Effect of ph on the stability of red beet extract (Beta vulgaris l.) microcapsules produced by spray drying or freeze drying

Abstract Red beets is rich in phenolic acids and has high antioxidant capacity, and can be used to produce a natural dye. This study evaluated the effect of pH (3 to 6) on the stability of red beet extract microcapsules, dried by freeze drying and spray drying and stored at room temperature. The microcapsules were produced using a combination of maltodextrin and xanthan gum as encapsulating agents and stored for 7 days. For all evaluated microcapsules, a degradation of betanin was observed, however, that degradation was independent of pH, with the exception of the sample with maltodextrin and dried by spray drying. The freeze dried products showed lower degradation constants and higher half-life (t1/2) when comparing with the spray dried samples. The microcapsules containing maltodextrin and xanthan gum, dried by spray drying, showed the highest change in the content of phenolic compounds after storage for 7 days. The color parameters showed a reduction for a*, and increase in b* and L*, for all samples during the storage time. In general, the microcapsules produced using maltodextrin and xanthan gum, and dried by freeze dryer, showed higher stability in terms of betanin content, phenolic compounds and color parameters during storage at different pHs.

Betanin down-regulates the protein coding transcripts of the pyruvate by-pathway in mitochondia of HeLa cells / 中国药学杂志

OBJECTIVE: To study the effects of batanin on proliferation of HeLa cells and the relationships with pyruvate metabolism and glycolysis. METHODS: The HeLa cells were cultured in vitro and betanin at 0, 62.5 and 500 mg·L-1 was added after the attachment of the cells. The cells were harvested after 48 h of culture for the cell counting and storaged at low temperature. Referring to human genome, the frozen cells were carried out for the analysis and calculation of high-throughout transcrip-tome. Utilizing internet data base, the parts related with glycolysis, pyruvate metabolism and citric cycle were selected and analyzed to study the effect of betanin on the protein coding transcripts of the glycolysis and citric cycle in HeLa cells. RESULTS: Betanin with both of the 2 concentrations inhibited the proliferation of the cultured HeLa cells, and affected the transcript reads of the cultured cells. There were 74 of protein coding transcripts expressed in HeLa cells, but only 40 of them had the reads >1 or <1 but with significant difference between treatments. Betanin significantly up-regulated the protein coding transcripts of the phosphofructokinase (platelet) (ENST00000381075) and fructose-1,6-bisphosphatase 1 (ENST00000375326) which were rate-limited enzymes in the glycolysis and gluconeogenesis respectively, it was benefit for cell metabolism, possibly being the stress response of the cell to betanin. However, betanin significantly down-regulated the protein coding transcript of the mitochondial lactate dehydrigenase D (LDHD) (ENST00000450168) of HeLa cell, and the mitochondial phosphoenolpyruvate carboxykinase 2 (PEPCK) also had a tendency to being down-regulated, which all were related with pyruvate metabolism. CONCLUSION: The inhibition of betanin on proliferation of HeLa cell is related with the down-regulation of the protein coding transcripts of the LDHD and PEPCK of the mitochondrial pyruvate metabolism of the cell.