EVALUATION OF NUTRITIONAL, BIOCHEMICAL AND FUNCTIONAL PROPERTIES OF UNPROCESSED AND PROCESSED FLOURS FROM THREE SELECTED UNDERUTILIZED SEEDS IN RATS

Abstract

In view of prevalent food shortages in most countries including Nigeria, ensuring food security has become an issue of key importance to countries with different degrees of economic development; hence attention is currently being drawn to the exploitation of underutilized and unconventional plant foods. The nutritional, biochemical and functional properties of flours from unprocessed and processed watermelon (Citrullus lanatus), moringa (Moringa oleifera Lam.) and fluted pumpkin (Telfaira occidentalis Hook. F) seeds were investigated. Flours were produced from soaked, germinated and boiled Citrullus lanatus, Moringa oleifera Lam. and Telfaira occidentalis seeds. Standard methods of analyses were used to determine their nutritional, functional, antinutritional and biochemical properties. Animal feed was compounded using each of the seed flours as a protein source in place of groundnut. The wistar rats were divided into thirteen (13) groups of six (6) per group and allocated to thirteen dietary treatments which are soaked watermelon seed flour (SWMSF), germinated watermelon seed flour (GWMSF), boiled watermelon seed flour (BWMSF), unprocessed watermelon seed flour (UWMSF), soaked moringa seed flour (SMSF), germinated moringa seed flour (GMSF), boiled moringa seed flour (BMSF), unprocessed moringa seed flour (UMSF), fluted pumpkin soaked fluted pumpkin seed flour (SFSF), germinated fluted pumpkin seed flour (GFSF), boiled fluted pumpkin seed flour (BFSF), unprocessed fluted pumpkin seed flour (UFSF) and groundnut cake served as control diet). After twenty eight (28) days of feeding, the rats were euthanized and blood samples were collected for biochemical and heamatological parameters while kidney and liver of rats were excised for histopathological analysis. The results revealed that soaking and boiling significantly (p < 0.05) increased the protein (16.90 % and 18.77 % respectively) and fat (29.05 % and 26.82 % respectively) contents of wetermelon seed flour. Germination significantly (p < 0.05) increased the protein content of moringa (32.13 %) and fluted pumpkin (25.70 %). Significant (p < 0.05) increase was observed in the carbohydrate contents of all the processed watermelon seed flours, significant (p < 0.05) increase was observed in soaked and boiled moringa seed flours while significant (p <0.05) decrease in carbohydrate contents was observed in all processed seed flours of fluted pumpkin. Fibre content was significantly (p < 0.05) decreased in all processed seed flours of watermelon, no significant (p > 0.05) difference was observed in all seed flours of moringa but significant (p < 0.05) increase was observed in fluted pumpkin seed flour when compared to their respective unprocessed seeds. Also, processing significantly (p

i. 0.05) decreased the antinutriet (tannins, saponins, cyanogenic glycoside, oxalate, phytate and trypsin inhibitor) composition of all the seed flours when compared to their respective unprocessed seed flours. Significant improvement in the functional properties of all the processed seed flours was observed. Significant (p < 0.05) elevation was also observed in some heamatological parameter of rats fed with supplemented diets of the processed seed flours while reduction was observed in all serum liver enzymes (AST, ALT and ALP) and bilirubin except for ALP of boiled moringa group where an elevation was seen. Serum creatinine levels of rats fed processed seed flours supplemented diet were significantly (p < 0.05) reduced, showing a better outcome interms of heamatological parameters and liver biomarkers. Histopathological examination of the liver of rats fed supplemented unprocessed seed fluted pumpkin revealed confluence fenthery degeneration of the hepatocyte but normal histoarchitecture of kidney and liver was observed in all other groups. This study revealed that processing of these underutilized seeds (watermelon, moringa and fluted pumpkin) had improved the nutrient quality, bioavailability and functional properties of the seeds recommending that they could be used in food formulations.