IntroductionOnion (Allium cepa L.)

Introduction

Onion (Allium cepa L.) is a biennial plant belonging to the Liliaceae family, one of the most important vegetable crops with a world production of about 55 million tons ( Shokoohinia et al., 2016, Griffiths et al., 2002, Teena et al., 2016 and Raja et al., 2016). It is known to contain many phytochemicals such as carotenoids, copaenes, flavonoids, minerals, phenolics, phytoestrogens, terpenoids, vitamins, anthocyanins, and amino acids. Approximately 80% of the onion bulbs consist of nonstructural carbohydrates such as glucose, fructose, sucrose, and low molecular weight fructooligosaccharides ( Benkeblia et al., 2007 and Galdon et al., 2008). Onion is a versatile vegetable and typically used as an ingredient in many dishes besides a variety of uses in the fresh form, such as salads and in sandwiches. The bulbs are the main edible part, with a distinctive strong flavor and pungent odor. They are classified based on their color into yellow, red and white and based on their taste as sweet and non-sweet (Miean and Mohamed, 2001). White, yellow and red types of onions are reported to be rich in flavonols including mainly quercetin, kaempferol, tannins and organosulfur compounds like allyl propyl disulfide and diallyl disulfide (Miean and Mohamed, 2001). Among the flavonols, quercetin was connected with a hydroxyl and carbonyl at the carbon position of benzene ring and a double bond between 2 and 3 carbons. Quercetin aglycone, quercetin-3,4′-O-diglucoside and quercetin-4′-O-glucoside are the predominant forms of quercetin in onions ( Price and Rhodes, 1996). A research conducted by Hertog et al. (1992) reported that onions ranked the highest in quercetin content of 28 vegetables and 9 fruits. Gorinstein et al., 2008 claimed that the levels of quercetin in red onions were 14-fold higher than that of garlic, whereas the levels were twofold higher than white onions. In addition, quercetin amounts in the onion peel were 48-fold more than the flesh.

In the recent years, many researchers involved in comparing the antioxidant activity of Allium species but a limited number of reports are available on the identification and quantification of some beneficial compounds, such as quercetin aglycone, quercetin 3,4′-O-diglucoside and quercetin-4′-O-glucoside ( Stratil et al., 2006, Yoo et al., 2010 and Ko et al., 2015). Therefore, the present paper reports the identification and quantification of quercetin glycosides from three kinds of onions (red, yellow, and chartreuse, commercial chartreuse) cultivated in Korea using HPLC technique.

Results (Indonesian) 1:

PengenalanOnion (Allium cepa L.) is a biennial plant belonging to the Liliaceae family, one of the most important vegetable crops with a world production of about 55 million tons ( Shokoohinia et al., 2016, Griffiths et al., 2002, Teena et al., 2016 and Raja et al., 2016). It is known to contain many phytochemicals such as carotenoids, copaenes, flavonoids, minerals, phenolics, phytoestrogens, terpenoids, vitamins, anthocyanins, and amino acids. Approximately 80% of the onion bulbs consist of nonstructural carbohydrates such as glucose, fructose, sucrose, and low molecular weight fructooligosaccharides ( Benkeblia et al., 2007 and Galdon et al., 2008). Onion is a versatile vegetable and typically used as an ingredient in many dishes besides a variety of uses in the fresh form, such as salads and in sandwiches. The bulbs are the main edible part, with a distinctive strong flavor and pungent odor. They are classified based on their color into yellow, red and white and based on their taste as sweet and non-sweet (Miean and Mohamed, 2001). White, yellow and red types of onions are reported to be rich in flavonols including mainly quercetin, kaempferol, tannins and organosulfur compounds like allyl propyl disulfide and diallyl disulfide (Miean and Mohamed, 2001). Among the flavonols, quercetin was connected with a hydroxyl and carbonyl at the carbon position of benzene ring and a double bond between 2 and 3 carbons. Quercetin aglycone, quercetin-3,4′-O-diglucoside and quercetin-4′-O-glucoside are the predominant forms of quercetin in onions ( Price and Rhodes, 1996). A research conducted by Hertog et al. (1992) reported that onions ranked the highest in quercetin content of 28 vegetables and 9 fruits. Gorinstein et al., 2008 claimed that the levels of quercetin in red onions were 14-fold higher than that of garlic, whereas the levels were twofold higher than white onions. In addition, quercetin amounts in the onion peel were 48-fold more than the flesh.Dalam beberapa tahun terakhir, banyak peneliti terlibat dalam membandingkan aktivitas antioksidan spesies Allium tetapi sejumlah laporan tersedia di identifikasi dan kuantifikasi beberapa senyawa yang bermanfaat, seperti quercetin aglycone, quercetin 3, 4 '-O-diglucoside dan quercetin-4 '-O-glukosida (Stratil et al., 2006, Yoo et al., 2010 dan Ko et al., 2015). Oleh karena itu, laporan kertas hadir identifikasi dan kuantifikasi glikosida quercetin dari tiga jenis bawang (merah, kuning, dan chartreuse, komersial chartreuse) dibudidayakan di Korea menggunakan HPLC teknik.

