EFEKTIVITAS MEDAN LISTRIK BERDENYUT TERHADAP PENURUNAN POPULASI Salmonella typhi PADA SUSU (Effectiveness of Pulsed Electrical Field on Salmonella Typhi Population Reduction In Milk) (UPN VETERAN JAWA TIMUR, 2015)
Abstract Milk is an almost perfect food for a complete nutritional content and is a good medium for the growth of microbes, both pathogenic and non-pathogenic. One of pathogenic bacteria that may contaminate the milk is Salmonella typh., All dairy products: either fresh milk, pasteurized, UHT milk, milk powder and Salmonella sp. should not be there at all. One of the non-thermal pasteurization method that can be used for milk pasteurization by using Pulsed Electric Field ( PEF). PEF keep fresh food in physical, chemical and nutritional properties, as well as increasing the shelf life of food. The purpose of this research studid Influence of the number of beats and the distances between the collection rate of the decline in the population of Salmonella typhi, and Influence of the number of pulses and pulse sets the distance between the physicochemical properties of milk). Data were analyzed descriptively. The results showed that the inoculation of Salmonella typhi (incubation for 5 hours at 37 ° C) with a number of 1.98 x 107 cfu / ml effect on the value of total acid, pH, alcohol test, test reductase, and emulsion stability, but has no effect on specific gravity of milk. PEF treatment does not affect the value of total acid, pH, alcohol test, emulsion stability, and density, but the effect on bacterial population decline of Salmonella typhi and test reductase. The decrease in population was obtained from the Salmonella typhi bacteria treatment rate number 1000 and the distance between nodes 2 microseconds pulse. Increased time highest reductase obtained after treatment the number of beats in 1000 and the distances between the collection of 241 microseconds pulse 2 minutes. Initial number of Salmonella typhi was 7.296 log cfu / ml. The highest decline rate was obtained from the treatment the number 1000 and the distance between nodes is 2,225 microseconds pulse 2 log cycles. Keywords: pulsed electric field, Salmonella typhi, population, milk Abstrak Susu merupakan makanan yang hampir sempurna karena kandungan zat gizinya yang lengkap dan merupakan media yang baik untuk pertumbuhan mikroba, baik patogen maupun non patogen. Salah satu bakteri patogen yang dapat mencemari susu adalah Salmonella typh., Semua produk susu, baik susu segar, pasteurisasi, bubuk maupun susu UHT, Salmonella sp. tidak boleh ada sama sekali. Salah satu metode pasteurisasi non-thermal yang dapat digunakan untuk pasteurisasi susu yaitu dengan menggunakan Medan Listrik Berdenyut (MLB/ Pulsed Electric Field/PEF). MLB menyebabkan pangan tetap segar secara fisik, sifat kimia dan nutrisinya, serta peningkatan daya simpan pangan. Tujuan dari penelitian ini adalah mempelajari : 1. Pengaruh jumlah denyut dan jarak antar kumpulan denyut terhadap penurunan populasi Salmonella typhi, 2. Pengaruh jumlah denyut dan jarak antar kumpulan denyut terhadap sifat fisikokimia susu). Data yang diperoleh dianalisis secara deskriptif. Hasil penelitian menunjukkan bahwa inokulasi Salmonella typhi (inkubasi selama 5 jam pada suhu 37°C) dengan jumlah 1,98 x 107 cfu/ml berpengaruh terhadap nilai total asam, pH, uji alkohol, uji reduktase, dan stabilitas emulsi, tetapi tidak berpengaruh terhadap berat jenis susu. Perlakuan MLB tidak berpengaruh terhadap nilai total asam, pH, uji alkohol, stabilitas emulsi, dan berat jenis, tetapi berpengaruh terhadap penurunan populasi bakteri Salmonella typhi dan uji reduktase. Penurunan populasi bakteri Salmonella typhi diperoleh dari perlakuan jumlah denyut 1000 dan jarak antar kumpulan denyut 2 μs. Peningkatan waktu reduktase tertinggi diperoleh setelah perlakuan jumlah denyut 1000 dan jarak antar kumpulan denyut 2 μs 241 menit. Jumlah awal Salmonella typhi adalah 7,296 log cfu/ml. Penurunan tertinggi diperoleh dari perlakuan jumlah denyut 1000 dan jarak antar kumpulan denyut 2 μs yaitu 2,225 log cycle. Kata Kunci :medan listrik berdenyut, Salmonella typhi, populasi, susu