Batches of fried onion were prepared using diced onion (975 g,
approx. 3 mmcubes), which were fried with rapeseed oil (25 g) until
the weight of onion and rapeseed oil was 500 g (the frying pan
was weighed before and during frying to achieve the desired final
weight). After cooling, fried onions were kept frozen at 18 C until
needed (maximum 15 days). Fried onion and tomato puree were
then added to a pre-heated pan containing the additional oil. The
spices were mixed in and the ingredients fried for 2 min over a
medium flame after which the water was added and the mixture
heated to a temperature of 80 C. Sauces were freshly prepared
and used within 3 h of preparation.
Table 1 shows the basic curry sauce composition, which was
varied to produce samples with different oil contents (2.5, 5 and
10 g oil/100 g sauce) and different amounts of the major spice
ingredients (coriander, turmeric and cumin). The amounts of fried
onion, tomato puree, chili, black pepper, ginger and salt were kept
constant in all curry sauce samples. When oil content was varied,
the water content was adjusted so