Moisture sorption characteristics of full fat and defatted pistachio kernel flour  

作　　者：Ling Bo Li Rui Gao Haiyan Shaojin Wang 

机构地区：[1]College of Mechanical and Electronic Engineering,Northwest A&F University,Yangling 712100,China [2]Institute of Food Science,Zhejiang Academy of Agricultural Sciences,Hangzhou 310021,China [3]Key Laboratory of Fruits and Vegetables Postharvest and Processing Technology Research of Zhejiang Province,Hangzhou 310021,China [4]Department of Biological Systems Engineering,Washington State University,Pullman,WA 99164-6120,USA

出　　处：《International Journal of Agricultural and Biological Engineering》2017年第3期283-294,共12页国际农业与生物工程学报（英文）

基　　金：General Program of National Natural Science Foundation of China(No.31371853);Open Fund from Zhejiang Academy of Agricultural Sciences(2010DS700124-ZM1605)。

摘　　要：The sorption isotherms of full-fat(FPKF),partially defatted(PDPKF),and totally defatted(TDPKF)pistachio kernel flour were performed in the range of water activity(aw)from 0.113 to 0.859 at 15℃,25℃and 35℃,and the applicability of six mathematical models(Smith,Oswin,Henderson,GAB,Halsey and BET)in data prediction was evaluated.Sorption isotherms were typeⅡ,according to Brunauer’s classification.Equilibrium moisture content(EMC)increased with an increase in aw at constant temperatures.The sorption isotherms of all three flour samples exhibited hysteresis.Significant differences were found among equilibrium data of FPKF,PDPKF and TDPKF samples.TDPKF showed higher hygroscopic characteristics than PDPKF,and PDPKF showed higher hygroscopic characteristics than FPKF at any temperature and aw studied.It was found that the Smith model was the most satisfactory one for representation of the sorption data of full fat sample,but for defatted samples,Halsey was the best model.The average monolayer moisture content(MMC)calculated by GAB model were 2.443-3.781 g/100 g(d.b.),3.585-4.886 g/100 g(d.b.)and 5.093-6.918 g/100 g(d.b.)for FPKF,PDPKF and TDPKF,respectively.The isosteric sorption heat(Qst)calculated by means of Clausius-Clapeyron equation decreased with increasing moisture content.The Qst values were 44.76-74.67 kJ/mol,44.75-99.44 kJ/mol and 44.80-133.28 kJ/mol for FPKF,PDPKF and TDPKF,respectively,in the range of moisture content of 2%to 41%(d.b.)at 25℃.

关 键 词：pistachio kernel flour equilibrium moisture content sorption isotherm isosteric sorption heat monolayer moisture content 

分 类 号：O64[理学—物理化学]