Catharanthus roseus or “Kemunting Cina” and Clitoria ternatea or “Bunga Telang" had a long reputation as a traditional remedy in South East Asia. One of the important components that contribute to these plants' remedial capabilities is the secondary metabolic known as phenolic. In this study, the Total Phenolic Contents or TPC in Catharanthus roseus and Clitoria ternatea leaves extract have been obtained and compared. Leaves from both species were dried and the extract was acquired using 90% ethanol via a rotary evaporator. Two major tests were conducted which are the qualitative test and quantitative test. The qualitative test was done to ensure the existence of phenolic in the samples. Meanwhile, the quantitative test is to measure the concentration of phenolic in the samples. Both samples show a positive result in a qualitative test where the extract of the sample changed from green to dark green in the Ferric Chloride test. Next, Folin- Ciocalteu assay acted as the quantitative test to determine the TPC in the samples, and the absorbance was measured at 760 nm. The test was triplicated to ensure the consistency of the results. The total phenolic content for Catharanthus roseus is 36.33600 ± 0.935313mg/GAE and Clitoria ternatea is 7.35767 ± 0.046188mg/GAE. The TPC in Catharanthus roseus is higher than Clitoria ternatea. The t-test shows that there is a significant difference in concentration of total phenolic content between Catharanthus roseus and Clitoria ternatea (p

In the beverages industry, the stabilizer and emulsifier were used to enhance the quality of Pink Guava Juice Drink (PGJD) in terms of colour, taste, and texture. Thus, the product is favourable and marketable. This study was conducted to find the best emulsifier combination for PGJD. The combination of six different stabilizers such as Guar gum (GG), Carboxyl methyl cellulose (CMC), Arabic gum (AG), Xanthan gum (XG), Propylene glycol alginate (PGA), and Pectin were applied to PGJD formulation. Meanwhile, about three emulsifiers which are Arabic gum (AG), Polysorbate 80 (P80), and Propylene glycol alginate (PGA) were used to emulsify vitamin E in PGJD. The ratio for both stabilizers and emulsifiers varied accordingly. The most stable and suitable combination of stabilizers and emulsifiers was later added to PGJD. The combination of XG and CMC at the concentration of 70:30 with 0.2% (w/v) was the best stabilizer. Meanwhile, P80 was found to be the best emulsifier at a concentration of 0.8% (w/v) and PGJD fortified with 225 mg of vitamin E was chosen as the most acceptable PGJ among panelists. This finding of the present study can be a guideline for beverage manufacturers in selecting the best stabilizers and emulsifiers.

This study was undertaken to assess the changes in viscosity, colour, emulsion stability, and vitamin E stability of pink guava juice fortified with vitamin E (PGJD) during 180 days of storage at 5°C, 15°C, and 25°C. PGJD with a combination of 70% (w/v) Xanthan Gum (XG), 30% (w/v) Carboxyl methyl cellulose (CMC), 0.8% (w/v) Polysorbate 80 (P80), and 225mg vitamin E was prepared and stored for 180 days at 5°C, 15°C, and 25°C. For every 30 days of storage, viscosity, emulsion, colour, and vitamin E stability were determined using a viscometer, chromameter, emulsion stability index (ESI), and high-performance liquid chromatography (HPLC), respectively. The result indicates that the viscosity of PGJD increased significantly slower when stored at a lower storage temperature. In addition, emulsion stability will be maintained for approximately 30 days longer when stored at a lower temperature as opposed to a higher temperature. The L* value of the colour increased for all samples, however, the C* values indicated red colour intensity from PGJD was gradually fading through time. In addition, the Ho value of all PGJD samples exhibited a steady increase during storage, whereas vitamin E exhibited a consistent deterioration pattern. The findings of the present study can be used as a guideline for beverage manufacturers and retailers in selecting the best storage temperature for their products.