Preparation of skim milk powder tablet and finite element analysis of its pressing die

Abstract

AbstractThe skim milk powder (SMP) has problems of quantification and handling during milk reconstitution for tea and coffee making. To address these issues, a novel product, “SMP tablet,” was made by varying moisture content (3, 5, 10, and 15% wet basis) of SMP and compression force (625, 750, 875, 1,000, and 1,125 N) during tableting. A die containing upper, lower, and grooved punches was designed, fabricated, and analyzed with finite element method. The tetrahedral type of mesh with 1.9078–2.356 mm element size, 0.095–0.118 mm tolerance, 80,420–85,107 nodes, and 53,041–57,252 elements resulted in 40.53–68.60 MPa maximum stress and 1.9–4 minimum factor of safety advocating acceptability of design. The SMP was pressed inside die through universal testing machine in controlled manner and disintegration time (DT), tensile strength (TS), and insolubility index (ISi) of SMP tablets were evaluated. Response surface methodology showed cubic model as best fit (p < .0001 and R2 > .97) for all the responses. The numerical optimization showed 4.6% wb moisture and 1,125 N compression force favorable for good quality attributes (103.8 kPa TS; 318 s DT; 40.5 mg ISi). Further, sugar addition (10%), as a disintegrating agent, improved DT (178 s) and TS (159 kPa). The SMP tablet with sugar had 14.90 ± 0.05 mm average diameter, 5.04 ± 0.18 mm thickness, 625 ± 6 mg weight, and 3.45% weight variation with similar total soluble solids (5%) at 60°C compared with SMP. The direct consumable, no artificial additives/binders and ease in quantification are tablets' novelty comparing SMP.Practical applicationsPoor quantification and handling are the two major issues with SMP. This can be easily combated by pressing the powder and converted into tablet form. The quantity of required number of SMP tablets for milk reconstitution can be easily remembered like sugar cubes. The SMP tablets can be marketed as novel dairy products and taken directly or used in coffee and tea making. Moreover, this study will provide an insightful information to dairy industry for commercial application of SMP tablets.