چكيده فارسي :
In this work modified Cellulose nanofibers was applied for extraction of Secondary Metabolites from oolang tea [1]. After the preparation of 5.0 g of the leaves, 250 mL hot water (15 min) was used to prepare the extracts. Then a chemometrics approach was applied for the optimization of the extraction parameters such as Sorbent mass, volume and concentration of aqueous solution of CTAB, percentage and type of acid and vortex time. The extraction yield acted as the comprehensive evaluation index. Total phenolic compounds, total flavonoid compounds, and antioxidant activity were used to evaluate these extracts. The individual phenolic compounds found in the extracts were characterized and quantified by HPLC.The oolang tea extract showed the highest total phenolic and flavonoid values, at 98.94 mg GAE/g and 73.12 mg RE/g, respectively. The HPLC results have shown that the levels of gallic, syringic, caffeic, ferulic, luteolin and apigenine were as follows: 61.008, 0.104, 1.115, 0.0394, 3.782 and 4.215 mg/g, respectively. Under the optimum conditions, the values of intra and inter day RSD were in the range of 3.67–5.19% and 6.37–10.02%, respectively. The limits of detection (LODs) ranged between 3.15 – 6.28 ngmL-1 respectively. The method was successfully applied for the preconcentration of phenolic compounds in oolang tea. Moreover, these experimental values were higher than those obtained from previously reported. This study suggests that surfactant assisted solid phase microextraction can be utilized as sustainable and safe extraction method for natural product extractions.
