Simple extraction methods for chitinase in food?

Are there simple methods for extraction of chitinase from food such as bananas, avocados, kiwis, chestnut, beans and so on? That is, the extracted chitinase need not be entirely pure, just in significantly higher concentrations than in the food material the process starts with. It does, however, need to avoid degradation that permanently compromises chitinase activity. Temporary inactivation during the extraction process is acceptable as long as it is easily reactivated afterwards, but degraded homologs derived from chitinase that merely retain other attributes such as chemical similarity and allergenicity won't do it if their chitinase activity is permanently lost. Since the question is about simple methods, specialist reagents or chromatographs are not the answers the question seeks. Are there simple methods based on simple "reagents" such as water, ethanol, common household chemicals, easily extracted DIY substances and other easily obtainable chemicals? That is, the product need not be pure but it should increase chitinase levels compared to untreated food.