魔芋葡甘聚糖胶体特性精细调控及其与饱腹感的数学相关性

Hunger is a most common challenge for individuals undergoing weight loss, which tremendously affect the final effect. So the prior treatment for weight management is to use dietary fiber as food additives. However, the systematic correlationship between gel-like properties of dietary fiber and satiety was far from building up. Currently available knowledge just focuses on the qualitative relationship between dietary fiber properties and satiety including viscosity, solubility and gel property, which were proved to be discrete. In this study, duo to the highly controlled colloidal properties of konjac glucomannan (KGM), it can be designed as a characteristic sol forming agent with different particle size, hydration rate, viscosity, degree of sol/gel and instant/controlled release behavior in stomach, synergetic/steady/subdued properties in viscosity. Additionally, the thermal reversible/irreversible KGM-gels or broken KGM-gels with different strength were acquired. Such specific types of samples with different properties were under detailed analysis about its rheological behavior and gel-like properties to build up a correlationship to satiety ratings (VAS、AUC、MAR、SQ) and evaluate the effect on satiety-related hormones(CCK、PYY、GLP-1、leptin) after long-term feeding of the test animals. Finally, the present study aimed to establish a systematic mathematical correlationship between colloidal physical parameter and satiety and achieve a regulating rule about the gel-like property of KGM in the simulated stomach conditions, which will add new systemic knowledge into the colloidal physics-nutrition effect theory and provide theoretical and digitising references for making satiating foods.

饥饿是体重控制中经常面临地挑战，并极大影响到最终效果，提供强饱感膳食纤维配料已被认为是优选方案，但迄今膳食纤维胶体特性与饱腹感的系统相关性仍远未建立，仅停留在粘度、是否可溶(凝胶)等零星且离散的定性判断。本课题利用魔芋葡甘聚糖这一胶体特性可在大范围内调节的特色配料，设计不同粒度、水化速度、粘度、溶胶/凝胶度、胃液中速溶/缓溶、粘度协效增强/持平/减弱组可溶胶样品，以及系列强度不同的热不可逆/热可逆魔芋凝胶及其破碎体，进行模拟胃环境下流变特性和凝胶特性的详细分析，并建起与饱腹感指标（VAS、AUC、MAR、SQ）的关联，评估对实验动物长期摄入后饱腹感相关激素（脑肠肽、CCK、PYY、GLP-1、瘦素）的影响。从而系统建立胶体物理参数与饱腹感的数学相关性，获得模拟胃环境下魔芋葡甘聚糖胶体特性的调控规律，为胶体物理-营养效应理论填补一个系统化认识，为制造强饱腹感膳食纤维配料提供理论和数据参考。

本研究以不同物性的KGM为切入点，通过体外模拟消化实验并结合人群试验和动物实验，系统探讨了KGM物性对食欲的影响及其背后可能存在的调控机制，构建物性与其营养效应的数学相关性，为饱腹感食品的设计和开发提供更明确的理论参考。主要研究结果如下：.以高仿真动态人胃消化系统DHS-IV检测了食糜黏度对其胃排空特性的影响，探讨了食糜黏度对受试者食欲响应及第二餐食物摄入量的影响。研究结果表明，测试餐的高黏度显著延长了食糜的胃内滞留时间；受试者的主观饱腹感随之得以强化，其饥饿感、进食欲望和期望进食量也大幅下降。对其食欲生物标记物的监测结果显示，膳食黏度地提升有助于稳定餐后血糖和胰岛素地波动，促进CCK-8、GLP-1、PYY3-36地分泌并降低血浆饥饿素水平，从而减少其后续随意午餐的食物摄入量。.持水力、膨胀力和黏度作为KGM物性的重要内容，两两之间存在很强的正相关性，随着KGM水合特性地增强，消化道内食糜的质量及含水量也随之增加，提高了胃部张力，促进了饱腹感地产生。水化后的KGM提升了食糜体系的黏度，由此强化了营养素与小肠远端组织地接触，促进了饱感激素CCK-8、GLP-1和PYY3-36地分泌。.饱感行为学研究结果表明，由于水化速率地限制，相比于刺激胃部以触发动物的饱腹感，Pd-KGM在小肠消化过程中水化充分后，可更大程度地提升大鼠的饱感。因此，日粮中的Pd-KGM更有可能通过强化大鼠的饱感而非饱腹感以降低其全天的食物摄入量，并最终抑制其体重地过快增长。