Influence of solvent extraction, maturity stage, and thermal treatment on the determination of capsaicin in capsicums (Capsicum annuum spp.) and their products

The rapid increase and consumption of ethnic foods has motivated the search for improved methods to evaluate the quality and pungent characteristics of capsicum products. In addition, little information is available about pungency changes during the ripening stage of capsicums, as well as changes during their heating. Accordingly, the objectives were: (a) to evaluate different organic solvents on the extraction efficiency of capsaicinoids in hot salsas; (b) to evaluate the composition, aroma, and pungency in commercial serrano peppers (Capsicum annuum) at three maturity stages: green, yellow, and red; and (c) to evaluate the thermal degradation of capsaicin in different matrixes under conventional and microwave heating.; Magnetic stirring for 10 min extracted 95% of capsaicin in Cayenne pepper compared with a 1-h Goldfish extraction using 95% ethanol. No difference was found among different solvents on the extraction efficiency of dry Cayenne pepper, but diverse results were obtained from hot salsas. Extraction efficiency was affected by texture, capsaicin content, and sample preparation. Salsas labeled as "mild", "medium", and "hot" covered a broad range of pungency levels with some of them overlapping independent of the label.; In serrano peppers, the red stage contained more soluble solids. The sugar/acid ratio was higher for the yellow and red stages. No difference was found in titratable acidity or the capsaicin content in different maturity stages. The three stages showed differences in the electronic nose mapping. Untrained panelists were unable to identify different stages and discriminate which sample had the highest intensity in aroma.; Thermal degradation of capsaicin was evaluated in different matrixes (pure capsaicin, palmitic acid, soybean oil, a mixture of palmitic acid-soybean oil, and Cayenne pepper in soybean oil) heated in conventional and microwave ovens. Degradation of pure capsaicin and capsaicin in palmitic acid during conventional heating followed a pseudo first-order reaction rate. Activation energy was calculated as 9.3 Kcal/mol. No degradation was observed during the conventional heating of capsaicin and Cayenne pepper in a soybean oil matrix. In the mixed palmitic acid-soybean oil, capsaicin degradation was observed at high concentrations of palmitic acid. No degradation was detected in any matrix during microwave heating.