Judul: Stability Analysis of Phenolic Compounds in Ready-To-Drink Coffee Beverage Products During Room Temperature Storage
Abstrak: Minuman kopi ready-to-drink (RTD) atau siap minum merupakan salah satu inovasi konsumsi kopi yang saat ini telah beredar luas di pasaran dan cukup digemari oleh berbagai kalangan masyarakat. Minuman ini memiliki beberapa jenis wadah simpan seperti gelas, botol, dan sachet. Penelitian ini bertujuan untuk mengetahui pengaruh waktu penyimpanan terhadap kestabilan senyawa fenolik dalam minuman kopi ready-to-drink. Minuman kopi dibuat dari ekstrak kopi Robusta yang ditambah dengan ingredien lain (gula dan pengawet potassium sorbat ), dipasteurisasi, diisikan panas (hot filling) ke dalam kemasan gelas plastik, dan disimpan pada suhu ruang (0, 2, 4, 6, 8, dan 10 minggu). Kandungan total fenol dan total tanin dalam kopi RTD dianalisis menggunakan metode Spektrofotometri UV-visible dengan pereaksi Folin-Ciocalteu yang sebelumnya telah divalidasi. Validasi terhadap metode spektrofotometri Folin-Ciocalteu menggunakan empat parameter uji berupa linearitas, presisi, akurasi, dan sensitivitas (LOD-LOQ) memberikan hasil yang baik ditandai dengan kesesuaian antara hasil uji dengan literatur standar yang ditetapkan. Kandungan asam klorogenat kopi (5-CQA, 4- CQA, dan pengamatan terhadap sifat kestabilan 3-CQA) dianalisis dengan menggunakan metode Ultra-High Performance Liquid Chromatography (UHPLC). Analisis menunjukkan bahwa ketiga senyawa yang diamati yaitu fenol, tanin dan asam klorogenat mengalami degradasi komponen secara signifikan seiring pertambahan waktu simpan. Penurunan senyawa CQA secara signifikan hanya terjadi pada senyawa 5-CQA. Persentase penurunan total fenol dan total tanin sejak awal pengamatan (minggu ke-0) hingga akhir pengamatan (minggu ke-8) secara berturut sebesar 19,3% dan 11,06%. Sedangkan untuk senyawa 5-CQA mengalami penurunan sebesar 5,4%., Ready-to-drink (RTD) coffee is one of the innovations in coffee consumption that is currently widely circulated in the market and is quite popular by various groups of people. This drink has several types of storage containers such as cups, bottles, and sachets. This study aims to determine the effect of storage time on the stability of phenolic compounds in ready-to-drink coffee. Coffee drinks were made from Robusta coffee extract added with other ingredients (sugar and potassium sorbate preservative), pasteurized, hot filled into plastic cups, and stored at room temperature (0, 2, 4, 6, 8, and 10 weeks). The content of total phenols and total tannins in RTD coffee was analyzed using the UV-visible spectrophotometric method with Folin-Ciocalteu reagent which had previously been validated. Validation of the Folin-Ciocalteu spectrophotometric method using four test parameters such as linearity, precision, accuracy, and sensitivity (LOD-LOQ) gave good results characterized by the conformity between the test results and the standard literature set. The content of coffee chlorogenic acid (5-CQA, 4-CQA, and observations on the stability properties of 3-CQA) was analyzed using the Ultra- High Performance Liquid Chromatography (UHPLC) method. The analysis showed that the three compounds observed, namely phenol, tannin and chlorogenic acid, experienced significant degradation of the components as the storage time increased. A significant decrease in CQA compounds only occurred in the 5-CQA compound. The percentage decrease of total phenols and total tannins from the beginning of observation (week 0) to the end of observation (week 8) was 19,3% and 11,06%, respectively. Meanwhile, the 5-CQA compound decreased by 5,4%.
Keyword: chlorogenic acid, method validation, phenols, ready-to-drink coffee, tannins