High resolution-liquid chromatograph mass spectrometer characterization of bioactive compounds in pineapple wastes: Valorization of antioxidant and enzymatic activity

Abstract

An high resolution liquid chromatograph-mass spectrometer (HR-LCMS) Orbitrap system was employed to detect bioactive compounds within pineapple fruit and peel waste. The primary objective was to analyze flavonoids, polyphenols, and the antioxidant capacity present in these waste materials. Methanol extracts from both pineapple fruit and skin trimmings exhibited a higher concentration of phenolic components compared to aqueous and hexane extracts. HR-LCMS analysis identified seventeen diverse polyphenols, including derivatives of benzoic acid, hydroxyl-cinnamic acid, and hydroxyl-benzoic acid groups. Regarding total phenols and flavonoids, the pineapple peel demonstrated a higher concentration of these compounds than the pineapple pulp. In addition, the methanol extract demonstrated superior antioxidant capacity compared to the aqueous and hexane extracts. The study also found that the methanol extracts from pineapple fruit and peel residues were effective in inhibiting the DPPH radical in a concentration-dependent manner. High-temperature SDS-Tris-HCl buffered protein extraction and digestion resulted in maximum protein production. The bromelain’s proteolytic activity revealed that the fruit waste had a higher pH than the peel waste. HR-LCMS analysis identified 302 proteins in fruit waste and 77 proteins in peel waste. In silico analysis characterized 154 differentially expressed proteins, of which 110 were commonly expressed, and 38 remained uncharacterized. These proteins were categorized into seven functional groups. Going forward, the research will focus on separating and purifying proteins and phenolic compounds from the waste materials. The biological potential of these compounds will be assessed for various applications, including pharmaceuticals, nutraceuticals, and the food industry. This study aims to harness the valuable resources present in pineapple fruit and peel waste for practical utilization in diverse fields.