Jam lost its shine, how do I fix it.

So I made onion and wine jam but because I wanted it in gel format, I added some agar agar powder to set it. Once set, I blitzed it. But after blitzing it, it lost its glossy shine. Looked very matte.

I’ll try reducing the agar agar powder and also cover it in the fridge when I’m setting it.

Does Xantham gum help? Or should I add oil? Help.