In which foods can i find l-glutamine, if i am vegetarian? i want muscle gain.

See a dietician: Beans, milk, yogurt, ricotta cheese and cottage cheese raw spinach, cabbage and parsley provide glutamine. If there is a specific reason to gain muscle mass then it would be wise to see a registered dietician to make sure you have a balanced diet. You may want to discuss with your physician also.

You flunked the quiz: Glutamine isn't an essential AA. You make all the glutamine you need from glutamate, which is made from alanine or aspartic acid. If you consume exogenous glutamine, you just synthesize less. Excess glutamine, like all excess AAs, is burned as fuel & excreted as waste. You want muscle gain? Work out. Let your body worry about the glutamine. It's much smarter than you about this.