Simultaneous Optimal Production of Flavonol Aglycones and Degalloylated Catechins from Green Tea Using a Multi-Function Food-Grade Enzyme

Abstract

1) Background: Green tea (GT) contains well-known phytochemical compounds; namely, it is rich in flavan-3-ols (catechins) and flavonols comprising all glycoside forms. These compounds in GT might show better biological activities after a feasible enzymatic process, and the process on an industrial scale should consider enzyme specificity and cost-effectiveness. (2) Methods: In this study, we evaluated the most effective method for the enzymatic conversion of flavonoids from GT extract. One enzyme derived from Aspergillus niger (molecular weight 80-90 kDa) was ultimately selected, showing two distinct but simultaneous activities: intense glycoside hydrolase activity via deglycosylation and weak tannin acyl hydrolase activity via degalloylation. (3) Results: The optimum conditions for producing flavonol aglycones were pH 4.0 and 50 • C. Myricetin glycosides were cleaved 3.7-7.0 times faster than kaempferol glycosides. Flavonol aglycones were produced effectively by both enzymatic and hydrochloride treatment in a time-course reaction. Enzymatic treatment retained 80% (w/w) catechins, whereas 70% (w/w) of catechins disappeared by hydrochloride treatment. (4) Conclusions: This enzymatic process offers an effective method of conditionally producing flavonol aglycones and de-galloylated catechins from conversion of food-grade enzyme.

Fermentation of chickpea flour with selected lactic acid bacteria for improving its nutritional and functional properties

“…The interactions between tannases from LAB and several phenolic compounds reported in chickpea flour involve catalytic residues LYS343, GLU357 and ASP421 and HIS451, characteristic of the active site of tannases from L. plantarum. The importance of these amino acid residues was also highlighted in previous studies dealing with molecular docking (de Las Rivas et al, 2019;Rha et al, 2019). It has been reported that lysine, glutamic and aspartic acid and histidine residues found in tannases from Fusobacterium nucleatum may interact hydroxyl groups of ethyl gallate during molecular dynamics simulations (Mancheño et al, 2020), in agreement with chemical interactions determined in our study.…”

Application of Food-Grade Enzymes, Bacteriocins And Probiotics as Biological Food Preservatives

“…The examples include the Bactoferm range that contains the sakacin and pediocin that produce strains and is used in making cured dry meat and the fermented sausages and also the protective cultures of HOLDBAC. Moreover, it contains a mix of the bacteriocin to produce a strain that is used in protecting seafood, dairy products, and meat from moulds, yeast and Listeria (Rha et al 2019). In the current scenario, the novel bacteriocins that are potential as the food preservatives that include the plantaricyclin A, the circular bacteriocins that are produced by isolating the Lactobacillus Plantarum.…”