Perhaps you've seen this scene from Sex and the City before? It brings up what many are wondering, "what affects the taste of semen?" Unfortunately, the research does not seem to exist on the topic, but there are a good number of subjective ideas floating around.
These are the most agreed upon thoughts:
The better one takes care of his body, the better the taste will be. For example, a diet rich in fruits and vegetables with limited red meats will (likely) produce a better tasting ejaculate. On the other side, things like caffeine, cigarettes, strong tasting foods (onions/garlic), and alcohol could play a role in making one's semen taste unpleasant.
So, to summarize, having a healthy, nutrient rich diet isn't just good for the heart, but for the whole body (plus a potential partner's taste buds).