The Effect of One-Year Fermentation of Maesil Fruit (Prunus mume) Sugar Syrup on Amygdalin Level: A Natural Toxic Compound

Abstract

Prunus mume (maesil) is an economically important fruit in Korea. Recently, public interest in maesil sugar syrup is increasing. However, the presence of toxic amygdalin in the fruit syrup is a concern. Thus, the current investigation aimed to observe effects of maesil maturity, ripening methods, processing, and fermentation period on the amygdalin level in maesil sugar syrup. Six different types of maesil sugar syrup were prepared and amygdalin content was monitored at 3-month intervals. Higher levels (>63 mg/L) of amygdalin were found in syrups prepared from unripe fruit compared to those in syrups made from ripe fruit after 3 months of fermentation. A rapid reduction in amygdalin content was observed until 9 months in all syrups, gradually reducing to <5 mg/L at 12 months. More than 9 months of maturation is crucial for reducing the amygdalin content maesil sugar syrup, regardless of fruit maturity, source of fruit, and processing method.