Pineapple (Ananas comosus [L.] Merr.) Cv. queen peel herbal tea with a variety of drying temperatures: bioactive compounds, antioxidant activity and antimicrobial activity

Abstract

Pineapple peel is a by-product that is potentially developed to be herbal teas. The research objectives were to find out the proper drying temperature on total biochemical content, antioxidant and antimicrobial activity, and sensory properties of pineapple peel herbal tea. The pineapples peel herbal tea was prepared by drying peels in a cabinet dryer for 12 hours at 50, 60 and 70oC. Qualitatively, phytochemical screening was analyzed for the presence of flavonoids, alkaloids, tannins, phenols, and terpenoids. Quantitatively, total phenols, flavonoid, and alkaloid were determined by the colourimetric method. The DPPH methods applied to measure free radical scavenging activity, and the diffusion method was determined antimicrobial activity. The phytochemical screening showed the absence of terpenoid in pineapple peel teas dried at three different temperatures. The drying temperature at 60oC and 70oC produced total bioactive compounds (phenolic, flavonoid, and alkaloid) better than 50oC. Furthermore, the most significant antioxidant activity against DPPH was obtained from the product dried at 60oC with an IC50 of 448.31 ppm. All those herbal teas were suitable for the growth suppressing of Bacillus subtilis and Candida albicans. This study found that pineapple peel tea herbal with 60oC drying temperature was the most significant value based on bioactive components, antioxidant and antimicrobial activity, which are considered potential herbal tea products.