ences nutritional value) of three orange varieties that
are cultivated on a large scale in South Africa. These
are the varieties Mandarin, Navel and Valencia. She
also compared the content of frozen orange concentrate, the juice which is eventually made from it, and
freshly squeezed juice. The anti-oxidant levels, which
are a measure of good health value, were also ascertained for each.
She collected orange juice samples from two cultivation areas (the Western and Eastern Cape) over three
seasons. It was analysed to ascertain what influence
variety, seasonality and cultivation area can have on
fruit content. The way in which the fruit was handled
after harvesting can also have an influence.
Dr Hunlun found, among other things, that the antioxidant levels of Eastern Cape oranges are higher than
that of fruit produced in the Western Cape, and that it
therefore has more nutritional value. These aspects are
also higher in locally produced Navel and Valencia
oranges than in Mandarins.
Most orange juice in South African shops is made from
concentrate which is frozen and then sold to juice producers. Dr Hunlun found that such juice had appreciably less health value than a glass of freshly squeezed
Dr Cindy Hunlun
juice. The freshly squeezed option enjoyed higher phenolic levels and contained more anti-oxidants than
concentrate versions.
“If you are in search of the maximum amount of
health value in a glass of orange juice, it is best to
drink freshly squeezed juice,” Dr Hunlun advises.
In addition, it was found that the health value of orange juice made from frozen concentrate is also affected by the extent to which it is diluted with the juice of
other fruits.
The formulation of juice is determined by legislation,
according to which the juice of a specific fruit type
(like orange) may be diluted with the juice of another
(for example apple, pear or grape), but may still be
sold as the original 100% orange juice blend.
“In the process, however, this drink loses many of the
healthy characteristics which consumers assume are
part of the juice made from a specific kind of fruit,”
says Dr Hunlun.
She therefore believes that legislation should change
to protect consumers. This is because not everyone
sufficiently understands how to read and interpret the
product labels on which dilution is indicated.