The oral processing of food is important for eating and digestion in order to gain energy and nutrients. Due to disease, accident, or aging individuals may experience difficulties in this process. These difficulties often lead to dysphagia which is strongly associated with malnutrition.  Thus, it is of importance to find solutions and strategies that can facilitate intake of food. 

It is well known that sour and/or carbonated foods and drinks increase saliva secretion and trigger the swallowing reflex. However, knowledge of how subsequent food intake is impacted is low. The aim of this study is to clarify whether sour and/or carbonated foods and drinks have a subsequent impact on swallowing function. 

Twelve healthy participants evaluated eleven different foods and drinks due to their ability to increase saliva production and make swallowing of a subsequent food easier. 

As expected, results showed that sourness and carbonation had a positive impact on saliva secretion and swallowing. No correlation was found between pH / sourness and ease of swallowing these foods. It could be concluded that some sour foods, in this study exemplified by cherry tomatoes, natural yoghurt, and in particular citrus juice made it easier to swallow a neutral cracker after ingestion of these sour products. The results may be used to increase food intake among dysphagia patients.