Effect of pulsed electric field processing on reduction of sulfamethazine residue content in milk.

The whole milk spiked with sulfamethazine was treated under thermal and pulsed electric field processing for maximum reduction. The low-temperature long-time (LTLT, 62.5 °C for 30 min), high-temperature short time (HTST, 72 °C for 15 s) pasteurization and ultra-high temperature processing (UHT, 138 °C for 2 s) resulted in the reduction of sulfamethazine 7.3, 5.2 and 4.6% respectively. PEF and combination treatment (thermal + PEF) were found to reduce sulfamethazine content in milk by 67-72% and 73-76% respectively. Combined treatment of milk resulted in a higher percentage of reduction. Similar predicted and actual values proved that they fit the linear regression model and successful application of pulsed electric field technology in reducing antibiotic residues. PEF and mild thermal treatment can be a promising technology to reduce the antibiotic residues with ensuring minimal negative impact on the nutritional quality of food.

Impact of pulsed electric field processing on reduction of benzylpenicillin residue in milk.

PURPOSE: The presence of residues of veterinary drugs in animal-derived food is one of the major problems for food safety. The consumption of milk containing antibiotic residues can evoke allergic reactions in hypersensitive individuals, disorders of intestinal flora and produces the risk of emerging antibiotic resistance microorganism. METHODS: In this study, the effect of the thermal treatments and pulsed electric field (PEF) on the reduction of benzylpenicillin (PNG) spiked artificially in milk was evaluated quantitatively by calculating the loss of the concentration using HPLC. Fresh raw milk was subjected to a high-temperature short-time (72 °C for 15 s, HTST), low-temperature long- time (62.5 °C for 30 min, LTLT) and ultrahigh-temperature processing (138 °C for 2 s, UHT). The PEF process factors output voltage (20-65%) and pulse width (10-26 µs) were optimized for maximum reduction of PNG by employing the statistical tool response surface methodology (RSM). RESULTS: HTST, LTLT, and UHT have resulted in the reduction of PNG 13.5%, 6.1%, 1.2% respectively. The optimized parameters of the PEF treatment had reduction efficiency in the range of 79-86%. The saddle response surface obtained from RSM showed that the center was neither at maximum point nor at the minimum point. The predicted and experimental values of the response were nearly similar which proved the suitability of the fitted quadratic model. Combined thermal and PEF treatment has a significant synergistic effect in reducing the PNG. CONCLUSIONS: PEF induced reduction efficiency achieved was 79-86%. The reduction percentages were observed higher in the combined pasteurization and PEF treatment of milk. The pulsed electric field can be adopted as a unique processing tool for degradation of antibiotic residues whilst retaining nutritional quality parameters.