BACKGROUND: The aim of this study is to separate polyphenols from grape pomace using a surfactant-based separation, colloidal gas aphrons (CGA) and to investigate their inhibitory activity against skin relevant enzymes, collagenase and elastase. Ethanolic (EE) and hot water crude extracts (HWE) were produced first and then the CGA generated using TWEEN20 were applied resulting in polyphenols enriched fractions (CGA-EE and CGA-HWE, ethanol and hot water extracts derived fractions, respectively). RESULTS:Both crude extracts inhibited the enzymes in a dose-dependent manner, however, further extraction by CGA led to fractions with higher inhibitory efficiency against collagenase. Although gallic acid was the main component of the CGA-HWE, others such as kaempferol must have contributed to its potency which was more than six times that of gallic acid. The CGA-EE was found to be about four times more efficient than its crude extract and more than six times more efficient than gallic acid for collagenase inhibition; quercetin was the major polyphenol in this fraction. CONCLUSION: It is evident that ethanol and hot water extraction processes led to different polyphenols composition and thus different inhibitory activity against collagenase and elastase. Further separation with CGA increased the inhibitory potency of both extracts against collagenase. Overall the results here showed the potential for application of CGA fractions from grape extracts in cosmetics.

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.

Tea fermentation relates to the enzymatic oxidation of the leaves of the tea and the formation of dark pigments. This method is usually conducted in a setting where temperature and humidity can be regulated. However, the impact of fermentation time on the antioxidant characteristics of Napier grass herbal tea is still unanswered. This study aimed to determine the effect of fermentation time on antioxidant properties of Napier grass black tea. Napier grass was subjected to fermentation for 3, 6, 9, 12 and 24 hrs. Fresh and dried samples were extracted in water (95°C, 30 mins) and the extracts were then analysed by total phenolic content (TPC) assay, total flavonoid content (TFC) assay, diphenyl-picryl-hydrazyl (DPPH) assay, Ferric reducing antioxidant potential (FRAP) assay, ferric thiocyanate (FTC) method and thiobarbituric acid (TBA) method. Sample fermented for 9 hrs showed the highest results in TPC (18.32±0.38) and FRAP assay (91.00±2.78). Whereas, the highest flavonoids and antioxidant activity were found in dried sample without fermentation (control) in TFC (97.82±13.00) and DPPH (90.02±1.11). However, samples fermented for 3 to 9 hrs showed no significant difference with that of the fresh sample in TFC and DPPH indicating 3 to 9 hrs fermentation time did not affect the antioxidant properties of Napier grass. In FTC and TBA, all the fermented samples showed lower antioxidant activity than that of fresh samples and control. The results suggested that 9 h of fermentation time is suitable for the preparation of Napier grass black tea as it exhibited high antioxidant properties in TPC, TFC, DPPH and FRAP assays.

This study aimed to determine the effect of steaming time on antioxidant properties of Napier grass green tea. Napier grass was subjected to steaming for 1, 2, 3, 4, 6, 8 and 10 mins. Fresh and dried samples were extracted in water (95°C, 30 mins) and the extracts were then analysed by total phenolic content (TPC) assay, total flavonoid content (TFC) assay, diphenyl-picryl-hydrazyl (DPPH) assay, Ferric reducing antioxidant potential (FRAP) assay, ferric thiocyanate (FTC) method and thiobarbituric acid (TBA) method. Sample steamed for 8 mins showed the highest TPC (18.32±0.26), TFC (152.71±5.74) and 109.88±5.44 in FRAP assay. High antioxidant activity was found in sample steamed for 3 to 10 min (81.63±1.19 to 83.50±1.10) in DPPH which were not significantly different with the fresh sample indicating steaming can retain the phytochemical compounds. Samples undergone 6 to 10 mins steaming time were found to have high lipid peroxidation in ferric thiocyanate (75.02±2.96 to 81.01±6.68) and thiobarbituric acid (85.99±1.56 to 86.21±1.44) assays. The results suggested that 8 mins of steaming time is suitable for Napier grass green tea as it exhibited the greatest antioxidant properties