CENTESIMAL ANALYSIS AND TECHNOLOGICAL PROPERTIES OF THE COFFEE SILVERSKIN

The coffee silverskin (Coffea arabica), a residue from the roasting process, is a by-product little used by the industry, although it has promising characteristics from a nutritional and functional point of view. With prominence in its composition, high fiber content and phenolic compounds, this fraction of the grain has aroused interest for its potential application in food products with sustainable appeal and circular economy. The objective of this work was to perform the centesimal characterization, evaluation of the technological properties and phenolic compounds in the silverskin of medium roast coffee. The determinations of moisture, ash, protein (Kjeldahl's method), lipids (Soxhlet method) and total carbohydrates (by difference) used official methodologies (AOAC). The technological properties were evaluated by the water absorption index (IAA), water solubility index (ISA), oil absorption capacity (CAO), emulsifying activity, gel formation capacity, pH and total phenolic compounds. All analyses were performed in triplicate, obtaining the mean and standard deviation (g/100g): 6.81 ± 0.22; 5.79 ± 0.13; 2.1 ± 0.07; 15.68 ± 0.08; 69.62 ± 0.08 for moisture, ash, lipids, proteins, and total carbohydrates, respectively. The properties IAA (7.18 ± 0.20g absorbed water/g sample), CAO (8.43 ± 0.53g absorbed oil/g sample) and ISA (19.27% ± 0.95) were considered satisfactory, although no emulsifying activity was observed in the coffee silverskin flour.