Table of contents

Commercial honey is widely available in the market, raising questions whether the honeys are good in quality or otherwise, Thus, this research was designed to compare the quality of harvested stingless bee honey and commercial honey available in the Malaysian market by measuring their sugar profile and enzyme activity. The analysis showed that the honey contained moisture between 16.6% - 32.1%, various sugar starting with fructose (15.03 – 48.44 g/100 g), glucose (12.16 – 40.09 g/100 g), sucrose (<0.01 – 7.29 g/100 g), Fructose + Glucose (F+G) (15.03- 80.25 g/100 g), Fructose/Glucose (F/G) (0.78 – 1.63), and G/W (0.47 – 1.89). Also, diastase activity and Invertase activity of the honey varied from 1.82 to 6.11 DN and 0.27 IN to 4.94 IN, respectively. Eight honey samples including harvested honey, H. Itama and G.Thoracica showing comparable results with past studies and within the limits of Malaysian Standard. However, all honey samples demonstrate lower enzyme activity suggesting that honey from stingless bee has low enzyme activity compare to Apis mellifera honey.

Petroselinum crispumis a herb belonging to the Apiaceae family,it has been usually used for the management of many inflammatory disease due to many pharmacological effects of corticosteroid with a strong anti-inflammatory and immunosuppressant properties (ex. dexamethasone), it is famous to cause side effects. It was clearly observed that dexamethasone could induced liver renal and increase the lipid profile in mice. The Petroselinum crispum methanol extract was prepared by soaking of 200 g of each of the pure dry in 1 liter of 90% methyl alcohol with shaking for 5 days, The selected animal groups (eight animals per each group) were grouped as follows Positive control group 1, negative control group 2, group 3 (10%) Petroselinum crispum treated and group 4 (20%). Petroselinum crispumtreated group it was found that Petroselinum crispumhas a clear ant atherosclerosis and a potent liver protection effects.

Recently, the outbreak and severe damage to the shrimp farming industry is Early Mortality Syndrome (EMS) or Acute Hepatopancreatic Necrosis Disease (AHPND). The selection of Bacillus strains inhibition disease resistance of the acute hepatopancreatic necrosis disease on the shrimp is a research filed that is much attention due to Bacillus subtilis is a group of beneficial bacteria that presents in the majority of biological products for aquaculture, especially for shrimp. Competitiveness of Bacillus subtilis towards the harmful bacteria firstly is the number of bacterial cells. Beside, Bacillus has capacity to create a large amount of extracellular enzymes aid digestion, antibiotics or the inhibitor has the characteristic for resistance to the strains of Vibrio Parahaemolyticus. In this work, the inhibition ability of the Bacillus strains for the AHPND on the brackish water shrimp is studied. In which, the Bacreria is isolated and filtered from shrimp farm in Can Gio province that contain the characteristic of antagonizing Vibrio parahaemolyticus, which cause AHPND on shrimp in laboratory conditions. The results show that Bacillus subtilis produced 2,5 – Diketopiperazines capable to inbihite the growth of pandemic strain of Vibrio parahaemolyticus in Landy media for hightest activity was 200 AU/mL after 24 h of culture. This research is create the possibility of using probiotics to control the pantogenic clones Vibrio parahaemolyticus that cause AHPND for brackish water shrimp farming in Can Gio province as well as other areas in Vietnam.

In this paper, we have successfully synthesized BiVO₄ by co-precipitation method. Results of BiVO₄ are synthesized under the support of urea, forming a single-line scheelite structure of BiVO₄. The synthesized sample were characterized by X-ray diffraction, scanning electron microscopy, raman and UV-visible diffuse reflectance spectra. In this work, the degradation of Ciprofloxacin (CFX) irradiated under visible light (Lamp LED 60W) by BiVO₄. The results of SEM images of BiVO₄ show that the crystal structure is granular, nanoparticle size and uneven. The Eg value of BiVO₄ is 2,312 Ev. The decrease in CFX concentration at pH=3, concentration of 10 ppm and catalyst dosage of 100 mg is the most optimal condition with photodegradation efficiencies of CFX is 75% after 180 min of irradiation. Material obtained in study can be applied in the decomposition of other antibiotics.

