Non-thermal pasteurization of milk by elongated electrode moderate electrical field: Chemical and sensory analysis during cold storage and shelf-life determination

Abstract

Elongated electrodes moderate electric field (EEMEF), an emerging milk pasteurization technology, has been proven to reduce energy consumption. The current study aims to investigate EEMEF impacts on milk's sensory and chemical parameters and shelf-life. Independent variables, i.e., electric field intensity (EFI) of 25–35 V/cm and mass flow rate (MFR) of 0.0167–0.0333 kg/s, were imported to central composite design response surface methodology (RSM), followed by process verification at predicted optimal conditions and a comparison with thermal pasteurization (TP). Optimal processing conditions were 30 V/cm EFI and 0.018 kg/s MFR, which reduced microbial count by 2.07 log cycles. EEMEF yielded pasteurized milk with similar peroxide value, pH, and acidity to TP but with 25% longer shelf-life and higher sensory scores. Gas Chromatography–Mass Spectrometry (GC–MS) disclosed that TP altered fatty acid profile significantly while EEMEF mainly affected shorter chain fatty acids such as butyric and caprylic acid. Fourier-transform infrared spectroscopy (FTIR) reveals that EEMEF milk composition was similar to raw milk, free from extensive protein denaturation and Maillard reaction products detected in TP milk. Extended shelf-life and enhanced sensory and nutritional quality could motivate EEMEF industrial applications to achieve net zero emissions and sustainable development goals (SGDs 7 and 12).