Large volumes of waste are generated in the processing operations of the fishing industry. These effluents contain potentially useful proteins. However, it is necessary to concentrate them for utilization. The stickwater (SW) resulting from this operation was subjected to a protein-fractionation step, pH adjustment (acid + alkaline) and ultrasonic pulsing in order to aid in hydrolysis and evaluate its functional and nutritional properties. The protein fractions, as well as the protein hydrolysates present in the tail water, had a chemical composition of 54.85 ± 4.21 and 74.81 ± 3.89 protein (%), 0.8 ± 0.1 and 0.2 ± 0.015 fat (%), 7.21 ± 0.67% ash (%), respectively. The increase in low-molecular-weight peptides results in an increase in free-radical scavenging activity. However, the increase in ferric-reducing antioxidant power may be due to the HCl treatment performed by the company. An increase in the functional properties of the samples treated with ultrasonic pulses was observed. Therefore, the chemical, nutritional and functional characteristics of stickwater suggest its potential use as a food additive.

Introduction. In Mexico, 85 % of the crops are white maize, 10 % white yellow and 5 % other colors. Biochemical studies of pigmented native maize have been carried out, but there is little information on colour-improved maize. Objective. To evaluate the phytochemical content and antimicrobial capacity of two pigmented maize hybrids grown at the Tecnológico Nacional de México-Valle del Yaqui. Materials and methods. Extraction of biocompounds from a portion of the maize grains grown in southern Sonora, Mexico, during the summer-winter 2020 cycle was performed on red and purple maize hybrids. A thirty-part solution of ethanol, acetic acid and water was used. Proximal composition, anthocyanin, polyphenol and flavonoid content were determined by standardized methods. Antioxidant capacity was determined by ABTS (2,2’-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid)) and DPPH (2,2-diphenyl-1-picrylhydrazyl) methodologies. In addition, antimicrobial capacity and minimum inhibitory concentration were determined. Results. Purple maize showed higher content of anthocyanins (340.98±5.21 mg/100 g) and polyphenols (173.68±24.23 mg gallic acid/100 g) compared to red maize. Flavonoids are more abundant in purple maize (575.10±27.88 mg quercetin/100 g). Both maize hybrids exhibited more than 50 % antioxidant capacity against ABTS and DPPH radicals. Regarding antimicrobial activity, higher inhibition was observed for Escherichia coli and Salmonella (18 % and 47 %), and lower for Staphylococcus aureus and Shigella (19 % and 34 %) compared to gentamicin. Conclusion. Purple maize showed higher content of anthocyanins, polyphenols and flavonoids. Both hybrids had an antioxidant capacity higher than 50 %. Antimicrobial activity was higher against E. coli and Salmonella, than against S. aureus and Shigella.

En los últimos años, el sector acuícola ha experimentado un rápido crecimiento debido a su relevancia en la producción alimentaria. No obstante, las industrias de peces de agua dulce se enfrentan a grandes desafíos, incluyendo enfermedades causadas por Oomicetos, como Saprolegniae. En este proyecto se evaluó el efecto del extracto de Larrea tridentata sobre la inhibición de Saprolegnia Sp. mediante un bioensayo in vitro. Las cepas de Saprolegnia fueron obtenidas de peces infectados con este Oomiceto. La identificación del hongo se realizo vía morfológica obteniéndose dos cepas S. parasítica y S. Ferax. Las cuales fueron usadas en el ensayo inhibitorio. El rendimiento fue de 167.5 mg/mL en metanol y 113 mg/mL en etanol, el análisis fitoquímico reveló la presencia de fenoles, flavonoides y taninos, así como una intensa actividad antioxidante. En cuanto a la inhibición del Oomiceto, se encontró que a una concentración arriba de 50 mg/mL presentaba una inhibición completa del microorganismo. Lo anterior permite concluir que el uso de extracto etanólico es una opción potencial para su uso en organismos acuáticos.