The aim of this research is to evaluate the stability of anthocyanins in extracts obtained from the flower of butterfly pea flower (Clitoria ternatea L.). Different combinations of solvents were created by mixing ethanol 50%, distilled water and different amounts of acids (ethanol 50 %, ethanol 50 % with 1.5N HCL, ethanol 50 % with 1.5N CH³COOH, distilled water, distilled water with 1.5N HCL, distilled water with 1.5N CH3COOH). To evaluate the stability of extracted pigment, it was kept for 3 months in oven at 45°C, ambient 25°C and refrigerated conditions at 10 °C. The temperature exerted dramatic effects on the total anthocyanins properties of the butterfly pea flower when stored in these conditions. The retained anthocyanin content of all treated samples was all higher than 60%, with distilled water 50% of 1.5N HCl (61.93%) and distilled water with 1.5 N CH3COOH (65.59%).

The present study was aimed to evaluate the phytotoxic activity of crude leaf extract from Dilleniaceae family on seed germination of goosegrass (E. indica) under different concentrations, ranging from 0-10 mg/mL. The total phenolic content (TPC) was studied and found to be about 209 mg GAE/g extract. Crude extract was significantly inhibitory towards germination of E.indica seeds. Concentration of 10 mg/mL extract demonstrated high germination inhibition rate at 90 % of goosegrass seeds as compared to the control. The bioassay results illustrated that the extract markedly inhibited the germination of goosegrass seeds which may require further investigation for the potential use in crop protection. Introduction

To reduce the problem and secondary pollution of agricultural wastes in Taiwan, this research prepared biomass nutrient solution (BNS) was prepared from three kinds of agricultural wastes, sugarcane peel, peanut shells, and rice husks, under an equal mixing ratio in a hydrothermal reactor with pure water at a higher temperature of 200 °C and at a higher pressure of 15 atm. BNS was used to irrigate soil for the tomato growth experiments in a nethouse. In comparison with blank, the plant height was increased by 15cm, the stem thickness was increased by 0.4mm, the number of green leaves for a single plant was increased by 2, the number of fruits was increased by 2, and the fruit weight for each plant was increased by 108g. Therefore, the application of spraying the BNS on tomato can improve the plant growth in height, the control late tomato blight disease was also observed.

This paper presents the encapsulation of Phaleria Macrocarpa Scheff. Boerl or Mahkota Dewa extracts with maltodextrin using spray drying. The extracts of dried Mahkota Dewa fruit was obtained using subcritical water extraction process. The inlet dry air temperatures of the spray drying process was investigated at 100 °C, 125 °C, 150 °C, 175 °C and 200 °C. The spray dried powder was characterised for antioxidant activity, moisture content analysis and particle size distribution analysis. Results showed that the increased of inlet air dry temperature decreased the value of antioxidant activity, moisture content and mean diameter of the particles. The inlet air dry temperature of 200°C produced 92.19±0.18% antioxidant activity, 6.82% moisture content and 8.38 μm mean diameter particle size. Thus, can be suggested as the best inlet air temperature to encapsulate Mahkota Dewa extracts with maltodextrin using spray drying technique.

Membrane filtration has been proved as a viable harvesting candidate to harvest microalgae for biofuels application. Though largely limited by membrane fouling that lowers overall process efficiency. The novel finned spacer is proposed to reduce fouling control in Chlorella vulgaris harvesting. The assessment of this work is focusing on these aspects: evaluation performance of finned spacer in directing air bubbles toward the membrane surface, study the effect of fin's gap on membrane fouling control perfor mance, the impact of aeration rate on membrane fouling control and operation under fins switching mode. Effectiveness of finned spacer has been obviously proved by its function to direct and encourage air bubbles toward the membrane surface thus improve their contacts and their foulant scouring impact. The projection of air bubbles is more effective at the narrowest fins gap applied of about 2cm gap. The increasing aeration rate proportionally increases flux of 90 L/(m².h) at 1.5 L/min aeration. Switching mode was applied to increase module packing density without reducing specific membrane performance. It was found effective at periods of below 5 min. Overall results are very encouraging and promising to obtain significant improvement in fouling control for C. vulgaris filtration. Further study on fundamental aspects as well as parameters optimization can still be done to increase the finned spacer efficiency.

