SUMMARY
Peanut sauce is a product made from peanuts with some seasonings and processed into paste form. Previous research results have showed that “cilok” (a traditional condiment made of tapioca starch) and the peanut sauce in Surakarta city are unfit for consumption. The addition of a few kinds of lime juice is expected to inhibit the growth of microbial pathogens in the sample. This study was conducted to determine the capability of lime extract to inhibit the growth of microbial contamination on peanut sauce from the 10 street vendors. Total Staphylococci, total coliform, total Salmonella-Shigella, total plate count (TPC), and total yeast were counted before and after the addition of lime extract. The results showed that the addition of kaffir lime gives the best results in inhibiting the growth of bacteria compared with the addition of key lime and lime. The results of TPC in the samples with the addition of kaffir lime after incubation of 4 hours was 3.5 × 104 CFU/mL. Kaffir lime gives the highest percentage of inhibiting TPC at 91.86%, yeast 40.51%, coliform 21.31%, Salmonella-Shigella 78.09%. The addition of key lime and lime gives the highest percentage of inhibiting the Staphylococci with each result 93.97% and 92.54%m respectively. The pH value of the peanut sauce with the addition of kaffir lime was 3.5, the titratable acidity was 0.31%, the RSA DPPH was 29.9 %, and total phenolic content 161.9 mg GAE/g sample. The lime extract either lime, key lime, or kaffir lime, has the potential to be added to peanut sauce as a natural antimicrobial agent.Keywords: Lime juice, microbiological contamination; peanut sauce ABSTRAKSaus kacang merupakan produk dari kacang tanah yang ditambah beberapa bumbu dan diolah menjadi bentuk pasta. Hasil penelitian sebelumnya menyebutkan bahwa cilok dan saus kacang yang beredar di kota Surakarta belum layak dikonsumsi. Penambahan air perasan beberapa jenis jeruk diharapkan mampu menghambat pertumbuhan mikroba pathogen pada saus kacang cilok. Penelitian ini dilakukan untuk menentukan jenis jeruk terbaik dalam menghambat pertumbuhan mikroba cemaran pada saus kacang dari 10 penjual cilok. Pengujian yang dilakukan yaitu menentukan jumlah mikrobia dari Staphylococcus, Koliform, Salmonella-Shigella, total plate count (TPC) dan total yeast sebelum dan sesudah penambahan air perasan jeruk. Hasil menunjukkan bahwa penambahan air perasan jeruk purut memberikan hasil terbaik dalam menghambat pertumbuhan bakteri dibandingkan dengan penambahan jeruk nipis dan jeruk limau. Hasil TPC pada sampel dengan penambahan jeruk purut setelah diinkubasi 4 jam adalah 3,5 × 104 CFU/mL. Saus kacang dengan penambahan jeruk purut menghasilkan persentasi tertinggi dalam menghambat TPC yaitu 91,86%, yeast 40,51%, Koliform 21,31%, Salmonella-Shigella 78,09%. Penambahan jeruk nipis dan jeruk limau menghasilkan prosentase tertinggi dalam menghambat Staphylococcus aureus yaitu 93,97% dan 92,54%. Hasil analisa kimia dari sampel saus kacang dengan penambahan air perasan jeruk purut yaitu nilai pH sebesar 3,5, total asam tertitrasi sebesar 0,3057%, aktivitas antioksidan sebesar 29,9 % dan total fenol sebesar 161,9 mg GAE/g sampel. Penambahan air perasan jeruk nipis, jeruk purut dan jeruk limau memiliki potensi ditambahkan dalam saus kacang sebagai senyawa antimikrobia alami.Kata kunci: Cemaran mikrobiologi; sari buah jeruk; saus kacang