Review on Degradation Technology of Polymeric Proanthocyanidin

Proanthocyanidins are a kind of flavane-3-alcohols which exist widely in nature. Because most of the proanthocyanidins obtained from nature are high polymer proanthocyanidins with benzene ring or long carbon chain, their physiological activity is weak. Through degradation, the physiological activity and application range of proanthocyanidins can be enhanced. Therefore, the degradation technology of high polymer proanthocyanidins has became a research hotspot at home and abroad. In this paper, the literature reports on the degradation technology of proanthocyanidin polymers at home and abroad are sorted out in detail, and the chemical, biological and physical degradation technologies are reviewed in detail. Among them, the chemical degradation technology mainly breaks the link bond between C₄-C₈ in proanthocyanidin polymer to obtain low molecular weight fragments through acid, alkali, nucleophile and hydrogenation degradation, and biodegradation technology uses microorganisms and biological enzymes to open the benzene ring of proanthocyanidin polymer to oligomer. Physical degradation technology reduces high polymer proanthocyanidins to oligomeric proanthocyanidins by using physical techniques such as ultrasonic, pulsed strong light, ultra-high pressure, microfluidic and electron beam irradiation. In this paper, the degradation effects, degradation processes, degradation mechanisms, advantages and disadvantages of various degradation technologies of proanthocyanidins are summarized, and the degradation technology of proanthocyanidins is prospected.