Effect of the different encapsulation methods on the physicochemical and biological properties of Clitoria ternatea flowers microencapsulated in gelatine

Abstract

Clitoria ternatea flowers are known as butterfly pea flowers which contain many bioactive compounds and can be found in tropical countries. However, the bioactive compounds are easily lost when exposed to various environmental conditions. Encapsulation technologies are introduced to provide maximum protection to the encapsulated bioactive compounds. The main objectives of this study were to determine the physicochemical properties of C. ternatea flowers encapsulated in gelatine prepared using different encapsulating methods and the microbiological properties of the best encapsulating methods for C. ternatea flowers with gelatine. In this study, the moisture contents for ultrasonic spray dried powders recorded the lowest (5.94±0.44%) while samples of convection oven recorded the highest (14.33±1.30%). However, the ultrasonic spray dried powders demonstrated the highest total flavonoid contents, but convection oven dried powders showed the lowest. The results for total anthocyanin contents were similar to total flavonoid contents. The highest encapsulation efficiency based on anthocyanin contents was found in freeze dried powders (95.75±0.24%). These results showed the same antioxidant activity (DPPH assay) with the highest percentage inhibition of freeze dried powders and the lowest percentage inhibition of ultrasonic spray dried powders. The phytochemical functional group that revealed from Fourier Transform Infrared spectroscopic (FTIR) analysis also indicate the presence of high amount of phenolic compounds in freeze dried powders although with ‘collapse building’ shape with fibrillary structure. The freeze dried powder showed the highest L* value (45.62±0.54), yet ultrasonic spray dried powders highest a*, b* and C* value. Thus, the analysis for microbial properties was carried out on freeze dried powders as freeze dryer was chosen as the best encapsulating methods. The freeze dried powders showed inhibition against gram positive and gram negative bacteria such as Bacillus cereus, Staphylococcus aureus, Escherichia coli and Salmonella enterica and fungi such as Aspergillus niger and Candida albicans. The current study demonstrated the potential of using gelatine to encapsulate technique to retain antioxidant compounds in gelatine encapsulated C. ternatea flowers. This finding provides useful information on the use of different encapsulated methods for the development of functional food products for gelatine encapsulated flowers of C. ternatea.

Clitoria ternatea Flower and Its Bioactive Compounds: Potential Use as Microencapsulated Ingredient for Functional Foods

“…Microencapsulation of C. ternatea flower extract was carried out with gelatin as the wall material and dried by three different types of dryer, namely, freeze dryer, ultrasonic spray dryer, and convection oven [80]. This study reported that freeze drying indicated the most effective encapsulating method due to its highest encapsulation efficiency and antioxidant activity compared to other drying methods.…”

“…This study reported that freeze drying indicated the most effective encapsulating method due to its highest encapsulation efficiency and antioxidant activity compared to other drying methods. Moreover, freeze dried powders have the lowest moisture content and the most acceptable color, which is magenta, with the highest L* value [80]. Compared to the spray-drying method, the freeze-drying method tended to sustain the bioactive compounds due to its low temperature process.…”

“…Several studies presented the improvement of the physicochemical properties of extracts from C. ternatea after microencapsulation. Microencapsulation can maintain the intensity of anthocyanin color from C. ternatea extract [13,78,80,81]. The extract of C. ternatea microencapsulated with maltodextrin, cassava flour-maltodextrin, and gelatin-maltodextrin showed high solubility in water, around 99%, which was caused by the water-soluble encapsulants used, primarily maltodextrin [13].…”

“…One study compared three different drying methods to microencapsulate C. ternatea extract with gelatin as the wall material; the freeze-dried C. ternatea flower extract indicated the strongest inhibition of DPPH radicals, although the total anthocyanin contents were the lowest compared to the spray-dried and oven-dried samples [80]. This phenomenon conforms with Yu [100], who reported that the antioxidant activity of freeze-dried raspberry was higher than the spray-dried sample due to the higher drying temperature, which caused a significant decrease in DPPH free radical scavenging activity.…”

Microencapsulation of three natural dyes from butterfly pea, Sappan wood, and turmeric extracts and their mixture base oncyan, magenta, yellow (CMY) color concept

“…The turmeric residue was re-macerated for 24 hours with water at a 1:2 w/v ratio, then filtered with filter paper. The extracts were then concentrated using a rotary evaporator at 40 o C for four hours and dried using a vacuum oven at 50°C for four hours to get the powdered extracts (21).…”