STABILITAS SENYAWA FENOLIK DALAM EKSTRAK DAN NANOKAPSUL KELOPAK BUNGA ROSELLA PADA BERBAGAI VARIASI pH, SUHU DAN WAKTU

Abstract

The extract which is still in liquid form, has several weaknesses, such as unstable in enviroment changes, low flexibility uses and trouble in material handling and transportation. For these reasons, nanoencapsulation technique using β-siklodextrin as matrix agent is an alternative way. The aims of this research were characterization of total phenols, antioxidant activity of nanoencapsulation and the stability of the extract as well as nanocapsules against the changes of pHs, temperatures and boiling times. Nanocapsules of roselle extract was containing phenol 4,53 + 0,26 mg/g, anthocyanin 2,99 + 0,18 mg/g, vitamin C 2,77 + 0,04 mg/g and water moisturizer 5,16 + 0,03%, antioxidant activity 49%. Nanocapsules more resistence against the enviroment changes than the extract itself. The stability test against the enviroment changes, the nanocapsules form more stable than the extract. Showed with the slope of linier regression of nanocapsules form for phenols and antioxidant activity, respectively were: 0,111; 1,307 lower than the extract : 2,825; 7,634. Nanocapsules more resistence against temperature and boiling time than the extract itself. The stability test against temperature and boiling time, the nanocapsules form more stable than the extract. Showed with the slope of linier regression of nanocapsules for phenols and antioxidant activity respectively were: 1,3315; 0,3162 lower than the extract : 1,5864; 0,5389

Antibacterial Potential of Star Anise (Illicium verum Hook. f.) Against Food Pathogen Bacteria

“…As the pH increase, effectiveness of fatty acid absorption would decrease, thus the antibacterial activity also decreased (McGaw et al 2002). Purbowati et al (2016) and Pan et al (2014) added that phenolic compounds in the extract are damaged by increased pH and causing the antibacterial activity became less effective. In reverse, a decrease in + pH (an increase in H ions) causes bacterial cytoplasm became less stable and it needs more energy to restore the cell's internal pH to normal state.…”

“…Cell metabolism will be disturbed as more energy required to keep the normal state of cell's internal pH, then the bacteria cells will die over time (Naufalin et al 2006). The decrease in pH also increases the stability and effectiveness of phenolic compounds which are more hydrophobic in acidic conditions thereby facilitating the dissolution of bacterial membrane fat (Purbowati et al 2016;Pan et al 2014).…”

Acidity level control formulation of roselle tea functional drinks based on variations in the addition of flower petals and sugar type

“…These mixtures were then transferred into the microwave and extracted in 250 W power for 5 mins. Every two minutes of radiation and then rested for one minute to keep the temperature from rising above the boiling point (Purbowati et al, 2016). These mixtures were filtered using Whatman 42 paper, and then the filtrate was added with one of the sugar types used about 10% (w/v) from filtrate volume.…”

“…Based on the characteristic of roselle bioactive compound, MAE is an effective extraction technique to withdraw dissolved materials within roselle petals (Purbowati et al, 2016). This technology is suitable for thermolabile compound's extraction due to its better temperature control compared to conventional heating process.…”

Performance Improvement of Yogurt Through the Variation of Roselle Extract Addition and Fermentation Time

“…The bioactive compounds in the cell plant were obtained by the extraction processed. According to Purbowati et al (2016), MAE was an effective technique for extracting bioactive roselle compounds. The 4.91 minutes extraction time and extraction power of 250 W, extracted pHenolic compounds (19.45 ± 0.32 mg/g), anthocyanins (13.51 ± 0.03 mg/g) and vitamin C (20.47 ± 0.34 mg/g) efficiently.…”