You need to catch them in the right phase. Unripe are sour and hard and overripe are just nasty, they have sharp chemical taste, almost like acetone smells. The right ones are very aromatic with well balanced sweet and sour taste. The white part in the middle is typically sweet and green is sourer and aromatic. If it's deep green that usually means it's overripe and can be too sweet or even fermenting with that chemical taste to it. I can't describe aroma as nothing else but if you can smell it, that's approximately how it tastes. Seeds are crunchy and can tingle on the tongue if you bite through them.
