| Castanopsis Calathiformis is a kind of evergreen arbor of Fagaceae, the fruit ofwhich were rich in starch. Relevant researches indicated that this kind of starch hadhygienical and excellent efficacy which can help people to get rid of illness and loseweight. The prospect of marketing on this starch is magnificent. The chemicalconstituent, solubility, retrogradation, morphological feature of granule, crystaltexture, gelatinization temperature range, glass transition, viscosity and gellingproperties of the starch isolated from Castanopsis Calathiformis fruit wereinvestigated in this study. The main conclusions were as follows:1. The purified starch contained82.17±0.01%starch,12.15±0.002%moisture,0.16±0.004%crude protein,0.21±0.02%crude lipid,4.79±0.08%total dietary fiber,0.14±0.001%ash and0.36±0.1%others, the Total phosphorus of the sample was42.10ppm, the whiteness and acidity of the sample were72.68±0.70and2.14±0.01respectively.2. The maximum value of water solubility index and swelling power of thisstarch were26.30±0.05%and32.17±0.03%respectively under95℃. Theretrogradation of this starch was better than potato starch and worse than maize starch.Water holding capacity of this starch after alternating freeze-thaw cycle was increasedwith the concentration of the starch and when the concentration was7%, it gottenmaximum value99.8±0.2%. The digesting rate of the starch under α-amylase was81.96±0.02%, the paste clarity of1%starch gelatin was0.072, and both of them werelower than potato and maize starch.3. SEM indicated that the starch granules were irregular in shape which wereellipsoidal and like cobblestones, mostly with diameters rang were3-5and11-13μm,some ones were as big as16-17μm.4. This starch had a C-type X-ray diffraction pattern and the degree ofcrystallinity was37.49%exhibited by a wide X-ray diffraction.5. The onset gelatinization, peak and conclusion temperature of the starch were61.72℃,69.26℃and83.47℃respectively in DSC test, and the enthalpy ofgelatinization (ΔH) was4.64J/g, the glass transition temperature (Tg) was82.79℃.6. The additive affection to the peak, tough and final viscosities of acorn starchhas been modified by RVA test. The result indicated that the maximum peak viscositywas gotten at pH5.0-7.1. The measurement of affection is fructose﹥sucrose﹥ glucose. Salt can help in increasing the peak viscosity and peak temperature.Aluminum potassium sulfate decreased the final viscosity while stearic acid increasedit; both of them affected the peak viscosity insignificance.7. The gelling properties of this starch were performed with a texture analyzer.The result indicated the strength of this starch gel was stronger than maize gel butweaker than potato, the strength of the starch gel was positive correlation with theconcentration of starch and better than others when pH6.5. All the additives haveaffection to the gelling properties of this starch, the starch indicated a resistance toacid hydrolysis, both of saline and lipid affection were decrease after increase.Microwave heating could help to get the strongest gel in all kinds of heating processand frozen storage has gotten the strongest gel in storage temperature. |
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