葡萄高温高湿气体射流冲击漂烫促干和护色机理及优化调控研究

The objective of this project is to reveal the mechanism of drying acceleration and color protection of seedless grapes by high-humidity hot air impingement blanching (HHAIB) and optimization strategy. Transmission electron microscope (TEM), atomic force microscopy (AFM) and low-field nuclear magnetic resonance (LF-NMR) techniques will be used to qualitatively and quantitatively characterize the effects of different HHAIB treatments on the ultrastructure of the peel and the cross-linked status of polysaccharides, moisture status and its transfer and distribution during drying by thus to reveal the mechanism of drying promotion by HHAIB. The final contents of chlorophyll degradation derivatives in PaO and OCB pathways will be detected by HPLC to demonstrate the mechanism of color protection by HHAIB and to clarify the degradation flows of chlorophyll and the relationship between the two degradation paths. The key factors affecting degradation of chlorophyll and cell-wall polysaccharides and the optimization mechanism will be identified through elucidating the effect of different HHAIB factors on degradation of chlorophyll and cell-wall polysaccharide. The chlorophyll degradation kinetics models and the correlation models between cell wall polysaccharides degradation and the formation and evolution of macro quality characteristics of dried raisins will be established for the prediction, analysis and optimization of grape processing quality under different blanching conditions. This project will provide scientific and technical support for the application and optimization of HHAIB technology for grape drying, which is very important for enhancing drying process and quality of raisins.

项目以揭示葡萄高温高湿气体射流冲击漂烫（HHAIB）促干和护色机理及优化调控为目标。采用TEM、AFM和LF-NMR技术，定性和定量表征不同HHAIB处理对葡萄果皮超微结构和果胶等的交联状态及干燥中水分存在状态和迁移分布的影响，揭示促干机理；采用HPLC技术检测葡萄在HHAIB漂烫后PaO和OCB两条降解路径中叶绿素最终衍生物的含量，明确叶绿素降解流向，阐明两条路径之间的关系，揭示其护色机理。其次，通过解析不同漂烫因素对叶绿素和葡萄细胞壁大分子多糖降解的影响规律，筛选出影响其降解的关键因素，阐明优化调控的相关机制；构建关键影响因素下葡萄叶绿素降解动力学模型和细胞壁中大分子多糖降解与葡萄干燥中宏观品质特性形成和演化的相关关系模型，为不同漂烫条件下葡萄干燥品质的预测、分析和优化提供技术依据。项目的实施将为HHAIB技术的应用和优化提供科学依据和技术支持，对提高葡萄干燥效率和品质具有重要意义。

针对葡萄HHAIB漂烫促干和护色所涉及的关键科学问题，项目主要开展了以下研究工作：首先为了保证原料的一致性，研究了葡萄原料成熟度对其理化特性及干燥动力学影响，解析了葡萄成熟度的异质性对后续加工的影响规律；通过研究葡萄细胞壁中纤维素、半纤维素和果胶物质等大分子多糖的含量和交联状态的变化及其对干燥过程中水分含量、存在状态、空间分布等的影响，揭示了葡萄HHAIB促干的机理。结果表明，漂烫使果胶大分子显著解聚，链长变短，导致细胞壁结构变化，果实软化；随着漂烫时间的增加，部分结合水变成自由水、水分由葡萄内部向表皮部位迁移。此外，通过揭示不同HHAIB处理条件下葡萄漂烫过程中纤维素、半纤维素和果胶物质等大分子多糖的变化与葡萄干燥动力学和宏观品质特性（质构、复水特性、抗氧化特性等）形成和演化的相关关系，为优化调控漂烫过程提供依据。叶绿素是葡萄呈现黄绿色泽的物质基础，项目通过研究葡萄高温高湿气体射流冲击漂烫处理过程中叶绿素的降解流向和影响因素，揭示了HHAIB漂烫护色的机理。此外，通过研究叶绿素在漂烫过程中的降解规律和动力学模型，解析了减少叶绿素降解的关键控制点和最佳调控策略。项目还研究了HHAIB漂烫过程中热质传递规律，为优化漂烫设备的设计提供了启示。.在Critical Reviews in Food Science and Nutrition、Carbohydrate Polymers、Food Chemistry等食品科学领域权威杂志发表SCI论文10篇；获得国家授权发明专利1项、申请发明专利3项、获得实用新型专利2项、软件著作权1项；获得陕西省科学技术一等奖1项，河南省科学技术二等奖1项，中国商业联合会特等奖1项，国际干燥学会颁发的干燥研究杰出贡献奖等。项目研究成果为葡萄高温高湿气体射流冲击漂烫技术的应用和优化提供科学依据和技术支持，对于探索葡萄和其他果蔬新的干燥预处理加工方法、提高产品品质具有重要意义。