Improvement of extraction and stability of anthocyanins, the natural red pigment from roselle calyces using supercritical carbon dioxide extraction. (February 2022)

• Record Type: Journal Article
• Authors: Idham, Zuhaili; Putra, Nicky Rahmana; Aziz, Ahmad Hazim Abdul; Zaini, Ahmad Syahmi; Rasidek, Noor Azwani Mohd; Mili, Norlisa; Yunus, Mohd Azizi Che
• Is Part Of: Journal of CO₂ utilization. Volume 56(2022)
• Publication Date: 2022-02
• Subjects: Anthocyanins -- Natural colourant -- Roselle calyces -- Supercritical carbon dioxide -- Phenolic compounds -- Optimization -- Storage stability; Carbon dioxide -- Periodicals; Carbon dioxide -- Environmental aspects -- Periodicals; Carbon dioxide mitigation -- Periodicals; Carbon dioxide; Carbon dioxide -- Environmental aspects; Carbon dioxide mitigation; Periodicals; 628.53205
• DOI: 10.1016/j.jcou.2021.101839
• Languages: English
• ISSNs: 2212-9820

Abstract

Highlights: SC-CO2 with EtOH/H2 Omaximized anthocyanin recovery from roselle calyces. Pressure and co-solvent ratios affected anthocyanins, polyphenol and colour quality. SC-CO2 outperforms the SLE methods in TAC and other polyphenols recovery. Due to greater co-pigment in extract, SC-CO2 improved anthocyanin stability. Abstract: In this work, anthocyanins, a natural red pigment, were isolated from roselle calyces using supercritical carbon dioxide (SC-CO2 ). Three process conditions, namely pressure, temperature, and co-solvent ratio (ethanol-water), were investigated using a three-factorial design from response surface methodology (RSM). The method was used to model the extraction of anthocyanins, total phenolic content, total flavonoid content, and colour characteristics (i.e., lightness (L*), chroma (C*), and hue (h°)). The best conditions were 27MPa, 58 °C, and 8.86 % co-solvent ratio at maximal anthocyanin, phenolic, and flavonoid content, with minimal L* and C* values. The anthocyanin production was 1197 mg/100 g of dried roselle calyces. Next, the high relative value of cyanidin 3-sambubioside and phenolic compound in SC-CO2 extract was analyzed using an ultra-high-performance liquid chromatogram (UHPLC). Anthocyanins stored at 4 °C, 25 °C, and 37 °C had average reaction rate (k) and half-life (t1/2 ) values of 0.0032 and 216 days, 0.0098 and 70 days, and 0.024 and 28 days for SC-CO2 and 0.0093 and 74 days, 0.0222 and 31 days, and 0.0444 and 15 days for solid-liquid extraction (SLE), respectively, in first-order degradation kinetics. These findings demonstrated that the studied conditions using SC-CO2 provided lower degradation rates and a longer t1/2 than the conventional SLE methods.