Heat transport model for the deliquescence kinetics of crystalline ingredients and mixtures

Na Li a, Lynne S. Taylor b, Lisa J. Mauer a, *

a Department of Food Science, Purdue University, 745 Agriculture Mall Drive, West Lafayette, IN 47907, United States

b Department of Industrial and Physical Pharmacy, Purdue University, 575 Stadium Mall Drive, West Lafayette, IN 47907, United States

關(guān)鍵成果

• 基于晶體材料壓片的傳熱潮解動力學(xué)模型可成功用于粉末材料系統(tǒng)中
• 有效接觸面積（樣品盤尺寸），樣品組成，和溫度是決定潮解速率的因素，而樣品粒徑和質(zhì)量對潮解的水分吸收速率并無顯著影響
• 這個一般模型可用于預(yù)測晶體粉末材料在恒濕箱中的潮解水分吸收速率

Key results:

• The heat transport model of deliquescence from compressed crystalline disks was successfully applied to powder systems
• Effective contact area (pan size), sample composition, and temperature are rate-determining factors, whereas particle size and sample mass did not significantly affect the water vapor sorption rate
• This general model may enable the prediction of water sorption rates of crystalline solids during deliquescence in controlled humidity conditions

關(guān)鍵詞：吸附速率，晶體材料，潮解，傳熱

Key words:

Sorption rate, crystalline ingredients, deliquescence, heat transport

http://www.proumid。。ｃｏｍ.cn/product_detail_1.html

摘要：

當(dāng)環(huán)境的相對濕度超過潮解點RH₀時，易潮解的晶體發(fā)生一級溶解過程。對于壓片易潮解材料，潮解的速率隨著RH超出RH₀差值的增加而加速；但是，迄今還沒有關(guān)于晶體食物材料粉末的潮解動力學(xué)模型被發(fā)表。本文采用一種多樣品重量法水分吸附儀(型號：SPSx-1μHigh Load，生產(chǎn)廠家：德國 ProUmid GmbH & Co. KG)測定了常見的粉末食品材料（如檸檬酸、氯化鈉、蔗糖、果糖、山梨糖醇和木糖醇）及其混合物的水分吸附速率。水蒸氣的吸附速率與樣品的直徑、溫度和組成有關(guān)。實驗證明樣品壓片的潮解傳熱模型能夠成功的應(yīng)用于粉末材料和其混合物，其實驗結(jié)果進一步的論證了潮解的理論基礎(chǔ)，為在可控的恒濕箱內(nèi)預(yù)測潮解過程中的水分吸附速率提供了有力的工具。

Abstract:

Deliquescent crystalline solids undergo the first order dissolution process of deliquescence when the environmental relative humidity (RH) exceeds the deliquescence point (RH0). The rate at which deliquescence occurs increases as the RH increases above the RH0 in compressed disks of select deliquescent ingredients; however, a kinetic model for the deliquescence of powdered crystalline food ingredients and blends thereof has not been published. The water vapor sorption rates of commonly used powder food ingredients (citric acid, sodium chloride, sucrose, fructose, sorbitol, and xylitol) and blends were determined using a multi-sample gravimetric moisture sorption analyzer. The water vapor sorption rate was dependent on sample radius, temperature, and sample composition. The heat transport model for the deliquescence of compressed disks was successfully extended to the powder ingredients and blends. Such results enable further understanding of fundamental theories of deliquescence and provide a useful tool in the prediction of water vapor uptake rate during deliquescence in controlled RH chambers.