Produção de embalagem para camarões a base de biocompósitos (xantana de Xanthomonas campestris/alginato de sódio/montmorilonita) e extrato aquoso de orégano (Origanum vulgare L.)

Abstract

Food “Active packaging” are based on the incorporation of components with properties that help in the process of controlling modified variations, such as antioxidants and antimicrobials, in addition to adding environmental value (biodegradability, use of residual raw materials, low toxicity, and others). This work aimed to elaborate a biocomposite with Xanthomonas campestris xanthan, sodium alginate, and montmorillonite (MMT) in the form of active films incorporated with aqueous extract of dehydrated leaves of Origanun vulgare L. (EAO), to pack/coat shrimp fillets. After evaluating several formulations with solutions of xanthan gum, sodium alginate, and MMT, the best combination was composed of different aliquots of EAO (mg/mL): 0.083; 0.0207; 0.0249; 0.0332; 0.0415; 0.622; 0.083; 0.012 and 0.016. We analyzed the films and EAO according to their color, thickness, mechanical properties, infrared spectrophotometry (FTIR), energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), swelling, moisture, solubility, water vapor permeability (WVP), antioxidant capacity, total phenolic content, antimicrobial activity and as coating of shrimps (Litopenaeus schmitti), without exoskeleton and cephalothorax, crushed and cooked, subjected to freezing for 30 days. EAO and biofilms incorporated with different aliquots demonstrated antioxidant capacity against the DPPH radical (respectively 62% and about 47-87.5%), in addition to phenolic content justifying such action, however, antimicrobial agents for strains of Pseudomonas aeuruginosa, Escherichia coli and Staphylococcus aureus were not known. The addition of EAO in the films works as optimized mechanical data, with the sample AXMEAO9 being the best film. Color analysis (L*) revealed a tendency towards light colors, with the control film (sodium alginate/xanthan/montmorillonite) having yellowish tones. The average thickness of the films was 0.10 mm, with the rupture stress (𝜎_𝑅𝑈P) altered according to the concentration of EAO created. Shrimp fillets coated with the studied film, at the highest tested dose of EAO, did not deteriorate when stored in a freezer for 30 days, and their carotenoid content showed excellent antioxidant capacity (DPPH radical). Therefore, the biopolymer produced with xanthan, sodium alginate, clay montmorillonite and EAO, in addition to its mechanical and antioxidant properties, has immense potential for use as coating packaging for foods such as shrimp.