Impact of pectin or xanthan addition to mashed potatoes gelled with κ-carrageenan on texture and rheology, oral processing behavior, bolus properties and in mouth starch digestibility

Oral processing behavior affects starch bioavailability, but the impact of the oral phase on starch digestibility in potato dishes enriched with polysaccharides has not been clearly established. Therefore, pectin (1 %) or xanthan (1 %) were added to mushed potatoes (MP), which was gelled with kappa-carrageenan (0.6 %), to produce the samples named MP-CarP MP-CarX, and MP-Car, respectively. Rheological, textural, sensory and electromyographic tests were conducted on the samples, along with bolus analysis. Both pectin and xanthan softened MP by 23 and 30 %, respectively, and reduced gel strength. The MP-CarP and MP-CarX were orally processed for shorter chewing times; however, their boluses exhibited a 20 % increase in cohesiveness. Chewing the MP-CarP highly enhanced salivation, resulting in a 45 % increase in bolus fragmentation, while the MP-CarX had the highest cohesiveness and lowest fragmentation. The variations in oral processing of MP with pectin or xanthan resulted in differing levels of starch hydrolysis and glucose release in the mouth. Chewing the MP-CarX resulted in lower levels of these processes, highlighting the importance of considering the oral phase of digestion when studying the hypoglycemic effects of polysaccharides. This is essential for developing new and effective approaches to improving glycemic control by incorporating fibers into commonly consumed starchy foods.