STORAGE STUDIES ON PULSED ELECTRIC FIELD PROCESSED MOTHER’S MILK

Abstract

This paper investigates the shelf life of mother’s milk at refrigerated storage (5˚C) processed by pulsed electric field technology (PEF), which is one of the novel, non–thermal methods of processing. Mother’s milk was processed using PEF technology by applying voltage gradient 35kV with different treatment times (3000 μs and 4500 μs). The processed samples were collected in sterile bottles and stored at 5˚C. The physico – chemical parameters (pH and acidity) of the PEF treated samples were analyzed at regular intervals and the results were compared with the pasteurized (62.5°C for 30 minutes) mother’s milk samples. Mean value for pH and acidity (ºD) was observed as 6.8±0.07 and 5.84±0.48 respectively during the 19th day of storage at 5ºC when the samples were treated at 35kV with a PEF treatment time of 4500 μs (T2). For pasteurized samples, mean value for pH and acidity (ºD) was observed as 6.75±0.09 and 6.17±0.61 respectively during the 7th day of storage at 5ºC. The results revealed that PEF treated samples stored at 5ºC remained shelf stable for 19 days whereas pasteurized milk samples stored at 5ºC remained shelf stable for 7 days.