成膜预处理提高扇贝柱超声波辅助热泵干燥效率及品质  

Coating pretreatment improved drying efficiency and quality attributes of ultrasonic assisted heat pump dried scallop adductors

作　　者：赵亚[1] 朱智壮 石启龙[1] 刘静 Zhao Ya;Zhu Zhizhuang;Shi Qilong;Liu Jing(School of Agricultural Engineering and Food Science,Shandong University of Technology,Zibo 255000,China)

机构地区：[1]山东理工大学农业工程与食品科学学院,淄博255000

出　　处：《农业工程学报》2022年第18期274-283,共10页Transactions of the Chinese Society of Agricultural Engineering

基　　金：山东省自然科学基金资助项目(ZR2020MC215)。

摘　　要：热泵干燥(Heat Pump Drying,HPD)因条件温和、能效高,特别适用于水产品的干燥。但是,由于HPD温度低,导致干燥时间长、干制品品质劣变严重,限制了HPD在水产品中的应用。为了强化扇贝柱HPD效率,提高干制品品质,该研究首先采用超声波(Ultrasonic,US)预处理扇贝柱,然后再分别采用3种可食性膜(海藻酸钠(Sodium Alginate,SA),低甲氧基果胶(Low-Methoxy Pectin,LMP)和印度树胶(Gum Ghatti,GG))预处理,US处理后未经过成膜预处理的扇贝柱作为对照组(Control Group,CK),探究成膜预处理对扇贝柱US辅助HPD动力学及品质特性的影响。基于低场核磁共振(Low-Field Nuclear Magnetic Resonance,LF-NMR)技术,采用单变量线性(Univariate Linear,UL)模型和偏最小二乘回归(Partial Least Squares Regression,PLSR)模型量化扇贝柱LF-NMR弛豫参数与干制品含水率(Moisture Content,MC)和水分活度(Water Activity)的关系,以期监测扇贝柱HPD进程。研究结果表明:相比于CK,成膜预处理导致扇贝柱有效水分扩散系数(Effective Moisture Diffusivity)提高了1.32%~8.41%。SA和GG成膜预处理可以减缓扇贝柱干燥过程中不易流动水向结合水迁移的速率,同时增加了干燥过程中自由水的流动性,进而强化了干燥效率。相比于CK,SA和GG成膜预处理增加了扇贝柱硬度、弹性、内聚性和咀嚼性,降低了复水比、收缩率和总色差值;而LMP成膜预处理降低了硬度和总色差值。综合考虑,US-SA为扇贝柱US辅助HPD较适合的预处理方式。LF-NMR横向弛豫时间与大部分干制品品质之间具有显著(P<0.05)关联性。扇贝柱LF-NMR图谱中,当横向弛豫时间主峰<10 ms时,而且仅出现1个主峰,即可作为扇贝柱干燥终点。UL模型表明,MC和水分活度与不易流动水峰面积和总峰面积呈显著(P<0.05)正相关,与结合水峰面积呈显著(P<0.05)负相关。PLSR模型表明,以4个LF-NMR参数为变量的回归模型可高精度地预测MC和水分活度。该研�Heat Pump Drying(HPD)is especially suitable for the drying of aquatic products,owing to the mild conditions and high energy efficiency.However,the low drying temperature can result in a long drying time for the quality degradation in aquatic products processing.This study aims to enhance the drying efficiency of scallop adductors and quality attributes of dried products,particularly for better HPD application.The scallop adductors were firstly pretreated with ultrasonic(US)pulses.Then,three kinds of edible coating were selected,including Sodium Alginate(SA),Low-Methoxy Pectin(LMP),and Gum Ghatti(GG).Subsequently,the HPD was carried out for the samples with different coating pretreatment.The pretreatment without coating(i.e.,merely pretreated with US)was set as the control group(CK).Finally,an investigation was made to determine the effects of three kinds of edible coating pretreatment on the drying kinetics and quality attributes of scallop adductors during US-assisted HPD.The low-field nuclear magnetic resonance(LF-NMR)was utilized to monitor the drying process of scallop adductors.The Univariate Linear(UL)and partial least squares regression(PLSR)models were employed to correlate the LF-NMR parameters with the Moisture Content(MC)and water activity(aw).The effective moisture diffusivity(Deff)of scallop adductors increased with the edible coating pretreatment in the range of 1.32%-8.41%,compared with the CK.The SA and GG pretreatment slowed down the migration rate of immobilized water towards bound water.As such,the flow of free water increased during drying,thus enhancing the drying efficiency of scallop adductors.More importantly,the SA and GG pretreatment increased the hardness,elasticity,cohesion,and chewiness of dried scallop adductors,whereas,decreased the rehydration ratio,shrinkage rate,and total color difference of dried products.There was a decrease in the hardness and total color difference of LMP pretreated samples.In summary,the US-SA was the most suitable pretreatment for the US-assisted HPD of sca

关 键 词：干燥 低场核磁共振 成膜预处理 热泵干燥 扇贝柱 品质特性 

分 类 号：TS254.4[轻工技术与工程—水产品加工及贮藏工程]