Ocimum gratissimum L. essential oil was studied in this research for its physicochemical characteristics and composition. The essential oil extraction performance achieved 0.3-0.45% by hydrodistillation process. The physicochemical properties of the obtained oil were also discovered including specific gravity at 0.9645 g/cm³, acid index at 13.035 mg KOH/g, ester index at 14.745 mg KOH/g, refractive index at 1.526, and optical rotation at +15.6°. Through gas chromatography/mass spectrometry (GC/MS), it was revealed that the oil is extremely rich in eugenol (59.448 %), trans-ß-Ocimene (10.382 %), β-Cubebene (11.783 %), Caryophyllene (6.966 %) and Copaene (2.479 %). Therefore, optimizing the preservation conditions for the essential oils is suggested as potential pathway to extend the application and enhance the value of Ocimum gratissimum essential oils.

Annona muricata Linn. (soursop) plant is a medicinal plant that has been utilized in folk medicine for treatment of infectious and inflammatory diseases. This study aimed to determine the phytochemicals content, total phenolic and flavonoid contents and antioxidant activities of A. muricata leaves. Antioxidant activity was performed via 2, 2'-azino-bis(3- ethylbenzothiazoline-6-sulphonic acid) (ABTS) and 2,2-diphenyl- 1-picrylhydrazyl (DPPH) radical scavenging assays. The phytochemical was extracted separately with distilled water and 96% ethanol by maceration. The results show that a wide variety of pharmacologically active compounds such as alkaloids, coumarins, tannins, flavonoids, carbohydrates, phenols, terpenoids, saponins were present in the leaves of A. muricata. The total phenolic and flavonoid content of ethanol extract in A. muricata leave achieved 609.08±5.82 mgGAE/g and 209.52±1.88 mgQE/g, respectively. The antioxidant activity of the ethanol extract of A. muricata was correlated with total phenolic and flavonoid content with values IC₅₀ of 20.75±0.28 μg/ml, 12.84±0.21 μg/ml for DPPH and ABTS scavenging activity, respectively.

Annona squamosa Linn. (custard apple) has been used extensively in India traditional medicine for treatment of dysentery, cardiac problems, fainting, worm infections, constipation, hemorrhage, dysuria, fever. This study assessed the phytochemicals present in the leaves of A. squamosa. The phytochemical was extracted separately with distilled water and 96% ethanol. A wide variety of pharmacologically active compounds such as alkaloids, coumarins, tannins, cardiac glycosides, flavonoids, carbohydrates, phenols, and saponins were found to present in the leaves of A. squamosa. However, terpenoids and phlobatannins were absent in this plant. This study also assessed the contents of phenolics and flavonoids for their in vitro antioxidant activity. The total polyphenol content of ethanol extract of A. squamosa measured by Folin-Ciocalteau reagent in terms of gallic acid equivalent achieved 242.88±6.13 mg GAE/g. The flavonoid content of the plant sample as quercetin equivalent achieved 82,61±0.82 mg QE/g. The antioxidant activity of the ethanol extract of A. squamosa was correlated with total phenolic and flavonoid content with values IC50 of 132.96±1.33 μg/ml, 64.74±0.52 μg/ml for DPPH and ABTS scavenging activity, respectively.

