Characterization of the Technofunctional Properties and Three-Dimensional Structure Prediction of 11S Globulins from Amaranth (Amaranthus hypochondriacus L.) Seeds.

Amaranth 11S globulins (Ah11Sn) are an excellent source of essential amino acids; however, there have been no investigations on the characterization of their techno-functional properties at different pH conditions and NaCl concentrations, which are necessary for food formulations. In this work, we report a new two-step purification method for native Ah11Sn with purity levels of ~95%. LC-MS/MS analysis revealed the presence of three different Ah11Sn paralogs named Ah11SB, A11SC, and Ah11SHMW, and their structures were predicted with Alphafold2. We carried out an experimental evaluation of Ah11Sn surface hydrophobicity, solubility, emulsifying properties, and assembly capacity to provide an alternative application of these proteins in food formulations. Ah11Sn showed good surface hydrophobicity, solubility, and emulsifying properties at pH values of 2 and 3. However, the emulsions became unstable at 60 min. The assembly capacity of Ah11Sn evaluated by DLS analysis showed mainly the trimeric assembly (~150-170 kDa). This information is beneficial to exploit and utilize Ah11Sn rationally in food systems.

Proteomic analysis of differentially accumulated proteins during ripening and in response to 1-MCP in papaya fruit.

Papaya (Carica papaya L.) is a climacteric fruit susceptible to postharvest losses due to the ethylene-induced ripening. The inhibitor of ethylene action, 1-methylcyclopropene (1-MCP), has been used worldwide as a safe postharvest non-toxic agent, but the physiological and biochemical modifications induced by 1-MCP are not well understood. Using the 2-DE analysis, we report the changes in the protein profiles after 6 and 18 days of postharvest and the effect of the effect of 1-MCP treatment on fruits. Twenty seven protein spots showing differences in abundance during ripening were successfully identified by nano-LC-ESI/MS/MS. Some spots corresponded to the cell wall degrading enzymes related to fruit ripening; others were involved in oxidative damage protection, protein folding, and cell growth and survival that were induced by 1-MCP. This is the first proteomic report analyzing the effect of 1-MCP in papaya ripening. The present data will help to shed light on papaya fruit ripening process.