Pengaruh Ekstrak Jeruk Nipis (Citrus aurantifolia) terhadap Karakteristik Keju Lunak dengan Milk Clotting Enzyme Lactobacillus rhamnosus SKG 34 - Listia Liantania, Kadek; Mayun Permana, I Dewa Gde; Nocianitri, Komang Ayu (Study Program of Food Technology, Faculty of Agricultural Technology, Udayana University, 2025)
Abstract Cheese production involves coagulating milk proteins through the use of coagulating agents such as enzymes and acids. The Milk Clotting Enzyme (MCE) from Lactobacillus rhamnosus SKG 34 can serve as an alternative to rennet in cheese manufacturing processes, although the resulting soft cheese exhibits low yield and protein content. The addition of acid can assist the coagulation process, thereby improving the quality of the resulting cheese. Lime extract is expected to lower the pH of milk and optimize the activity of the enzyme, thus enhancing the characteristics of the soft cheese produced. This study was conducted to evaluate how lime extract influences the properties of soft cheese made using milk clotting enzyme derived from Lactobacillus rhamnosus SKG 34, as well as to identify the most effective concentration of lime extract for achieving optimal soft cheese quality. This study used a Randomized Block Design (RBD) with five concentrations of lime extract (0%, 2%, 4%, 6%, and 8%) repeated three times, creating 15 experimental units. Yield, pH, moisture content, protein content, hardness, and sensory evaluation were observed as research variables. ANOVA was used for data analysis, with Duncan's test as a follow-up analysis when treatments showed significant effects (P<0.05). The results showed that adding 4% lime extract produced the best soft cheese using MCE L. rhamnosus SKG 34 with pH 4,19, moisture content 57,77%, protein content 16,44%, yield 21,52%, hardness 3,15N, and hedonic values for color, aroma, taste, texture, and overall acceptance preferred by panelists. Keywords: lime extract, soft cheese, Lactobacillus rhamnosus SKG 34, milk clotting enzyme Abstrak Proses pembuatan keju dilakukan melalui koagulasi protein susu menggunakan agen penggumpal seperti enzim dan asam. Milk Clotting Enzyme (MCE) dari bakteri Lactobacillus rhamnosus SKG 34 dapat digunakan sebagai alternatif pengganti rennet dalam produksi keju, akan tetapi keju lunak yang dihasilkan memiliki rendemen dan kadar protein yang rendah. Penambahan asam dapat membantu dalam koagulasi susu sehingga keju yang dihasilkan lebih optimal. Penambahan ekstrak jeruk nipis diharapkan dapat menurunkan pH susu dan mengoptimalkan aktivitas enzim sehingga meningkatkan karakteristik keju lunak yang dihasilkan. Penelitian ini bertujuan untuk mengetahui pengaruh ekstrak jeruk nipis terhadap karakteristik keju lunak dengan MCE L. rhamnosus SKG 34 serta mengetahui konsentrasi ekstrak jeruk nipis paling tepat sehingga menghasilkan keju lunak dengan karakteristik terbaik. Penelitian ini menerapkan Rancangan Acak Kelompok (RAK) dengan lima taraf konsentrasi ekstrak jeruk nipis (0%, 2%, 4%, 6%, dan 8%) yang diulang sebanyak tiga kali menghasilkan 15 unit percobaan. Rendemen, pH, kadar air, kadar protein, kekerasan, dan evaluasi sensoris diamati sebagai variabel penelitian. ANOVA digunakan untuk analisis data, dengan uji Duncan sebagai analisis lanjutan ketika perlakuan memberikan pengaruh signifikan (P<0,05). Hasil penelitian menunjukkan penambahan ekstrak jeruk nipis 4% menghasilkan keju lunak terbaik menggunakan MCE L. rhamnosus SKG 34 dengan pH 4,19, kadar air 57,77%, protein 16,44%, rendemen 21,52%, kekerasan 3,15N, serta nilai hedonik warna, aroma, rasa, tekstur, dan penerimaan keseluruhan yang disukai panelis. Kata kunci: ekstrak jeruk nipis, keju lunak, Lactobacillus rhamnosus SKG 34, milk clotting enzyme