Cum tastes like cum, everyone's is different and that's how it's supposed to be. What you eat changes how semen or orgasmic juices taste just like it affects how sweat or tears taste. No matter what you eat your cum will not taste like a strawberry milkshake or Beef Wellington, it is cum, it tastes like cum. Making your orgasmic juices taste sweeter or saltier or more savory requires a significant change to your body chemistry, which would be a long-term major change to diet and activity.
The easiest way to improve the taste of your body if you are a man or a woman is simply not to consume toxins or noxious chemicals, reduce your smoking, alcohol consumption, reduce artificial foods and carcinogens.
Yeah, male semen has more protein than cooked eggs. However a quarter ounce of cooked eggs doesn't have a lot of protein. It's also rich in vitimin D and natural lipids, more so than most shampoos or skin lotions. But once again, nobody would ever treat their hair of skin with the small quantities that a normal man ejaculates. If you want protien eat a chicken breast, if you want good skin and hair wash with good soaps.
I've heard that vaginal doesn't contain any calories or carbohydrates so that kind of rules out proteins. I'm guessing any vitamins would also minimal. But I've only heard that word of mouth, no scientific data that I know of. Sorry.
Accepting that cum or vaginal fluid will never taste like a Boston creame pie, makes it taste better. It is what it is. Every person tastes different. I've never been with a man or woman that didn't taste like a man or a woman. Some taste better to me than others but you're not really giving oral sex because you love the flavor.