Expanded popcorn grain is widely consumed as a healthy snack all around the world; however, the study of the behavior of its components by processes such as nixtamalization is scarce. Therefore, the aim of this work was to characterize the nanomechanical, structural, and antioxidant properties of nixtamalized popcorn grain pericarp. FT-IR results showed that the secondary structure of proteins of the nixtamalized pericarp was α-helix with 42.10%, the turn was 21.5% and 36.33% β-sheet, and proteins of the pericarp did not present the random coil structure. Pericarp showed antioxidant activity, as their values were 550.1 ± 2.9 and 44.2 ± 1.6 (TE)/mL for ABTS and DPPH, respectively; total phenols content was 0.21 ± 0.008 (TE)/mL; reducing power values were around 29 to 31%; hydroxyl radical scavenging ranged from 36 to 55% and iron chelation around 115 to 140% compared to the standard acids. Thickness values of the nixtamalized pericarp by SEM image analysis were 0.15 ± 0.1 mm near the pedicel inferior tip, 0.07 ± 0.01 mm at middle, and 0.03 ± 0.02 mm at upper of the grain. Young’s modulus value was 261.72 ± 23.58 MPa with a Gaussian function fitting at the distribution of all values. This research provides novel and valuable information for understanding the nanomechanical and protein arrangement, as well as and the antioxidant activity of nixtamalized popcorn grain pericarp in order to promote other processes and uses for this kind of pericarp maize.

Nejayote and pericarp derived from nixtamalization are an environmental problem. Therefore, there is research interest in using these residues as new compostable and environmentally friendly materials. This work aimed to create, characterize (color, thickness, water solubility, water adsorption capacity, microstructure, and degradability), and apply biodegradable films using residues of nejayote and pericarp of nixtamalized popcorn. Three types of films were compared, pericarp (P), nejayote–pericarp (NP), and nejayote (N), and were applied to avocado stored at room temperature. Results showed that the P film was the best because it was significantly (p < 0.05) more transparent (L = 94.75 ± 2.21) and thicker (0.27 ± 0.02 mm). It had higher water adsorption capacity (162.60 ± 14.05%) and higher elastic modulus and toughness (0.004 ± 0.001 MPa, 2.25 ± 0.25 J/m³) values than the N and NP films; in addition, its microstructure showed a roughness value (Ra) of 6.59 ± 0.57 nm that was intermediate compared to other films. Moreover, the P coating slowed down the maturing process of avocado and showed a visual effect against fungal infection. All films were generally soft and had a degradation time between 11 and 12 days. The novelty of this study is to provide the alternative of using nejayote and pericarp in a film that is compostable and maintains the lifespan of avocados.

A lo largo de su ciclo de vida, los plásticos sintéticos están asociados a problemas ambientales, ello se ha incrementado por sus aplicaciones en todas las áreas de la industria, particularmente en la alimentaria, ya que en medida que esta crece, la demanda de material de embalaje también, por lo que en los últimos años se ha buscado la disminución y sustitución de los empaques sintéticos, en este sentido, el desarrollo de los bioplásticos forman una clase de materiales poliméricos en rápido crecimiento que se presentan comúnmente como alternativas, ejemplos de ello es el desarrollo de recubrimientos alimentarios a partir de fuentes renovables-biodegradables, apoyados de la nanotecnología, que es un nuevo campo de investigación que transforma la industria alimentaria cambiando la forma de proceso de producción, envasado y consumo, por lo cual, el objetivo de esta revisión es brindar información sobre la nanotecnología, su implementación e importancia en la generación de nanomateriales, nanocápsulas y recubrimientos aplicados en los alimentos.

Molecular structure characterization of extracted cellulose from different apple cultivars by transmission electron microscopy. - Volume 27 Issue S1