Mapping the Occurrence and Characteristics of Type 1 Resistant Starch

Resistant starch (RS) encompasses starch that escapes digestion in the upper gastrointestinal tract and is therefore delivered to the colon. RS may have health beneficial effects associated with its low-glycaemic properties and its utilisation by the colonic microbiota. Type 1 RS (‘RS1’) is one of the less widely studied forms of RS and exists within a range of plant-based foods. However, current analytical methodologies for quantifying RS in food are inadequate, particularly for RS1. There is also a limited understanding of where, how and to what extent RS is broken down during digestive transit in vivo, which makes it challenging to interpret and predict the metabolic and physiological consequences of RS consumption. Moreover, the occurrence of RS in food has never been systematically documented.
This research aims to a) provide new understanding of the critical plant material characteristics that are responsible for RS1 occurrence in food, and b) understand its digestion which has consequences for metabolism and gut health.
The objectives are to:
i) Develop new methodologies to quantify the occurrence of RS1 in plant foods.
ii) Identify critical characteristics that are responsible for the presence of RS1 in cooked plant materials.
iii) Examine susceptibility of RS1 to physical/biochemical breakdown during digestive passage.
iv) Evaluate implications of findings from obj. i - iii for using RS1 in the design of functional food products with nutritional benefits and identify future research needs.
Approach: Microscopy techniques and in vitro starch digestibility methods will be purposefully developed and used to screen for RS1 in cooked pulses, potatoes, pseudo-cereals etc., which have contrasting plant material characteristics. Subjecting plant materials to simulated digestive conditions, e.g. based on INFOGEST protocol, will provide insight into the digestive fate of RS1 and potential nutritional implications.