Results (Indonesian) 2:

Pendahuluan

Onion (Allium cepa L.) adalah tanaman dua tahunan milik keluarga Liliaceae, salah satu tanaman sayuran yang paling penting dengan produksi dunia sekitar 55 juta ton (Shokoohinia et al., 2016, Griffiths et al., 2002, Teena et al., 2016 dan Raja et al., 2016). Hal ini diketahui mengandung banyak fitokimia seperti karotenoid, copaenes, flavonoid, mineral, fenolat, phytoestrogen, terpenoid, vitamin, anthocyanin, dan asam amino. Sekitar 80% dari umbi bawang merah terdiri dari karbohidrat nonstruktural seperti glukosa, fruktosa, sukrosa, dan fructooligosaccharides berat molekul rendah (Benkeblia et al., 2007 dan Galdon et al., 2008). Bawang merupakan sayuran serbaguna dan biasanya digunakan sebagai bahan dalam banyak masakan selain berbagai penggunaan dalam bentuk segar, seperti salad dan sandwich. Lampu adalah bagian yang dapat dimakan utama, dengan rasa yang kuat khas dan bau menyengat. Mereka diklasifikasikan berdasarkan warna menjadi kuning, merah dan putih dan berdasarkan selera mereka manis dan non-manis (Miean dan Mohamed, 2001). Putih, jenis kuning dan merah bawang dilaporkan kaya akan flavonol termasuk terutama quercetin, kaempferol, tanin dan senyawa organosulfur seperti alil propil disulfida dan dialil disulfida (Miean dan Mohamed, 2001). Di antara flavonol, quercetin terhubung dengan hidroksil dan karbonil pada posisi karbon dari cincin benzena dan ikatan ganda antara 2 dan 3 karbon. Quercetin aglycone, quercetin-3,4'-O-diglucoside dan quercetin-4'-O-glukosida adalah bentuk dominan dari quercetin di bawang (Harga dan Rhodes, 1996). Sebuah penelitian yang dilakukan oleh Hertog et al. (1992) melaporkan bahwa bawang peringkat tertinggi dalam konten quercetin dari 28 sayuran dan 9 buah. Gorinstein et al., 2008 menyatakan bahwa kadar quercetin di bawang merah yang 14 kali lipat lebih tinggi dari bawang putih, sedangkan tingkat yang dua kali lipat lebih tinggi dari bawang putih. Selain itu, jumlah quercetin di kupas bawang yang 48 kali lipat lebih dari daging.

Dalam beberapa tahun terakhir, banyak peneliti yang terlibat dalam membandingkan aktivitas antioksidan dari spesies Allium tetapi sejumlah laporan yang tersedia pada identifikasi dan kuantifikasi beberapa menguntungkan senyawa, seperti quercetin aglycone, quercetin 3,4'-O-diglucoside dan quercetin-4'-O-glukosida (Stratil et al., 2006, Yoo et al., 2010 dan Ko et al., 2015). Oleh karena itu, tulisan ini melaporkan identifikasi dan kuantifikasi glikosida kuersetin dari tiga jenis bawang (merah, kuning, dan hijau kekuningan, hijau kekuningan komersial) dibudidayakan di Korea menggunakan teknik HPLC.