Proteases are protein digesting biocatalysts long time used in the food industry. Although many authors
reported the crystallization of papain and chymopapain from papaya latex, the powder of crude papain had
the largest application as food supplements due to its highly positive effect on the degradation of casein
and whey proteins from cow's milk in the stomach of infants. As the industrial preparative procedures have
not been extensively applied, this study aims at producing dehydrated crude papain from fresh papaya
pulp, planning lab-scale trials, followed by process development toward the pilot industrial-scale.
In the lab-scale experiments, the enzyme activity (EA), expressed as protease unit (PU) /g, were evaluated
on pulp and papain standard before and after a 2 h thermal treatment at 70 °C, 90 °C, and 120 °C, and the
thermal behavior was monitored by means of differential scanning calorimeter (DSC). The process
development toward the pilot-scaling optimized: the homogenization of the fresh pulp, followed by its
filtration at high pressure (HP) in order to obtain the vegetation water and the pre-dehydrated pulp which
was then oven dried varying the time-temperature conditions (4 h-80 °C; 2 h-120 °C; 30 min-150 °C).
Proceeding at higher temperatures for a shorter time allowed obtaining commodity-related and
technologically valid products.