【作者】 刘悦；

【导师】 孙爱东； 甘芝霖；

【作者基本信息】 北京林业大学 ， 农业硕士（专业学位）， 2023， 硕士

【摘要】 欧洲越橘含有15种花色苷,总花色苷含量为42.04%,花色苷的结构中存在多个活性羟基和含正离子的母核,具有不稳定、易水解开环等化学性质,因此,不利于加工和贮藏。现有研究表明,当花色苷和果胶结合时,可提高花色苷的稳定性,但目前对该复合物性质表征的研究较少,对其形成机理尚未阐明。本试验主要探究不同条件下越橘花色苷与苹果果胶、柑橘果胶和蓝莓果胶的结合效果,形成多种花色苷-果胶复合物,通过其微观结构及化学键初步阐明其形成机理,再对其进行稳定性和抗氧化性评价,并基于花色苷-果胶复合物为原料,开发出新型功能性果冻。主要结论如下:(1)探究了果胶添加比例、溶液p H值和结合时间对花色苷-果胶复合物结合率的影响。结果表明,结合率随着果胶添加比例的增加而不断提升;随着溶液p H值的升高先上升后下降;随着结合时间的增加先上升后下降。制备花色苷-果胶复合物的最佳条件为:花色苷与果胶的质量比1:2.5,p H 3.0,反应时间80 min。花色苷与苹果果胶结合率为89.75±0.43%;花色苷与柑橘果胶结合率为87.83±0.24%;花色苷与蓝莓果胶结合率为85.20±0.49%。(2)选取最佳条件下的复合物初步探究其形成机理。扫描电镜表明复合物的粗糙程度和稳定性有关;红外光谱表明花色苷和果胶复合过程中主要是氢键和离子间的相互作用;XRD图谱发现复合物均未表现出晶体存在的特征峰,表明果胶是以非晶态固体存在花色苷-果胶复合物中。(3)选取最优结合条件下的花色苷-果胶复合物,探究其稳定性和抗氧化性。结果表明,在不同温度、光照、金属离子等条件下,花色苷-果胶复合物均显著提高了越橘花色苷的稳定性,其中与苹果果胶结合的花色苷稳定性最强;同时花色苷-果胶复合物具有较强的DPPH清除能力、ABTS~+·清除能力和还原能力。(4)基于越橘花色苷-果胶复合物开发新型果冻。研究结果表明:以100 g果冻为基准,当复合凝胶剂添加量1.24%、越橘花色苷添加量0.08%、柠檬酸添加量0.21%、白砂糖添加量16.78%时加工工艺条件最优,在此条件下,果冻的感官评分为89.38。本试验筛选出了对越橘花色苷与苹果果胶、柑橘果胶和蓝莓果胶结合率有影响的因素,探究了最佳条件下形成的复合物的结构特征以及在不同条件下的稳定性和抗氧化活性,最后利用原材料开发新型功能性果冻。为越橘在加工过程中花色苷易降解的难题提供了解决方法,扩大了果胶的的应用范围,同时提高了果蔬加工副产物的综合利用,减少资源浪费,产生一定的经济和社会效益。更多还原

【Abstract】 Bilberry contains 15 types of anthocyanins,with a total anthocyanin content of 42.04%.The structure of anthocyanins contains multiple active hydroxyl groups and mother nuclei containing positive ions,which have chemical properties such as instability and easy water release.Therefore,it is not conducive to processing and storage.Existing researches shown that the stability of anthocyanins can be improved when combined with pectin.However,there is currently limited research on the characterization of the properties of this complex,and the formation mechanism has not been elucidated yet.This research mainly discusses the combination of bilberry with apple pectin,orange pectin and blueberry pectin under different conditions,forms a variety of anthocyanin pectin complexes,preliminarily clarifies its formation mechanism through its microstructure and chemical bond,and then evaluates its stability and antioxidant capacity.Based on the anthocyanin pectin complex as raw materials,a new type of functional jelly is developed.The main conclusions are as follows:(1)The effects of pectin addition ratio,solution p H value,and binding time on the binding rate of anthocyanin pectin complex were investigated.The results showed that the binding rate continuously increased with the increase of pectin addition ratio;As the p H value of the solution increased,it firstly increased and then decreased;As the binding time increased,it firstly increased and then decreased.The optimal conditions for preparing anthocyanin pectin complex were:the mass ratio of anthocyanin to pectin was 1:2.5,p H was 3.0,and reaction time was 80 minutes.The binding rate between anthocyanins and apple pectin was 89.75±0.43%;The binding rate between anthocyanins and citrus pectin was87.83±0.24%;The binding rate between anthocyanins and blueberry pectin was 85.20±0.49%.(2)Select the composite under the optimal conditions to preliminarily explore its formation mechanism.Scanning electron microscopy showed that the roughness and stability of the composite are related;The infrared spectrum indicated that the main form of binding between anthocyanins and pectin is hydrogen bonding and ion interactions;The XRD pattern showed that the complexes did not exhibit characteristic peaks of crystal presence,indicating that pectin exists as an amorphous solid in the anthocyanin pectin complex.(3)Select the anthocyanin pectin complex under the optimal binding conditions to explore its stability and antioxidant activity.The results showed that under different conditions such as temperature,light,and metal ions,the anthocyanin pectin complex significantly improved the stability of bilberry anthocyanins,with the anthocyanin bound to apple pectin having the strongest stability;Meanwhile,the anthocyanin pectin complex has strong DPPH and ABTS~+·scavenging capability,and reducing capability.(4)According to the bilberry anthocyanin pectin complex,a new type of jelly was developed.The results showed that the processing conditions were optimal when the content of compound gel agent was 1.24%,the content of bilberry anthocyanin was 0.08%,the content of citric acid was 0.21%,and the content of white granulated sugar was 16.78%.Under this condition,the sensory score of the jelly was 89.38.This experiment screened the factors that affect the binding rate of bilberry anthocyanins with apple pectin,citrus pectin,and blueberry pectin,explored the structural characteristics of the composite formed under the optimal conditions,as well as its stability and antioxidant activity under different conditions.Finally,a new type of functional jelly was developed using raw materials.This provides a solution to the problem of easy degradation of anthocyanins in the processing of bilberry anthocyanins,expands the application range of pectin,and improves the comprehensive utilization of by-products in fruit and vegetable processing,reducing resource waste,and generating certain economic and social benefits.更多还原