Nutritional Composition and Sensory Evaluation of Malted Sorghum (Sorghum bicolour) Beverage Fortified with Cocoa (Theobroma cacao)

Abstract

In this study, the fortification of malted sorghum with cocoa powder to produce non–alcoholic beverage was investigated. Cocoa powder was blended with malted sorghum in different proportion to produce fortified sorghum beverage products at ratio MS 10- (90% malted sorghum and 10% cocoa powder), MS 20 - (80 % malted sorghum and 20% cocoa powder), MS30 - (70% malted sorghum and 30% cocoa powder), MS 40 - (60% malted sorghum and 40%cocoa powder), MS 50 - (50% malted sorghum and 50% cocoa powder), MS 60 - (Ovaltine beverage) as control. The vitamins, minerals, alkaloids, glucose, and sensory properties of all the fortified sorghum beverage samples were determined using standard methods. The range of results for vitamin B and C contents of the samples were (1.27mg/100g 1.97mg/100g) and (24.77mg/100g 54.48mg/100g) respectively. The respective values for glucose and alkaloids of the samples were (67.55%-71.02%) and (0.99%-3.13%).The contents of calcium (24.03mg/100g-274.26mg/100g), Magnesium (217.28mg/100g-322.97mg/100g), potassium (269.20mg/100g-699.63mg/100g), phosphorus (20.80mg/100g-81.91mg/100g) and zinc (2.21mg/100g-7.18mg/100g) of the malted sorghum beverage. The fortification of malted sorghum with cocoa powder enhanced the mineral content of the beverage except phosphorus. Also, the addition of cocoa powder had varying effects on the organoleptic perception of the developed food products. This work showed that all the samples were accepted by panelist with sample MS 20 - (80%malted sorghum and 20% cocoa powder) preferred to other samples except the control (ovaltine). Aims: To investigate the effects of malted sorghum with cocoa powder to produce non–alcoholic beverage on vitamins, minerals, alkaloids, glucose contents and sensory properties. Study Design: The vitamin, minerals, alkaloids, glucose, and sensory properties of all the fortified sorghum beverage samples were determined using standard methods. Place and Duration of Study: Department of Food Technology, Federal Polytechnic Offa, Kwara State, between June 2019 and July 2020. Methodology: The method of Owolarafe et al. (2007) was adopted for production of cocoa powder. The method of Hallen et al. (2004) was used to produce malted sorghum flour. The method of Belšcak-Cvitanović et al. (2010) was adopted for the production of cocoa/sorghum beverage. Sample: Alkaloids in the sample were determined using the method of Harbone, 2003. Vitamin B and were determined, total glucose, minerals were analysed/calculated and sensory evaluation was also carried out. Results: There was consistent increase in vitamin B12 of all the samples. The vitamin B content of all the samples ranged from (1.27mg/100g –1.79mg/100g). Sample MS 60 (Ovaltine beverage) which is the control sample had the highest value with (1.79mg/100g). The result of vitamin C content obtained from this study showed an inconsistent increase. The value obtained ranged from 24.77mg/100g to 54.48mg/100g.Fortifying malted sorghum with 50% cocoa powder improved the vitamin C content. The result obtained from this study showed that cocoa was a good source of alkaloids. Alkaloids values in this study were significantly (p<0.05) higher in fortified malted sorghum samples than in the control sample MS 60 (Ovaltine beverage) except sample MS 10 (90% malted sorghum and 10% cocoa powder which showed (0.99%).The glucose content obtained from this study indicated that there was an inconsistent increase among the samples. Glucose value ranged from (67.55% -71.02%). All the sample variations had increase in minerals studied except phosphorus which decreased with increase in percentage of malted sorghum. It can be deduced from the result of this study that sample MS20 was rated best after the control sample (ovaltine) while sample MS50 was rated lowest in terms of sweetness. Conclusion: The fortification of malted sorghum with cocoa powder enhanced the nutritional content of the beverage. The fortified beverage had radical scavenging activity due the increase in antioxidant such as alkaloid and could be used for health promotion and disease prevention as an alternative to beverages with low nutritional / nutraceuticals value.