Response surface methodology (RSM) was used for the optimization of the pickling process of whole jalapeno pepper, using a vacuum pulse. The pickling variables were the brine to pepper mass ratio (R=1-10, w/w), sodium chloride concentration in the pickling brine ([NaCl](brine)= 10-15%), and processing time (t(2)=10-30 d). The main response variables were solutes gain to water loss ratio (SG/ WL), weight reduction (WR), concentration of sodium chloride ([NaCl](pepper)), acetic acid ([CH3COOH](pepper)) in the pepper tissue, and water activity of treated pepper and pickling solution. The polynomial models developed by RSM were highly significant to describe the relationships between the studied factors and the responses (p < 0.0001). Analytical optimization gave water activity values near equilibrium, the highest SG/WL ratio (2.1), and up to 6% of [NaCl](pepper) and 2% of [CH3COOH](pepper), when using a [NaCl](brine)=12%, R=4.6 and t(2)=22d. (c) 2006 Published by Elsevier Ltd.