POSSIBILITIES OF THE CALORIMETRIC METHODS OF STUDYING THERMOPHYSICAL CHARACTERISTICS OF BIOPOLYMERS
Keywords:
differential scanning calorimeter (DSC), thermophysical characteristics (TFC), water activity (Av), glass transition temperature (Tc), freezing temperature (Tc), phase transitions, thermogram reproducibility, plasticizer for hydrofilmers – distilled waterAbstract
The results of research enhanced calorimetry for determination the thermophysical properties of plant powders as biopolymers presented. The maximum temperature range of calorimetric scanning for biopolymers with natural humidity is chosen within their glass transition temperatures, for hydrated biopolymers with 20% humidity is chosen within the dehydration temperature of polymer decomposition or before the formation of a polymer network that suppresses its hydrophilicity. We found that the final scanning temperature depends linearly from the humidity level. The dependence of phase transition temperatures from particle size, molecular weight and active humidity of biopolymers was established. We have identified that the freezing temperature of amorphous powder with active humidity below 0,926 is shifted below zero. Dry powders with low glass transition temperatures below 150 °C after hydration are characterized by freezing temperatures below 0 °C. Powders with high glass transition temperatures above 153 °C after hydration are characterized by freezing temperatures of 0 °C. As a result of this work we found that maximum dehydration temperatures of 120 °C and 153 °C are typical for amorphous powders with natural humidity and glass transition temperatures not exceeding these dehydration temperatures very much, which can characterize these temperatures also as temperatures responsible for the preservation of the hydrophilic structure
References
Rahman M.S. State diagram of foods: Its potential use in food processing and product stability// Trends in Food Science technology. – 2006. – V. 17, № 3. – P. 129–141. DOI: 10.1016/j.tifs.2005.09.009
Любарев А.Е., Курганов Б.И. Изучение необратимой тепловой денатурации белков методом дифференциальной сканирующей калориметрии // Успехи биологической химии.
– 2000. – Т. 40. – 43 c.
Zhang M., Li C.L., Ding X.L. Technical note thermal denaturation of some dried vegetables // Dryinq technology. – 2002. – V. 20(3). – P. 711–717. DOI: 10.1081/DRT-120002826
Бойко Б.Н. и др. Способ раздельного определения содержания свободной и связанной воды в сухом растительном порошке банана с применением дифференциального сканирующего калориметра. Патент на изобретение RU 2686104, 24.04.2019. Заявка № 2017109195 от 21.03.2017.
Кулагин В.Н. Изменение активности воды как показателя качества продуктов при термообработке // Мясная индустрия. – СССР. – 1982. – № 3. – 13 c.
Rouilly A., Jorda J., Rigal L. Thermomechanical processing of sugar beet pulp. II. Thermal and rheological properties of thermoplastic SBP // Carbohydrate Polymers. 2006. – V. 6. – P. 117–125. DOI: 10.1016/j.carbpol. 2006.02.031
Emily J. Mayhew, Cheyenne H. Neal, Soo-Yeun Lee, Shelly J. Schmidt. Glass transition prediction strategies based on the couchmankarasz equation in model confectionary systems //
Journal of Food Engineering. – 2017. – P. 1–16. DOI: 10.1016/j.jfoodeng.2017.07.007
Douglass I., Harrowell P. Kinetics of Dissolution of an Amorphous Solid // J. Phys Chem B. – 2018. 1;122(8). – P.2425-2433. DOI:
1021/acs.jpcb.7b12243
Drake A.C. et al. Effect of water content on the glass transition temperature of mixtures of sugars, polymers, and penetrating cryoprotectants in physiological buffer // PLoS One. – 2018. –
1. DOI: 10.1371/journal.pone.0190713
Roos Y.H. Water activity and physical state effects on amorphous food stability // J Food Process Preserv. – 1993. – V. 16. – P. 433– 447. DOI: 10.1111/j.1745-4549.1993.tb00221.x
Sablani S.S., Kasapis S., Rahman M.S. Evaluating water activity and glass transition concepts for food stability // Journal of Food Engineering. – 2007. V. 78. – P. 266–271. DOI: 10.1016/j.jfoodeng.2005.09.025
Ibrahim M.M., El-Zawawy W.K., Juttke Y., Koschella A., Heinz T. Cellulose and microcrystalline cellulose from rice straw and
banana plant waste: preparation and characterization // Cellulose. – 2013. DOI: 10.1007/s10570-013-9992-5
Rouilly A., Jorda J., Rigal L. Thermo-mechanical processing of sugar beet pulp. II. Thermal and rheological properties of ther-moplastic SBP // Carbohydrate Polymers. – 2006. – V. 6. – P. 117–125. DOI: 10.1016/j.carbpol. 2006.02.031
Martı́nez-Navarrete N., Moraga G., Talens & Amparo Chiralt. Water sorption and the plasticization effect in wafers // International Journal of Food Science and Technolo-gy. – 2004. – V. 39. – P. 555–562. DOI: 10.1111/j.1365-2621.2004.00815.x
Sablani S.S., Kasapis S., Rahman M.S. Evaluating water activity and glass transition concepts for food stability // Journal of Food Engineering. – 2007. – V. 78. – P. 266–271. DOI:10.1016/j.jfoodeng.2005.09.025.





