Structuring Pea-Protein Meat Analog Fortified With Resistant Starch: Retention of Resistant Starch and Impact on Gut Microbiota Diversity

IntroductionThe growth of the meat analogs (MAs) market is projected to increase from $4.6 billion in 2018 to $85 billion in 2030, reaching the milestone of $30.9 billion by the year 2026. One of the key challenges in the structuring and engineering of MAs is the difficulty in achieving a highly fibrous structure and organized fiber alignment that closely mimics the appearance and mouthfeel of animal meat. The incorporation of dietary fibers has gained increasing attention for their potential to promote anisotropic (fibrous) structure formation. This study aims to structure pea-protein MAs with green banana flour (GBF), a source of resistant starch, as a strategic approach to promote anisotropic structure formation during high moisture extrusion and to deliver dietary fiber to enhance gut microbiota diversity.MethodsPea protein MAs formulated with 5%, 10%, and 15% w/w GBF, as well as the control that is pea protein MA without GBF, were produced using a twin-screw co-rotating extruder. The processing conditions were screw speed of 200 rpm, five heating barrels’ temperatures set at 50-70-90-120-120℃, cooling die temperature set as 50℃, and moisture content of 65% on dry weight basis. Proximate composition, texture profiles, and protein solubilities by selective chemical solubilization were determined to probe the effects of GBF addition on the physicochemical properties of the MAs. In vitro upper gastrointestinal digestion followed by fecal fermentation of the MAs was conducted to investigate the impact of GBF addition on gas and acid production during fecal fermentation. 16S rRNA gene sequencing was done to evaluate the gut microbiota diversity.ResultsMAs with anisotropic structures were successfully structured via high moisture extrusion. The addition of GBF resulted in softer MAs in a dose-dependent manner. GBF is a source of microbiota-accessible-carbohydrate that could increase the production of short-chain fatty acids (e.g., propionate) and sustain a high-diversity gut microbiota revealed through 16S amplicon sequencing.SignificanceThis study elucidates the role of resistant starch in driving anisotropic structure formation and presents a novel strategy for delivering microbiota-accessible carbohydrates through the incorporation of GBF. This approach has the potential to sustain high gut microbiota diversity and improve gut health in human hosts.