ABSTRACT This work looks at the antibacterial efficacy of Gracilaria vermiculophylla and Ulva flexuosa aqueous extracts when added to the feed of Penaeus vannamei in an experimental infection with Vibrio parahaemolyticus (M0904AHPND+strain). Results show that the minimum inhibitory concentration (MIC) for both extracts was 50 mg mL-1, with inhibition zones of 18.00 ± 0.60 mm for G. vermiculophylla and 14.00 ± 0.29 mm for U. flexuosa. G. vermiculophylla gave a higher total content of phenolic compounds (10.58 ± 2.31 mg GAE g-1) (gallic acid equivalent) and lower flavonoid content (10.32 ± 0.73 mg QE g-1) in comparison to U. flexuosa, while using ABTS (2,2-diphenyl-1-picrylhydrazyl) and ferric reducing antioxidant power (FRAP) to measure antioxidant capacity showed that G. vermiculophylla gave a better result than U. flexuosa. The challenge with V. parahaemolyticus resulted in 67% survival for organisms fed G. vermiculophylla and 60% for those fed U. flexuosa, resulting in twice the amount of survival as opposed to 30% in the positive control at 24 h post-infection. Histopathological alterations in the hepatopancreas with hemocytic infiltration within the intertubular connective tissue were observed. Also, tubules with severe cell detachment and tubular atrophy were detected in the positive control organisms, and organisms treated with macroalgae only had vermiform structures in the tubular lumen, cell detachment, and infiltration hemolymph in intertubular connective tissue. According to the analysis of the studied variables, it can be concluded that the aqueous extracts of these macroalgae are a promising alternative for V. parahaemolyticus (M0904AHPND+strain) control in shrimp culture.

Abstract Enormous amounts of by-products and waste are generated during the processing of seafood, sometimes representing about 65% of the raw material employed. Seafood by-products (SB) include solid waste such as skin, head, viscera, trimmings, and bones; however, liquid wastes (effluents) derived from operations such as washing, thawing, cooking and the production of fishmeal are also produced. SB contain considerable amounts of protein and others biomolecules, which has been regularly processed as food ingredients for animal nutrition. But also, sometimes SB are used as fertilizers or discarded to environment without a previous treatment. Nowadays, there is an increasing interest in adding value to the protein material within SB by improving their properties through hydrolysis and thus releasing of peptides with bioactive properties. Thus, this review aims to present an overview of the potential of SB, focused on effluents, as a source of protein hydrolysates, summarizing their methods of production, bioactive property evaluation and structural characteristics.

Abstract Biochemical composition was assessed in green (Ulva expansa, Caulerpa sertularioides, Rhizoclonium riparium, Codium isabelae), red (Spyridia filamentosa, Gracilaria vermiculophylla), and brown (Padina durvillaei) seaweeds collected from different tropical lagoons on the Pacific coast of Sinaloa, Mexico. Protein content was higher in C. sertularioides, S. filamentosa, and G. vermiculophylla (10-12%), followed by R. riparium, P. durvillaei, and U. expansa (8%, 6%, and 4%, respectively). Lipid content was in the range of 0.3-1.5%, with the highest value found in R. riparium. The highest content of nitrogen-free extract (i.e., carbohydrates) (69%) and the lowest ash value (25%) were assessed in P. durvillaei. Polyunsaturated fatty acid content was in the range of 5-45%, with higher values in R. riparium (45%), C. sertularioides (39%), and P. durvillaei (23%). Red seaweeds showed the highest value of cholesterol+dehydrocholesterol (>90%), while green seaweeds showed the highest contents of β-sitosterol (71-77%), except for U. expansa, for which fucosterol+isofucosterol (79%) was highest. Pigment composition was different among seaweeds but coincided with previous reports. The biochemical components used as biomarkers were assessed by principal component analysis to discriminate among assessed variables and to cluster seaweed species according to the common variability of their biochemical composition. Results showed that composition was similar within seaweed divisions but particularly different in U. expansa and P. durvillaei. Biochemical compounds that contributed to total variability were β-sitosterol, 20:4n-6, 20:5n-3, chlorophyll a and b, and β-carotene, and to a lesser extent fucosterol+isofocusterol and 22:6n-3. Results showed that the analyzed seaweed species may be useful for animal nutrition and appropriate for human consumption.

Resumen Se determinó la composición bioquímica de algas verdes (Ulva expansa, Caulerpa sertularioides, Rhizoclonium riparium, Codium isabelae), rojas (Spyridia filamentosa, Gracilaria vermiculophylla) y parda (Padina durvillaei) recolectadas en diferentes lagunas tropicales en la costa del Pacífico en Sinaloa, México. El contenido de proteínas fue más alto en C. sertularioides, S. filamentosa y G. vermiculophylla (10-12%), seguido de R. riparium, P. durvillaei y U. expansa (8%, 6% y 4%, respectivamente). El contenido de lípidos se encontró en el intervalo de 0.3-1.5%, con el valor más alto encontrado en R. riparium. El contenido más alto del extracto libre de nitrógeno (i.e., carbohidratos) (69%) y el valor más bajo de cenizas (25%) se encontró en P. durvillaei. El contenido de ácidos grasos poliinsaturados (AGPI) se encontró en el intervalo del 5% al 45%, con los valores más altos en R. riparium (45%), C. sertularioides (39%) y P. durvillaei (23%). Las algas rojas mostraron el mayor valor de colesterol+dehidrocolesterol (>90%), mientras que las algas verdes mostraron el mayor contenido de β-sitosterol (71-77%), excepto U. expansa, para la cual el principal esterol fue el fucoesterol+isofucosterol (79%). El contenido de pigmentos fue diferente entre las algas, aunque coincidió con reportes previos. Los componentes bioquímicos usados como biomarcadores se analizaron por componentes principales para discriminar entre las variables analizadas y agrupar las especies de algas en función de la variabilidad de su composición bioquímica. Los resultados mostraron una composición similar en cada grupo de algas, pero particularmente diferente en U. expansa y P. durvillaei. Los compuestos bioquímicos que contribuyeron a la variabilidad total fueron β-sitosterol, 20:4n-6, 20:5n-3, clorofila a y b, β-caroteno y, en menor grado, fucosterol+isofucosterol y 22:6n-3. Los resultados indican que las especies de algas analizadas podrían ser utilizadas como alimento para animales, pero también para consumo humano.

Abstract Agave tequilana Weber azul variety is a valuable source of fructans. In this study, a response surface methodology was employed to optimize the extraction yield of fructans from agave pines. A Box Behnken factorial design was applied to evaluate the effects of several conditions such as extraction temperature, water raw material ratio and extraction time on extraction yield. Under the optimum extraction conditions (extraction temperature of 79.1 °C, water raw material ratio of 5.13 mL/g, and extraction time of 1.48 h) fructans extraction yield was 83.12%. The chromatographic profile of the agave crude extract presented four peaks, out of which fructans were the most preponderant (~87%). The obtained results suggest that the response surface methodology is adequate to optimize fructans extraction from Agave tequilana Weber azul variety.