Houttuynia cordata Thunb (H. Cordata), an aromatic medicinal herb belonging to family Saururaceae, is a plant that grows in moist habitats, well known for its medicinal properties and widely used worldwide. H. Cordata is an aromatic medicinal herb belonging to family Saururaceae and is restricted to specialized moist habitats. Three extracts, successively obtained from the leaves of H. cordata, namely the diethyl ether leaves extract (DELE), the ethanolic leaves extract (ELE) and the aqueous leaves extract (ALE), were used to determine the polyphenol and flavonoid content in the leaves. Phytochemical screening of plant extracts showed the presence of flavonoid, saponin, alkaloid, tannin, and steroid compounds. Quantitative determination of total phenolics, total flavonoids of methanolic extract were carried out using colorimetric methods. The result of quantitative determination showed that total polyphenol content of the DELE, ELE and ALE were 32.18 ± 2.64, 97.98 ± 1.77, and 22.22 ± 2.00 mg of gallic acid equivalents per gram dry extract, respectively. Meanwhile total flavonoid content of the DELE, ELE and ALE achieved 31.65 ± 1.07, 35.72 ± 1.23, and 4.06 ± 0.54 mg of quercetin equivalents per gram dry extract, respectively.

In this study, we compared the content of nutritional indicators including lipid, moisture, pH, protein, and ash between original and Butterfly Pea cupcake baked at 170°C for 20 minutes. Moreover, the sensory properties of Butterfly Pea cupcake favorite also are determined. There was an increase in the content of moisture, protein compared with those of the control cupcake, reaching 22.12 ± 1.87 and 3.69 ± 0.51, respectively. In contrast, the level of pH, ash, and lipid witnessed marginal decreases, reaching 7.08 ± 0.54, 1.01 ± 0.21, 12.10 ± 2.77 respectively. Notably, the Butterfly Pea cupcake had anthocyanin content of 2.58 ± 0.06 mg/L, which accounted for 41.82 ± 0.92% retention. The ability to decompose anthocyanin biological compounds is lower than 60%. The slight green color is determined to be influenced by the pH factor in the dough environment.

Roselle calyces (RC) are a valuable crop for export and manufacture of a typical drink in Vietnam. The RC is widely applied as a natural colorant in different fields such as food and pharmaceutical industries. The objective of this research was to determine the effect of extraction parameters on the nutritional value and sensibility of cupcake added with RC. Examined indicators included lipid, moisture, pH, protein, and ash. Moreover, the sensory properties of cupcakes formulated with Roselle calyces extract were also determined. Compared with the control cupcake, the RC-added cupcake exhibited higher content of moisture, protein, and ascorbic acid, achieving 30.16 ± 0.25, 2.76 ± 0.07 and 37.65 ± 0.64 respectively. In contrast, the level of pH, ash, and lipid experienced a marginal drop, achieving 7.02 ± 0.25, 1.05 ± 0.13 and 14.78 ± 1.01 respectively. Moreover, the Roselle cupcake had 3.74 ± 0.02 mg/L anthocyanin content. The percentage of retention of anthocyanin content at 180°C for 20 minutes was 60.53 ± 0.48. RC cupcakes have high sensory scores (P<0.05) comparing with control RC cupcakes. RC cupcake can be a functional food which has a cost- effective advantage.

Polyphenol-rich fruits are plant materials of interest due to the high anthocyanin content and number of antioxidant compounds. Besides, anthocyanins also possess other various beneficial properties, including antioxidant activity and mitigation of risk of circulatory diseases. In this study, different polyphenol-rich fruit species including Ficus racemosa, Fragaria ananassa, Passiflora edulis, Carissa carandas Linn, and Rhodomyrtus tomentosa were harvested and compared for total anthocyanin content, total phenolic, and antioxidant activity. Extraction conditions included solvent of 50% ethanol, material/solvent ratio of 1:5, temperature of 60°C temperature and extraction time of 30 minutes. In terms of total phenolic content, Fig fruit achieved 136.08 mg GAE/g. Among examined fruits, strawberries contained the largest amounts of anthocyanin (355.27 mg cy-3glu L⁻¹). Passion fruit showed the highest antioxidant activity (409.89ug/mL). The results of this study are expected to contribute to further development in utilization of the said fruits and open new pathways in enhancing value of agricultural products in Vietnam.

