Amino acid and fatty acid composition of two sweet tomatillo species (Physalis gracilis and Physalis grisea)

Sweet tomatillos Physalis gracilis (costomate, costomatillo) and Physalis grisea (ground cherry) are underutilized species with potential nutritional value. This study evaluated the physicochemical properties, amino acid composition, and fatty acid profiles of ripe fruits from both species. Ripe fruits were harvested from open-field cultivation at the University Center for Biological and Agricultural Sciences (CUCBA), University of Guadalajara, in Zapopan, Jalisco, Mexico. Fruits were transported to the laboratory for physicochemical evaluation, then were frozen and freeze-dried. The resulting material was used for amino acid composition and fatty acid profile determination using standardized analytical methods. Fruits from both species showed total soluble solids content above 10º Brix, indicating high sugar levels typical of sweet fruits. Glutamine was the predominant amino acid in both species, in P. gracilis (4.17 g/100g DW) and P. grisea (4.10 g/100g DW), followed by glutamic acid (2.33 and 2.71 g/100 g DW, respectively). Essential amino acids such as leucine, valine, and lysine were present in both species, contributing to their nutritional value. Unsaturated fatty acids predominated in the lipid profile of both species. Linoleic acid, an essential fatty acid, was the major fatty acid, reaching 5.09% DW in P. grisea and 1.26% DW in P. gracilis. Polyunsaturated fatty acids accounted for 6.50% and 1.33% DW, respectively. The presence of essential amino acids and unsaturated fatty acids highlights the nutritional value of sweet tomatillos, provides novel compositional information for two understudied Physalis species.