Effect of Processing Treatments on the Proximate, Functional and Sensory Properties of Soy-Sorghum-Roselle Complementary Food

Abstract

Aim: The objective of this work was to produce complementary foods from germinated/fermented sorghum, germinated/roasted soybean and dried roselle calyces. Methodology: Complementary foods were formulated from sorghum, soybean and roselle calyces by varying the processing methods (fermentation, germination and roasting) applied to them. Proximate, functional, colour and sensory properties of the complementary foods were determined. Results: The protein contents for the seven formulations were significantly different (p≤0.05) from each other. The sample consisting of sorghum flour, germinated soybean and roselle flour (SFGS) had the highest protein content followed by the sample made from germinated sorghum, germinated soybean and roselle flour (GSGS). The ash content ranged from 2.00% to 4.50%. Fat content ranged from 4.95% to 16.35%. Fat was significantly different for all the formulations. FSRS made from fermented sorghum and roasted soybean, had the highest fat content followed by SF. The moisture content of the formulations ranged from 6.28-10.75%. From the values obtained, there were significant differences (p≤0.05) in the water absorption capacity, oil absorption capacity, loosed and packed bulk density as well as swelling capacity among the samples. Swelling capacity (SC) values ranged between 2.60% for GSRS and 6.95% for SF. Water absorption capacity (WAC) of the flour mixes ranged from 1.20 ml/g to 2.40 ml/g for FSRS and SFGS respectively. The values for oil absorption capacity (OAC) were between 0.84 mL/g for SFRS and 1.67 mL/g for SFGS. From the result obtained, there was significant difference (P≤0.05) in loosed and packed density of the complementary foods. Packed bulk density (PBD) was between 0.71 g/cm3 for FSRS and 0.86g/cm3 for SF. The samples varied significantly (P≤ 0.05) from one another in all the colour parameters evaluated. FSGS and FSRS scored highest in L* (64.14 and 59.44 respectively), a* (12.06 and 11.23 respectively) and b* (17.88 and 14.18 respectively). There were significant differences (p≤ 0.05) among the complementary foods in colour, aroma, and taste, while there were no significant difference (p≥ 0.05) among them in mouthfeel and overall acceptability. Conclusion: The results from this study showed that processing methods employed had marked effect on the proximate, functional and sensory properties of the complementary foods produced from soybean, sorghum and roselle calyces.