Development of Edible Films Based on Nostoc and Modified Native Potato Starch and Their Physical, Mechanical, Thermal, and Microscopic Characterization.

Considering the potential of biopolymers from underutilized Andean sources in Peru to improve the characteristics of edible films, this work aimed to evaluate the formation of a polymeric matrix composed of Nostoc and modified potato starch for the formulation of edible films for food coating. The effects of polymer matrix ratio and drying temperature on films obtained by thermoforming were studied, determining the water vapor permeability and mechanical properties using a multifactorial design. Additionally, thermal properties were characterized by TGA and DSC, and structural properties by FT-IR and scanning electron microscopy. The results showed that the films exhibited lower solubility, lighter hues, better water vapor resistance, higher tensile strength, and improved thermal stability with increasing modified starch content. The formulation with higher Nostoc content exhibited a more homogeneous surface according to microscopy images, and no new chemical bonds were formed by adding modified starch and Nostoc to the polymer matrix, according to FT-IR spectra. These findings are promising and suggest using Nostoc for elaborating edible films composed of native and modified starch from native Andean potatoes as bio-based materials with potential application in the food industry.

A High Andean Hydrocolloid Extracted by Microatomization: Preliminary Optimization in Aqueous Stability.

Aqueous suspensions rely on electrostatic interactions among suspended solids, posing a significant challenge to maintaining stability during storage, particularly in the food and pharmaceutical industries, where synthetic stabilizers are commonly employed. However, there is a growing interest in exploring new materials derived from natural and environmentally friendly sources. This study aimed to optimize the stability parameters of a novel Altoandino Nostoc Sphaericum hydrocolloid (NSH) extracted via micro atomization. Suspensions were prepared by varying the pH, gelatinization temperature and NSH dosage using a 23 factorial arrangement, resulting in eight treatments stored under non-controlled conditions for 20 days. Stability was assessed through turbidity, sedimentation (as sediment transmittance), ζ potential, particle size, color and UV-Vis scanning. Optimization of parameters was conducted using empirical equations, with evaluation based on the correlation coefficient (R2), average relative error (ARE) and X2. The suspensions exhibited high stability throughout the storage period, with optimized control parameters identified at a pH of 4.5, gelatinization temperature of 84.55 °C and NSH dosage of 0.08 g/L. Simulated values included turbidity (99.00%), sedimentation (72.34%), ζ potential (-25.64 mV), particle size (300.00 nm) and color index (-2.00), with simulated results aligning with practical application. These findings suggest the potential use of NSH as a substitute for commercial hydrocolloids, albeit with consideration for color limitations that require further investigation.

Co-Microencapsulation of Cushuro (Nostoc sphaericum) Polysaccharide with Sacha Inchi Oil (Plukenetia huayllabambana) and Natural Antioxidant Extracts.

Cushuro (Nostoc sphaericum) polysaccharide was used to co-microencapsulate sacha inchi oil, natural antioxidant extracts from the oleoresin of charapita chili peppers (Capsicum frutescens L.) and grape orujo (Vitis vinifera L.). Encapsulation efficiency, moisture, particle size, morphology, oxidative stability, shelf-life, solubility, essential fatty acid profile, sterol content and antioxidant capacity were evaluated. The formulations with grape orujo extract showed higher oxidative stability (4908 ± 184 h), antioxidant capacity (4835.33 ± 40.02 µg Trolox/g ms), higher phenolic contents (960.11 ± 53.59 µg AGE/g ms) and a smaller particle size (7.55 µm) than the other formulations, as well as good solubility and a low moisture content. Therefore, grape orujo extracts can be used as natural antioxidants. The fatty acid composition (ω-3) remained quite stable in all the formulations carried out, which also occurred for sterols and tocopherols. In combination with gum arabic, grape orujo extract offered oxidative protection to sacha inchi oil during the first week of storage.

Novel glycosylated mycosporine-like amino acid, 13-O-(ß-galactosyl)-porphyra-334, from the edible cyanobacterium Nostoc sphaericum-protective activity on human keratinocytes from UV light.

