Development and evaluation of spray-dried Illinois mulberry (Morus rubra) fruit juice

Abstract

The study developed Illinois mulberry (Morus rubra) as a fruit juice through a spray drying method with maltodextrin as the carrier agent. M. rubra was prepared and underwent a spray drying method to develop three treatments of the powdered product. Among the three treatments (Treatment 1 with 16% maltodextrin, Treatment 2 with 18% maltodextrin, and Treatment 3 with 20% maltodextrin), the most acceptable M. rubra fruit juice was determined through sensory evaluation (consumer acceptability test) and the degree of difference test. The result yielded Treatment 3 as the most favourable sample which was rated as Liked Moderately with mean values ranging from 6.98 - 7.58 for all sensory properties. Likewise, the degree of difference in terms of flavor gave a computed average of 4.86 which indicates that there was a slight difference between fresh mulberry fruit juice (control) and the sample product from all treatments. Treatment 3 was further subjected to various tests to determine the physicochemical properties and microbiological properties. The findings showed the proximate composition as 9.92% moisture, 1.59% ash, 0.06% crude fat, 0.82% crude fiber, 1.77% crude protein, and 88.57% nitrogen-free extract. In addition, the pH level, phenolic content, total soluble solids, particle size, and bulk density were determined to be 4.77, 33.01 ± 0.55 mg GAE/g dry sample, 17 °Brix, 33.40% in sieve no. 20 and 24.84% in sieve no. 40, and 44.66 g/L, respectively. In terms of microbiological properties, the results showed 735 CFU/g for the Standard Plate Count (SPC)/ Aerobic Plate Count (APC) while <10 CFU/g for the total coliform count. Hence, the M. rubra has high potential to be developed as a powdered fruit juice based on the sensory evaluation and laboratory analyses conducted. Data showed acceptable results as compared with the standard values; however, further tests are warranted to ensure the overall food safety and quality of the product.