Plectranthus amboinicus (Lour.) Spreng is a valuable medicinal plant that has been used for a long time in Vietnam. Previous studies have shown that Plectranthus amboinicus exhibited several useful pharmacological effects. This study evaluated total polyphenol, flavonoid contents and anti-oxidant potential of the leaf extract of Plectranthus amboinicus. The phenolic content and flavonoid content achieved 26,84 ±0.91 μg GAE/mg and 12,14 ± 0,42 μg QE/mg, respectively. Ethanol extract (IC50 = 48,23 μg/ml) showed potent antioxidant activity. According to the results of the present investigation, the plant showed significant antioxidant activity that is applicable for the treatment of various diseases.

Recently, the trend of enhancing daily consumed foods with functional ingredients has been increasing. Bread, being a food product, which is consumed regularly, contains most nutrients but lacks antioxidant rich polyphenolic compounds due to the usage of refined wheat flour. Green coffee beans (GCB) are known for their green colour, which is the colour of coffee beans prior to roasting. The aroma is described as mild, green, and bean-like, which deters many from trying to consume the product. This experiment is conducted to determine antimicrobial properties and the sensory response to study the physiological effect of caffeine in bread incorporated with GCB. The bread was baked with three (3) variable parameters which were: the concentration of GCB powder, baking time, and baking temperature. The effect of concentration of GCB powder, baking time, and baking temperature on bacteria growth were also observed. It is concluded that to control the bacteria growth, the optimum condition of incorporated bread was determined at baking temperature of 180.3°C, baking time of 39.9 minutes, and GCB powder concentration of 4.85 wt%. Sensory evaluation analysis for the optimised bread (enriched with GCB) and control bread (without GCB) were conducted by a series of sensory judges. The sensory evaluation determined the differences in all aspects of appearance, aroma, taste, and texture between the enriched and normal bread. The most significant differences are that the bread incorporated with green coffee bean was darker in colour, has more distinctive wood, caramel, and smoke smell, more pungent and less salty. In addition, it is also more bitter, and harder with a stronger aftertaste when compared to normal bread. In conclusion, bread enriched with GCB exhibits strong antimicrobial properties and acceptable differences in appearance, aroma, taste, and texture compared to normal bread.

Most of nutrients can be found in normal breads but there is lack of antioxidant rich polyphenolic compounds. Green coffee bean (GCB) is chosen as functional ingredients to be incorporated in the bread as it contains high amount of phenolic acid namely chlorogenic acid which contributed to antimutagenic, anticarcinogenic and antioxidant activities. Therefore, GCB was chosen as natural sources in order to enrich the wheat bread with their phenolic antioxidant's characteristics. The objective of this study is to investigate the effect of concentration of green coffee bean, baking temperature, and baking time on the physical properties of the incorporated bread. The physical properties such as moisture content, volume, colour, and texture were analysed. The data obtained were statistically analysed using Analysis of Variance (ANOVA). The results show that the incorporation of GCB has a positive influence on the physical properties of the bread especially on moisture content and volume. The factors with the largest effect on the moisture content were the baking temperature and GCB concentrations (p < 0.05). The use of high baking temperature causes higher moisture content and volume of bread after baking. While for bread crust and crumb colour, it was observed that increasing the baking temperature and time resulted in dark crust colour and reduced the colour saturation. For crumb colour, the addition of GCB powder caused a slight decreased in lightness and yellowness, whereas the redness of bread was almost unchanged. Nevertheless, the incorporation of green coffee bean had a little influence on the texture of the bread. High hardness of the bread demonstrated from the high baking temperature and high baking time. From optimization process, it could be concluded that the optimum baking temperature was found at 180°C, baking time of 40 minutes and GCB concentration of 1 wt% in order to get the better quality of the bread. In conclusion, GCB has a great potential as functional ingredient in bread. The addition of GCB does not only affect the antioxidant properties of the bread but also increase the quality of the bread itself.

