Green Chemistry and the Biorefinery - The Economic Utilisation of Food Co-Products - page 11

sugar-cane waxes. Furthermore the wheat straw contains a relatively high
amount polycosanols 5 (164 mg/kg) which makes it an attractive component to
extract. Sterols also exhibit similar health benefits and are currently extracted
from vegetable oil and pinewood, which do not meet the ever increasing
demand. 6 Although polycosanols and sterols employ different mechanisms to
reduce cholesterol levels, mixtures of both extracts could offer enhanced
effectiveness and this would mean more of the wheat straw wax is used.
The use of sterols in food products has also been approved by the EU Novel
Food program in 2004, where cholesterol reducing ingredients can be used in a
wide variety of products such as margarine, milk, yoghurt, cheese, soymilk,
dressings and rye bread. 7 The sterols are now being used in one-shot drinks and
special milks with the market still growing. Large companies such as Unilever
have taken the lead, however, smaller companies are also entering this lucrative
market. Although in Europe there are some restrictions for use in some foods,
in the US there are no restrictions and sterols are generally regarded as
safe. A report from Frost & Sullivan valued the European plant sterols
market at $185million and this is estimated to rise to $395million in 2012,
see Figure 1.1.

d n 9 r 3 n g | 1

1.2.2 Oat Extracts
Sterols also exist in oats, however, oats also have a considerable amount of
antioxidants such as tocols (vitamin E), phytic acid, phenolics and avenan-
thramides. 8 These important components are concentrated on the outer layers
of the kernel and although they are consumed as part of the grain, they can be
extracted using solvents such as methanol or choloroform/propanol mixtures
to be used in food supplements or blended with other food products.

.

Figure 1.1

Sterols from wheat straw wax could also be used in consumer health
products.