Combination of Ultraviolet and High Pulsed Electric Field Method towards Physical, Chemical and Microbiological Quality of Goat’s Milk Recontaminated by Salmonella Typhimurium ATCC 14028

Abstract

Milk is a perfect food because it contains all nutrients needed for human growth. Goat‟s milk has some superiority compared to cow‟s milk such as does not cause allergic, contains more medium chain triglycerides and essential amino acids. The high nutrients in milk supported with an almost neutral pH and high aw (water activity) makes it not only advantageous for human, but also for pathogenic bacteria such as Salmonella Typhimurium. Heat treatment such as pasteurization is the effective way to minimize microbial contamination in milk, but the method causes changes towards physical, chemical and sensorial quality of fresh milk. Therefore, non thermal treatment has been developed to inactivate microorganism as well as maintaining the fresh like of milk. Combination of Ultraviolet Irradiation and High Pulsed Electric Field is being developed in this occasion for that purpose. This research aimed to obtain the best combination of both method to reduce total plate count of fresh goat‟s milk and Salmonella Typhimurium recontaminated on goat‟s milk. The result showed that combination of UV and HPEF method was successfully reduce 0.49 log cycle of the total plate count and 47.8% of Salmonella Typhimurium ATCC 14028 without giving a significant impact (P>0.05) on physical and chemical quality of fresh goat‟s milk. Peroxide number of milk did not change after treatment. Protein denaturation on molecular level was observed, which gives an advantage to increase the protein‟s bioavailability.

Susu merupakan pangan yang sempurna karena mengandung hampir semua nutrien yang dibutuhkan oleh manusia. Susu kambing memiliki banyak kelebihan dibandingkan dengan susu sapi. Susu kambing tidak menyebabkan alergi, mengandung lebih banyak medium chain triglycerides yang terbukti secara ilmiah dapat mengurangi deposisi kolesterol dalam darah, juga mengandung lebih banyak asam amino esensial. Susu kambing juga merupakan salah satu komoditas yang berpotensi untuk dikembangkan sebagai salah satu sumber susu di Indonesia, untuk mengurangi kebutuhan impor susu nasional. Kandungan nutrien yang tinggi dalam susu, didukung oleh pH yang mendekati normal dan nilai aw (aktivitas air) yang tinggi membuat komoditas tersebut juga menguntungkan bagi pertumbuhan bakteri pembusuk. Salah satu bakteri pembusuk yang sering mengontaminasi susu dan produk olahannya adalah Salmonella Typhimurium. Kontaminasi Salmonella sp. pada produk pangan dapat menyebabkan salmonellosis bagi orang yang mengonsumsinya. Bakteri tersebut merupakan bakteri patogen berbahaya sehingga Badan Standarisasi Nasional Indonesia (BSN) mensyaratkan bakteri tersebut tidak terkandung dalam susu segar.