Abstract: Disclosed are agents for phase-adjusting or enhancing the amplitude of an endogenous melatonin secretion rhythm and for improving a circadian rhythm, as well as functional food containing such an agent, which may prevent or ameliorate various symptoms, such as sleep disorder or prolonged sleep latency. The agent contains whey as the active component.

Abstract: The invention provides agents for phase-adjusting or enhancing the amplitude of an endogenous melatonin secretion rhythm and for improving a circadian rhythm, which may be taken daily and continuously, have excellent safety, and may effectively prevent or ameliorate disorders of an endogenous melatonin secretion rhythm or of a circadian rhythm without administration of exogenous melatonin, as well as functional food containing such an agent, which may prevent or ameliorate various symptoms, such as sleep disorder or prolonged sleep latency. The agent for phase-adjusting or enhancing the amplitude of an endogenous melatonin secretion rhythm according to the invention contains whey as the active component. The functional food for improving an endogenous melatonin secretion rhythm according to the invention contains the agent for phase-adjusting or enhancing the amplitude of an endogenous melatonin secretion rhythm.

Abstract: The invention provides agents for phase-adjusting or enhancing the amplitude of an endogenous melatonin secretion rhythm and for improving a circadian rhythm, which may be taken daily and continuously, have excellent safety, and may effectively prevent or ameliorate disorders of an endogenous melatonin secretion rhythm or of a circadian rhythm without administration of exogenous melatonin, as well as functional food containing such an agent, which may prevent or ameliorate various symptoms, such as sleep disorder or prolonged sleep latency. The agent for phase-adjusting or enhancing the amplitude of an endogenous melatonin secretion rhythm according to the invention contains whey as the active component. The functional food for improving an endogenous melatonin secretion rhythm according to the invention contains the agent for phase-adjusting or enhancing the amplitude of an endogenous melatonin secretion rhythm.

Abstract: A process for efficiently, easily and stably producing tripeptides Val-Pro-Pro and Ile-Pro-Pro, which are useful as hypotensive drugs, anti-stress drugs, etc., by an enzymatic method. This process involves the step of cleaving a milk casein-containing material with a proteinase to form an intermediate peptide selected from the group consisting of a peptide containing the sequence Val-Pro-Pro but having no Pro other than this sequence, a peptide containing the sequence Ile-Pro-Pro but having no Pro other than this sequence, and a mixture of these peptides, and then cleaving the intermediate peptide with a peptidase to thereby give at least one of the tripeptides Val-Pro-Pro and Ile-Pro-Pro.