Amaranthus spp. is a highly nutritive pseudocereal, rich in macronutrients and micronutrients, including vitamins and minerals. Amaranth grain is rich in essential amino acids, particularly lysine, with high nutritional quality. In addition, recent research studies demonstrate that Amaranthus spp. essential nutrients, such as phytochemicals, have potential beneficial health effects. This review focuses on the amaranth grain's nutritional composition and antioxidant capacity. Also, limitations on its intake and strategies to improve its digestibility, bioaccessibility and bioavailability are summarized in this review. Finally, the most recent literature studies reporting food applications of amaranth (e.g., as encapsulating material) are discussed in order to deepen the understanding of potential health benefits and functionalities of this nutritious grain.

This research work investigates the development of alginate-based films incorporating phenolic compounds extracted from Amaranthus cruentus grain using different solvents. Alginate, glycerol, and amaranth grain phenolic compounds at various concentrations were used to produce the films. An experimental Central Composite Rotatable Design (CCRD) was used to evaluate the effect of these variables on different film’s properties, i.e., water vapor permeability, hydrophobicity, moisture content, solubility, thermal, mechanical, and optical properties. This study demonstrated that high phenolic compound content and antioxidant capacity were obtained from amaranth grain using ethanol as the extraction solvent. Alginate films incorporating amaranth phenolic compounds were successfully manufactured, and this study can be used to tailor the formulation of alginate films containing amaranth phenolic compounds, depending on their final food application. For example, less flexible but more resistant and water-soluble films can be produced by increasing the alginate concentration, which was confirmed by a Principal Component Analysis (PCA) and Partial Least Squares (PLS) analysis. This study showed that active alginate films with amaranth phenolic compounds can be tailored to be used as food packaging material with potential antioxidant activity.