【作者】 张苒； 刘咏； 王军辉；

【Author】 Zhang Ran;Liu Yong;Wang Junhui;School of Food Science and Engineering,Hefei University of Technology;

【机构】 合肥工业大学食品科学与工程学院；

【摘要】 柠檬皮是果汁生产过程中的副产物,富含果胶。本研究采用乳酸（ALPP）、木瓜蛋白酶（PLPP）和732型阳离子交换树脂（RLPP）分别从柠檬皮中提取果胶,对3种果胶的理化性质和流变特性进行了研究和比较。结果表明,ALPP和RLPP为高甲氧基果胶,而PLPP为低甲氧基果胶,总半乳糖醛酸（GalA）含量约为果胶聚合物的50%。在3个组分中,ALPP具有最低的溶解度,RLPP含有更多的蛋白质。3种果胶溶液（ALPP_S、PLPP_S和RLPP_S）均为典型的假塑性流体,果胶溶液的表观粘度随温度的升高而降低,而随Ca²⁺、Na⁺和蔗糖浓度的增加而增加。在相同条件下,RLPP_S的表观黏度高于ALPP_S和PLPP_S。在同一浓度下,果胶溶液的模量G′和G″随振荡频率的增加而增加,随着样品浓度的增加,凝胶点逐渐减小。此外,RLPP_S在高浓度下具有更好的热稳定性。这些结果为柠檬皮果胶的进一步研究提供了有价值的数据。更多还原

【Abstract】 Lemon peels,by-product of juice manufacturing process,are rich in pectin.In this study,three fractions of pectins from lemon peels were extracted using lactic acid（ALPP）,papain（PLPP） and 732-type cation-exchange resin（RLPP）,respectively.The physicochemical and rheological properties of the three pectins were investigated and compared.The results showed that ALPP and RLPP were high methoxyl pectins,but PLPP was low methoxyl pectin.The content of total galacturonic acid（GalA） was about 50% of these pectin polymers.Among the three fractions,ALPP has the lowest solubility and RLPP contains more protein.The three pectin solutions（ALPPs,PLPPs and RLPPs） were typical pseudoplastic fluids.The apparent viscosity of pectin solutions decreased with the increase of temperature,and increased with addition of Ca²⁺,Na⁺ and sugar.Apparent viscosity of RLPPs was higher than that of ALPPs and PLPPs under the same conditions.The modulus G’ and G" of pectin solutions increased with the increase of oscillation frequency at the same concentrations.And the gelation point decreased gradually with concentration of samples increasing.Additionally,RLPPs had much better thermal stability at a high concentration.The results are interesting and can provide valuable data for further research of pectins from lemon peels.更多还原