RELATION OF MOISTURE CONTENT TO QUALITY OF VANILLA BEANS

Abstract

The moisture content of uncured vanilla beans was found to decrease with maturity. The average value obtained for whole beans entirely green was 81.2 percent and for whole, blossom-end yellow 79.2 percent. The moisture of split beans varied to a large degree with the extent and time of splitting. Losses in weight in vanilla beans, other than those due to loss of moisture, were shown to be negligible during the curing process, regardless of the procedure used. Although the greatest loss in weight in the beans occurred during the sweating and drying periods, a significant loss in weight also occurred during the first 3 months of the conditioning period. Moisture losses during conditioning were greater for beans of higher moisture content. A nomograph is included showing the weights to which 100-pound lots of beans of different moisture contents should be reduced during curing to obtain a known moisture content in the end-product. Moisture content was found to affect the appearance and aroma of the beans but did not produce any effect in the phenol value. Beans cured by different procedures with a moisture content of over 50 percent had a fermented aroma generally lacking suavity and development. Beans with 24 to 27 percent moisture had a more developed and suave aroma but little flexibility while those with 31 to 34 percent had well-developed arid suave aroma and good flexibility. Beans with similar moisture content, subjected to hot-water or freezing treatments were found to be less liable to mold infection than sim or ethylene-treated beans. Commercial lots of vanilla beans from Mexico, Madagascar, Comores, and Tahiti were found to contain over 30 percent moisture. Puerto Rican vanilla beans should be cured to a final moisture content of 30 to 35 percent if good flexibility and development and suavity of aroma, which are the principal factors affecting the sales value are to be obtained, judging from the results of our experiments.