Partha Choudhury P

(During the Period of 2019-2023) 

1. Washing of tomato under running water dislodges 63 to74% of pesticide residues. Boiling of tomato juice to puree/sauce is the major steps to eliminate pesticides. The rate of degradation of imidacloprid is lower than that of other pesticides during processing of tomato into its products. During the processing of tomato, imidacloprid was degraded to different compounds, which were chracterised as imidacloprid urea (I), imidacloprid guanidine (II), N-methyl nitrosoguanidine (III), 6-chloro nicotinaldehyde (IV), deschloro imidacloprid guanidine(V), and 6-chloro nicotinicacid (VI).
2. Peeling of guava is the best option to avoid contamination of many pesticides in processed products. Different degradation products of imidacloprid and lambdacyhalothrin were isolated and characterized during the processing of guava.
3. During the processing of mango to its RTS juice, beverage, osmotically dehydrated product and bar, the residues of acephate, carbendazim and imidacloprid went down to significant levels. In OD and bar, the degradation level of acephate and carbendazim were found above 85%, whereas imidacloprid was found below detectable limit. During the preparation of dry mango powder, sundry was found more effective to degrade some pesticides than oven drying process.
4. During the processing of moringa leaf powder, washing of leaf with running water did not dislodge pesticides in significant amount. Only 5 to 30% reduction of pesticides during drying process was observed. Hot water treatment of contaminated moringa dry leaf powder for 10 min removed deltamethrin and chlorpyriphos by 94 and 86%, respectively.
5. The tested pesticides, lambda cyhalothrin, tebuconazole, difenoconazole, and trifloxystrobin were found to be dissipated above 85% during the processing of papaya bar and osmotically dehydrated products.
6. During the processing of onion to its dry powder, drying in hot air oven at 45⁰C was found more efficient in dissipating pesticides than that in solar dryer maintained at the same temperature. Among the pesticides, the dissipation of chlorpyriphos is more than other three pesticides.  The degradation of lambda cyhalothrin and hexaconazole in hot air oven was moderate, whereas it was very low in solar drying process.
7. In the market samples of dry curry leaf powder, pesticides viz., imidacloprid, carbofuran, acetamiprid, thiomethoxam, profenophos, ethion, azoxystrobin, pyraclostrobin, tebuconazole and buprofezin were detected in significant level. Washing of fresh curry leaf with running water did not dislodge pesticides in significant amount. Running water and hot water treatment dislodged about 22 and 38% of ethion, respectively.
8. During the processing of red chilli to powder, the levels of  pesticide  residues were found to decrease; however the processing factors for  many pesticides are very high. Washing of fresh chilli before drying was found to decrease pesticide load in chilli powder. Processing factors for cyfluthrin, thiomethoxam, carbendazim, acephate, acetamiprid and tebuconazole are alarmingly high (>3.0).