BITTERNESS OF SWEET-PEPPER (CAPSICUM-ANNUUM-L) .1. BITTER COMPOUNDS PRODUCTION DURING HEAT-TREATMENT OF SWEET-PEPPER

Bitter compounds production in fresh green sweet pepper fruits was studied. The fruits were extracted with isobutanol and the extracts sensory evaluated. The threshold concentrations were compared with the one of chinine hydrochloride. The proportion of these values expresses a bitterness value. It was found that the bitter compounds content in fresh pepper was dependent on the variety and the maturity degree. Relative bitterness values of fresh pepper (varieties Jubilantka, PCR, and Rubin) ranged from 11 to 19.5 x 10(-4). The values were higher in green immature fruits. The dependency of bitter compounds production on heating-treatment duration was examined. The longer was the treatment the higher was the pepper bitterness value at 80 degrees C, reaching the maximum of about 19% after 85 min comparing with the control. Nevertheless, holding the treatment on for next 3h caused the bitterness lowering to the value higher by about 4% than the control. Similarly at 100 degrees C, the bitterness raised by 18.3% in 2h and lowered to about 3% in 2h comparing with the control. The conclusions, important for canning practice, are given.