Influence of Dietary Spices on Protein Digestibility and Absorption in Experimental Rats

Since spice diets are known to cause significant
reduction in food transit time, an animal study was carried
out to verify if there is any undesirable compromise with
nutrient bioavailability, especially fat and protein digestion
and absorption. Young rats were maintained for 6 weeks on
diets containing (in gram percent): ginger (0.05), ajowan
(0.2), cumin (1.25), and piperine (0.02). Soya protein and
casein were incorporated to the basal semisynthetic diets to
make up the sole protein source at 9 % protein level
(N×6.25) in an otherwise isocaloric and isonitrogenous
diets. Nitrogen content of urine and feces were determined
during the last week of feeding regimen. True
protein digestibility, biological value, nitrogen balance,
and net protein utilization were calculated. Dietary fat
absorption was also determined. It was observed that the
test spices reduced food transit time, but there was no
undesirable compromise with the protein (casein or soya
protein) digestion and absorption. All the four test
spices in both the test protein groups showed increased
protein and fat absorption and utilization. Thus, dietary
intake of spices—ginger, ajowan, piperine, and cumin—
enhances fat and protein digestion as well as their
absorption despite causing a significant reduction in
the ororectal food transit time.