Edible Films Based on Black Chia (Salvia hispanica L.) Seed Mucilage Containing Rhus microphylla Fruit Phenolic Extract

Abstract

Functional films based on black chia (Salvia hispanica L.) seed mucilage (BCm) containing Rhus microphylla (Rm) fruit phenolic extract were built and characterized. A hydro-alcohol extract (HAE) of Rm was incorporated as the bioactive agent due to its noteworthy phenolic profile, and good antioxidant and antifungal activities. The effects of the BCm concentration (0.2% and 0.4%, w/v), HAE incorporation, and their interaction with glycerol (1.0%, w/v) and calcium chloride (0.05%, w/v) on the films’ physicochemical properties were evaluated. The filmogenic solutions successfully fitted to the Herschel–Bulkley model (R2 < 0.999), exhibiting a pseudoplastic and shear thinning character, typical of polymer solutions. Interestingly, their rheological properties were not (p > 0.05) changed by the HAE addition, but their surface tension was enhanced (p < 0.05), which could favor their coating ability. The polyanionic nature of the systems (zeta potential-Zp values from −26.9 to −33.3 mV) allowed them to interact with Ca2+ cations, thus forming stable and resistant films. All the films showed low water solubility (15.0% to 22.3%) and high permeability (3.7 to 4.0 × 10−10 g m−1 s−1 Pa−1), as well as high biodegradability (moisture content from 66.0% to 80.9%); although the moisture content was reduced (p < 0.05) with HAE addition. The combination of higher BCm ratio and HAE addition (BCm0.4+Rm) led to a more resistant, thick, opaque, and dark film compared with the others obtained. This study reveals the BCm-based films’ potential, highlighting those with HAE, representing a novel alternative to improve the quality of food products.

Phenolic Composition and Biological Properties of Rhus microphylla and Myrtillocactus geometrizans Fruit Extracts

“…Conventional agitation was carried out following the method previously described by Charles-Rodríguez [ 17 ]. Initially, 11.5 g of dried sample was placed in a flask containing 125 mL of water and a hydroalcohol solution (50:50) and extracted at 150 rpm for 24 h at room temperature (Innova 44 Incubator, New Brunswick Scientific Co., Inc., Edison, NJ, USA).…”

“…The capacity of free radical capture of extracts was determined by the DPPH assay [ 17 ]. The DPPH microplate-adapted assay was conducted using 25 µL of each diluted sample at 20 to 2500 mg/L, dissolved in its respective extraction solvent, then the samples were mixed with a 200 µL of DPPH solution (150 µM, dissolved in absolute ethanol) in a 96-well microplate.…”

“…Console (known as garambullo) (Mg) and Rhus microphylla Engelm. (known as agrito) (Rm), develop interesting fruits composed mainly of flavonoids, phenolics acids, betacyanins, and betaxanthins [ 17 , 18 ]. The fruits vary in size and color, while Mg fruits are juicy, spheric, and purple, Rm fruits are small, spheric, orange, and dry drupe [ 19 , 20 ].…”

“…Mg fruit has been reported for its high antioxidant [ 1 ] and antihyperglycemic [ 21 ] activities, while the methanol extracts from roots and aerial parts of Mg have shown an insecticidal effect on the fall armyworm ( Spodoptera frugiperda ) [ 22 ]. Regarding Rm fruits, their ethanol and aqueous extracts were recently reported for their strong antifungal activity in vitro against two important crop pathogens, Fusarium oxysporum and Corynespora cassiicola [ 17 ]. The application of novel green extraction technologies, such as OH, represents an excellent tool for the recovery of crude extracts and BCs from these species.…”

Seed coat mucilages: Structural, functional/bioactive properties, and genetic information

“…Seed coat mucilages such as CSM, BSM, SSM, and cress seed gum (CSG) have been used to modify and improve the physical properties of hydrophilic edible films (Barzegar et al., 2020; Charles‐Rodriguez et al., 2020; Nourozi & Sayyari, 2020; Salarbashi & Tafaghodi, 2018;). Glycerol has an essential role in making homogenous flexible films and also affects the physical and mechanical properties of edible film.…”