Relationship between Sensory Test, and Chemical and/or Physical Properties of Japanese Bunching Onion

Abstract

For characterization of chemical and/or physical taste evaluation of Japanese bunching onion (welsh onion), the relationship between sensory descriptions of pungency, sweetness and texture, and the chemical and/or physical properties were investigated. Pungency score of the fresh bunching onion and the amount of pungent precursors estimated by pyruvic acid production showed a strong positive correlation (r = 0.94**). Sweetness score of the heated bunching onion and brix value did not show a positive correlation, while the concentrations of glucose, fructose, total free sugar, and sucrose equivalent sweetness showed a good agreement with the sweetness score (r = 0.98** to 0.99**). Texture scores (scores of organoleptic hardness) of boiled and grilled bunching onion showed a strong positive correlation with the penetration resistance measured by cylindrical plunger (Φ3 mm) (r = 0.90* to 0.99**). As shown above, pungency and hardness of the bunching onion can be expressed as the amount of pyruvic acid and penetration resistance, respectively. The sweetness should be estimated by the concentrations of glucose, fructose, total free sugar, and the sucrose equivalent sweetness, but not the brix value. Key Words：brix, free sugar, intrusive stress, pyruvate, texture キーワード：貫入抵抗値，ピルビン酸，テクスチャー，糖度，遊離糖 緒 言 近年， 野菜の健康機能性が注目されているにも関わらず， 野菜の消費量は減少傾向を示し，2007 年度の 1 人当たりの 消費量は 1 日 260 g 程度（農林水産省，2009）で，目標と する 1 日当たり 350 g の摂取量にはるかに及ばない状況で ある．また，ネギなどの一部野菜は，近年の輸入野菜の増 加などで市場価格が低迷し，生産農家は大きな打撃を受け ている．例えば，国内におけるネギの年間産出額は，平成 10 年の約 1,720 億円をピークに，平成 17 年には約 1,270 億 円まで減少している（ （独）農畜産業振興機構，2010a） ．ネ