Effect of Variations Concentration and pH of Liquid Smoke in the Immersion With Various Types of Fish

Abstract

Rubber seeds contain cellulose and lignin, therefore rubber seed could be used as raw material for liquid smoke. Liquid smoke contains lactic acid and phenol which have antibacterial properties. The purpose of this study is to test the antibacterial activity of liquid smoke shells and rubber seeds on the number of bacterial colonies in Mackarel fish (Euthynus affinis)(furthermore cited as mackerel). Mackarel fish is a sea fish that has 69.40% moisture content, 100 kcal energy, 13.7 protein, 1.5 g fat, 8 g carbohydrate, 92 mg calcium, 606 mg phosphorus, and 1.7 mg iron. Variations made in this study in the form of raw materials, the concentration of dilution of liquid smoke, and soaking time of the fish in liquid smoke. The raw materials used are rubber seed shells, rubber seeds, and a mixture of both. Concentrations used to dilute liquid smoke are 3%, 6%, 9%, 12%, and 15%. While the fish soaking time is 30 minutes, 60 minutes, and 90 minutes. Identification of qualitative chemical compounds using the GC-MS method, while identification of the number of bacterial colonies using the total plate number (ALT) method. The results of this study are the rubber seed shell is the best raw material in the manufacture of liquid smoke. The 9% concentration can reduce the number of colonies, but better results will be obtained at concentrations of 12% and 15%. Then, the best soaking time is 90 minutes, but at the time of immersion 60 minutes can reduce the number of bacterial colonies. Thus, the best results obtained were rubber seed shell raw material with a concentration of 15% and a soaking time of 60 minutes, with a bacterial colony of 2.12 x 102 CFU/ gram of fish.