Evaluation on the Compatibility between Alkali-treated glutens Corn Starch

• Main Authors: Lin, Jean Yu, 林珍宇
• Other Authors: Chien,John Tung
• Format: Others
• Language: zh-TW
• Published: 1994
• Online Access: http://ndltd.ncl.edu.tw/handle/20780044246994059156

碩士 === 輔仁大學 === 食品營養學系 === 82 === A mixed gel consisted of gelatinized corn starch (GCS) and alkali-treated glutens (ATG) with different hydrophilicity was used as a model system to investigate effects of protein hydro- philicity and storage temperatures on the gel structure when ana- lyzed by using a rheometry and a differential scanning calorimet ry.Further studies were proposed tounderstand how the physico-che micalchanges in foods could be related to the contents of amylos e/amylopectin and the protein hydrophilicity in the mixed gels during storage.both hardness andmodulus of elasticity of the ATG/ GCS mixed gels decreased as anincrease of ATG hydrophilicity.This maybe associated with highercompatibility of GCS to ATGs of low h ydrophilicity than those ofhigh hydrophilicity. Moreover, the har dness and the modulus ofelasticity ofthe mixed gels were quadrati cally related to thetemperature,and reached a maximum value at 3. 5℃. A distinct endo-thermic peak,indicatinga meltingofthe recryst allized amylopectin,was observed between 55and 85℃.The melting e nthalpy decreasedwith a decrease in hydrophilicity of ATGs when t he mixed gelwas stored at temperatures below 10℃.The realignment ofamylo-pectin or an increase of entropy under elevated temperatu res.The effects of amylopectin content and storage time on the mo le-cular structure of mixed gelwere conducted by examining thecha nges of their rheometrical and thermal properties.Two kinds ofmix ed gels,a low hydrophilic 25℃ATG/GCS and a high hydrophilic60℃A TG/GCS were used. This confirmed our hypothesis that ATGs of low hydro-philicityw ere more compatible with amylopectin,presumably bothmolecules mig ht exist in forms of an entanglement or a intermo-lecular interac tion.The mixed gel of 25℃ ATG/GCS showed a highergel strength an d a lower recrystallization enthalpy than that of60 ℃ ATG/GCS,ind icating that the low hydrophilic ATG was more co- mpatible to star ch than the high hydrophilic 60℃ATG.