Effect of gamma irradiation and storage time on microbial growth and physicochemical characteristics of pumpkin (Cucurbita Moschata Duchesne ex Poiret) puree

GLIEMMO MF; LATORRE ME; NARVAIZ P; CAMPOS C; GERSCHENSON LN

FOOD SCIENCE AND TECHNOLOGY INTERNATIONAL

SAGE PUBLICATIONS LTD

Lugar: London; Año: 2014 p. 71 - 80

1082-0132

A factorial design was developed to study the effect of gamma irradiation (0-1-2 kGy) and storage time (0-14-28 days) on microbial growth and physicochemical characteristics of a packed pumpkin puree containing potassium sorbate, glucose and vanillin, stored at 25ºC. The growth of aerobic, anaerobic, lactic acid bacteria, yeasts and moulds increased by 3 log cycles in non-irradiated purees after 28 days of storage. Yeast and mould counts diminished by 2 log cycles after irradiation at 2 kGy. Colour stability decreased with time and irradiation, but it was not evidenced by visual examination. Sorbate content was only affected by time. From the microbial viewpoint, a puree absorbing 1.6 kGy would have a shelf life of 4 days. However, when the puree was heated before irradiation, the dose diminished to 0.75 kGy increasing the shelf life to 28 days at 20ºC. Furthermore, heating allowed improving the colour but it increased sorbate loss; however microbiological stability was not affected.