Amaranth is a plant naturally resistant to various types of stresses that produces seeds of excellent nutritional quality, so amaranth is a promising system for food production. Amaranth wild relatives have survived climate changes and grow under harsh conditions, however no studies about morphological and molecular characteristics of their seeds are known. Therefore, we carried out a detailed morphological and molecular characterization of wild species A. powellii and A. hybridus, and compared them with the cultivated amaranth species A. hypochondriacus (waxy and non-waxy seeds) and A. cruentus. Seed proteins were fractionated according to their polarity properties and were analysed in one-dimensional gel electrophoresis (1-DE) followed by nano-liquid chromatography coupled to tandem mass spectrometry (nLC-MS/MS). A total of 34 differentially accumulated protein bands were detected and 105 proteins were successfully identified. Late embryogenesis abundant proteins were detected as species-specific. Oleosins and oil bodies associated proteins were observed preferentially in A. cruentus. Different isoforms of the granule-bound starch synthase I, and several paralogs of 7S and 11S globulins were also identified. The in silico structural analysis from different isoforms of 11S globulins was carried out, including new types of 11S globulin not reported so far. The results provide novel information about 11S globulins and proteins related in seed protection, which could play important roles in the nutritional value and adaptive tolerance to stress in amaranth species.

Amaranth is a promising staple food that produces seeds with excellent nutritional quality. Although cultivated species intended for grain production have interesting agronomic traits, relatively little is known about wild species, which can prosper in diverse environments and could be a rich genetic source for crop improvement. This work focuses on the proteomic comparison between the seeds of wild and cultivated amaranth species using polarity-based protein extraction and two-dimensional gel electrophoresis. Differentially accumulated proteins (DAPs) showed changes in granule-bound starch synthases and a wide range of 11S globulin isoforms. The electrophoretic profile of these proteins suggests that they may contain significant phosphorylation as post-translational modifications (PTMs), which were confirmed via immunodetection. These PTMs may impact the physicochemical functionality of storage proteins, with potential implications for seed agronomic traits and food system applications. Low-abundant DAPs with highly variable accumulation patterns are also discussed; these were involved in diverse molecular processes, such as genic regulation, lipid storage, and stress response.

Background: Overweight and obesity are chronic diseases that result from complex interactions including genetics, environment, eating behaviors, and limited access to a healthy diet. Amaranth protein (AmProt) has several health benefits, but no studies have examined its effects on the modulation of children’s gut microbiota. The work aimed to analyze serum levels and changes in gut microbiota in children aged 8–10 years with different body mass index (BMI) values after supplementation with AmProt. Methods: Participating children were allocated into three groups according to their BMI: normal weight (NW), overweight (OW), and with obesity (OB). Children received AmProt for 90 days. Levels of fasting blood glucose, cholesterol, triglycerides, and insulin were analyzed before and after diet supplementation. HOMA-IR and adinopectin/leptin ratio were evaluated. Feces were collected and metagenome analysis was carried out. Results: No changes in glucose levels were observed across groups and treatments; however, cholesterol and triglycerides levels tended to decrease. The HOMA-IR value increased in relation to BMI and no changes were observed after treatment. Firmicutes were highly abundant in all groups. The lower abundance of Ruminococcus was observed in the OW and OB groups. In the OW group, Blautia, Butyricicoccus, and Roseburia were also observed in increased abundance. In all groups, AmProt consumption tended to increase the abundance of Coproccus, Prevotella, and Collinsella. Conclusions: Supplementation of the children’s diet with AmProt showed an improvement in serum cholesterol and triglyceride levels, which could be related to changes in the microbiota related to lipid metabolism.