Velásquez Valderrama, Ángela María2012-05-142012-05-142004Revista LASALLISTA De Investigaciónhttp://hdl.handle.net/10567/274Introduction: Green rejected bananas are a remain from harvests, they contain high quantities of tannins and polyphenols and low contents of fibers and proteins. Tannins are antinutritional substances, and that is why they do not allow the use of rejected green bananas (“boleja”) in animal feeding, as an energy source. The selective extraction with solvents is a route of separation to obtain tannins. The results shown in this work are an evidence that this separation method is effective to remove tannins from the “boleja”. Objective: Extract the tannins from rejected green bananas (“boleja”) using the extraction with solvents. Materials and methods: The obtaining of alcoholic and watery extracts and their qualitative evaluation was made by combining different extraction and qualitative tannin´s determination procedures, thoroughly shown in the chemical and instrumental analysis literature. The quantitative tannin´s analysis was made by colorimetric methods, using a UV/VIS spectrophotometer in which the samples were read at 700 mn and referred to tannic acid. As a reference substance tannic acid from the Merck brand was used. To measure the absorbing rate a UV-VIS SPECTRONIC-20 spectrophotometer was used. Results: the lineal correlation coefficients calculated for the calibration curves were: From tannic acid: 0.9983, from sample A –alcoholic extract: 0.9977, from sample A –watery extract: 0.9822, from sample B: -Alcoholic extract: 0.9999 and from sample B watery extract: 0.9938. Conclusion: The extraction of tannins from rejected green bananas (“boleja”) with a 1:1 methanol-water solution is more efficient and effective than tannin´s extraction with water.esTaninosBanano verdeResiduos de cosechaCorporación Universitaria LasallistaSustancias antinutricionalesResiduos agrícolasArticle