Comparative Analysis of Sensory Properties and Proximate Composition of Yogurt Produce from Coconut (Cocos Nucifera) and Soy (Glycine Max) Milks

Abstract

This study compared the sensory properties and proximate composition of plant-based milk yogurt, specifically focusing on coconut milk yogurt (CMY) and soy milk yogurt (SMY). The study adopted a pure experimental research design approach. Two purposes, research questions and null hypotheses respectively, guided the study. The raw materials, Coconut (Cocos nucifera) and soybean(Glycine max) were bought from Itam market in Uyo, Akwa Ibom State. Coconut and Soy milk were processed from the materials and substituted in an adapted standard recipe for the preparation of diary youghurt. The reliability of the samples was established by producing them 10 times in the Home Economics laboratory. Sensory evaluation was also conducted in the same location using 10 panelists drawn from the University of Uyo community. Each of the panelist was presented with: three coded samples- CMY (Coconut Milk Yoghurt); SMY(Soymilk Yoghurt) and DMY(Diary Milk Yoghurt);they were also given three copies of the sensory evaluation forms rated on a 9-point hedonic scale to assess their preferences. Some of the samples were later taken to the Food Science Laboratory for proximate analysis. Data obtained from the sensory evaluation was analysed using mean statistical analysis, while data obtained from the proximate analysis was analysed used mean and standard deviation. The hypotheses were tested using independent t-test at 0.05 level of significance. Findings of the sensory evaluation revealed that CMY (Coconut Milk Yoghurt) was most preferred to SMY (Soy Milk Yoghurt). The Coconut milk yoghurt had the following mean values:  appearance (x=7.90); aroma (x=7.00); taste(x=6.70); texture (x=7.50) and the overall acceptability was (x=6.90) while SMY(Soy Milk Yoghurt) had lower mean values of appearance (x=5.70); aroma (x=5.10); taste(x=5.60); texture (x=6.10)  with overall acceptability of (x=4.60). Findings of the proximate analysis revealed that CMY had the following values: moisture (85.58±0.20); protein (3.67±0.41); fat (6.79±0.60); ash(0.50±0.15); fiber (0.02±0.01); carbohydrate (3.44±0.12) and energy (89.55±0.21) whereas, SMY had moisture (83.98±0.81); protein (6.13±0.30); fat (1.90±0.81); ash(0.66±0.40); fiber (0.01±0.00); carbohydrate (7.32±0.11) and energy (70.90±0.10). The result shows that CMY is high in moisture, fat and energy than SMY while SMY is higher in protein and carbohydrates than CMY. The result of the hypothesis showed that there is a significant difference in sensory properties of yoghurt produced from coconut milk and soymilk p>0.05 whereas findings showed that there is no significant difference in the proximate composition of the two samples p<0.05. The researchers therefore conclude that plant-based milks can serve as good substitute for diary milk in the production of yoghurt, with coconut milk possessing higher overall acceptability and soymilk yoghurt possessing higher nutritive values. The study recommends amongst others the adoption of plant-based milk as substitutes for animal milk which have become very expensive in recent times in the production of yoghurt. Also, people who experience lactose intolerance will find these products beneficial.