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This paper presents a method to enhance the thermal stability of Phyllanthus niruri polyphenols during spray drying. The major polyphenol content of the extracts derived from the aerial part of the plant was analyzed, using ultra-highperformance liquid chromatography, whereas the surface composition of the microcapsule was analyzed by X-ray photoelectron microscopy (XPS). Three encapsulant formulations that were made of maltodextrin (MD), whey protein isolate (WPI), and their combinations (WPI:MD = 1:9) were compared with a control formulation without encapsulation. The microencapsulation method by WPI:MD proposed in this work increased the average polyphenols retention percentage after spray drying from 72.7% (without encapsulation) to 87.2%. The powder encapsulated with WPI:MD (1:9) yielded the best retention of phyllanthin (84.33%), gallic acid (88.93%), and quercetin (88.39%), compared to the system encapsulated solely by WPI or MD. The XPS results confirmed the existence of surface protein, which acts as a protective layer, thereby enhancing the polyphenols stability in the microcapsule. The finding from this work shows that quercetin is more susceptible to thermal degradation than phyllanthin and gallic acid during spray drying.

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The effect of auxiliary energy to the kaempferol extraction yield from Cassia alata is presented in this paper. The effect of auxiliary energy ranging from 0.045 to 20 W/ml was studied by performing extraction using ultrasonic assisted extraction (UAE), maceration (ME) and microwave assisted extraction (MAE). A ultra-performance liquid chromatography coupled photodiode array (UPLC-PDA) was used for kaempferol identification and quantification. Matching of residence time and UV spectrum between the authentic standard and plant extract was observed to confirm the presence of kaemferol. It was found that MAE method has the highest extraction yield of kaempferol at 21.55 mg/g DW followed by UAE (18.60 mg/g DW) and ME (12.01 mg/g DW). Besides that, the extraction time of MAE was the shortest which is only 4 minutes. The optimum conditions to obtain a high kaempferol yield was achieved using 100% ethanol to extract C. alata powdered leaves with PSD ≤125µm and plant solid to solvent ratio of 1:20. The findings in this work may serve as a useful guide to obtain highest extraction yield of kaempferol from C. alata.

Abstract. This paper presents the effect of auxiliary energy on rhein, kaempferol and astragalin extraction from Cassia alata. The effect of auxiliary energy was examined by performing extraction using either the ultrasonic assisted extraction (UAE) or microwave assisted extraction (MAE). A dried plant material with size ranging from 125 μm to 800 μm was used throughout this work. The rhein, kaempferol and astragalin quantification and identification was performed using ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometer. The presence of rhein, kaempferol and astragalin were identified and compared with external standards.The residence time, neutral mass and mass fragmentation pattern between the standard and plant extract are also observed. It was found that the extraction yield of rhein, kaempferol and astragalin were higher with UAE method compared to MAE method due to degradation of active component occur. The findings in this work may serve as a useful guide to select the extraction method used to maximise the yield of rhein, kaempferol and astragalin extraction from C. alata.