Chemical and sensorial changes in milk pasteurised by microwave and conventional systems during cold storage

Raw milk was submitted to a continuous-flow microwave treatment at 80 or 92°C for 15 s or in a conventional heat exchanger under the same conditions. After pasteurisation, samples were bottled in sterile containers and stored at 4.5±0.5°C for up to 15 days. Samples were taken every 2 days and analysed for pH, sensory properties, volatile compounds and monosaccharides. Volatiles (including aldehydes, ketones, alcohols, esters and aromatic hydrocarbons) in freshly pasteurised samples were very similar to those found in raw milk. Evolution of all analysed parameters during storage was similar for the two series of samples; microwave heating had no adverse effects on flavour.