Dwi wulandari1) , Soemitro Djojowidagdo2), Suharjono Triatmojo3)
The objective of the research is to find out the characteristic of gelatin of chicken legs skin receiving treatment of soaking with acid and base of different concentration. The subject matter used in this research was 860 sheets of chicken legs skins of broiler Hubbard strain of 40 days old. The subjects were divided into 4 treatments with 3 repetitions ,they were T1 ( soaking consecutively in NaOH 0.1% ; H2SO4 0.1% ; citrate acid 0.4%) , T2 ( soaking in NaOH 0.3% ; H2SO4 0.3% ; citrate acid 0.7%), T3 (soaking in NaOH 0.5% ; H2SO4 0.5% ; citrate acid 1% ) ,T4 ( soaking in NaOH 0.7% ; H2SO4 0.7% ; citrate acid 1.3%). The data were analyzed using Anova of Completely Randomized Design (CRD) One Way mode, and if there were significant differences, then the analysis was continued using the Duncan’s New Multiple Range Test. Result of the research showed that the influence of concentration of acid and base on the soaking was not significant upon the rendement, viscosity, fat value, water content, ash value and pH, while it was significant ( P< 0.05) to gel strength and protein values. Gelatin characteristics made of chicken legs skin from this study were rendement value of 12.13% ; gel strength 136 g/cm2 ; viscosity 7.5 poise; protein content 83.23% ; fat value 1.09% ; ash value 0.27% ; water content 6.75% and pH 4.5. Each treatment produced 7 types of protein molecules of protein weighing around T1 = 9.233 – 41.2 x 103 k DA, T2 = 9.233 – 38.806 x 103 k Da, T3 = 9.233 – 36.551 x 103 k DA and T4 = 9.233 – 28.76 x 103 k DA. The analysis of amino acid showed that there were 17 essential amino acids containing high enough glisine and hidroxyproline.
Keywords : Chicken legs skin, extraction and Gelatin.