A UV-absorbing compound was purified and identified as a novel glycosylated mycosporine-like amino acid (MAA), 13-O-ß-galactosyl-porphyra-334 (ß-Gal-P334) from the edible cyanobacterium Nostoc sphaericum, known as "ge xian mi" in China and "cushuro" in Peru. Occurrence of the hexosylated derivative of shinorine (hexosyl-shinorine) was also supported by LC-MS/MS analysis. ß-Gal-P334 accounted for about 86.5% of total MAA in N. sphaericum, followed by hexosyl-shinorine (13.2%) and porphyra-334 (0.2%). ß-Gal-P334 had an absorption maximum at 334nm and molecular absorption coefficient was 46,700 at 334nm. Protection activity of ß-Gal-P334 from UVB and UVA+8-methoxypsoralen induced cell damage on human keratinocytes (HaCaT) was assayed in comparison with other MAA (porphyra-334, shinorine, palythine and mycosporine-glycine). The UVB protection activity was highest in mycosporine-glycine, followed by palythine, ß-Gal-P334, porphyra-334 and shinorine in order. ß-Gal-P334 had highest protection activity from UVA+8-methoxypsoralen induced cell damage followed by porphyra-334, shinorine, mycosporine-glycine and palythine. We also found an antioxidant (radical-scavenging) activity of ß-Gal-P334 by colorimetric and ESR methods. From these findings, ß-Gal-P334 was suggested to play important roles in stress tolerant mechanisms such as UV and oxidative stress in N. sphaericum as a major MAA. We also consider that the newly identified MAA, ß-Gal-P334 has a potential for use as an ingredient of cosmetics and toiletries.

Composición química y actividad antioxidante in vitro del extracto acuoso de Nostoc sphaericum (Cushuro), laguna Cushurococha - Junín / Chemical composition and in vitro antioxidant activity of the aqueous extract of Nostoc sphaericum (Cushuro), Cushurococha lagoon - Junin

Objetivo: Determinar la composición química y actividad antioxidante in vitro del extracto acuoso liofilizado de Nostoc sphaericum (cushuro) de la laguna Cushurococha, Junín. Materiales y métodos: Estudio de enfoque cuantitativo; con diseño, descriptivo, observacional, transversal, la muestra biológica fue el extracto acuoso liofilizado de Nostoc sphaericum (cushuro) que se recolectó de la laguna Cushurococha en el departamento de Junín. Se utilizaron los métodos Lowry, Antrona, Folin-Ciocalteu, el ensayo de captación de ABTS+. Resultados: La cantidad, por muestra liofilizada, de proteínas solubles fue de 15.1 mg/g, carbohidratos totales 949ug/g, polifenoles totales 2.98mg EAG/g; así también, el porcentaje de inhibición del radical ABTS+ a una concentración de 0.15mg/mL de muestra liofilizada fue de 52 por ciento, un valor de IC50 entre 10-15 ug/mL y una capacidad antioxidante equivalente a trolox (TEAC-ABTS) igual a 0.384 ugEq. Trolox/ mg extracto de muestra seca. Conclusiones: El extracto acuoso liofilizado de Nostoc sphaericum constituye una buena fuente natural de antioxidantes.

Objective: To determine the chemical composition and in vitro antioxidant activity of lyophilized aqueous extract of Nostoc sphaericum (cushuro) of Cushurococha, Junín lagoon. Materials and Methods: Quantitative research approach; with design, descriptive, observational, cross-sectional, the biological sample was lyophilized aqueous extract of Nostoc sphaericum (cushuro) that was collected from the lagoon Cushurococha in the department of Junín. The method of Lowry, Anthrone, Folin-Cioealteu, assay ABTS+ capture methods were used. Results: The amount, lyophilized sample of soluble proteins was 15.1 mg/g, total carbohydrates 949ug/g, total polyphenols 2.98mg GAE/g; so too, the percentage inhibition of ABTS+ radical at a concentration of 0.15 mg/mL of lyophilized sample was 52 per cent, an IC50 value between 10 to 15 ug/mL and trolox equivalent antioxidant capaeity (TEAC-ABTS) equal to 0.384 ugEq. Trolox/mg dry extract sample. Conclusions: The lyophilized aqueous extract of Nostoc sphaericum is a good natural source of antioxidants.