加工工艺对芝麻酱稳定性的影响

为探明影响芝麻酱贮藏稳定性的关键工艺和核心指标，比较了炒制工艺（焙炒温度、时间）、不同原料处理方式（脱皮与未脱皮）、磨酱次数等关键工艺条件，测定其离心析油率、沉降析油率等贮藏稳定性指标以及粒径、比表面积等物化特性，通对不同工艺条件下各指标的变化进行分析归纳以及相关性分析，阐明加工工艺与贮藏稳定性之间的相关性。结果表明:芝麻的焙炒时间对酱体沉降析油率影响显著，焙炒时间延长析油率呈现先下降趋势，后趋于平稳，焙炒温度对芝麻酱沉降析油率影响不显著，但是温度不宜超过230 ℃，否则产品有焦糊味，研究发现芝麻酱离心析油率与30、60、90 d的沉降析油率的相关系数分别为0.966、0.955、0.967，呈现极显著正相关，离心析油率与芝麻酱的中位径D50、平均粒径Dav值也为显著正相关，相关系数为0.952和0.913，但是与比表面积S/V呈现负相关，相关系数为?0.930。另外，对比了脱皮芝麻和未脱皮芝麻加工成芝麻酱的离心析油率和黏度，发现芝麻皮的存在可以提高酱体黏度而有利于稳定贮藏，降低离心析油率，综合来看，在焙炒温度220 ℃，焙炒时间20 min，磨酱次数3次，离心析油率为3.34%，该条件下加工的芝麻酱的离心析油率最低，稳定性最佳。

Effects of Processing Techniques on Stability of Sesame Paste

In this paper,the key processes and core indexes that affect the storage stability of sesame paste are investigated,the key technological conditions were compared,such as the making process(roasting temperature and time),different treatment methods of raw materials(peeling and unpeeling),grinding paste number.The storage stability indexes such as centrifugal oil extraction rate,sedimentation oil extraction rate and physicochemical properties such as particle size and specific surface area were measured.Through the analysis and induction of the changes of each index under different technological conditions and the correlation analysis,the correlation between processing technology and storage stability was clarified.The results showed that the roasting time of sesame had a significant effect on the oil evolution rate of the paste sedimentation,and the oil evolution rate showed a decreasing trend at first and then tended to be stable with the extension of roasting time.Baking temperature had no significant effect on the sedimentation rate of sesame paste,but the temperature should not exceed 230℃,otherwise the product will have a burnt taste.The correlation coefficients between the centrifugal oil extraction rate and the sedimentation rate on 30,60 and 90 days were 0.966,0.955 and 0.967 respectively,showing a very significant positive correlation.The centrifugal oil extraction rate was also significantly positively correlated with the median diameter(D50)and average particle size(Dav)of sesame paste,and the correlation coefficient were 0.952 and 0.913.However,the centrifugal oil extraction rate was negatively correlated with specific surface area S/V,and the correlation coefficient was-0.930.The centrifugal oil extraction rate could be used as the evaluation index of the storage stability of sesame paste.The centrifugal oil extraction rate was used as the evaluation index to compare the centrifugal oil extraction rate of peeled and unpeeled sesame into sesame paste.It was found that the existence of sesame peel could improve the paste viscosity and facilitate stable storage and reduce the centrifugal oil extraction rate.Compared with the number of times of grinding,the centrifugal oil extraction rate was 3.34%under the conditions of 220℃baking temperature,20 min baking time and 3 times of grinding.The centrifugal oil extraction rate was the lowest and the stability was the best under this condition.