Natural defense mechanisms of animals by using probiotics, prebiotics, and synbiotics have been seen as an alternative way to improve animal health and to overcome the food-borne diseases among the livestock. This is as the previous use of antibiotics as the growth promoter in the poultry industry has been banned by the European Union. Synbiotic is a combination of probiotics and prebiotics where probiotics are live microorganisms that give a gainful medical advantage on the host whereas prebiotics are nondigestible food ingredients that influence the host by stimulating the development and the action of a set number of microscopic organisms in the colon. This study was conducted to assess the viability of probiotic strains in the synbiotic powder samples from Myternak Trading as well as to see the correlation between the viability of probiotic strains with the amount of its selective prebiotics. Two different types of prebiotics; fructooligosaccharides (FOS) and inulin with seven different compositions of prebiotics had been used in this study. The viability of probiotic strains in synbiotic powder samples were assessed by enumeration of probiotic strains in two different selective media which are TOS and MRS agar. The highest average colony forming units (CFU) for Bifidobacterium sp. can be found in Batch 7 samples (4.10 χ 10¹¹ CFU/ml ) as the volume of FOS is the highest, which is 0.5 mL. While the highest CFU for Lactobacillus sp.can be found in Batch 1 samples (5.560 χ 10¹¹CFU/ml) as the weight of inulin is the highest, which is 5.0 g. These results proved the effects of prebiotic compositions in synbiotics towards the viability of the probiotic strains.. The viable counts of each probiotic strains that contain in the synbiotic powder sample significantly decreases as the amount of selective prebiotic decreases. Therefore, the maximum CFU obtained as the composition of prebiotic increases. Hence it can be concluded that the produced synbiotic powder samples by MyTernak Trading could be used as an alternative feed additive in boosting the livestock health due to the viability of both probiotic strains which are Bifidobacterium sp. and Lactobacillus sp in the synbiotic samples.

The thermal column at the TRIGA PUSPATI (RTP) research reactor can produce thermal neutron. However, the optimization on the thermal neutron flux produced should be performed to gain a sufficient thermal neutron for boron neutron capture therapy purpose. Thus, the objective of this review is to optimize the thermal neutron flux by designing the collimator with different materials at the thermal column. In order to fulfil the requirement, set by the IAEA standard, the study of BNCT around the world was being reviewed to study the suitable measurement, material, design, and modification for BNCT at the thermal column of TRIGA MARK-II, Malaysia. Initially, the BNCT mechanisms and history was review. Then, this paper review on the design and modifications for BNCT purpose around the world. Based on this review, suitable material and design can be used for the BNCT in Malaysia. Moreover, this paper also reviews the current status of BNCT at the RTP with the measurement of the thermal neutron flux was conducted along the thermal column at 250 kW. The thermal column of RTP was divided into 3 phases (Phase 1, Phase 2 and Phase 3) so that an accurate measurement can be obtained by using gold foil activation method. This value was used as a benchmark for the neutron flux produced from the thermal column. The collimator was designed using different types of materials, and their characteristic towards gamma and neutron flux was investigated. The reviewed demonstrated that the final thermal neutron flux produced was significantly for BNCT purpose. Lastly, this paper recommends the future research can be conducted on BNCT at RTP.

Boron Neutron Capture Therapy (BNCT) is a nuclear application to cure cancer by using the interaction between the boron compound and the slow (thermal and epithermal) neutron beam obtained from the neutron source. The previous feasibility study shows that the thermal column can generate higher thermal neutrons for BNCT application at the TRIGA MARK II reactor. Currently, the BNCT facility is planned to be developed at the thermal column. Thus, to fabricate the nuclear application such as BNCT required several required such as the study of design, material, neutron desired and safety for the application. Therefore, the use of simulation software such as Monte Carlo N-Particle (MCNP) was extensively essential to identify and determine the most convenient design of the BNCT facility with proper safety requirement standard. Besides that, the simulation also useful in terms of identifying good material and best geometry and the uses of simulation can guide to make sure this research achieves the best results. Generally, MCNP function to track the particle over its energy range using the irradiation transport and the neutron flux and the gamma flux produced from the simulation using MCNPX code was consider right if the relative errors contributed was lower than 5%. This research simulates that the uncovered collimator provides high neutron flux and high collimator performance compared to the fully covered collimator. This research is useful in the simulate on the desired neutron from the BNCT facility design at the TRIGA MARK II reactor.

