With fish-flavor lotus root balls as the research objects,the effects of-18 ℃ refrigerator freezing,-40 ℃ blast freezing and-80 ℃ liquid nitrogen spray freezing on the quality are explored.The results show that with the decrease of freezing temperature,the time of fish-flavor lotus root balls by refrigerator freezing,blast freezing and liquid nitrogen spray freezing to pass through the maximum ice crystal formation zone is 89,25,5 min respectively,and the equivalent diameter of the formed ice crystals is 50.94,44.65,38.48 μm respectively.The water distribution of NMR T2 relaxation shows that fresh fish-flavor lotus root balls are mainly composed of immobilized water with the content of 95.10％.Freezing makes bound water and immobilized water migrate to free water.Under the three freezing methods,the migrated free water content is 54.22％,53.61％,47.12％respectively.The sensory quality,texture properties and gel strength of fish-flavor lotus root balls by blast freezing and liquid nitrogen spray freezing are not significantly different,but the difference is significant compared with that by refrigerator freezing.
维普
万方数据