Study On Extraction, Separation, Identification And Stability Of Carotenoids In Orange(Owari)

This paper mainly study the extraction, separation and identification of carotenoid in citrus and stability of the pigment. The study laid theoretical foundation for industrialization manufacture, storage and transportation of orange juice.Carotenoid were extracted by soaking with organic solvents from orange .The optimum conditions of extraction were as follows: petroleum ether: acetone =1:1 (v/v);the rate of solution phase to solid phase 20:l;the temperature 4CTC; the number of extraction:3;extraction time 120min.The analysis method of carotenoids by thin-layer chromatography (TLC), column chromatography and high performance liquid chromatography (HPLC), LC-MS was studied in this paper. A column chromatographic determination was made for the seperafion of carotenoid, the solid phase was magnesium oxide-hyflosuperce (diatomaceous earth) , elution were acetone : petroleum =3:7 and acetone : petroleum =1:1. The elutions were detected by HPLC with hypersilODS2 C18 column and a mobile phase of acetonitrile: methanol: dichloromethane (85:13:2 v/v ) with the constant eluention were used, in this way ,more than 9 carotenoid pigments were sepatated.Since carotenoid is easy to degradation with separation, directly analysed through LC-MS. MS parameters: APCI⁺; source temperature, 150℃;m/z: 500-800. LC parameters: A YMC C30-reversed phase column, The mobile phase consisted of mixtures of acetonitrile , methanol, tert butyl methyl ether, with the gradient eluention. :initial condition was 95%/5%B, 0-9min,86%A,14%B, 9-19min75%A,25%, 19-34min,50%A,50%,34-40min,95%A,5%B,40-50min,95%A,5%;column temperation 25℃, flow rate of 1 ml/min, in this way, more than 10 carotenoids were identified.Carotenoids were acylated with fatty acids generally in plant tissue, more than 7 carotenoids ester were found by HPLC analysis of non-saponified extraction. Whatever fatty acid link to carotenoid, it needs to study farther.The stability of carotenoid were studied, The result showed that high temperature influence the stability of carotenoid; carotenoid was sensitive to sunlight and UV. However, it is not so sensitive to lamplight. Carotenoid was stable in alkaline condition compared to acid condition; The Stability of carotenoid is reduced when Fe³⁺. Fe²⁺, Cu²⁺, Al³⁺ is respective added to its medium whereas other metal ions have no such effect on its stability. Oxidants had destructive effect on carotenoid, reducing agents had hardly effect, and it had protective effect.