基于LF-NMR探究冻融对压差膨化扇贝柱水分分布与品质影响

Effects of freeze-thaw on water distribution and quality of explosion puff dried scallop adductors based on LF-NMR

该文分别采用-15、-35℃冻融扇贝柱以未经冻融的扇贝柱为对照(CK),采用低频核磁共振分析扇贝柱横向弛豫时间(T2);以膨化度、平均干燥速率、复水率、色差、硬度、脆度为指标,探究冻融对压差膨化扇贝柱水分分布与品质的影响。结果表明与CK相比冻融降低了扇贝柱的T2值不易流动水T23值由73.18 ms减小至59.37、51.63 ms。预干燥后扇贝柱结合水随冻融增加,而膨化度和真空干燥速率呈降低趋势。冻融降低了扇贝柱的复水率、脆度增加了平均干燥速率、色差和硬度。一定条件下,冻融降低了扇贝柱压差膨化产品品质。扇贝柱品质与解冻后T23和不易流动水比例(mT23)显著相关;膨化度、复水率、硬度、平均干燥速率与预干燥后单分层及多分子层结合水比例之和(mT21+mT22)、mT23显著相关。

Scallop adductors were freeze-thawed of-15 and-35 storage to investigate the effects of freeze-thaw on the quality of explosion puff dried scallop adductors.Scallop adductors without freeze-thaw were used as control(CK).Transverse relaxation time(T2)of samples was measured by low frequency nuclear magnetic resonance(LF-NMR).With puffing degree,average drying rate,rehydration ratio,total color difference,hardness and crispness as indexes,the effects of freeze-thaw on the quality of explosion puff dried scallop adductors were investigated.Compared with CK,T2 decreased with freeze-thaw.When scallop adductors were treated with freeze-thaw at-15℃and-35℃,T2 of immobilized water,namely T23 decreased from 73.18 ms to 59.37 ms and 51.63 ms,respectively.After pre-drying,the bound water of scallop adductors increased with freeze-thaw,while puffing degree and vacuum drying rate decreased.Freeze-thaw reduced the rehydration rate and crispness of the explosion puff dried scallop adductors,whereas the average drying rate,total color differences and hardness were increased.Under certain conditions,the quality of explosion puff dried scallop adductors was decreased with freeze-thaw.The indexes of scallop adductors were significantly correlated with T23 and the proportion of immobilized water,namely mT23 after thawing.The puffing degree,rehydration rate,hardness and average drying rate were significantly correlated to the proportion of monolayer and multilayer bound water,namely(-T21+mT22)and mT23 of scallop adductors after pre-drying.This research provides a theoretical basis for the explosion puff drying of aquatic products,especially of scallop adductors.