UTRITIONAL, PHYSICO-CHEMICAL AND MICROBIOLOGICAL EVALUATION OF CEREAL-BASED COMPLEMENTARY FOODS FORTIFIED WITH PIGEON PEA (Cajanus cajan) FLOUR

Abstract

Undernutrition during complementary feeding period remains a significant public health problem and contributes to growth failure, increased morbidity and mortality in children. Pigeon pea is an under-utilised legume that is rich in protein and minerals; however, report on the nutritional quality of cereal-based complementary food (CF) formulated with Pigeon Pea (PP) is scanty. This study was designed to evaluate the nutritional, physico-chemical and microbiological characteristics of two cereal-based complementary foods fortified with PP.

Two diets, fermented PP (CompifO) and roasted PP (CompifR), were formulated from maize, PP, fish, carrot, pumpkin leaves, oil and sucrose in the ratio of 50:20:10:6:4:5:5. The formulated diets were evaluated for physico-chemical and microbial properties using standard methods and compared with Commercial CF (CCF). Thirty-six weanling rats divided in six groups of six were acclimatised on 4% casein diet for five days. One group was sacrificed at zero day for baseline data while five groups were fed the formulated diets, CCF, Casein (protein isolate) and protein-free diets for 21 days. Feed intake measured daily and weight twice weekly were monitored for Protein Efficiency Ratios (PER) and weight change. Urine and faeces were collected for evaluation of protein quality parameters (Biological Value (BV), net protein utilization (NPU)). Blood samples were collected for haematology and serum biochemistry (albumin, globulin, cholesterol,aspartate amino transferase). Data were analysed using one-way ANOVA and Duncan’s multiple range test at𝛼0.05.

The protein contents of CompifO (17.2%) and CompifR (16.8%) were comparable but calcium (83, 118 mg/100g), iron (3.60, 1.95 mg/100g), zinc (3.35, 1.15 mg/100g), vitamin A (104.21RE, 90.61RE) and phytate (179.0, 146.0 mg/100g) levels of CompifO and CompifR respectively were significantly different (p<0.05). CCF had lower protein (15.5g) but significantly higher calcium (410mg), iron (8.52mg), and vitamin A (370RE) contents than CompifO and CompifR. The viscosity values of CompifO (320cps) and CompifR (322cps) were similar but significantly different from that of CCF (268cps). The microbial counts of the diets ranged from 0.00 to 0.20 (x 104cfu/g) and were within safe limits. Casein diet (2.64) had the highest PER followed by CCF (2.22), CompifO (1.69) and CompifR (0.48). Rats fed CCF (+33.1±9.8g), Casein (+32.7±7.5g), and CompifO (+24.1±4.9g) diets had similar weight changes (p=0.09), which varied significantly with those fed CompifR (+5.8±3.6g) and protein-free diets (-14.2± 6.6g) (p<0.05). The BV and NPU values of CompifR (47.1%, 43.8%) were significantly low compared to those of Casein (99.5%; 91.0%), CCF (85.9%; 79.2%) and CompifO (78.0%; 71.5%). Haemoglobin level (g/100ml) was highest in the Casein group (15.43), followed by CCF (11.85), CompifR (11.55), CompifO (9.65) and protein-free (7.83) groups. Serum iron and zinc were significantly lower in CompifR (1.88±0.30;0.75±0.24mg/dl) compared to CompifO (3.33±0.44;1.58±0.50mg/dl), Casein (3.25±0.72;2.50±0.53mg/dl) and CCF (4.05±0.70;3.24±0.19mg/dl).

The fermented pigeon pea complementary food compared favourably with commercial complementary food in terms of macronutrient content and growth support. It is therefore recommended for use in formulating quality complementary food rather than roasted pigeon pea.