乳清蛋白对以麦芽糊精为助剂桑葚汁喷雾干燥性能影响  

Effect of Whey Protein Isolate as Complementary Drying Aid of Maltodextrin on Spray Drying Behavior of Mulberry Juice

作　　者：石启龙[1] 王瑞颖 赵亚[1] 刘彦爱 

机构地区：[1]山东理工大学农业工程与食品科学学院,淄博255000

出　　处：《农业机械学报》2017年第9期337-343,311,共8页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家自然科学基金项目(31171708)

摘　　要：桑葚富含多酚类物质,具有一定的营养与保健功能。多酚类物质在加工及贮藏过程中非常不稳定,喷雾干燥法微胶囊包埋是保护生物活性成分常采用的方法。但是,果汁喷雾干燥过程中极易出现黏壁现象,导致粉末回收率较低。基于此,研究不同比例乳清分离蛋白(WPI)与麦芽糊精(MD)对喷雾干燥桑葚粉理化特性的影响。结果表明,进料液中以少量WPI取代MD能显著提高桑葚粉的回收率,WPI较高的表面活性与良好的成膜性是使桑葚粉回收率提高的主要原因。随着进料溶液中WPI质量分数的增加,桑葚粉含水率增加;水分活度、堆积密度、粒径、水溶性指数和玻璃化转变温度呈降低趋势,而吸湿性则无明显变化。随着进料溶液中WPI质量分数的增加,桑葚粉L值、b值增加,a值降低,色差ΔE增加。桑葚粉的总酚含量与清除自由基能力随进料溶液中WPI质量分数的增加呈降低趋势。当进料溶液中桑葚汁/MD/WPI质量比为65∶(34.5~30.0)∶(0.5~5.0)时,既能有效解决黏壁问题,又能较好地抑制桑葚汁中多酚类成分降解,使桑葚粉具有较高的抗氧化能力。Mulberry is rich in polyphenols with characteristics of nutritional qualities and bioactive phytonutrients. However, the capacity and health benefit potential are limited due to their weak stability during processing and preservation. Spray drying encapsulation was well-established and widely utilized for protecting bioactive substances such as polyphenols. However, undesirable phenomena such as stickiness on the drier chamber wall arose during spray drying of sugar-rich solution such as fruit juice. Furthermore, powder recovery was decreased owing to stickiness issue during spray drying. Therefore, effect of different total solid ratios of whey protein isolate （WPI） and maltodextrin （MD） in the feed solution on physical and chemical properties of spray dried mulberry juice powders was investigated. The results showed that the powder recovery of spray dried mulberry juice powders was significantly increased when MD in the feed solution was replaced by small amount of WPI. The reason can be attributed to the high surface activity and excellent film-forming properties of WPI. The moisture content of spray dried mulberry juice powders was increased with the increase of WPI mass fraction in the feed solution. However, water activity, bulk density, particle size, water solubility index and glass transition temperature were decreased with the increase of WPI mass fraction in the feed solution. The hygroscopicity of mulberry juice powders was not significantly influenced by WPI/MD ratio in the feed solution. The color parameters of spray dried mulberry juice powders such as L, b and △E were increased with the increase of WPI mass fraction in the feed solution. Whereas, opposite behavior was observed for parameter a. The total phenol content and DPPH scavenging capacity of spray dried mulberry juice powders were decreased with the increase of WPI mass fraction in the feed solution.

关 键 词：桑葚汁 乳清分离蛋白 麦芽糊精 喷雾干燥 玻璃化转变温度 理化特性 

分 类 号：TS201.1[轻工技术与工程—食品科学] TS255.36[轻工技术与工程—食品科学与工程]