Recently when i eat, food particles are somewhat getting into my nostrils from the back of my mouth ?

Yes = atypical GERD: Healthtap is full of answers regarding gerd's (gastroesophageal reflux) manifestations, causes, variations, approaches for treatment, & prevention. Ear, nose, and throat manifestations of LPR (laryngo-pharyngeal reflux) commonly include the throat, ears, airway, nasal passages, etc. Please type "gerd" in the search box, and i think you'll find all the responses you could want!

Hmm.: Are the food particles still alive and trying to find safe passage. You are not eating while hanging upside down, laughing coughing or singing. Neuromuscular dysfunction due to disease or poisoning can occur as well as in-coordination due to cranial nerve or brain-stem injury,MS, stroke, infection or mass (tumor) like craniopharyngioma. Time to see a neurologist. .At least have a swallowing test.

While many: Always bring up reflux, which is always possible as a source of food entering the nasopharynx. Realize there is also the possibility of velopharyngeal insufficiency. Usually this manifests with a very nasal voice due to the soft palate not completely sealing off the nasopharynx while you speak, but it can also manifest with food entering the nasopharynx when swallowing.