Nutrient Composition, Physicochemical Properties and Sensory Evaluation of Protein Rich Mixed Fruit Juice Beverages Enriched with Soy Protein Powder

Abstract

Background: Soy protein powder (SPP) has poor consumer acceptability and minimal use in value added drinks principally because of  the “beany flavor”. The use of flavoring, sweeteners, fruit pulps and other extracts is a technologically viable option for industries to mask the undesirable taste.

Objective: This study determined the nutrient composition, physicochemical properties and sensory evaluation of protein rich mixed  fruit juice beverages enriched with soy protein powder.

Methods: Pineapple, orange and watermelon fruits were weighed and juiced together at varying proportions, and mixed with different  proportions of soy protein isolate (SPI). The samples were tagged A-E, and centrifuged. The centrifuged samples were tagged G-K.  Sample F served as the control and did not contain SPI. The samples were analysed for nutrient, physicochemical, and sensory properties  using standard methods.

Results: The moisture content of the control and the SPI enriched samples ranged from 83.26-92.56%, while the centrifuged samples  recorded moisture contents ranging from 87.46-90.98%. The crude protein content of the control and SPI enriched samples ranged from  1.28-11.28%, and the centrifuged samples recorded crude protein content ranging from 2.00-5.72. The pH of the control and the SPI  enriched samples ranged from 3.83-4.94, and increased further (4.49-5.13) after centrifuging. Overall acceptability score of the sample showed that sample F (7.70) was ranked best.

Conclusion: The study has showed that inclusion of soy isolates improved the protein content of mixed fruit juice, however the sensory  evaluation result showed that panelists preferred the sample without soy protein isolates.