[Problem] To provide a composition containing arginine and protein which enables the addition of more arginine while suppressing astringency and charring resulting from heating, especially in beverages. [Solution] A liquid nutritional composition that contains arginine and a non-micelle forming protein such as sodium caseinate or potassium caseinate. The composition has a pH of 6.0-7.3 and is heat-treated. By adding an insoluble calcium compound such as calcium phosphate, charring is suppressed, and an excellent flavor is achieved.