ACTA ALIMENTARIA VOL. 6 (A QUARTERLY OF THE COMMITTEE ON FOOD SCIENCE OF THE HUNGARIAN ACADEMY OF SCIENCES, 1977)
1977 / 1. sz. - KOZMA-KOVÁCS, E.-KEVEI-PICHLER, E.-LENDVAI, I.: Determination of the capsaicin content in raw green paprika
Acta Alimentaria, Vol. 6 (1), pp. 1—19 (1977) DETERMINATION OF THE CAPSAICIN CONTENT IN RAW GREEN PAPRIKA E. KOZMA-KOVÁCS, E. KEVEI-PICHLER, E. and I. LENDVAI (Received May 7, 1975) Two procedures were developed for the determination of capsaicin in raw green paprika. It is expedient to carry out the two determinations successively from the same stock solution. By means of the first rapid procedure, a colour reaction developed on filter paper, it may be established whether or not the paprika is pungent. At the same time the approximate capsaicin content may be determined (capsaicin quantities above 0.5 fig can be detected). If the above reaction is positive a quantitative determination is performed by thin-layer chromatography. Two adsorbents (ready-made DC SIL G-25 UV 254 layer and Kieselgel G layer, made in the laboratory), two detection reagents (ferric chloride-potassium ferricyanide and Gibbs reagent) and a common solvent mixture (chloroform-ethyl alcohol, 99 : 1) were used. The average standard deviation of the method in the first detection was s= 0.0714 mg% and in the second s = 0.1085 mg%. It was established that the error of the method did not vary significantly with any of the solvents and/or adsorbents. The time requirement of the capsaicin determination, including the informatory test, is 3 to 3.5 h. However, if only pungency has to be tested, 2 to 3 min suffice to give final information. The literature on this subject matter is mostly concerned with the capsaicin content of ground red paprika and of oleoresins. Classical methods are based on some colour reaction of capsaicin which is evaluated by photometry (HIPPENHEIMER, 1949; NORTH, 1949; BENEDEK, 1953, 1959; SCHULTE & KRÜGER, 1955; SPANYÁR et al., 1956, 1959). The common shortcoming of these methods is that the elimination of pigments, fats and of other troublesome substances is difficult and they are not sufficiently sensitive, they are not suitable for the determination of capsaicin below 10 mg in 100 g. In recent years methods of thin-layer and gas chromatography have been developed. Column, thin-layer and paper chromatography were first used only for the purification of the capsaicin containing extract, since after chromatography pigments and other substances did not disturb determination by photometry (HOLLÓ et al., 1957; FRIEDRICH & RANGOONWALA, 1965; KARAWYA et al., 1967; GOVINDARAJAN & ANANTHAKRISHNA, 1974). The drawback of these methods is that they are lengthy and the preparations cause losses, therefore Acta Alimentaria 6,1977