Highlights The ultrasound can release of bioactive compounds of the crystallized matrix of honey. Some honeys liquefied with ultrasound showed increases in the bioactive compounds. The treatment with ultrasound increased inhibitory effect against S. Typhimurium in some honeys.

In the present study, the effects of ultrasound (10, 20, and 30 min) on the bioactive compounds, antioxidant capacity, enzymatic inhibition, and in vitro digestion of six honey extracts from the Oaxaca state, Mexico, were analyzed. Significant differences were found in each honey extract with respect to the ultrasonic treatment applied (p < 0.05). In the honey extract P-A1 treated with 20 min of ultrasound, the phenols reached a maximum concentration of 29.91 ± 1.56 mg EQ/100 g, and the flavonoids of 1.92 ± 0.01 mg EQ/100 g; in addition, an inhibition of α-amylase of 37.14 ± 0.09% was noted. There were also differences in the phases of intestinal and gastric digestion, presenting a decrease in phenols (3.92 ± 0.042 mg EQ/100 g), flavonoids (0.61 ± 0.17 mg EAG/100 mg), antioxidant capacity (8.89 ± 0.56 mg EAG/100 mg), and amylase inhibition (9.59 ± 1.38%). The results obtained from this study indicate that, in some honeys, the processing method could increase the concentration of bioactive compounds, the antioxidant capacity, and the enzymatic inhibition; however, when subjected to in vitro digestion, the properties of honey are modified. The results obtained could aid in the development of these compounds for use in traditional medicine as a natural source of bioactive compounds.

ResumenSe determinó la composición de la microbiota del queso de Aro que se comercializa en el municipio de Teotitlán de Flores Magón, Oaxaca, México. Se cuantificó el contenido de: mesófilos aerobios, psicrófilos, coliformes totales, Escherichia coli, Staphylococcus aureus, Salmonella, Enterococcus, Streptococcus, bacterias ácido lácticas, mohos y levaduras. Los resultados muestran que el queso de Aro contiene microorganismos alterantes, patógenos y de importancia industrial. Ninguna muestra analizada cumple con la NOM-243-SSA1-2010. Por lo tanto, este queso pueden ser un vehículo de transmisión de enfermedades alimentarias, por su elevado contenido de: E. coli, Staphylococcus aureus y Salmonella. La vida de anaquel del queso puede verse afectada provocando pérdidas económicas a los productores. Por otro lado, se pueden obtener microorganismos de importancia industrial (Lactobacillus y Streptococcus). Es necesario implementar sistemas se aseguramiento de la calidad que garanticen la producción de quesos inocuos. Palabras-clave: Queso fresco; Microorganismos alterantes; Patógenos; Vida de anaquel. SummaryThe composition of the microbiota of the Aro cheese marketed in the municipality of Teotitlan de Flores Magon, Oaxaca, Mexico, was determined, quantifying the aerobic mesophilic bacteria, psychrophilic bacteria, total coliforms, Escherichia coli, Staphylococcus aureus, Salmonella, Enterococcus, Streptococcus, lactic acid bacteria, moulds and yeasts. The results showed that the Aro cheese contained pathogenic and spoilage microorganisms as well as those of industrial importance. None of the samples analysed complied with NOM-243-SSA1-2010. Thus this cheese could transmit foodborne illnesses, due to its high content of E. coli, Staphylococcus aureus and Salmonella. The shelf life of the cheese could also be affected causing economic losses to the producers. On the other hand, microorganisms of industrial importance can be obtained (Lactobacillus and Streptococcus). It is necessary to implement quality assurance systems to guarantee the production of innocuous cheeses.

The objective of this research was to determine the content of total phenols, total flavonoids, and the antioxidant and antimicrobial activity of the ethanolic extracts of propolis obtained by two methodologies during in vitro digestion. Ethanolic extracts of propolis were obtained by ultrasound and maceration and the yield and content of the bioactive compounds, as well as their antimicrobial and antioxidant activity, were evaluated. Yields higher than those reported in other investigations (71.6%) were obtained. The highest content of phenols and flavonoids in the ethanolic extracts was 34,406.6 mg GAE/100 g in propolis from San Pedro, obtained by maceration (SP M), and 19,523.2 mg QE/100 g in propolis from Teotitlán, obtained by ultrasound (TU), respectively, being higher than what is established in Mexican regulations. The antioxidant and antimicrobial activity of the extracts was not affected by the method of obtaining. At the end of the in vitro digestion there was an 80% loss of the phenolic content and a 90% loss of the flavonoid content. Therefore, antioxidant activity was affected. On the other hand, ultrasound improves the obtaining of bioactive compounds. In vitro digestion decreases the content of bioactive compounds; therefore, their functional properties are affected. Thus, it is important to consider technologies that allow extracts to be protected from in vitro digestion conditions.

El propóleo es una sustancia recolectada por las abejas. El extracto de propóleo es de interés por su gran variedad de compuestos bioactivos, para ello se han implementado tecnologías sustentables con el fin de mejorar y potencializar su extracción, entre las técnicas utilizadas se encuentran la extracción asistida por ultrasonido, extracción asistida por microondas y la extracción con CO2 supercrítico. Siendo el método de ultrasonido el más utilizado y parece ser el óptimo para la extracción de propóleo tomando en cuenta el tiempo y rendimiento.