In this study, vinegar extract was produced from immature seedless Shiikuwasha (Citrus depressa Hayata, Nakamoto seedless) that was harvested from June to August for fruit thinning reasons. The polymethoxyflavone content in the vinegar extracts was 27.7 to 31.6mg/100mℓ. The vinegar extracts contained 1.3 to 1.5mg/100mℓ of limonin, and the sensory test evaluated the taste as being weakly bitter. The content ratio of monoterpenes to monoterpene alcohols in the vinegar extract increased due to the early harvest time. Based on the taste and polymethoxyflavone content, young Shiikuwasha harvested in August is suitable for the production of vinegar extract.
