Yeomans Martin R, Gould Natalie J, Mobini Sirous, Prescott John
Department of Psychology, University of Sussex, Brighton, BN1 9QH, UK.
Physiol Behav. 2008 Mar 18;93(4-5):958-66. doi: 10.1016/j.physbeh.2007.12.009. Epub 2007 Dec 23.
Monosodium glutamate (MSG) is known to enhance liking for the flavor of savory foods, but whether associations between flavors and effects of MSG lead to changes in subsequent liking and intake for the flavor alone is unclear. To test this, 32 volunteers evaluated and consumed a novel savory soup with no added MSG before and after four training sessions where the same soup was consumed either unchanged (Control) or with added MSG. The addition of MSG during training increased both pleasantness and savory character of the soup and resulted in a larger increase in rated pleasantness of the soup in the MSG-trained relative to control condition when the soup was re-evaluated Post-training without MSG. There was also a significant increase in voluntary soup intake Post-training after the soup had been paired with MSG but not in the Control condition, and rated hunger increased more after tasting the soup Post-training in the MSG-trained but not Control condition. These findings demonstrate that co-experience of a savory flavor and MSG can result in increased subsequent liking and intake for the flavor in the absence of MSG, and possible explanations for how MSG reinforces learning are discussed.
味精（MSG）已知能增强对咸味食物风味的喜爱，但风味与味精效果之间的关联是否会导致随后仅对该风味的喜爱和摄入量发生变化尚不清楚。为了对此进行测试，32名志愿者在四个训练阶段前后对一种未添加味精的新型咸味汤进行了评估和饮用，在训练阶段，同样的汤要么保持不变（对照组），要么添加味精。训练期间添加味精增加了汤的愉悦感和咸味特征，并且当训练后重新评估未添加味精的汤时，与对照组相比，接受味精训练的组对汤的愉悦感评分增加幅度更大。在汤与味精配对训练后，自愿汤摄入量也显著增加，但对照组没有，并且在接受味精训练的组中，训练后品尝汤后饥饿感评分增加更多，而对照组没有。这些发现表明，咸味风味与味精的共同体验会导致随后在没有味精的情况下对该风味的喜爱和摄入量增加，并讨论了味精强化学习的可能解释。
