AC impedance and microstructure of rye starch exposed to water vapour

• Autorzy: Starzyk F. , Chrzanowska A. , Łużny W. , Śniechowski M.
• Języki publikacji: EN

Abstrakty

EN

Purpose: The purpose of this paper was to record and analyse mass (m) changes of population of micro-granules of rye starch, effective alternative current (AC), (electric) complex impedance (EACI) of this system taking place during humidification as well as insight into microstructure evolution by X-ray diffraction (XRD). Design/methodology/approach: Mass changes of biopolymeric micro-granular sample occurring during its exposition to saturated water vapour at room temperature, was recorded in time by means of precise torsional balance equipped with special chamber. The same was done in case of microstructure by XRD method. Monitoring of EACI was performed by means of interdigit comb capacitor and precise RLC meter equipped with PC software. Specially designed and constructed measuring chamber was applied to control temperature and relative humidity (RH %) in ambient sample atmosphere. Electric measurements were carried out for 5 selected frequencies. Findings: Interdigit dielectric spectroscopy method turned out to be more sensitive technique to follow details of long lasting humidification than only mass changes recording. Correlation of changes of EACI with simultaneously occurring mass increase can be a way to describe the humidification stages processes involving water molecules adsorption and absorption by micro-granular biopolymeric sample. Frequency dependence of EACI gives insight into mechanism of water molecules inclusion, binding and immobilization on the starch granules surface as well as inside of its internal physical structure. Research limitations/implications: The recording duration of m(t) was limited to &sim104 s in case of humidification by balance resolution and character of the process. The whole range of measurements was limited to max &sim23 RH % of water uptake in order to prevent over molecular structure irreversible changes. The above limitations enable us to collect data for modelling reversible water uptake and connected EACI micro-granular biopolymeric population sample. Practical implications: EACI monitoring of humidification turned out to be much more selective than only gravitational measurement of mass change. Modelling purpose correlation of both can give new possibilities to modelling approach. Achieved data can contribute to better understanding of active adsorption and absorption centres in starch granules. Originality/value: For the first time practically important humidification process was monitored in statu nascendi, without disturbing geometry of starch granules population by means of EACI evolution record. It was enabled by application of interdigit comb capacitor as a sensing unit. This is the first report of four stages for EACI evolution as well as the first XRD direct record of granular starch reversal swelling.

Słowa kluczowe

EN

biopolymers; dielectrometry; water vapour

PL

biopolimery; dielektrometria; para wodna

• Wydawca: International OCSCO World Press
• Czasopismo: Archives of Materials Science and Engineering
• Rocznik: 2009
• Tom: Vol. 40, nr 1
• Strony: 23--26
• Opis fizyczny: Bibliogr. 15 poz.

Twórcy

autor

Starzyk F.

autor

Chrzanowska A.

autor

Łużny W.

autor

Śniechowski M.

• Institute of Physics, Technical University, ul. Podchorążych 1, 30-084 Kraków, Poland,

Bibliografia

• [1] Z. Pawlak, J. Kotyńska, Z.A. Figaszewski, A. Gadomski, A. Gudaniec, A. Oloyede, A biochemical model for characterising the surface – active phospholipide bilayer of articular cartilage relative to acid – base equilibrium, Archives of Materials Science and Engineering 29/1 (2008) 24-29.
• [2] M. Kaczmarek, W. Walke, W. Kajzer, Chemical composition of passive layers formed an metallic biomaterial, Archives of Materials Science and Engineering 28/5 (2007) 273-276.
• [3] A. Krauze, J. Marciniak, Biomechanical analysis of plaks used in treatment of pectus excavatum, Archives of Materials Science and Engineering 28/5 (2007) 301-304.
• [4] A.N. Donald, P.A. Perry, T.A. Weigh, The impact of internal granule structure on processing and properties in starch advances in structure and function, The Royal Society of Chemistry (2001) 45-52.
• [5] L. Czepirski, E. Komorowska-Czepirska, J. Szymońska, Fitting of different models for water vapour sorption on potato starch granules, Applied Science 196 (2002) 150-153.
• [6] F. Starzyk, Interdigit dielectrometry of water vapour induced changes in granular starch, Archives of Materials Science and Engineering 29/1 (2008) 30-35.
• [7] S.R. Erlander, The mechanism for the synthesis of starch and its relationship to flageline and to the newly proposed structural modes for DNA, Starch/Staerke 22 B (1970) 393-401.
• [8] D.J. Gallant, B. Bouchet, P.M. Baldwin, Microscopy of starch: evidence of a new level of granules organization, Carbohydrate Polymers 32 (1997) 177-191.
• [9] H.F. Zorbel, Starch Crystal Transformations and Their Industrial Importance, Starch/Staerke 40/1 (1998) 1-7.
• [10] A. Imberty, A. Buleon, V.Tran, S. Perez, Recent Advantages in Knowledge of Starch Structure, Starch/Staerke 43/10 (1991) 375-384.
• [11] F. Starzyk, Chengy-yi, P. Tomasik, Visible light absorption, transmission and scattering by potato starch granules, Polish Journal of Food and Nutrition Sciences 10/51 No 4 (2001) 27-34.
• [12] F. Starzyk, W. Bąk, C. Kajtoch, M. Gabryś, Influence of electric field DC-component on AC-response of ferroelectric powder, Archives of Materials Science and Engineering 29/1 (2008) 36-39.
• [13] K.C. Huber, J.N. Bemiller, Visualization of channels and cavities of corn and sorgum starch granules, Cereal Chemistry 74 (1977) 537-541.
• [14] E.M. Synder, Starch Chemistry and Technology, (R.L. Whistler J.N. Bemiller, E.F. Pashall eds) Academic Press, New York, I, 1984, 661-772.
• [15] F. Starzyk, Polymers and fractals, Polymers – Macromo-lecular Plastics 7 (1992) 298-303 (in Polish).