Isolasi dan Evaluasi Sifat Antioksidan dan Kasein Susu Kambing Peranakan Etawah dan Sapi Friesan Holstein di Wilayah Bogor

Abstract

Kasein merupakan protein utama susu yang berpotensi sebagai sumber senyawa bioaktif, termasuk antioksidan alami. Perbedaan komposisi protein antara susu sapi Friesian Holstein (FH) dan susu kambing Peranakan Etawah (PE) diduga memengaruhi karakteristik dan aktivitas biologis kasein. Penelitian ini bertujuan mengisolasi, mengkarakterisasi, dan mengevaluasi aktivitas antioksidan kasein dari susu sapi FH dan susu kambing PE asal Caringin, Bogor. Karakterisasi meliputi analisis komposisi susu, rendemen kasein, profil protein (SDS-PAGE), gugus fungsi (FTIR), komposisi asam amino (HPLC), dan aktivitas antioksidan (DPPH). Rendemen kasein susu sapi (22,73%) lebih tinggi dibandingkan susu kambing (14,75%). Analisis FTIR dan SDS-PAGE menunjukkan perbedaan karakteristik kasein dari kedua sumber susu. Kasein susu kambing memiliki kandungan glutamat dan prolin lebih tinggi, sedangkan kasein susu sapi menunjukkan kapasitas antioksidan lebih tinggi, yaitu 0,552 mg EVC 100 g-1 dibandingkan 0,227 mg EVC 100 g-1. Hasil penelitian menunjukkan bahwa kasein susu lokal berpotensi dikembangkan sebagai bahan baku pangan fungsional.

Casein Casein is the major protein in milk and has potential as a source of bioactive compounds, including natural antioxidants. Differences in protein composition between Friesian Holstein (FH) cow milk and Peranakan Etawah (PE) goat milk may influence the characteristics and biological activity of casein. This study aimed to isolate, characterize, and evaluate the antioxidant activity of casein from FH cow milk and PE goat milk collected from Caringin, Bogor. Characterization included analysis of milk composition, casein yield, protein profile by SDS-PAGE, functional groups by FTIR, amino acid composition by HPLC, and antioxidant activity using the DPPH method. The casein yield of cow milk (22.73%) was higher than that of goat milk (14.75%). FTIR and SDS-PAGE analyses confirmed differences in casein characteristics between both milk sources. Goat milk casein contained higher levels of glutamic acid and proline, whereas cow milk casein exhibited greater antioxidant capacity (0.552 mg VCE 100 g-1) than goat milk casein (0.227 mg VCE 100 g-1). These findings demonstrate the potential of local milk casein as a functional food ingredient.