Microencapsulation of steroidal saponins from agave sap concentrate using different carriers in spray drying.

Concentrated agave sap is a product with in vivo proven hypocholesterolemic and hypoglycemic activities, as well as in vitro anticancer potential. In the present work, a factorial design was used to determine the suitable drying conditions of concentrated agave by studying the effect of inlet temperature (150 °C, 180 °C and 210 °C) and the type of carrier agent (maltodextrin, hydroxypropyl methylcellulose, guar gum and xanthan gum). The response variables for each treatment were the product recovery and microencapsulated saponins. Further characterization of concentrated agave powders was performed: solubility in water, hygroscopicity, moisture content, tap density, bulk density, Carr's index followability and morphology by scanning electron microscopy analysis. The hydroxypropyl methylcellulose proved to improve physicochemical properties and enhance product yield, using 210 °C inlet temperature and a mix of carrier agents of maltodextrin/hydroxypropyl methylcellulose/xanthan gum at 50/48.5/1.5 (w/w/w) proportion exhibited the highest saponin recovery of 53.81%. Moreover, different carrier agents in powders revealed two shapes, regular spherical shape with smooth surface and collapsed shapes. The use of polymers excipients helped to decrease the stickiness of the desired product and enhanced the powder stability and microencapsulation of the steroidal saponins.

Nutraceutical Potential of Five Mexican Brown Seaweeds.

In search of pharmaceutically active products to control type 2 diabetes, five brown seaweeds (Silvetia compressa, Cystoseira osmundacea, Ecklonia arborea, Pterygophora californica, and Egregia menziesii) from the Northwest Mexican Pacific coast were investigated. Proximate composition and total polyphenol content (TPC) as phloroglucinol equivalents (PGE) were determined for the five seaweed powders and their respective hydroethanolic (1 : 1) extracts. Extracts were screened for their radical scavenging activity (DPPH and ORAC) and glycosidase inhibitory activity. HPLC-DAD, HPLC-MS-TOF, and ATR-FT-IR methodologies were used to identify the most abundant phlorotannins and sulfated polysaccharides in the extracts. Hydroethanolic extracts contained minerals (17 to 59% of the dry matter), proteins (4 to 9%), ethanol-insoluble polysaccharides (5.4 to 53%), nitrogen-free extract (NFE) (24.4 to 70.1%), lipids (5 to 12%), and TPC (2.6 to 47.7 g PGE per 100 g dry extract). S. compressa and E. arborea dry extracts presented the lowest ash content (26 and 17%, respectively) and had some of the highest phenolic (47.7 and 15.2 g PGE per 100 g extract), NFE (57.3 and 70.1%), and soluble polysaccharide (19.7 and 53%) contents. S. compressa and E. arborea extracts had the highest antioxidant activity (IC50 DPPH 1.7 and 3.7 mg mL-1; ORAC 0.817 and 0.801 mmol Trolox equivalent/g extract) and the highest α-amylase and α-glucosidase inhibitory capacities (IC50 940 and 1152 µg mL-1 against α-amylase and 194 and 647 µg mL-1 against α-glucosidase). The most abundant phlorotannins identified in the extracts were phloretol, fucophloroethol, and two- and three-phloroglucinol unit (PGU) phlorotannins. Laminarin, fucoidan, and alginate were among the sulfated polysaccharides identified in the extracts. The bioactivities of S. compressa and E. arborea extracts were mainly related with their contents of three PGU phlorotannins and sulfated polysaccharides (e.g., fucoidan, laminarin, and alginate). These results suggest S. compressa and E. arborea are potential candidates for food products and nutraceutical and pharmaceutical preparations, and as additives for diabetes management.

Effect of ultrasound transducer design on the acoustically-assisted supercritical fluid extraction of antioxidants from oregano.

Power ultrasound is applied in food technology to intensify extraction processes, due to the phenomena ultrasonic energy induces in the medium, enhancing mass transfer. The purpose of this work was the acoustic characterization of four transducers of different geometries and the evaluation of their performance in the ultrasonically assisted supercritical fluid extraction of antioxidants from oregano. The transducers differed in the amount of energy transmitted into the medium. Designs varied from the base model (T1), a larger cylindrical headmass (T2), a stepped circular section sonotrode (T3) and a multiplate configuration (T4). The highest nominal power density provided according to the calorimetric method was for T4 (151.6 ±â€¯7.1 W/L). The T2 produced a more uniform acoustic field and a higher acoustic pressure (150.6 ±â€¯20.5 kPa). Both parameters had an impact on total phenolics and antioxidants extraction with CO2 under supercritical conditions (35 MPa, 35 °C, 2.3% ethanol as co-solvent). T4 and T2 were equally efficient (4.0 ±â€¯0.2 and 4.2 ±â€¯0.2 mg GA/g) for phenolic extraction, and with respect to antioxidant capacity, the best performance was that of T4 (26.4 ±â€¯1.1 µmol TE/g). Of the antioxidant compounds extracted, flavones and flavanones were identified. Therefore, transducer geometry influenced the amount and distribution of energy transmitted into the medium, thus determining the efficiency of the extraction process.

