Utjecaj nanočestica kitozana koje sadržavaju antioksidanse izolirane iz biljke Salvia hispanica L. na svojstva filmova pripremljenih od šćirovog brašna

Research background. Amaranth (Amaranthus hypochondriacus) flour produces films with excellent barrier properties against water vapor, allowing food preservation, but the mechanical properties are poor compared to synthetic films. One strategy to improve these properties is the incorporation of nanoparticles. The particles can also serve as a vehicle for the addition of antioxidant agents into the films. The objective of this work is to optimize the formulation for the preparation of amaranth flour films treated with antioxidant chia (Salvia hispanica L.) extract-loaded chitosan particles using response surface methodology (RSM). Experimental approach. Chitosan nanoparticles with the extract were synthesized by ionic gelation, and the films were made by the casting method. Three independent variables were assigned: amaranth flour (4-6%), glycerol (25-35%) and chitosan nanoparticles loaded with the chia extract (0-0.75%). We then evaluated the physical (thickness), mechanical (tensile strength, Young´s modulus and elongation), barrier (water vapor permeability, moisture and water solubility) and antioxidant properties of the films. The experimental results of the properties were analyzed using a Box-Behnken experimental design generating 15 runs with three replicates at the central point. Results and conclusions. Second and third order polynomial models were obtained from the ANOVA analysis of the evaluated responses, and high coefficients of determination were found (0.91–1.0). The water vapor permeability of the films was 0.82−2.39·10-7 (g·mm)/(Pa·s·m2), tensile strength was 0.33−1.63 MPa and antioxidant activity 2.24−5.65%. The variables had different effects on the films: glycerol negatively affected their properties, and the permeability values increased with increased amaranth flour content. The nanoparticles improved the mechanical, barrier and antioxidant properties of the films compared to the films without nanosystems. The optimal formulation was 4% amaranth flour, 25% glycerol and 0.36% chitosan nanoparticles. The optimized films had better mechanical (1.62 MPa) properties, a low water vapor permeability value (0.91·10-7 (g·mm)/(Pa·s·m2)) and moderate antioxidant activity (6.43%). Novelty and scientific contribution. The results show the effect of chitosan nanoparticles on the properties of amaranth flour films for the first time. The resulting equations are useful in the design of food packaging.Pozadina istraživanja. Brašno od amaranta odnosno šćira (Amaranthus hypochondriacus) može se upotrijebiti za izradu filmova s odličnim svojstvom propusnosti vodene pare, što omogućuje čuvanje hrane, no ti filmovi imaju lošija mehanička svojstva od sintetičkih filmova. Jedan od mogućih načina poboljšanja mehaničkih svojstava filmova je dodatak nanočestica, koje ujedno mogu poslužiti kao nosač antioksidansa. Svrha je ovoga rada bila metodom odzivnih površina optimirati pripremu filmova od šćirovog brašna dodatkom čestica kitozana koje sadržavaju antioksidanse iz ekstrakta chia (Salvia hispanica L.) sjemenki. Eksperimentalni pristup. Nanočestice kitozana s ekstraktom chia sjemenki dobivene su ionskim geliranjem, a filmovi su pripremljeni metodom izlijevanja. Određene su tri nezavisne varijable: šćirovo brašno (4-6 %), glicerol (25–35 %) i nanočestice kitozana s ekstraktom chia sjemenki (0–0,75 %). Zatim su procijenjena fizikalna (gustoća), mehanička (vlačna čvrstoća, Youngov modul elastičnosti i istezljivost), barijerna (propusnost vodene pare, vlaga i topljivost u vodi) i antioksidacijska svojstva filmova. Dobiveni su rezultati ispitani pomoću Box-Behnkenovog plana izvođenjem 15 eksperimenata s tri ponavljanja u centralnoj točki. Rezultati i zaključci. Analizom odziva pomoću ANOVA testa dobiveni su modeli oblika polinoma drugog i trećeg stupnja te visoki koeficijenti određivanja (0,91–1,0). Propusnost vodene pare bila je 0,82−2,39·10–7 (g·mm)/(Pa·s·m2), vlačna čvrstoća 0,33−1,63 MPa, a antioksidacijska aktivnost filmova 2,24−5,65 %. Svaka je varijabla imala drugačiji učinak: povećanje udjela glicerola negativno je utjecalo na svojstva flimova, a njihova propusnost se povećala s povećanjem udjela šćirovog brašna. Dodatkom nanočestica poboljšana su mehanička i antioksidacijska svojstva te propusnost filmova u usporedbi s filmovima koji nisu sadržavali nanočestice. Optimalni dodatak filmovima bio je 4 % šćirovog brašna, 25 % glicerola i 0,36 % nanočestica kitozana. Optimirani filmovi imali su bolja mehanička svojstva (1,62 MPa), malu propusnost vodene pare (0,91·10–7 (g·mm)/(Pa·s·m2)) i umjerenu antioksidacijsku aktivnost (6,43 %). Novina i znanstveni doprinos. Rezultati ispitivanja po prvi put prikazuju utjecaj nanočestica kitozana na svojstva filmova od šćirovog brašna. Dobivene jednadžbe mogu se korisno upotrijebiti u projektiranju jestive ambalaže

