Physical characteristic and antioxidant activities of liquid bath soap with substitution of ß-carotene crude extract from Gracilaria sp.

Synthetic antioxidant BHT is widely used in bath soap products as an antioxidant and prevents rancidity in bath soaps, but BHT is harmful to the skin if the addition is excessive. So we need natural antioxidants that can replace the role of BHT as an antioxidant. The purpose of this study was to determine the effect of substitution of BHT with ß-carotene Gracilaria sp. on the physical properties of liquid bath soap and determine the best concentration of BHT substitution with ß-carotene Gracilaria sp. added to liquid bath soap formulations. This study used a completely randomized design (CRD) consisting of 3 substitution treatments for BHT with ß-carotene, namely (1g BHT : 0g ß-carotene), (0,5g BHT : 0,5g ß-carotene), and (0g BHT : 1g ß-carotene) in 100 ml of liquid soap, with 6 repetitions each. Parameters observed were pH, foam stability, viscosity, hedonic, physical stability, and antioxidant activity. The results of this study the substitution of ß-carotene Gracilaria sp. the liquid bath soap had a significant effect (p<0.05) on the pH parameter and no significant effect (p<0.05) on the foam stability test and viscosity test parameters. Based on the hedonic test value, soap with the addition of 0,5 g BHT: 0,5g ß-carotene has the highest test value to produce the best quality soap.