Variability in Saponin Content, Cancer Antiproliferative Activity and Physicochemical Properties of Concentrated Agave Sap.

Concentrated agave sap (CAS) has gained popularity as an unrefined sweetener. It is obtained by boiling "aguamiel" that contains phytochemicals with diverse bioactivities. Saponins have been the most widely studied agave phytochemicals due to their cancer antiproliferative effect but their concentration may vary due to maturity of the agave plant and collection site. In this study, 18 CAS samples produced in different states of Mexico were analyzed using multivariate methods to determine which physicochemical or phytochemical parameters were responsible for variation. Additionally, extracts with different saponin profiles were tested to determine possible correlations with antiproliferative activity. Total soluble solids, pH, and water activity were similar to those reported for other agave sweeteners. Antioxidant capacity of samples was correlated to browning index. Eleven steroidal saponins were found in CAS samples and they were the main source of variability. Magueyoside B, a kammogenin tetraglycoside, was the most abundant saponin in all samples. With respect to bioactivity, multivariate analysis indicated that magueyoside B and a gentrogenin tetraglycoside were compounds strongly related with bioactivity. CAS from Hidalgo, Puebla, and Veracruz had higher concentration of magueyoside B than from the other kamogenin tetraglycoside found in the samples from other Mexican states. These results could be used as a first approach to characterize and standardize CAS to validate the potential health benefits derived from its consumption.

Fast Centrifugal Partition Chromatography Fractionation of Concentrated Agave (Agave salmiana) Sap to Obtain Saponins with Apoptotic Effect on Colon Cancer Cells.

Separation of potentially bioactive components from foods and plant extracts is one of the main challenges for their study. Centrifugal partition chromatography has been a successful technique for the screening and identification of molecules with bioactive potential, such as steroidal saponins. Agave is a source of steroidal saponins with anticancer potential, though the activity of these compounds in concentrated agave sap has not been yet explored. In this study, fast centrifugal partition chromatography (FCPC) was used coupled with in vitro tests on HT-29 cells as a screening procedure to identify apoptotic saponins from an acetonic extract of concentrated agave sap. The three most bioactive fractions obtained by FCPC at partition coefficients between 0.23 and 0.4 contained steroidal saponins, predominantly magueyoside b. Flow cytometry analysis determined that the fraction rich in kammogenin and manogenin glycosides induced apoptosis, but when gentrogenin and hecogenin glycosides were also found in the fraction, a necrotic effect was observed. In conclusion, this study provides the evidence that steroidal saponins in concentrated agave sap were potential inductors of apoptosis and that it was possible to separate them using fast centrifugal partition chromatography.

Effect of Agave americana and Agave salmiana Ripeness on Saponin Content from Aguamiel (Agave Sap).

Steroidal saponins have shown beneficial health effects. Agave spp. leaves and rhizomes are sources of these compounds, but their presence has not been reported in the aguamiel. Aguamiel is the sweet edible sap from mature agave, and its quality is influenced by the plant ripening stage. The purpose of this research was to identify and quantitate saponins in aguamiel from Agave americana and Agave salmiana at two ripening stages. Saponins and sapogenins were identified with HPLC/ESI-MS/TOF and quantitated with HPLC/ELSD. Results proved the presence of saponins derived from kammogenin, manogenin, gentrogenin, and hecogenin. The saponin content in aguamiel from immature A. salmiana was 2-fold higher (478.3 protodioscin equivalents (PE) µg/g aguamiel (DM)) compared with A. americana (179.0 PE µg/g aguamiel (DM)). In both species, saponin content decreased when plants reached sexual maturity. This should be considered before evaluating the effects of Agave spp. as a source of bioactive saponins.

Comparative analyses of total phenols, antioxidant activity, and flavonol glycoside profile of cladode flours from different varieties of Opuntia spp.

The phenolic, flavonoid, and antioxidant contents of methanol extracts of nine samples of Mexican cactus ( Opuntia spp.) cladodes processed into flours were studied. Opuntia undulata contained the highest amount of phenols [905.08 ± 64.51 µg of gallic acid equivalents (GAE)/g]. The oxygen radical absorbance capacity (ORAC) of the cladode flour extracts indicated that Opuntia robusta var. Gavia [738.8 ± 89.9 µmol of Trolox equivalents (TE)/g] contained the highest antioxidant capacity. ORAC values significantly correlated to total phenols but not to flavonoid contents and were comparable to cranberries and blackberries. Glycosidic forms of isorhamnetin and kaempferol were identified via high-performance liquid chromatography-photodiode array (HPLC-PDA) and HPLC-mass spectrometry (MS), with isorhamnetin being the most abundant flavonol in all samples, except for Opuntia lindheimeri . The effectiveness of acid hydrolysis varied among species because of the different flavonol profiles. For some varieties, the triglycosidic forms were partially acid-hydrolyzed, giving an increase in the content of diglycosides. Optimization of hydrolysis for each species is required to estimate the total amount of each flavonol.