Variability and character association of bean biochemical traits of cocoa (Theobroma cacao) genotypes in four Nigerian field banks: Providing a platform for nutrition-based selection

Abstract

Abstract Assessment of variation in nutritional value of food crops is essential to complement agro morphological characteristics for an overall quality improvement. Fermented and well dried beans from seventy-seven cocoa genotypes belonging to four field banks in Nigeria were evaluated for seventeen proximate and nutritive traits. Their variability and genotype by trait associations were estimated. The cocoa genotypes showed significant differences (p ≤ 0.05) in moisture, protein, fat, crude fiber, ash, calcium, potassium, phosphorus, zinc, iron, magnesium, theobromine, flavonoids, caffeine, bulk density, water absorbability and oil absorbability. Among the local clones, T58/5 was superior in four mineral contents (potassium - 9.10 mg/100 g, phosphorus - 7.83 mg/100 g, zinc - 0.19 mg/100 g and iron - 0.23 mg/100 g). Among the hybrids, Hybrid P7 x T60/887 had the highest values for zinc (0.41 mg/100 g), iron (0.46 mg/100 g), magnesium (0.49 mg/100 g), caffeine (0.18 mg/100 g) and flavonoid (0.14 mg/100 g). The calcium (7.88 mg/100 g), phosphorus (10.41 mg/100 g) and flavonoid (0.14 mg/100 g) contents of T65/7xT79/501 was higher than other varieties of the regional trial. Among the introduced genotypes, APA-4 had the highest values for butter fat (23.80%), ash (3.15%), bulk density (0.41gcm3), water absorbability (1.14 g-l) and oil absorbability (0.53 g-l). The study showed the existence of significant variation in the nutritional content of cocoa beans of the studied genotypes, and a strong positive correlation among pairs of nutrients; this discovery seems to assure that improvement of nutritional quality of cocoa bean is possible.