All it depends on your interest, as the name suggest food quality assurance has very limited application, just quality assurance, that too in foods/flavors/dairies that will be the extend of your job opportunities.



The other degree food science and technology has much wider scope, it opens the door to production floor, where pure science grads will not cut it. And being a food science and technology grad you always have a chance to go to assurance side.



After completing Msc in food technology and quality assurance you can become a food technologist.



As a food technologist, you need to:

Provide correct information for labeling of food

Research ways to improve the freshness of food

Find quick and cheap ways of producing food

Test the quality of food

Understand and ensure the safety of food



You can even go for specializations in the below mentioned fields:



Cereals

Dairy

Sugar

Alcohol

Bakery and confectionary items

Fruits and vegetables

Meat/fish

Oil and oil seed processing



You can earn upto 20-30 K initially depending upon your skills and experience if any.



Hope this helps.

Good luck!