Morama bean (
Tylosema esculentum
) is an indigenous bean of the Kalahari region of
Botswana. It has high nutritional content and is believed to also contain high levels of
phytonutrients. The bean is traditionally eaten roasted as a snack but there is
increasing emphasis to develop other innovative high value morama products, while
maintaining its healthful properties. The effect of pre-processing treatments including
salt-water-blanching, sodium-bicarbonate-blanching, hot-water-blanching on the
proximate composition, total solids non-fat, colour, viscosity, sediments, pH and
titratable acidity of morama milk was assessed. Consumer preference of the morama
milk was also studied, using a soymilk control. Milk extracts were stored at 4°C for
up to 24 hours and analyses conducted using standard methods. The findings
indicated that the pre-processing treatments produced significant differences (p <0.05) in protein (1.50 ± 0.18g/100g) and carbohydrate (1.09 ± 0.94g/100g)
composition of the baking soda blanched milk sample. The viscosity of the baking
soda blanched milk (18.91 ± 3.38cps) was significantly higher than that of the other
milk samples, while the sediments of the salt water blanched milk (14.01 ± 1.63%)
was significantly higher (p < 0.05) than the others. Baking soda blanching resulted in
the highest pH (7.31 ± 0.32) and lowest titratable acidity levels (0.45 ± 0.24). The hot
water blanched and baking soda blanched samples were slightly darker in colour,
while the baking soda blanched sample had more greenness and less yellowness
characteristics than the other two samples. Baking soda blanched pre-treated morama
milk was the preferred morama milk by over 85% of the consumers; they also
preferred it over soymilk. This is the first reported study on the processing of morama
beans into milk and it demonstrated that it was possible to process high quality and
acceptable morama milk, which can be utilized as a supplement to the dairy industry.
