Hi rabbi how are you
The corn is kazayis but the part i ate is not what should i do say bore nefashot or i shouldnh
I am fine. Thank you for asking, and I hope things are also good by you.
Regarding your question since you didn’t eat a kazayis, (and you didn’t eat any other food that would be combined to the corn that you ate to make a kazayis), you will not say borei nefashos. For the future, it is preferable to be careful to eat a full kazayis when eating corn. The reason is because there are opinions among the Rishonim who say that when a person eats a “beriah”- a whole fruit or vegetable, since it is a whole being, it is considered prominent, and requires a borei nefashos. The poskim say that this even applies to a whole segment of an orange, even one whole sunflower seed, grape, pomegranate seed or kernel of corn. Although they are not the whole orange of cob of corn, still, each seed is considered a unit for itself and it is considered like numerous whole items attached together. Now, although there are those who are of this opinion, nevertheless it is controversial, and therefore even if one ate a “beriah” the bracha achrona would not be said. Therefore, the Shulchan Aruch advices to try and avoid this issue, and either break the beriah before eating it, i.e biting into half of it, and then eating the other half, so it isn’t considered to be eaten whole. Or, to make sure to eat a full kazayis and then say a bracha achrona.
Shulchan Aruch O:CH 210-1, M:B 210-6,8, Ohr L’tzion 14-ftnt 28, Kaf Hachayim 210-20, M’bais Levi 15 pg. 70.