The increasing demand for reliable food preservation strategies has driven the development of active biopolymer-based films as alternatives to conventional packaging. This study evaluates Nisin/Na-EDTA-enriched alginate and gelatin films for preserving Dosidicus gigas (jumbo squid) during refrigerated storage. Films were formulated using alginate, gelatin 220/280 Bloom, and glycerol, and characterized in terms of their mechanical, optical, and biodegradation properties. Their effectiveness for the preservation of squid fillets was tested, focusing on weight loss and color stability during refrigerated storage. The incorporation of Nisin/Na-EDTA significantly modified the film’s properties: elongation at break increased from 4.95% (alginate control) to 65.13% (gelatin 280 active), while tensile strength decreased from 8.86 MPa to 0.798 MPa (alginate). Transparency was reduced by up to 2.5 times in active agent-incorporated alginate films. All films degraded within 14 days under soil exposure, with polysaccharide-based films degrading faster. In refrigerated storage, squid fillets coated with gelatin–alginate films containing Nisin showed reduced weight loss (24.05%) compared with uncoated controls (66.36%), particularly in skin-on samples. Color parameters and whiteness index were better preserved with gelatin-based coatings. These results demonstrate the potential of gelatin–alginate films with Nisin/Na-EDTA as biodegradable, active packaging to extend the shelf life of high-protein seafood.
This study explored the production of a fermented beverage using Huiro negro (Lessonia spicata), a brown seaweed, as a substrate. The cellulosic saccharification (CS) process was optimized via response surface methodology, identifying that the best conditions were 60 U/g of enzyme at 60 °C for 1.9 h, yielding 2.5 g/100 g of reducing sugars. The resulting hydrolysate was fermented with Lactobacillus spp. for 48 h at 30 °C and compared with a non-saccharified control. The beverage’s proximate composition, total phenolic content (TPC), flavonoid content (TFC), antioxidant capacity (AC), and Lactobacillus spp. viability over 16 days of storage at 4 °C were assessed. CS-treated samples showed a progressive increase in TPC, reaching 126.59 ± 5.58 mg GA/L, which correlated with higher AC. However, no significant differences (p > 0.05) were observed in TPC and AC between saccharified and non-saccharified beverages. Notably, the CS-treated beverage achieved significantly higher (p < 0.05) Lactobacillus spp. counts (109 CFU/mL) compared to the control (107 CFU/mL), maintaining viability throughout storage. While further research is needed to confirm bioavailability and gut health effects, these findings shows that enzymatic saccharification substantially improves fermentation performance and functional properties in Lessonia spicata-based beverages.
Huiro negro (Lessonia spicata) is a brown alga with potential in the food, nutraceutical, and pharmaceutical industries. This study evaluated its convection drying at 30, 40, and 50 °C (2 ± 0.1 m/s; 83% RH), analyzing the kinetics using nine mathematical models. The Midilli–Kucuk model showed the best fit (R2 = 0.999). Drying at 50 °C significantly increased the fucoxanthin content (p ≤ 0.05) but had the highest energy cost (7.20 USD/kg). In contrast, 30 °C achieved the highest thermal efficiency (48.73%) and lowest cost (5.37 USD/kg), although with the lowest total phenolic compound (TPC) content. TPC was highest at 40 °C, while antioxidant capacity decreased to 30 °C and 40 °C, partially recovering at 50 °C. Higher temperatures also increased protein, fiber, and carbohydrates, while ash decreased. Tests on gastric cell lines (AGS and GES-1) showed low cytotoxicity at doses ≤ 1 mg/mL, with reductions in viability at concentrations ≥ 10 mg/mL. Overall, the extracts showed good biocompatibility at low doses and outstanding functional properties, especially after drying at 50 °C. The results show that the drying temperature significantly influences the nutritional and functional quality of L. spicata, favoring its use in functional foods.