e-journal

Temperature-dependent studies on the total phenolics, flavonoids, antioxidant activities, and sugar content in six onion varieties

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Heating effect on total phenol, flavonoids, antioxidant activity, and sugar content of six onion varieties has been quantitatively investigated to explore the effect of different temperatures. The onion varieties comprised one red-skinned variety, two white-skinned varieties,and three yellow-skinned varieties. The heating temperature was scanned at 80
C,100
C, 120
C, and 150
C for 30 minutes each, and quantitative analysis was performed relative to the powdered onion at ambient temperature. Quercetin, glucosides and sugar content were analyzed using high-performance liquid chromatography. The total phenolic and antioxidant content increased in all six varieties. The total flavonoid levels showed a considerable change. On heating the onion samples at 120
C for 30 minutes, the red-skinned variety showed the highest level of total phenolic content [13712.67 ± 1034.85 mg of gallic acid equivalent/g dry weight (mg GAE/g DW)] and total flavonoids [3456.00 ± 185.82 mg of quercetin equivalents/g dry weight (mg Q/g DW)], whereas the content of total phenolics and total flavonoids were 13611.83 ± 341.61 mg GAE/gDWand 3482.87 ± 117.17 mg Q/g DW, respectively,
for the yellow-skinned (Sunpower) variety. Quercetin and its glucoside contents increased up to 120
C and then decreased at 150
C, whereas the sugar content continuously decreased with heating. All cultivars showed the same pattern in the heating effect, and the predominant flavonoids were destroyed at higher temperatures. Therefore, it is improper to expose onion powder to a temperature higher than 120
C

Keywords:
antioxidant activity onion powder sugar content total flavonoids total phenolics

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Informasi Detail

Judul Seri

j ournal of food and drug anal ys i s

No. Panggil

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Penerbit

: Elsevier Taiwan., 2015

Deskripsi Fisik

j ournal of food and drug anal ys i s 2 3 ( 2 0 1 5 ) 2 4 3 e2 5 2

Bahasa

English

ISBN/ISSN

-

Klasifikasi

-

Tipe Isi

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Tipe Media

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Tipe Pembawa

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Edisi

-

Subjek

Food And Health

Info Detail Spesifik

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Pernyataan Tanggungjawab

Wati/Agus

Versi lain/terkait

Lampiran Berkas

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