Karakterisasi Enzim Polifenol Oksidase Biji Kakao (Theobroma cacao Linn.) - G.P. Ganda Putra; N.M. Wartini; A.A.M. Dewi Anggreni (Faculty of Agricultural Technology, Universitas Gadjah Mada, Yogyakarta, Indonesia, 2010)
This research was aimed to: (1) characterize polyphenol oxidase enzyme and (2) determine optimum condition (tem-perature, pH and incubation time) of polyphenol oxidase enzyme activity which isolated from cocoa beans. Those re-sult will be used to improve the quality of cocoa through rehydration technique. This research was carried out through:(1) isolation of polyphenol oxidase enzyme from 10 sampels of cocoa beans in Bali Province, (2) characterization ofpolifenol oksidase enzyme (activity, enzyme kinetics, MW), and (3) determination of optimum condition of tempera-ture, pH and incubation time. The results show that average value of polyphenol oxidase enzyme activity was 157,49± 58,03 U/gram (db) of cocoa beans with maximum and minimum values at 258,22 U/gram and 59,01 U/gram (db) of cocoa beans, respectively; V max equals to 595,24 U/gram (db) of cocoa beans and K equals to 0,20 M; result of SDS- PAGE of enzyme shows protein bands at M of 11,75; 17,80; 27,80; 36,03 and 131,52 kDa; and finally, optimumcondition of enzyme activity is at the temperature of 53,43oC; pH 5,42 and incubation time of 80,91 minutes.ABSTRAKTelah dilakukan penelitian dengan tujuan untuk: (1) mengetahui karakteristik enzim polifenol oksidase dan (2) menen- tukan kondisi (suhu, pH dan waktu inkubasi) optimum aktivitas enzim polifenol oksidase, yang diisolasi dari biji kakao kering. Hasil penelitian berupa kondisi (suhu, pH dan waktu inkubasi) optimum aktivitas enzim polifenol oksidase akan diaplikasikan untuk perbaikan mutu biji kakao kering melalui teknik rehidrasi. Penelitian ini dilakukan melalui tahapan: (1) isolasi enzim polifenol oksidase dari 10 sampel biji kakao kering di Provinsi Bali, (2) karakterisasi enzim polifenol oksidase (aktivitas, kinetika enzim, BM) dan (3) penentuan kondisi suhu, pH dan waktu inkubasi optimum. Hasil yang diperoleh menunjukkan bahwa: (1) aktivitas enzim polifenol oksidase rata-rata 157,49 ± 58,03 U/gram (bk) biji kakao dengan aktivitas maksimum 258,22 U/gram (bk) biji kakao dan minimum 59,01 U/gram (bk) biji kakao; maks sebesar 595,24 U/gram (bk) biji kakao dan K sebesar 0,20 M; hasil SDS-PAGE enzim menunjukkan pita-pita protein yang terbentuk pada BM 11,75; 17,80; 27,80; 36,03 dan 131,52 kDa; dan (2) kondisi optimum aktivitas enzimadalah suhu 53,43oC; pH 5,42 dan waktu inkubasi 80,91 menit.