Papers by Keyword: Phenolic

Abstract: Senna alata leaf is used as an active ingredient in various Ayurvedic preparations due to its bioactive components. This study examined the effect of extracting solvents on total phenolic and rhein contents as well as antioxidant and anti-inflammatory capacities in S. alata leaf extracts. 95% v/v and 50% v/v ethanol (EtOH) solutions were used as extracting solvents. In spite of its lower extraction yield, 95% EtOH extract with a lower moisture content should be considered more microbiologically stable than 50% EtOH extract. As a result of the analysis using thin-layer chromatography (TLC), Fourier-transform infrared (FTIR) spectrophotometry, and high performance liquid chromatographic diode array (HPLC-DAD), phytochemicals including anthrones, coumarins, and anthraquinones were found in both extracts. Additionally, the 95% EtOH extract possessed higher phytochemical contents and biological activities than the 50% EtOH extract. Thus, the 95% v/v EtOH was a powerful extracting solvent for preparation of S. alata leaf extractscontaining high contents of phenolics and rhein, together with antioxidant and anti-inflammatory activities.

Abstract: The purpose of this study was to determine and compare the effect of oven drying and spray drying treatments on the encapsulation of anthocyanin, flavonoid and phenolic extracted from watermelon rind. The analysis done in this work were as follow: total anthocyanin (TA), total flavonoid (TF) and total phenolic (TPC) content in the supernatant, yield of nanocapsule, Particle Size Analysis, and In Vitro test (test for flavonoid and phenolic release) in the supernatant food. The analysis results showed that the total anthocyanin content in watermelon rind with a spray drying treatment was 0.1113 mg/L, total flavonoid was 0.6159 g/mL, and total phenolic was 0.3410 g/mL. While using the oven, the anthocyanin content was 0.0891 mg/L, total flavonoid was 1.4590 g/mL, and total phenolic was 1.1349 g/mL. As noticed, the total content of anthocyanin resulted by using a spray dryer was greater than by using an oven. However, the total flavonoid and total phenolic resulted by using a spray dryer was smaller than by using an oven. During In Vitro analysis, the results of the release of flavonoid and phenolic resulted by using an oven into the distilled water were much larger and unstable than by using a spray dryer. This is likely because chitosan-Na (TPP) bonds are weak. Additionally, the yield of capsule on the use of spray dryer was 0.6, higher than the use of an oven, which was 0.48. While, the average particle size in the use of a spray dryer was 2.296 μm, smaller than the use of an oven, which was 61.998 μm.

Abstract: Ultrasound-Assisted Extraction (UAE) was applied to enhance the bioactive compound extraction from the intact red sorghum grains using water as a green solvent that is relatively more available, safe, and less contaminant to the product application. The UAE performance of the ultrasonic probe with 60, 70, and 80% amplitude were compared to evaluate the effect of ultrasound amplitude. A mechanistic model was applied for quantitative evaluation of the UAE performance and prediction of the concentration of total phenolic (TP) and proanthocyanidin (PC) in the extract during the extraction. This research evaluated the effect of amplitude on the extraction rate, the parameters in the model, and the predicted TP and PC concentration from the mechanistic model approach. The wave enhanced the extraction by its propagation, cavitation bubble, and pericarp destruction. The mass transfer coefficient was stretched between 1.271×10^–2 - 1.345×10^–2 cm^–1/minutes for TP and 5.979×10^–3 - 8.262×10^–3 cm^–1/minutes for PC, while the distribution coefficient was 2.222×10^–2 -2.248×10^–2 grain/cm^–3 solvent for TP and 6.739×10^–2 - 7.946×10^–2 grain/cm^–3 solvent for PC. The highest performance resulted from 80% amplitude. The model worked precisely to predict the concentration of TP and PC of UAE, illustrating the amplitude’s effect in enhancing the UAE from its parameter values.

Abstract: The black bamboo leaves that have been widely used by the community for a long time are thought to have bioactive compounds. To find out more, it is necessary to evaluate the levels of phenolic compounds and flavonoids which are reported to function as antioxidants and antimicrobials. In addition, antioxidant and antimicrobial activity tests also need to be carried out directly on black bamboo extracts from Indonesia. This study aims to evaluate the phenolic and flavonoid levels of a black bamboo leaf extract from Indonesia. Based on the research results, the total phenol content of the ethanol extract of bamboo leaves (Bambosa sp.) was 157.426 mg gallic acid extract (GAE)/g and the total flavonoid content was 19.406 mg equivalent to quercetin extract (QE)/g. The antioxidant activity using the DPPH method obtained IC50 of ethanol extract of bamboo leaves (Bambosa sp.) of 46.8672 μg/mL, and an IC50 BHT value of 9.5454 μg/mL. Based on these results, bamboo leaves (Bambosa sp.) have the potential to be developed as antioxidants and antimicrobials.