The development of the Boron Neutron Capture Therapy (BNCT) facility in Malaysia can be performed at the thermal column of the Malaysia research reactor. TRIGA MARK II is one of the facilities that can provide neutron source for BNCT facility. The specification of neutron flux and the gamma dose rate must consider for the development of the BNCT facility as a safety precaution for this research. Based on previous research, the thermal column identified as a suitable place for BNCT facility. To design the neutron collimator for BNCT purpose, the characterization of material towards thermal neutron flux explored using TLD and Microspec-6 and the collimator design was simulate using Monte Carlo N-Particle (MCNP) software based on the characterize materials in order to produce high thermal neutron flux. The combination of lead, HDPE, 30% borated polyethylene and aluminium as collimator design D1 simulate the highest thermal neutron 1.5770 x 10⁹ neutron.cm⁻²s⁻¹ and suitable for BNCT research purpose at the thermal column.

Rebaudioside A or Reb A is an extractable component from stevia leaves or scientifically known as Stevia rebaudiana. Reb A is famous for its exceptional sweetness and widely used as a non-caloric sweetener. Its potential widespread use requires an easy and effective extraction method. In this study, extraction of Reb A from stevia leaves with parameters such as temperature, material ratio and extraction time were investigated. Time of extraction were 1, 1.5, 2, 2.5 and 3 hours. Temperature was varied at 40⁰C, 45⁰C, 50⁰C, 55⁰C and 60⁰C. Material ratio was 1:5, 1:10, 1:15, 1:20 and 1:25. Then, using Design Expert software, the ranges of the parameters were entered in the Central Composite Design (CCD) to create 20 different combinations of parameters for extraction. After executing the experiments, the yield of Reb A obtained was keyed in Response Surface Methodology (RSM) for optimization. Finally, the optimum condition was tested and validated by calculating the percentage error. Since the percentage error was less than 10%, the optimum condition, which is, 35⁰C, 1:6 material ratio and 5 hours of extraction was accepted.

Anti-quorum sensing property has been a popular alternative approach over bactericidal/bacteriostatic property in combating bacterial infection while simultaneously tackling the dilemma of antibiotic resistance. We presented pyoverdin assay as an initial screening to qualitatively determine the anti-quorum sensing activity in Piper betle by measuring the loss of absorbance at wavelength 630 nm. Growth of Pseudomonas aeruginosa was proven to be unaffected by the presence of the P. betle leaves extract. The regression value (R²) of the quorum sensing (QS) activity in untreated supernatant of P. aeruginosa was 0.9636 and we presented the QS activity in fold-change, normalized to untreated sample for a fair comparison between batch of assays. We further assessed the QS activity in the extracts of P. betle leaves and found the QS activity of P. aeruginosa grown in the presence of ethyl acetate extract at 200 μg/ml was reduced to 0.6-fold. As the concentrations went lower, higher fold of QS activity was observed, suggesting that P. betle leaves extract is demonstrating anti-QS activity at a higher concentration. Further fractionate of ethyl acetate crude extracts resulted in three fractionates with high anti-QS activity with >50% reduction in QS activity and five fractionates with intermediate anti-QS activity. The use of pyoverdin assay to qualitatively portray the anti-QS activity could shorten the lengthiness of extracting and measuring the signaling molecule yet, produces reliable information to screen for anti-QS activity and guide for further fractionation and purification of bioactive compound.