Coffee is one of the most popular drinks, consumed for its refreshing, stimulating taste and health benefits; and ranked as second-traded worldwide commodity. Its high-price combined with certain ground roasted coffee characteristics, like brown color, particle size and oily texture, attracts fraudulent adulteration, allowing cheapest admixture of roasted and grinded fillers. As a matter of economic order, husks, sticks, corn, cocoa seeds, barley, wheat middling, chicory, soybean, triticale and acai seeds are commonly added. Since simple visual inspection enables to differentiate genuine ground roasted coffee from adulterated one; microscopy is conventionally applied. However, this technique is limited to semi-quantitative assays, requiring trained and skilled analysts. So, it remains great challenge to develop a non-subjective method, selective for distinct markers and quantitative reproducible for industrial quality control. Beside, carbohydrates as major grains macronutrient stand as tracer by its profile and content to assess coffee authenticity. Despite efforts from studies, food matrices complexity and variability still requires strategies to uncover adulteration. Thus, this approach uses HPLC analyses associated with chemometric tools on new analytical resources for detection of ground roasted coffee adulterations. A validated high-performance anion-exchange chromatography with pulsed amperometric detection method was investigated to determine total carbohydrates content profiles of pure roasted coffee beans and adulterants. The influence of each matrix was evaluated employing a simplex-centroid design for experiments with mixtures, relating mixing ratio with each monosaccharide by its response surfaces. Proposed models were effective in recognition and prediction of mixtures concentration, thereby allowing distinction of genuine coffee by principal component analysis. Predominantly, pure roasted coffee presented higher levels of galactose and mannose. Profile of diverse roasted grains as sources of fraud will be shown. All results correspond to polysaccharides from pure raw grains, confirming this approach as a feasible analytical tool for detect adulteration of ground roasted coffee.

Strategy to detect adulterations in ground roasted coffee: An association of carbohydrates content and profiles with chemometric tools

248th National Meeting (2014)

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