Caracterización de la oferta de moringa (Moringa oleifera Lam.) en México

Objective: To characterize the Moringa oleifera Lam. offer system in Mexico. Design / methodology / approach: Compilation and analysis of primary information sources, through interviews with producers and key informants who participate in the process of commercialization of products derived from moringa. In total, there were eight companies. To collect the information, the snowball chain sampling technique was used. Results: All moringa producing companies analyzed started activities less than 10 years ago. The owners of the companies are small and medium producers, with an average of 6.5 ha, characterized by an organic management and constant training. The main products offered in the Mexican market are: the crushed leaf, flour and capsules, whose main market is the national one. On the other hand, it was detected that the producers in the market do not interact among each other, which generates asymmetry of information. In addition, the real inventory of the total number of producers and moringa producing companies in Mexico is unknown, which limits the characterization of production and benefit. Limitations/implications: The producers are not so accessible in certain information; for example, regarding the sale prices of their products. Findings/conclusions: Moringa is a multipurpose tree with great potential, a database of producers is unknown. The products offered are organic and healthy products. However, more research is needed on the commercialization of moringa in Mexico.Objetivo: Caracterizar el sistema de la oferta de Moringa oleifera Lam. en México. Diseño/metodología/aproximación: Recopilación y análisis de fuentes de información primarias, a través de entrevistas a productores e informantes clave que participan en el proceso de comercialización de los productos derivados de la moringa; en total fueron ocho empresas. Para recabar la información se utilizó la técnica de muestreo en cadena de bola de nieve. Resultados: El total de las empresas de producción de moringa iniciaron actividades hace menos de 10 años. Los dueños de las empresas son pequeños y medianos productores, con un promedio de 6.5 ha, caracterizados por un manejo orgánico y constante capacitación. Los principales productos ofertados en el mercado mexicano son: la hoja triturada, harina y cápsulas, cuyo principal mercado es el nacional. Por otro lado, se detectó que los productores en el mercado no interaccionan, lo cual genera asimetría de información. Sumado a ello se desconoce el inventario real del número total de productores y de empresas productoras de moringa en México, que limita la caracterización de la producción y de su beneficiado. Limitaciones/implicaciones: Los productores no son tan accesibles en cierta información, por ejemplo, la referente a los precios de venta de sus productos. Hallazgos/conclusiones: La moringa es un árbol multipropósitos con gran potencial, y no se cuenta con una base de datos de productores. Los productos ofertados son productos orgánicos y saludables. Sin embargo, faltan más investigaciones sobre la comercialización de moringa en México