. A re­cent study found that a diet that ­em­pha­sises lesshealthy plant foods is ­as­so­ci­ated with a higher risk of coro­nary heart dis­ease. So, which plant foods are dodgy? In a ma­jor US study, re­searchers tracked 200,000 adults over 20 years and found those who stuck to a diet rich in such foods as whole grains, fruits, veg­eta­bles, nuts and legumes had a sig­nif­i­cantly lower heart dis­ease risk than peo­ple who con­sumed less-whole­some plant foods. The less-healthy foods in­cluded fruit juices, re­fined grains, pota­toes, fries and sweets, re­ported the Jour­nal of the Amer­i­can Col­lege of Car­di­ol­ogy.

Fries and re­fined grains are well known to be less than healthy, but it’s a sur­prise to many peo­ple that juice squeezed from a fresh, whole­some piece of fruit could be bad for us.

All fruit con­tains sug­ars, along with vi­ta­mins, min­er­als and di­etary fi­bre. So why is the sugar in fruit okay but the sugar in fruit juice a prob­lem?

In fruit’s nat­u­ral state, the sug­ars are neatly con­tained within the cells of the fruit pulp. Stud­ies sug­gest the fi­bre in whole fruits may slow ­emp­ty­ing of the stom­ach and there­fore how quickly the sug­ars are ab­sorbed into the cir­cu­la­tion.

A slower, more grad­ual rise in blood-sugar lev­els is prefer­able as that is linked to a re­duced risk of ­de­vel­op­ing type 2 di­a­betes and heart dis­ease; it may also help with healthy weight main­te­nance.

Chew­ing a piece of fruit re­leases the sug­ars in the juice from the ­cel­lu­lar struc­ture. In con­trast, when the fruit is squeezed, the pulp ­struc­ture is bro­ken to re­lease the fruit juice con­tain­ing the sug­ars. Even if juice con­tains some pulp, its re­moval from the fruit in­di­cates cells have been dis­rupted. The sug­ars in the re­sult­ing juice are then ab­sorbed more quickly.

On top of that, sev­eral pieces of fruit typ­i­cally go into a glass of juice, pro­vid­ing a much big­ger sugar hit than eat­ing a sin­gle or­ange, say.

Fruit is best en­joyed just the way na­ture in­tended – whole from the plant.

Ques­tion:

The Min­istry for Pri­mary In­dus­tries ad­vises that frozen im­ported berries should be boiled be­fore eat­ing. Does the freez­ing process not kill any bad bugs? If not, is mi­crowav­ing un­til thawed and steam­ing suf­fi­cient to ster­ilise the food?

An­swer:

Many harm­ful food-borne pathogens won’t grow or mul­ti­ply in frozen food, but nor are they de­stroyed by freez­ing. That means the food still has the po­ten­tial to cause a food-borne ­ill­ness. Ex­am­ples of such pathogens are sal­monella, E coli and lis­te­ria.

The hepati­tis A virus also sur­vives freez­ing and there have been a number of out­breaks of the dis­ease world­wide caused by frozen ­berries. Wash­ing frozen fruit doesn’t elim­i­nate the risk.

Boil­ing or cook­ing food or liq­uids for at least a minute at

85°C will kill the hepati­tis A virus. A mi­crowave can be used, but it’s im­por­tant to en­sure the ­berries are evenly heated to the re­quired tem­per­a­ture for the nec­es­sary length of time.

Sev­eral pieces of fruit typ­i­cally go into a glass of juice, pro­vid­ing a much big­ger sugar hit than eat­ing a sin­gle or­ange.

Newspapers in English

Newspapers from New Zealand

© PressReader. All rights reserved.