Equilibration of Solutes in Nonfermenting, Brined Pickling Cucumbers

The equilibration of solutes between whole cucumbers and the brine in which they were held was found to be consistent with a diffusion‐controlled first‐order rate process. First‐order rate coefficients for attainment of equilibrium (K D ) for sugar and malic acid (initially in cucumbers) and NaCl and lactic, tartaric, acetic and formic acids (initially in brine) varied up to threefold among four cucumber lots. However, the ratios of K D values among solutes were not significantly different (P>0.05). K D values increased as cucumber size decreased. Peeling increased K D values 3.7‐ to 11.1‐fold. Temperature dependency was greater for solute movement out of [apparent activation energies (E a ) of 6.5 and 6.3 kcal/mole for malic acid and sugar] than into (apparent E a of 4.5 and 4.2 kcal/mole for NaCl and lactic acid) cucumbers. The equilibration‐prediction model used may be helpful in studying rate limiting factors in the fermentation of brined vegetables and in other food preservation processes where solute movement is important.