Orange Tablet Production Enhancement by Intervention of a Dry Method: A Central Composite Strategy for Experimental Design and Optimization

The present study aimed to develop orange pomace tablets as an additive with nutritional value. Orange pomace powder was converted into tablets by the drying method under the effect of compression force, diameter die, and relaxation force changes. Some of the physicochemical properties (e.g., density, penetration resistance, tensile strength, stability in water, total phenol content, antioxidant capacity, and ascorbic acid) were investigated. The tableting process was optimized by central composite design. The Kawakita and Lüdde model with R2= 0.995 was used to describe the compressibility behavior of orange pomace powder. The effect of diameter die on the minimum tension of deformation changes was insignificant. The results proved that the changes in the value of the active ingredients were insignificant when the orange was dried, ground to powder, and converted to a tablet. Also, the effect of diameter dies changes on all of the responses was significant at 0.01, while the effect of compression force was insignificant just for penetration resistance. Effect of the relaxation force on the mechanical properties was significant (at level of 0.5 for penetration resistance and 0.01 for tensile strength), and on the density and stability in water was insignificant. Finally, the optimum point for tableting from orange pomace was suggested at the compression force of 8.6 kN, diameter die of 10 mm, and relaxation force of 1.14 kN for 1.13×10-3 g mm-3 of density, 111 N of penetration resistance, 52.4 MPa of tensile strength, and 51 g.s dl-1 of stability in water.