"Consuming pineapple or parsley helps sweeten the taste of the male sperm ejaculate. Can there be any truth to this and what other foods affect the taste, for better or for worse?"
Yes, what you eat can influence the taste and smell of your semen – sperm. This is similar to the smell of your sweat on the next day of a heavy spice and garlic full dinner.
Because the average ejaculate consists mostly of protein, citric acid, fructose, sodium, chloride and smaller amounts of ammonia, ascorbic acid, acid phosphates, calcium, carbon dioxide, cholesterol, prostaglandins, creatine, and other minerals and chemicals which are produced by the prostate gland, Cowpers gland, testicles and many other parts of your body, but shortly by "your body", and your body can only use its stocks and what you eat as the raw material.
Of course, every body has its own formula for semen – sperm creation, but eating less meat (and proteins) and more carbohydrates, vegetables and fresh fruits may improve the taste and smell. For example parsley is a healthy plant and may help making your body juices sweeter.
In general, dairy products create the foulest tasting fluids, alkaline based foods as meat and fish produce a butter, fish like taste. Fruits and high quality alcoholic drinks are good for a pleasant, sugary flavor. Chemically processed liquors may cause an acidic taste.
The semen – sperm ejaculate of each male has a unique taste. When some men have bitter, burnt, sour and strong tasting ejaculates, some others, particularly vegetarians, may have sweet, nut like tasting semen – sperm. But in order to produce healthy and fertile sperm your body will need protein rich in zinc as well.
Strong and significant semen – sperm smell may also indicate an infection in the genital area and men must consult an urologist without losing time.
In the other hand, women also have to improve the salty and acidic taste of their vaginal secretions, but the strong and foul smell may be caused by the lack of cleanness, better is to visit a gynecologist periodically and keep the consultation records.
Certainly your body's duty is not producing tasty semen – sperm, but healthy and fertile ejaculates. Everything healthy and good for your body is also healthy and good for your semen – sperm. Drink mild water when you wake up and keep drinking more water than you usually drink during the day! Water will help to clean your body's pipeline including your bowels, and drinking 6 – 8 glasses of water daily will help your body to detoxicate. Eat less meat, more vegetables, drink less alcohol and specially stop smoking!
If your partner really loves you, she/he must love everything about you and your body. Don't spend your precious time to be busy with small details, learn how to be a great lover that your partner is not interested with your semen – sperm taste or smell instead.
Finally, we believe that if two people are in love with each other they won't be too disturbed even the semen – sperm taste is unsupportable, and will find a way to cover this default with condom, flavored lubricant, mouthwash… But the important question is how to produce healthy and good quality sperm, and avoid the transmission of many diseases and addictions to future generations!