Gut metabolites from in vitro colonic fermentation of the Guava (Psidium guajava L.) fruit indigestible fraction

Póster presentado a la 6th International Conference on Food Digestion (ICFD), celebrada en Granada (España) del 2 al 4 de abril de 2019.

[Introduction+: Guava is a tropical fruit considered as an important source of indigestible fraction (IF), and phenolic compounds (PC). The peel and pulp of guava fruit are an excellent source of vitamins (A, C, thiamine, niacin, and riboflavin), minerals too. Most PC identified in the guava pulp has also been detected in guava leaves; such compounds include hydrolyzable tannins, guavin A, guavin B and quercetin.

[Objective]: The aim of this study was to identify and quantify the carbohydrates and PC present in complete guava (CG) and seedless guava (SG), besides; identify the gut metabolites produced during in vitro colonic fermentation.

[Methodology]: The carbohydrates composition in CG and SG was developed by GC/MS. Samples were submitted in gastrointestinal digestion and the IF of CG and SG were isolated and submitted to an in vitro colonic fermentation to evaluate the short chain fatty acids (SCFA) production.

[Main findings]: The soluble IF of CG and SG, comprised mainly arabinose and galactose. The major PC in both CG and SG were procyanidin isomers and guajaverin. This may be because some compounds, such as gallocatechins, are stable in gastric conditions and degraded in intestinal conditions. The colonic fermentation extracts showed significant (p<0.05) production of SCFA, during the first 12 h. Butyric acid is the SCFA that is produced mostly by the fermentation of CG and SG, and it was present at all the fermentation times analyzed. Butyric acid is the preferred substrate by colonocytes. CG and SG showed a higher fermentability index at 24 h; the value obtained from fermentability was 78.84% for the CG sample and 84.74% for the SG sample. These values were higher than those obtained in other studies where foods were analyzed as eaten.

[Conclusion]: Consumption of CG or SG may contribute to the daily requirements of DF consumption and enhance colon health.

FJBB thanks the financial support from Consejo Nacional de Ciencia y Tecnología, México (CONACyT) for the scholarship 378371 granted.

Peer reviewed