MONITORING HIDROLISIS PROTEIN KECAMBAH KACANG TUNGGAK (Vigna unguiculata L.) OLEH ENZIM ALKALASE PADA VARIASI WAKTU DAN RASIO ENZIM-SUBSTRAT

Abstract

            Kacang tunggak dengan kandungan protein 18,3-35% berpotensi digunakan sebagai substrat protein dalam pembuatan hidrolisat protein nabati. Kecambah kacang tunggak cukup mudah diperoleh di pasaran (khususnya di wilayah Bali) yang lebih dikenal sebagai kacang mentik. Penelitian ini bertujuan melakukan monitoring berjalannya reaksi hidrolisis konsentrat protein kecambah kacang tunggak yang dikatalisis oleh enzim alkalase, dengan perlakuan variasi waktu hidrolisis dan variasi rasio enzim-substrat (rasio E/S). Penelitian diawali dengan tahap ekstraksi protein dari tepung kecambah kacang tunggak sehingga diperoleh konsentrat protein. Selanjutnya dilakukan proses hidrolisis terhadap substrat konsentrat protein dengan enzim alkalase menggunakan variasi waktu hidrolisis 0, 1, 2 dan 3 jam serta variasi  rasio (E/S) yaitu 0,1%, 1,0%, 2,0% dan 3,0%. Masing-masing hidrolisat protein yang diperoleh dimonitor keberhasilannya dalam hidrolisis berdasarkan parameter kadar  kadar ?-amino bebas, nilai derajat hidrolisis dan kadar protein terlarutnya. Hasil ekstraksi protein mampu menghasilkan konsentrat protein kacang tunggak dengan kadar protein total mencapai 68,11%. Hasil monitoring terhadap perlakuan hidrolisis menunjukkan bahwa peningkatan rasio E/S dan lama waktu hidrolisis mampu meningkatkan kadar ?-amino bebas, kadar protein terlarut, dan nilai derajat hidrolisis (DH%) dari produk hidrolisat protein kecambah kacang tunggak (pada batas variasi perlakuan yang diberikan). Kadar ?-amino bebas  tertinggi sebesar 3,9573 mg/mL, kadar protein terlarut tertinggi sebesar  20,9972 mg/mL, dan nilai DH% tertinggi  sebesar 93,80% diperoleh menggunakan perlakuan rasio E/S 3%  dan waktu hidrolisis selama 3 jam.

Kata kunci:   alkalase, hidrolisis, kacang tunggak, kecambah, protein

ABSTRACT

           Cowpea usually contains 18.3-35% protein and is potentially used as a protein substrate for preparing vegetable protein hydrolysates. Cowpea sprouts, available in the market (especially in Bali), are known as “kacang mentik”. This study aimed to monitor the progress of the hydrolysis of the cowpea sprout protein concentrate, catalyzed by alcalase enzyme, with the variations of hydrolysis time and enzyme-substrate ratio (E/S ratio). The research began with the protein extraction stage from cowpea sprout flour to obtain the protein concentrate. Furthermore, the hydrolysis was carried out on the protein concentrate substrate with alcalase enzyme using the variations of hydrolysis time of 0, 1, 2, and 3 hours and the E/S ratio of 0.1, 1.0, 2.0, and 3.0%. Each protein hydrolysate obtained was monitored for its success in hydrolysis based on the parameters of soluble protein content, free ?-amino content, and the degree of hydrolysis. The result showed that the protein extraction produced cowpea protein concentrate with a total protein content reaching 68.11%. The monitoring results of the hydrolysis treatment showed that increasing the E/S ratio and the length of hydrolysis time were able to increase the free ?-amino content, soluble protein content, and the degree of hydrolysis (DH%) value of the cowpea sprout protein hydrolysate product (at the limit of the treatment variations given). The highest value of the free ?-amino content of 3.9573 mg/mL, the soluble protein content of 20.9972 mg/mL, and the DH of 93.80% was obtained when using the 3% E/S ratio treatment and 3 hours of hydrolysis time.

Keywords: alcalase, cowpea, hydrolysis, protein, sprout