Effect of processing temperature on antioxidant activity of ficus carica leaves extract

Ethanol is acknowledged as a good solvent for polyphenol extraction and is safe for human consumption. Therefore, it usually used in the extraction process of plant sample. However ethanol should be evaporated to obtain pure extract of the samples. Nevertheless, temperature involved during evaporation process would affect the antioxidant activity of the plant extract. Thus, the purpose of this study was to find out the effect of temperature used during evaporation of ethanol towards antioxidant activity of Ficus carica leaves extract. Dried powder of F. carica leaves were subjected to three sets of processing method which involve different temperatures: Set A involved maceration with 70% ethanol, followed by evaporation of ethanol in rotary evaporator at 60oC for 12 hours, set B involved maceration with 70% ethanol, followed by evaporation of ethanol in vacuum oven at 45oC for 12 hours, while set C involved maceration with 70% ethanol, followed by evaporation of ethanol at 25oC (room temperature) in fume chamber for 72 hours. Antioxidant activity of extracts from each set were measured using two different in-vitro assays, including scavenging abilities on 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and total phenolic content (TPC). F. carica extract from set B showed the highest antioxidant power in DPPH (3.78 mg/ml) and TPC (266.96 mg GAE/g) compared to set A and C. Thus, it can be concluded that temperature of 45oC could promote the antioxidant activities, while high temperature would decrease the antioxidant abilities of F. carica leaves extrac

Effect of Water Loading on the Chemical Structure and Mechanical Properties of Thermoplastic Tapioca Starch Film

The effect of water (as a primary plasticiser) content on the chemical structure and mechanical properties of thermoplastic tapioca starch (TPTS) film was evaluated. The TPTS films were produced by tape casting technique through mixtures of fixed amount of glycerol and varied contents of tapioca starch and water. There was observed increase in hydrogen bonding interaction between starch and water molecules depicted by the downward shift between 3303-3281 cm-1. The excessive amount of water loading portrayed increase in crystallinity due to free volume movement of the starch particles. The changes in water loading also showed variation in the tensile strength and elongation at break of the TPTS films. This observation is because of the dependence of mobility of polysaccharide plastics on the water content in the premix. Therefore, starch forms entanglements with the plasticisers to form a flexible film