INFLUENCE OF BAG MATERIALS ON THE MOISTURE LOSS AND FINAL AFLATOXIN CONTENT OF IN-SHELL PEANUTS STORED MOIST - FIRST STUDIES

In the present work the influence of bag materials on the moisture los s and final aflatoxin content of stored moist in-shell peanuts (MIP) w as studied in the rainy season of 1990, in Marilia, SBo Paulo, and in the rainy season of 1991, in Jaboticabal, Sao Paulo. In each season, M IP were ventilated, as they arrived from the field, to get rid of extr aneous materials and then put into 120 bags of jute and into 120 bags of polypropylene, and stored in stacks (12 bags base x 10 bags high). In the rainy season of 1990 (February-April) moisture and aflatoxin we re determined at the beginning (average moisture = 14.31%; aflatoxin n ot detected). Subsequently, moisture was determined twice a week in sa mples taken from the external part of the stacks for 80 days, when the stacks were dismantled and moisture and aflatoxin were determined in six samples of each stack. In the rainy season of 1991 (February-March ), because of operational difficulties, closed mesh jute bags were use d (green coffee type) and the experiment lasted only 30 days. Moisture and aflatoxin were determined only at the beginning (average moisture = 15%; aflatoxin not detected). At the end of the storage period thre e samples were taken from each lot, for moisture and aflatoxin analyse s. The results showed, in both experiments, that in jute bags, even wi th closed mesh, moisture loss was slightly faster with an average fina l moisture=9.68% in jute bags and 10.38% in polypropylene in 1990, and 9.50% in jute and 10.36% in polypropylene in 1991 and that the final aflatoxin content was considerably lower in jute bags, with average fi gure of 51 mu g/kg (1990) and 361 mu g/kg (1991) for jute against 1380 mu g/kg (1990) and 3703 mu g/kg (1991) for polypropylene. From the re sults it was concluded that the use of jute bags for storage of moist in-shell peanuts allowed a slightly better moisture loss when compared with polypropylene bags and that the use ofjute bags showed that this may be better than polypropylene and can be considered for preventing aflatoxin build-up during storage ofin-shell peanuts, especially when threshed and bagged moist. However, further studies are needed.