The effects of boiling and fermentation on betalain profiles and antioxidant capacities of red beetroot products

Characterization of the profile and concentration of betacyanin in the gastric content, blood and urine of rats after an intragastric administration of fermented red beet juice

The aim of the study was to evaluate the profile and level of betacyanins in the gastric content, blood (portal and main veins) and urine of rats after an intragastric administration of fermented red beet juice with various betacyanin doses. Samples were collected within 2 h after juice administration into the stomachs, separated from the digestive tract of a living rat. In the gastric content, betacyanins administered underwent intensive degradation and changes in their profile, as a result of the conditions prevailing in the stomach and the intensity of the absorption process. Detection of 19 betacyanins (8 native compounds and 11 metabolites) in rats' physiological fluids with the HPLC-MS/MS method proves betacyanin absorption from the stomach. In addition, the study results suggest that betacyanin dose affects the rate and extent of betacyanin degradation in the gastric content, as well as the intensity of absorption, metabolism and excretion of these pigments.

Ultrasound and Microwave Assisted Extraction of Opuntia Fruit Peels Biocompounds: Optimization and Comparison Using RSM-CCD

Ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) of bioactive compounds, peels from Opuntia engelmannii cultivar (cv.) Valencia were optimized by response surface methodology. Randomized extraction runs were performed for each of the technologies employed in order to build effective models with maximum (bioactive molecules content and yield) and minimum (antioxidant activity) responses. A 5-level, 4-factor central composite design was used to obtain target responses as a function of extraction time (t), solid to liquid ratio (S/L), methanol concentration (metOH), and temperature (T). Specific response optimization for each technology was analyzed, discussed, and general optimization from all the responses together was also gather. The optimum values for each factor were: t = 2.5 and 1.4 min, S/L = 5 and 5 g/L, metOH = 34.6 and 0% of methanol and T = 30 and 36.6 °C, achieving maximum responses of 201.6 and 132.9 mg of betalains/g, 13.9 and 8.0 mg of phenolic acids/g, 2.4 and 1.5 mg of flavonoids/g, 71.8% and 79.1% of extractable solid and IC₅₀ values for the antioxidant activity of 2.9 and 3.6, for UAE and MAE, respectively. The present study suggested UAE as the best extraction system, in order to maximize recovery of bioactive compounds with a high antioxidant activity.

Solid state fermentation process with Aspergillus kawachii enhances the cancer-suppressive potential of silkworm larva in hepatocellular carcinoma cells

Background

Mulberry silkworm larvae (Bombyx mori) are known as the oldest resource of food and traditional medicine. Although silkworm larvae have been reported to treat various chronic diseases, the effect of fermentation by microorganisms improving the biological activities of silkworm larvae was not reported. In the present study, fermented silkworm larvae was developed via solid-state fermentation with Aspergillus kawachii and investigated its anti-cancer activity in human hepatocellular carcinoma cells.

Methods

We investigated the anti-cancer effects of unfermented (SEE) and fermented silkworm larva ethanol extract (FSEE) on HepG2 human hepatocellular carcinoma cells as well as compared changes in free amino acid, fatty acid, and mineral contents. Anti-cancer activities were evaluated by SRB staining, cell cycle analysis, Annexin V staining, Hoechst staining, DNA fragmentation analysis and western blot analysis. Fatty acid, free amino acid and mineral contents of SEE and FSEE were determined by gas chromatography, amino acid analyzer and flame atomic absorption spectrophotometer, respectively.

Results

Compared with SEE, treatment with FSEE resulted in apoptotic cell death in HepG2 cells characterized by G0/G1 phase cell cycle arrest, DNA fragmentation, and formation of apoptotic bodies. Furthermore, FSEE significantly up-regulated pro-apoptotic as well as down-regulated anti-apoptotic proteins in HepG2 cells. However, an equivalent concentration of SEE did not induce cell cycle arrest or apoptosis in HepG2 cells. Moreover, fermentation process by Aspergillus kawachii resulted in enhancement of fatty acid contents in silkworm larvae, whereas amino acid and mineral contents were decreased.

Conclusion

Collectively, this study demonstrates that silkworm larvae solid state-fermented by Aspergillus kawachii strongly potentiates caspase-dependent and -independent apoptosis pathways in human hepatocellular carcinoma cells by regulating secondary metabolites.

Electronic supplementary material

The online version of this article (10.1186/s12906-019-2649-7) contains supplementary material, which is available to authorized users.

Effects of convective drying and freeze-drying on the release of bioactive compounds from beetroot during in vitro gastric digestion

Drying may alter the microstructure of vegetables and influence the release of bioactive compounds during digestion.