Penentuan Jenis Deliming Agent dan Kecepatan Pengadukan dalam Proses Penghilangan Kapur (Deliming) Kulit Liming Ikan Tuna

Abstract

Deliming is a removal process of lime in a skin which can disrupt the process of tanning and lowering quality of leather produced. The type of deliming agent and stirring speed become the factors affecting the deliming process. The research intended to know the effects of the type of deliming agent, stirring speed, and whether these interactions affect the quality of the delimed pelt. Besides that, this research aimed to know the best interaction of these two factors to produce expected responses and the characteristics of the pelts. The types of deliming agents used in this study were NH4Cl, (NH4)2SO4, and H3PO4. Stirring speeds used were 150, 200, 250 rpm. There were four responses measured, i.e. decrease of pelt thickness, pH, calcium content, and organoleptic characterictics of the pelts. The decrease of thickness was measured by thickness gauge; the pH was measured by pH paper; calsium content was measured by atomic absorption spectrophotometer. Based on this research, the types of deliming agent, stirring speed, and interaction of both variables affected highly significantly on the responses of thickness decrease and calcium content. The type of deliming agent affected highly significantly on the response of pH. The best treatment in this study was deliming agent of NH4Cl with stirring speed of 150 rpm. The treatment resulted delimed pelt with characteristics: thickness decrease of 13.42%, pH of 8.28, calcium content of 139.31 ppm, and good elasticity and pressure strength.