NUTRITIONAL COMPOSITION, TECHNOLOGICAL PROPERTIES, AND SENSORY CHARACTERISTICS OF IMPROVED PIGEON PEA [Cajanus cajan (L.) Millsp.] VARIETIES GROWN IN MACHAKOS COUNTY, KENYA

Abstract

Food insecurity and poor nutrition remain major challenges, particularly in Arid and Semi-Arid Lands (ASALs), where more than 4 million people face an eminent problem of acute food insecurity. Pigeon pea, a resilient pulse crop, offers a promising solution due to its adaptability and high protein content. Research institutions in Kenya have developed improved pigeon pea varieties with desirable agronomic traits. However, limited data exist on their nutritional composition, technological and sensory characteristics. This study determined the nutritional composition, technological properties and sensory characteristics of six improved and one control pigeon pea varieties grown in Machakos County. The experiment was set in a Completely Randomized Design (CRD). Data was analysed using on PROC GLM procedure of the statistical analysis systems (SAS) version 9.1.3. Analysis of variance (ANOVA) was conducted at 95% confidence level and Tukey's honestly significant difference (HSD) applied for mean separation. Proximate analysis revealed significant variations (p<0.05) across varieties: moisture (8.67–10.71%), fibre (7.26-8.75%), ash (3.99-5.51%), protein (24.52- 31.16%), fat (1.19-1.92%), and carbohydrates (44.64–52.63%). Mineral content was notably high particularly for zinc (54.26-74.31 ppm), iron (143.45-367.25 ppm), and phosphorous (2191.06-2909.00 ppm). Cooking significantly reduced antinutrients (tannins, phytates, and phenolics) with Egerton Mbaazi 2 showing the highest tannin reduction (57.6%). Technological properties also varied significantly. The control variety (ICEAP 00554) had the highest volumetric expansion before cooking (VEBC) and water absorption capacity (WAC), while KARI Mbaazi 2 exhibited the highest volumetric expansion after cooking (VEAC). KAT60/8 had the highest TSS at 26.67%, correlating positively with VEBC/VEAC (r = 0.76) and VEBC/D/RgD (r = 0.89). There was a significant variation in the sensory attributes with the Principle Component Analysis (PCA) explaining 58.8% of the total variation. Egerton Mbaazi 2 variety scored highest (5.88) in overall acceptability whereas KARI Mbaazi 1 variety was least preferred (4.50). While pigeon peas provide ample protein, they also contain notable levels of antinutritional factors such as phytates and tannin. These compounds can be reduced through cooking, although the process may lead to some nutrient loss. Sensory evaluation highlights consumer preference for specific varieties, emphasizing the need for breeding programs to only prioritise agronomic performance but also desirable sensory and nutritional traits. Conclusively, improved pigeon peas varieties demonstrate a strong potential to improve nutrition through value-added foods and alternative protein sources. Furthermore, their adaptability to ASALs regions positions them as a viable crop for generating income among low-income farming communities in these regions.