| In the present study, the effects of high pressure (HP) treatment on the diffusion ofβ-cyclodextrin (β-CD) into rice grain were investigated for feasibility analysis. It wasconfirmed that the high pressure can effectively promote β-cyclodextrin penetrat into the riceby two different methods. Then further explore the infiltration of beta cyclodextrin byultrahigh synergy impact on the retrogradation and edible quality of instant rice, in order toprovide an effective way for improving the edible quality of convenient rice.The research evaluated the effects of high pressure (HP)treatment on the diffusion ofβ-cyclodextrin (β-CD)into rice grain.2%(w/w) β-CD was added into the rice soakingsuspension.The mixture were presoaked at60for30min, then subjected to HP treatmentat different pressures (100-500MPa) for20min, finally this rice was steam cooked to begelatinized. The residue β-CD content in soaking liquid was quantitatied by High PressureLiquid Chromatography (HPLC). The results showed that β-CD in the soaking liquid wassignificantly reduced with the increase of pressure, indicating moreβ-CD penetrated into theinterior of rice.β-CD embedd1,8-two hydroxylanthraquinone traced the immersion processof β-CD under high pressure into the rice grain. The fluorescence inclusion distribution of ricesectioning after soaking and HP treatment was observed by the confocal laser microscopy.HP treatment can effectively promoteβ-cyclodextrin to penetrate into the interior of the rice.This paper was investigated the β-cyclodextrin penetration by High-Pressure on theretrogradation ofcooked rice.2%(w/w)β-cyclodextrin or hydroxypropyl branch-β-cyclodextrinwas added in rice soaking suspension. The mixture was soaked under normal pressure at60for30min, then to be treated under500MPa at40for20min, finally this rice wassteam cooked to be gelatinizated. The effects of this new process on the retrogradation ofcooked rice at4were evaluated by means of differential scanning calorimetry (DSC),thermogravimetric analysis (TG) and X-ray diffraction (XRD). The retrogradationenthalpy change value of the new process treated rice at4(35d) decreased by3.10J/gcompared with the control sample, the crystallinity decreased by7%. The results show thatthe new process significantly delayed the rice retrogradation, and improved the storageproperty of rice. The collaborative inhibition of high pressure treatment and β-cyclodextrincan provide an effective way to improve the edible quality of the instant rice.Finally, the gelatinization degree, crystallinity, hardness and viscosity of four groups ofdifferent processing conditions (normal control group, high pressure control group,2%β-CDcontrol group and high pressure+add2%β-CD group) before and after microwave heatingwere studied. The results show that the gelatinization degree of the four different groups notmicrowave heating in4during storage were rapid declined, and significantly negativecorrelation with the degree of retrogradation of rice samples. After microwave heating, thegelatinization degree of high pressure group was significantly higher than the atmosphericpressure group. High pressure promoted water infiltration, maked the distribution of internalmoisture rice evenly, so that rice can be fully gelatinization, the crystallites of retrogradationstarch had more opportunities to incorporate more internal free water by heating and gradually melted away.The retrogradation of rice samples can be obviously delayed. At the same time,the infiltration of the additive in the rice by high pressure treatment can obviously relieve theretrogradation of rice samples. High pressure+2%β-CD rice group at4storage periodafter microwave heating had the highest gelatinization degree, the hardness decreasedsignificantly, while the elastic cohesion increased significantly,relative crystalline degree ofB-type crystallization area was reduced greatly, decreased by6.68%compared with normalpressure. |
PDF Full Text Request