Electronic Theses and Dissertation

Susu kambing memiliki daya cerna yang tinggi, kandungan kimia yang bermanfaat bagi tubuh, dan tingkat alergenitas yang rendah, namun memiliki bau prengus. Yogurt merupakan salah satu produk susu fermentasi yang dihasilkan melalui aktivitas bakteri Lactobacillus bulgaricus dan Streptococcus thermophilus. Salah satu cara pengolahan untuk memperpanjang masa simpan dan mengurangi bau prengus adalah fermentasi dengan penambahan puree kuini. Penelitian ini bertujuan mengevaluasi pengaruh penambahan puree kuini terhadap Total Plate Count (TPC) bakteri asam laktat dan aktivitas antibakteri terhadap Staphylococcus aureus dan Escherichia coli pada yogurt susu kambing. Metode yang digunakan adalah 4 perlakuan konsentrasi puree kuini, yaitu P0 (100% yogurt tanpa penambahan puree), P1 (100% yogurt + 10% puree kuini), P2 (100% yogurt + 20% puree kuini) dan P3 (100% yogurt + 30% puree kuini), dengan 2 ulangan yang dianalisis secara deskriptif. Proses fermentasi dilakukan dengan menginokulasi starter Streptococcus thermophyllus 2,5% dan Lactobacillus bulgaricus 2,5% ke dalam susu kambing yang telah dipasteurisasi dan didinginkan, kemudian diinkubasi pada suhu 42°C selama 18 jam. Hasil penelitian menunjukkan bahwa susu kambing fermentasi dengan penambahan puree kuini (Mangifera odorata Griff) maupun tanpa penambahan puree menghasilkan Total Plate Count (TPC) bakteri asam laktat cenderung tinggi dan telah memenuhi persyaratan SNI 7552:2018. Aktivitas antibakteri terhadap Staphylococcus aureus dan Escherichia coli menghasilkan daya hambat yang tergolong kategori lemah hingga sedang. Aktivitas antibakteri terhadap E. coli lebih konsisten dibandingkan terhadap S. aureus. Dengan demikian, penambahan puree kuini maupun tanpa penambahan puree meningkatkan nilai Total Plate Count bakteri asam laktat yang tinggi dan menghasilkan daya hambat antibakteri dalam kategori lemah hingga sedang terhadap kedua bakteri uji.
Kata Kunci: Kuini, Yogurt, Bakteri Asam Laktat, Susu Kambing, Total Plate Count, Antibakteri

Goat milk has high digestibility, a beneficial chemical composition, and a low level of allergenicity, but it has a strong odor. Yogurt is one of the fermented milk products produced through the activity of Lactobacillus bulgaricus and Streptococcus thermophilus bacteria. One processing method used to extend shelf life and reduce the strong odor is fermentation with the addition of kuini puree. This study aimed to evaluate the effect of kuini puree addition on the Total Plate Count (TPC) of lactic acid bacteria and the antibacterial activity against Staphylococcus aureus and Escherichia coli in goat milk yogurt. The method used consisted of four treatments of kuini puree concentration, namely P0 (100% yogurt without puree addition), P1 (100% yogurt + 10% kuini puree), P2 (100% yogurt + 20% kuini puree), and P3 (100% yogurt + 30% kuini puree), with two replications analyzed descriptively. The fermentation process was carried out by inoculating Streptococcus thermophilus 2.5% and Lactobacillus bulgaricus 2.5% starter into pasteurized and cooled goat milk, followed by incubation at 42°C for 18 hours. The results showed that fermented goat milk with the addition of kuini puree (Mangifera odorata Griff), as well as without puree addition, produced a relatively high Total Plate Count (TPC) of lactic acid bacteria, which met the requirements of SNI 7552:2018. The antibacterial activity against Staphylococcus aureus and Escherichia coli produced inhibition zones classified as weak to moderate. Antibacterial activity against E. coli was more consistent than against S. aureus. Thus, the addition of kuini puree, as well as its absence, increased the Total Plate Count of lactic acid bacteria to a high level and produced antibacterial inhibition classified as weak to moderate against both test bacteria. Keywords: Kuini, Yogurt, Lactic Acid Bacteria, Goat Milk, Total Plate Count, Antibacterial