While cooking potatoes, I took potatoes which looked normal from outside, but when I cut open a raw potato it showed purple veins from inside. My mother-in-law told me to throw as it was poisonous. I wondered what it could be due to?
I scrapped a few cells on a slide to observe the difference and even tried some free-hand sections to understand the difference. No bacterial or fungal contamination was noticed and the scraped starch grains too looked perfectly normal except for a little pigmentation. I was convinced that it was a normal phenomenon.
I explored the literature on internet to find an answer and could find that the potato developed this pattern probably is a natural thing or due to cross-pollination. Purple colour is due to anthocyanin pigments and is considered healthy as these varieties of potatoes contain more antioxidants that protect the cells from oxidative damage and reduce the risk of certain types of cancer.