Paper Review “Determination of the Scoville Heat Value for Hot Sauces and Chilies: An HPLC Experiment James D. Batchelor, Bradley T. Jones Taken from the Journal of Chemical Education
Background Capsaicinoids are a group of compounds that give various peppers their characteristic taste. Capsaicin is comprised of seven capsacinoids, or closely related alkanoids. Upon contact with capsaicin, neurons in the nociceptors in the palate become excited, emitting a perception of pain, and release local inflammatory mediators. SHV = 16.1 million
Dihydrocapsaicin and Nordihydrocapsaicin Dihydrocapsaicin: accounts for 22% of total capsaicinoid mixture. The same pungency as capsaicin. SHV = 16.1 million Nordihydrocapsaicin: Accounts for 7% of the total capsaicinoid mixture. Half as pungent as capsaicin. SHV= 9.3 million
Scoville Heat Value First brought to light by in 1912 by Wilbur Scoville. The Scoville heat value is relative to the final concentration of capsaicin in a compound, expressed in grams of compound per gram of sample. The value is obtained by multiplying the literature established SHV of the pure compound by the final concentration.
Comparative Scoville Values
Purpose of Experiment To quantify and determine the Scoville Heat Value of various peppers through High Performance Liquid Chromatography. Three alkaloids were tested: Capsaicin, Dihydrocapsaicin, and Nordihydrocapsaicin. SHV was calculated from integrated absorbance data.
Materials Chemicals: Ethanol (95%) used as an extraction solvent Synthetic Capsaicin (97%) used to prepare working standards. Instruments: HPLC with a UV/Vis absorption detector Reference Instrument: UV/Vis A 50ppm sample was run through UV/Vis in order to find the wavelength of the capsaicin peak. Approx. 224 nm
Unknowns Tabasco Pepper Sauce- Red Pepper Homemade Hot Sauce – Jalapeno El Yucateco Hot Sauce – Habanero Dried Red Pepper
Procedure Preparation of samples: 1000 ppm stock was made by dissolving 25 mg in 25 mL of 95% ethanol. Serial Dilutions: (1000 ppm)(V1) = (50)(10) =.5 mL 1000 ppm stock (1000 ppm)(V1) = (40)(10) =.4 mL 1000 ppm stock (1000 ppm)(V1) = (30)(10) =.3 mL 1000 ppm stock (1000 ppm)(V1) = (20)(10) =.2 mL 1000 ppm stock (1000 ppm)(V1) = (10)(10) =.1 mL 1000 ppm stock (1000 ppm)(V1) = (5)(10) =.05 mL 1000 ppm stock (1000 ppm)(V1) = (1)(10) =.01 mL 1000 ppm stock
Preparation of Hot Sauce Ground Red Pepper: g dissolved in 50mL of ethanol. Stirred continuously, held at a slow boil for 30 minutes. El Yucateco: g dissolved in 50mL of ethanol. Stirred continuously, held at a slow boil for 30 minutes. Homeade: g dissolved in 50mL of ethanol. Stirred continuously, held at a slow boil for 30 minutes. Tobasco – g dissolved in 50mL of ethanol. Stirred continuously, held at a slow boil for 30 minutes.
Method Solutions were filtered via vacuum filtration, brought up to volume in a 100mL Erlenmeyer flask. Approximatley 10 uL was injected onto the column for each sample. All standards and samples were run three times.
Cayenne Ground Red Pepper: Literature Value: 30,000-50,000 SHV Calculated Value: 65,912 SHV Tabasco Sauce Literature Value: 30,000-50,000 SHV Calculated Value: 71,635
Jalapeno Literature Value: 2,500-8,000 SHV Calculated Value: 5,121 SHV
Taste Test Scale of = not hot. 10 = unbearable Jalapeno – 2 Tabasco – 6 Red Pepper – 5 Habanero - 8
Discussion Calculated values were not extremely accurate, however the pattern remained constant. Errors: Low baseline resolution Voltage range was not constant throughout experiment Peaks were truncated Heat of peppers could have varied based upon soil they were grown in and time of year they were harvested. Standards and calibration curves could have been made of the Dihydrocapsaicin and Nordihydrocapsaicin, however due to high cost and limited availability, this was not practical. Only 50mg of synthetic capsaicin was available, so only one stock solution was able to be made.
Future Experiments Stock solution would be remade each time standards were made and run. Dihydrocapsaicin and Nordihydrocapsaicin calibration curves could be made. Use of a wider variety of peppers.