If you look at a pepper, they are actually
quite shiny and reflective. The highlight in your old pepper shows that quite well. First thing you can do is to make the shape a big more interesting and maybe up the contrast if you want. While it isn't technically inaccurate, straight lines along with desaturated colors can really dull out a small piece. I know for some people using something like pure white or near pure white can be intimidating because it stands out significantly, but toying around with the hues leading up to the highlight can make it look proper.
Don't have too much time to do much of a pepper myself since it is almost 3 in the morning, but this is a bit of what I mean. A lot of contrast, reflected light and a more blobular(probably not a word) shape. I also exaggerated the contrast on the stem greatly since it was so small and it would be difficult to make out the details without some more extreme contrast or hue shifting.