Study of Using Different Processing Techniques for Extraction of Functional Components in Citrus Peels

Autor: Jhen-Rong Syu, 徐振榮
Rok vydání: 2013
Druh dokumentu: 學位論文 ; thesis
Popis: 102
Citrus peels contain functional methylated flavones, especially, nobiletin and tangeretin, are industrially valuable. A combination of a certain processing techniques, including hot-air drying under different temperatures, nano-powdered techniques and ultrasonic-assisted extraction, were applied in this study. First, citrus peels were treated with either 100℃ or 150℃ hot-air dry to afford raw powders (CP100,CP150). The auto sieving machine and jet mill were applied to obtain different particle sizes of powder (CP1-CP5), which were subjected to extraction under different ultrasonic frequencies. The contents of polyphenols and functional components as well as antioxidant activities were compared to find the best processing for extraction. The results indicated that by comparing the contents of polyphenols after extraction under different conditions, 20 kHz of ultrasound effectively micronized the CP powders, optimizing the extraction results, especially CP3 and CP5 produced from a certain processing. In addition, by comparing the antioxidant activities among the five extracts of CP powders, the groups treated with 20 kHz of ultrasound showed much less significant differences of antioxidant value among different particle sizes of samples, compared with those treated with 40 kHz. The result explained extraction with lower frequency of ultrasound effectively reduced the differerential physical of CP powders properties among the CP powders after various processing processes. The contents of basic components of CP powders, including crude fat and fiber, were also evaluated. The major functional components were isolated by column chromatography and identified as nobiletin and tangeretin after UV-Vis spectrometry and ESI-MS spectra analysis.
Databáze: Networked Digital Library of Theses & Dissertations
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