~ 209 ~ The Pharma Innovation Journal 2017; 6(3): 209-212 ISSN: 2277- 7695 TPI 2017; 6(3): 209-212 © 2017 TPI www.thepharmajournal.com Received: 01-01-2017 Accepted: 02-02-2017 Sujatha Singh Assistant Professor, Department of Veterinary Public Health and Epidemiology, P.V. Narasimha Rao Telangana Veterinary University, College of Veterinary Science, Rajendranagar, Hyderabad - 500030, Telangana. India Nelapati Krishnaiah Professor and Head, Department of Veterinary Public Health and Epidemiology, P.V. Narasimha Rao Telangana Veterinary University, College of Veterinary Science, Rajendranagar, Hyderabad - 500030, Telangana. India Thirtham Madhava Rao Professor and Head, Department of Veterinary Public Health and Epidemiology, Sri Venkateswara Veterinary University, College of Veterinary Science, Tirupati - 515701Andhra Pradesh. India Ramani Pushpa Professor and Head, Department of Veterinary Microbiology, Sri Venkateswara Veterinary University, NTR College of Veterinary Science, Gannavaram- Andhra Pradesh. India Gopala Reddy Professor and Head, Department of Veterinary Pharmacology and Toxicology, P.V. Narasimha Rao Telangana Veterinary University, College of Veterinary Science, Rajendranagar, Hyderabad - 500030, Telangana. India Correspondence Sujatha Singh Assistant Professor, Department of Veterinary Public Health and Epidemiology, P.V. Narasimha Rao Telangana Veterinary University, College of Veterinary Science, Rajendranagar, Hyderabad - 500030, Telangana. India Effect of heat processing on degradation of organophosphorus compounds in milk Sujatha Singh, Nelapati Krishnaiah, Thirtham Madhava Rao, Ramani Pushpa and Gopala Reddy Abstract In the present scenario, usage of pesticides are inevitable to meet the demands of growing population and to secure the food grain production, there is need for regular screening of milk and milk products for pesticide residues which is being felt in the trade and also at the consumers level. The present work was undertaken to study the effect of heat processing on degradation of various Organophosphorus compounds (Dichlorvos, Dimethoate, Diazinon, Chlorpyrifos, Malathion and methyl Parathion) in both natural and spiked samples of milk were heated to pasteurization temperature (63 ºC for 1/2hrs), sterilization (121 ºC for 15 minutes) and boiling (5min) respectively. Extraction and Cleanup of samples was done by employing QuEChERS method and analysed by GC-FPD. The mean concentration levels of pesticide residues were assessed and degradation percentage of respective pesticide in different food processing methods were calculated. Sterilization and boiling proved to be highly effective on degradation of Organophosphorus compounds than pasteurization temperatures. Keywords: Organophosphorus residues, QuEChERS method, gas chromatography- flame photometric detector 1. Introduction Agriculture plays a vital role in India’s economy and over 58% of the rural households depend on agriculture as their principal means of livelihood. Usage of pesticides are usually authorized and their toxic pattern is evaluated to determine the acceptable exposure for both farm workers and consumers but excessive use and misuse in developing countries is common practice [1] . Usage of older, non-patented, inexpensive and environmentally stable chemicals were creating serious acute health problems and producing local and global ecological imbalance [2] . Most of the applied pesticides find their way as “residues” in the environment, terrestrial and aquatic food chains where they concentrate and magnify biologically in nature. [3] . The use of Organochlorine compounds (OC) has been replaced by Organophosphorus compounds (OP), which becomes a major public health problem, usually spraying of pesticides and consumption of contaminated feed are main reason for accumulation of OP residues in fat, muscle and also in milk [4] . Since humans occupy the peak of food pyramid and the residue accumulation is more in them. Thus, food, mainly fatty foods, meat, fish and dairy product have been identified at the primary immediate intake route for pesticides in general population [5] . It is necessary to evaluate changes in the nature of the residues during commercial and household food processing and the fate of pesticides in food [6] . The concept of food processing is very much important in the present situation, to study the various metabolites, identify breakdown or reaction products generated by the different food processing methods and to find out the levels of residue in processed products and to evaluate dietary-exposure calculations. Effect of food processing on pesticide residue levels may be influenced by the physical location as well as the physio-chemical properties such as solubility, volatility and thermal degradation of pesticides [7] . 2. Materials and Methods 2.1 Collection of samples Raw Milk samples were collected from local markets of Hyderabad, India. Both natural and spiked milk samples (with respective Organophosphorus compounds) were processed according to the prescribed protocol for Pasteurization (63 ºC for ½ hrs), Boiling (5 min) and Sterilization (121 ºC for 15 mins).