New way of cooking rice removes arsenic and retains mineral nutrients, study shows
(10.11.2020)
Cooking rice in a certain way removes over 50 per cent of the naturally occurring arsenic in brown rice, and 74 per cent in white rice, according to new research.
Background:
Arsenic, which is
classified as a Group 1 carcinogen by the International Agency for
Research on Cancer, is water-soluble - so it accumulates in rice, which
is grown in flooded fields more than other cereals. Arsenic exposure
affects almost every organ in the body and can cause skin lesions,
cancer, diabetes and lung diseases.
Rice is known to accumulate
around ten times as much arsenic as other cereals. In rice grains ,
arsenic is concentrated in the outer bran layer surrounding the
endosperm. This means that brown rice, (unmilled or unpolished rice that
retains its bran) contains more arsenic than white rice. This milling
process removes arsenic from white rice but also removes 75-90% of its
nutrients.
Previous research from the University of Sheffield found half
of the rice consumed in the UK exceeded European Commission regulations
for levels of arsenic in rice meant for the consumption of infants or young children (see the News below).
The new study: This new study tested different ways to cook rice to try and reduce the arsenic content and the team from the Institute for Sustainable Food
found that by using a home-friendly way of cooking rice, the
‘parboiling with absorption method’ (PBA), most of the arsenic was
removed, while keeping most nutrients in the cooked rice.
The
PBA method involves parboiling the rice in pre-boiled water for five
minutes before draining and refreshing the water, then cooking it on a
lower heat to absorb all the water.
"For rice consumers, this is excellent news. There are genuine
concerns amongst the population about eating rice due to arsenic.
Previous studies have shown that cooking rice in excess water could
remove arsenic but the problem is it also removes nutrients.
Our
aim was to optimise the method to remove arsenic while keeping maximum
nutrients in the cooked rice. Our newly developed method, PBA, is easy
and home-friendly so that everyone can use it. We don't know the amount
of arsenic in each packet rice we buy; even though brown rice is
nutritionally superior to white rice as our data shows, it contains more
arsenic than white rice. With our new method we are able to
significantly reduce the arsenic exposure while reducing the loss of key
nutrients.
We highly recommend this method while preparing
rice for infants and children as they are highly vulnerable to arsenic
exposure risks," commented Dr Manoj Menon, Environmental Soil Scientist
in the Department of Geography at the University of Sheffield and lead
author of the study.
Source: This article has been republished from material presented by The University of Sheffield. Note: material may have been edited for length and content.
The original study:
M. Menon, W. Dong, X. Chen, J. Hufton, E.J. Rhodes. Improved rice cooking
approach to maximise arsenic removal while preserving nutrient elements.
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