RESUMEN
Dendrobium spp. were investigated for their chemical compositions with HPTLC/CMS, and biological properties, including antioxidant activities (DPPH and ABTS.+ assay), and anti-acetylcholinesterase (AChE). The ethanolic extracts of Dendrobium orchid pseudobulbs (D. chrysotoxum; DC, D. fimbriatum; DF, D. lindleyi; DL, and D. pulchellum; DP) were found to contain caffeic acid, gallic acid, quercetin, rutin hydrate and vanillin. While luteolin was shown in D. fimbriatum and D. lindleyi extracts. D. lindleyi, and D. pulchellum extracts presented the high value of total phenolic and flavonoid contents, resulting in a strong antioxidant property. Moreover, D. chrysotoxum extract expressed AChE inhibitory potential. This research indicated that chemical compounds in Dendrobium would be involved with their biological properties, i.e. antioxidant and anti-AChE. This information can be used to support further in-depth research and product development in health, food, and pharmaceutical.
RESUMEN
Five selected medicinal plants in the family Zingiberaceae, Alpinia nigra, Boesenbergia maxwellii, Etlingera araneosa, Meistera koenigii, and Wurfbainia biflora, were collected from Thailand. HPLC was used to determine the content of phenolic compounds in their ethanolic extracts. The total phenolic contents and the total flavonoid contents of M. koenigii were found to be higher than that of the others. The antioxidant activity of the extracts was assayed by two methods, namely ABTS and DPPH assays using HPTLC and a microplate spectrophotometer. Anticholinesterase activity was screened by the Ellman method against acetylcholinesterase, the chief enzyme of Alzheimer's disease. The results showed mild acetylcholinesterase effects. The results indicated that these five ginger species, especially M. koenigii have the potential to be a good source of natural antioxidants and anticholinesterase agents that could be further applied in the pharmaceutical industry.
RESUMEN
Anthocyanin-rich extracts derived from the bran of a select Thai black rice cultivar, Leum Pua, were encapsulated by spray drying. In this microencapsulation method, twelve wall materials comprising maltodextrin (M), gum arabic (G), whey protein isolate (W), and their combinations were employed. For comparison, an ionic gelation method was employed using alginate-whey protein isolate (AL-W) as a wall material. Thirteen microcapsules were analysed by scanning electron microscopy, and their encapsulation efficiencies were almost 100%, except for that of the W (83%). M (88%) and its combination with W exhibited the best anthocyanin retention, while pure W contained the highest amount of total phenolic compounds and antioxidant activity. An in vitro digestion study using simulated gastrointestinal fluids revealed the highest released total phenolic content and antioxidant activity of the intestinal fluids when the microcapsule was spray-dried with pure W.