The growing market of functional beverages requires characterize specifically the sources of bio-actives to select those with the highest quantity of the compound needed in the formulation. The composition of phenolic acids and the content of anthocyanins and proanthocyanidins, from aqueous extracts of the calyxes of three varieties of jamaica (Hibiscus sabdariffa L.) were assessed using HPLC-DAD: dark red (Sudan), light red (Criolla Nayarit) and white (Alma Blanca). Antioxidant activity was also determined. The experimental design was completely randomized with three replications. The highest contents of total phenolic acids were detected in Sudan and Alma Blanca (10.71±0.29 and 8.22±0.30 mg GAE g-1 DM). The fraction of free phenolic acids (FPA) was abundant and was highly complex in the calyxes of the three colors. Chlorogenic acid and its two isomers were predominant in the FPA, and the glycosylated phenolic acids (GPA) accounted for 77.4 to 81.5 % of the total phenolic acids in the three varieties. The white Alma Blanca calyxes contained more caffeic and protocatechuic acid derivatives than the red calyxes of the other varieties. The highest antioxidant activity (p≤0.05) was found in the Sudan extract (CI50=113.3 μg mL-1). The color of the calyxes can indicate the predominant type of phenols in H. sabdariffa L. and aid in the selection of varieties for formulations with particular nutraceutical properties.

El creciente mercado de bebidas funcionales requiere la caracterización específica de las fuentes de bioactivos, para seleccionar aquellas con la mayor cantidad del compuesto necesario en la formulación. La composición de ácidos fenólicos y contenido de antocianinas y proantocianidinas, de extractos acuosos de tres variedades de jamaica (Hibiscus sabdariffa L.), con rojo oscuro (Sudán), rojo claro (Criolla Nayarit) y blanco (Alma Blanca) en sus cálices, fueron evaluados mediante HPLC-DAD. Además, se determinó su actividad antioxidante. El diseño experimental fue completamente al azar y con tres repeticiones. El contenido mayor de ácidos fenólicos totales se detectó en Sudán y Alma Blanca (10.71±0.29 y 8.22±0.30 mg EAG g-1 MS). La fracción de ácidos fenólicos libres (AFL) fue abundante y con complejidad alta en los cálices de los tres colores. El ácido clorogénico y sus dos isómeros predominaron en las fracciones AFL y los ácidos fenólicos glucosilados (AFG) representaron entre 77.4 y 81.5 % del total de ácidos fenólicos en las tres variedades. Los cálices blancos tenían la cantidad mayor de ácido cafeico y derivados de protocatéquico. La actividad antioxidante mayor (p≤0.05) se presentó en el extracto de Sudán (IC50=113.3 μg mL-1). El color de los cálices puede ser un indicador del tipo predominante de fenoles en H. sabdariffa L. y ayudar en la selección de variedades para obtener formulaciones con propiedades nutracéuticas particulares.

A total of 221 strains of Aeromonas species isolated in Mexico from clinical (161), environmental (40), and food (20) samples were identified using the automated system bioMérieux-Vitek®. Antisera for serogroups O1 to 044 were tested using the Shimada and Sakazaki scheme. The K1 antigen was examined using as antiserum the O7:K1C of Escherichia coli. Besides, we studied the antimicrobial patterns according to Vitek AutoMicrobic system. Among the 161 clinical strains 60% were identified as A. hydrophila, 20.4% as A. caviae, and 19.25% as A. veronii biovar sobria. Only A. hydrophila and A. veronii biovar sobria were found in food (55 and 90% respectively) and environmental sources (45 and 10% respectively). Using "O" antisera, only 42.5% (94/221) of the strains were serologically identified, 55% (121/221) were non-typable, and 2.5% (6/221) were rough strains. Twenty-two different serogroups were found, O14, O16, O19, O22, and O34 represented 60% of the serotyped strains. More than 50% of Aeromonas strain examined (112/221) expressed K1 encapsulating antigen; this characteristic was predominant among Aeromonas strains of clinical origin. Resistance to ampicillin/sulbactam and cephazolin was detected in 100 and 67% of Aeromonas strain tested for their susceptibility to antibiotics. In conclusion, antibiotic-resistant Aeromonas species that possess the K1 encapsulating antigen and represent serogroups associated with clinical syndrome in man are not uncommon among Aeromonas strains isolated from clinical, food and environmental sources in Mexico.