Effect of different sterilization ways on quality of low-sugar banana jam

Boiling water,high pressure steam and irradiation sterilization effect on the quality of low-sugar banana jam were studied.Banana jam were treated with boiling water for 10 min,121℃ steam sterilization 5min and60Co-γ( irradiation dose was 1.1,4.1,9 and 13.8k Gy) ray,respectively.And sensory index,physicochemical properties and microbial changes were measured. The results showed that high pressure steam sterilization could make banana jam severely browned,total sugar,reducing sugar and soluble protein content increased significantly while vitamin C content decreased.Boiling water and high pressure steam sterilization could 't significantly inhibit the growth of microorganisms significantly since when the storage time was extended to 15 d,total aerobic bacteria and moulds and yeasts in jam were out of limits.However,the colour,viscosity,reducing sugar,titratable acid,soluble protein,free amino acid,vitamin C content of banana jam did not show significant change( p > 0.05) after processing by60Co-γ radiation sterilization( 4.1 k Gy dose) compared to the boiling water sterilization,and the total aerobic bacteria,coliform and moulds and yeasts in jam were also safe. Besides,the safety,sensory characteristics and nutritional of jam can be maintained,and the shelf life of jam also can be extended.