Work

Continuous wet granulation of cocoa powder using an integrated powder-to-granule line: Production of L. paracasei-loaded formulation

Year: 2026

Type: article

Abstract: The consumption of functional foods has been increasing in recent years, with probiotic products being among the most popular. In this feasibility study cocoa powder-based granules containing Lactobacillus paracasei ( LBP ) were formulated, demonstrating the technical feasibility of incorporating live bacteria into a solid cocoa matrix. The cocoa-granules were produced using a continuous twin-screw wet granulation line. The critical parameters were adjusted to protect the viability of the probiotic strain. In particular, the liquid-to-solid ratio was tested, as the probiotic cells were incorporated into the granulation liquid. Furthermore, the drying temperature (60 °C) and air flow rate (120 L/min) were set to reduce heat stress on the bacteria, while skim milk was added into the granulation liquid to potentially increase the stability of the bacteria during the formulation. The granules exhibited good to excellent flow properties based on Carr’s index and Hausner ratio, comparable to the commercial Nesquik® cocoa powder. In addition, granules showed a narrower particle size distribution than the reference cocoa powder, which enhanced the handling properties of the final formulation. The median particle diameter, d 50 of the final probiotic formulation reached 498.13 ± 13.03 µm, exceeding that of the commercial benchmark Nesquik® granules (246.51 ± 10.93 µm). Furthermore, the final granules showed a moisture content of 3.23%, which is similar to the commercial reference value (Nesquik®, 3.69%). The final LBP -loaded cocoa granules contained 6.38 × 10³ CFU/g of viable bacteria. The integrated, continuous twin-screw wet granulation-based manufacturing line demonstrated potential suitability for continuous production of LBP -loaded cocoa granules.

Source: Food and Bioproducts Processing

DOI: 10.1016/j.fbp.2026.10.003