Ultrasound-assisted extraction of bayberry tannin and optimization using response surface methodology

Abstract

The extraction of bayberry tannins has potential to maximize the utilization of a forest waste. This study employed a four-level central composite design through response surface methodology to optimize the extraction of tannin from bayberry barks through ultrasound-assisted extraction (UAE). The effects of solute to solvent ratio (STSR), solvent concentration (SC), extraction time (ET), and sonication temperature (ST) on the total extraction yield of total condensed tannin (TCT yield) and total phenolic content (TPC) were investigated. The extracts were characterized with matrix-assisted laser desorption-time of flight mass spectrometer (MALDI-TOF MS), nuclear magnetic resonance (NMR), and gel permeation chromatography (GPC). The optimized condition was reached when the STSR and ST were set at 1:57.16 g/mL and 71.3%, when the ET and the ST was 39.1 min and 48.75 °C. In these conditions, the TCT yield and TPC reached their maximum values of 17.55% and 365.01 mg GAE/g, respectively. Furthermore, the polyflavonoids of bayberry tannin ranged from dimers to heptamers, which were only composed of proanthocyanidins (PC) containing galloy groups.

Antioxidant Properties of Larch Tannins with Different Mean Polymerization Degrees: Controlled Degradation Based on Hydroxyl Radical Degradation

“…The larch bark was washed with deionized water, freeze-dried, pulverized, and passed through a 100-mesh sieve to obtain larch bark powder. The extraction process of larch tannins was carried out in an ultrasonic water bath system (KQ-300DE, Kunshan, China), 17 and the main process is as follows: the ratio of larch bark powder to the extraction solvent was 1:60 (g/mL), and the methanol aqueous solution at the concentration of 70% was extracted. The ultrasonic power was 300 W, the extraction time was 40 min, and the extraction temperature was controlled at 50 ± 2 °C.…”

Component and Structure of Aspergillus flavipes sp.-Biodegraded Bayberry Tannins: A Potential Routine for Condensed Tannin Cleaner Degradation and Disposal

“…Bayberry tree is a kind of subtropical plant which belongs to the Myricaceae family and is considered as an important economic plant and widely distributed in South China . Bayberry tannins are extracted from the bark and classified as the condensed type. , The high content of hydroxyl and galloyl groups in bayberry tannins is considered as its most obvious character and differentiates it from other condensed tannins .…”