Abstract: Special Region of Yogyakarta is one of the regions that has high potential for natural disasters. Food is the most consumable material which is needed when natural disasters occur. An alternative form of food preservative is needed to maintain nutritious foods that will be distributed to the victims of natural disasters. The foods must still appropriate to eat. In this research, watermelon rind was chosen as an ingredient to make natural preservatives because they contain flavonoids and anthocyanins. This research aims were to determine the total content of anthocyanins, flavonoids and phenolics in the red watermelon rind and yellow watermelon rind, also to determine the effect of chitosan composition to the ability of flavonoids and phenolics release in the food. This research was carried out by extraction and encapsulation methods. The analysis included the content of Total Anthocyanin (TA), Total Flavonoids (TF) and Total Phenolic (TPC) in the supernatant. The other analysis was in vitro tests that was done to know the ability of flavonoids and phenolics release in the food. The total anthocyanin content in the red watermelon rind was 0.0334 mg L^-1 while in the yellow watermelon rind was 0.0668 mg L^-1. The total content of flavonoids in the red watermelon rind was 0.7369 g mL^-1, while in the yellow watermelon rind was 0.3296 g mL^-1. The total phenolic content of red watermelon rind was 0.3669 g mL^-1, while in the yellow watermelon rind was 0.2273 g mL^-1. In both of red and yellow watermelon rind, the highest release of flavonoid and phenolic levels showed in the variations of chitosan mass 0.4 grams. The highest flavonoid content released was 0.0638 g mL^-1 in red watermelon rind and 0.0702 g mL^-1 in yellow watermelon rind. The highest phenolic content released was 0.0321 g mL^-1 in red watermelon rind and 0.0408 g mL^-1 in yellow watermelon rind.

Abstract: The objective of this study was to determine the optimal value of factors affecting the extraction of compounds such as, polyphenols, flavonoids of Roselle. The investigated factors included extraction temperatures (30, 40, 50, 60, 70 and 80°C), extraction time (30, 60, 90, 120 and 150 minutes) and solid to solvent ratio (1:5, 1:10, 1:20, 1:40 and 1:50 g/mL). The efficiency of extraction was evaluated based on total phenolic content (TPC) and total flavonoid content (TFC). The results showed that temperature range of 60–80°C was the appropriate temperature for TFC while extraction temperature over 60°C was suitable for achieving highest TPC. Considering the effect of extraction time, duration of 90–150 minutes facilitated the extraction of both phenolics and flavonoids. Moreover, the solid to solvent 1:20 was chosen for extraction process based on the balance of antioxidant contents and their yield.

Abstract: In the last decades, natural fiber composites have received much attention as important structural materials for lightweight components in automotive, and space industries because of low density, high specific strength, and environment-friendly materials. Some natural fibers, however, still not applied in more useful structure, one of which is the frond fiber of snake fruit (salacca zalacca). This fiber is usually just burned or fired as the agricultural waste. The present paper presents the result of the development of frond salacca fiber as the wear component of natural fiber reinforced phenolic. In this composite, the fiber and the phenolic are in the form of powder. The variation of fiber volume fraction was used as the main factor in the tribology characteristics of the composite. The specific wear and also the hardness is then compared to that of the existed commercially available motorbike brake pad as a comparison.

Abstract: This work presents an optimization study of polyphenol extraction from L. pumila with aid of sonication. The polyphenol content was evaluated using Singleton’s method and aluminium chloride colorimetric assay. The two level factorial design [2LF] was used to screen the significance of the extraction parameters. The results proposed that the polyphenols extraction are mainly affected by the total solid ratio [TSR] and residence time. The highest flavonoid content of 31.79 mg QE/ g DW and phenolic content of 19.65 mg GA/g DW was obtained from 80% and 10% aqueous ethanol [EtOH], respectively via 2LF design. Three most important parameters [TSR, residence time and amplitude] were then further optimized thru central composite design. The highest simultaneous flavonoid [21.77 mg QE/ g DW] and phenolic [21.86 mg GA/g DW] extraction yield were attained from the probe sonicator extraction with desirability of 0.998 at 10% aqueous EtOH with TSR 0.01, residence time of 13 min and amplitude of 55%.

Abstract: The ignition and combustion characteristics of the fibre-reinforced phenolic composite were studied experimentally employing cone calorimeter. Various parameters, including the ignition time, the mass loss and mass loss rate (MLR), the heat release rate (HRR) and the concentration of the carbon dioxide and carbon monoxide were measured and presented. Linear correlations of the transformed ignition time (1/t_ig)^0.55 and 1/t_ig, the first and second peak MLR, the average MLR and the peak HRR with the heat flux were demonstrated. Based upon the correlations and theoretical analyses, flammability properties including the critical heat flux (CHF) and the minimum heat flux, the ignition temperature, the heat of gasification and the heat of combustion were calculated. The specimen with the thickness of 3 mm was prone to be thermally thin material. The peak concentration of the carbon dioxide increased with the heat flux. However, the peak concentration of the carbon monoxide declined with an increase in the applied heat flux.

Abstract: In order to make clear the effects of modified-phenolic on the tribological properties, three kinds of carbon fiber reinforced phenolic friction materials (cashew-modified phenolic, boron-modified phenolic and chemigum-modified phenolic) were fabricated with the ethyl alcohol as the solvent by vacuum filtration. The tribological properties of samples were studied by the QM1000-II wet friction performance tester. The scanning electron microscope was employed to analyze the micro topography of specimens. Results show that the dynamic friction coefficient and variable coefficient of cashew-modified phenolic friction materials are better than other two materials. The temperature is the most stable during the continuous engagements. The friction torque curve is the smoothest and most symmetrical. Thus, the comprehensive performance of cashew-modified phenolic friction materials is excellent.