Snacking Interventions Differentially Influence Saliva, Salivary Alpha Amylase Activity, and Sensation

Pacheco, Kathryn Nichole. M.S. Purdue University, December 2022. Snacking Interventions Differentially Influence Saliva, Salivary Alpha Amylase Activity, and Sensation. Major Professor Dr. Cordelia A. Running.

Human saliva contains the enzyme alpha amylase, which greatly influences many facets of human health such as digestion, absorption of nutrients, and the sensory perception of certain foods. However, the complex relationships between chewing behavior, food texture preference, and salivary amylase require further investigation. In this study, we aim to observe salivary alpha amylase through a simple assay using pudding, and to examine whether salivary amylase activity relates to diet, the sensory properties of starchy foods, or mouth behavior. We hypothesized that the pudding/salivary amylase activity assay would show more activity (less pudding remaining) 1) at the end of the high dietary starch intervention week, with little or no change from baseline to the end of the low dietary starch intervention week and 2) for people with greater baseline starch consumption compared to less baseline starch consumption. A counter-balanced, crossover design was implemented for the study. 34 participants (11 Men, 23 Women, 0 Other) completed study tasks, consisting of a 3-day dietary recall, 2 separate weeks of dietary intervention consisting of high starch or low starch snacks, and 4 research visits. These research visits included participant taste and smell acuity assessments, sensory ratings of the study foods, a mouth behavior typing test, and our salivary amylase activity assay that determined flow rate of a mixture of participant saliva and starch-containing ready-to-eat pudding. After our higher and lower starch snack interventions, we saw minimal evidence of changes to salivary amylase activity in our assay; the only trend we observed was opposite our expectation (less amylase activity after the low starch intervention). However, we did observe mouth behavior grouping tended to associate with sensory ratings that validate the premise of the mouth behavior typing tool we utilized. Ultimately, more work on the consistency and usefulness of the salivary amylase activity assay will need to be conducted if it is to be utilized for research purposes, but our data do help validate the concept that different people prefer foods due to their preferred methods of orally manipulating foods. r.