Introduction

The complexity and the time needed to perform analytical standard procedures of coffee quality control can be excessive compared to commercialization needs. A comparative analysis was carried out, using standard and modern methodologies, with new equipment allowing quicker results between blends of encapsulated coffee with different proportions of C. arabica L., and C. canephora Pierre ex A.Froehner.

Methods

New methodologies were introduced to study the moisture content of green and roasted ground coffee for the determination of water weight loss, with two infrared balances. For the distribution of ground coffee size particles, and its influence on the physicochemical parameters of the drinks, a Fristch laser diffraction analyser was applied and compared with sieve tower results. Other characterization determinations and sensory analyses were performed with internal protocols and a trained panel.

Results

The expedited methods of moisture determination present values very similar to the standard methods. The fragmentation of the particles in the two species and various origins of coffee was carried out differently, influencing the way the particles were distributed. The blend, consisting mostly of robusta coffee, had the highest percentage of smaller particles, and the one with arabica had the lowest percentage of these particles. The evaluation with a laser particle size analyser allowed the faster and more detailed presentation of results in a diagram for each case. Different organoleptic profiles were obtained, which quantitatively and qualitatively had the most striking characteristics to define each product.

Conclusions

The approach of comparing the two methodologies of weight loss proved to be of interest mainly in the case of ground roasted coffee, while the method of ground particle distribution was more accurate and faster. The sensory and physicochemical characteristics used to evaluate the blends were in accordance with their different compositions, and the results obtained were consistent and reproducible.