An influential Israeli rabbi has ruled that a key ingredient in hummus was not kosher when prepared by non-Jews, presenting a religious challenge to followers who regularly savor the Mediterranean dish. The ruling regarding tahini sesame seed paste sent Israeli hummus companies scrambling to check their production processes. Some feared that the ruling would affect sales of the chick pea spread that many Israelis consider the national food. But others wondered if many Israelis would be able to actually forego eating hummus, religious edict or not, and some attributed the ruling to a turf war between rabbis. A leading hummus company said it did not expect the ruling to affect sales and said the decision came as a result of a debate between ultra-Orthodox Jews. Ex chief rabbi Mordechai Eliahu ruled that when sesame seeds used to make the tahini paste for hummus are roasted and shelled by non-Jews, the resulting hummus is not kosher, his aide was quoted by the "Associated Press".