The use guava (Psidium guajava) leaf extract as preservative of boiled salted skipjack

Study on application of guava (Psidium guajava) leaf extract to inhibit quality deterioration of boiled salted skipjack (Scomber australasicus CV) was carried out. In this experiment, 4 concentrations (0, 3, 6 and 9%) of leaf extract were used as boiling media during processing of boiled salted skipjack. The quality changes of boiled salted skipjack was monitored every 24 h organoleptically, chemically (TVB, TBA) and microbiologically (TPC, mold) while observation on the changes of fatty acids profile was conducted on the boiled salted skipjack with the best treatment. Result of the study showed that the use of guava leaf extract for cooking media during processing of boiled salted skipjack could inhibit the increase of TBA value, and prevent the oxidation of unsaturated fatty acids, but could not inhibit the increase of TVB value and microorganism growth during ambient temperature storage. Although the use of guava leaf extract resulted in darker color (brownish), the intensity of rancid flavor and taste of boiled salted skipjack treated with guava leaf extract was much lower and better in texture that that of control, The most effective treatment in this experiment was guava leaf extract at concentration of 9% (w/v).Original Abstract: Penelitian aplikasi ekstrak daun biji (Psidium guajava) untuk menghambat kemunduran mutu pindang tongkol (Scomber australasicus CV) telah dilakukan. Pada penelitian ini digunakan 4 konsentrasi ekstrak daun jambu (0, 3, 6 dan 9%) sebagai larutan perebus pada pengolahan pindang tongkol. Perubahan mutu ikan pindang diamati setiap 24 jam secara organoleptik, kimia (TVB, TBA) dan mikrobiologi (TPC, kapang), sedangkan pengamatan terhadap perubahan asam lemak dilakukan pada ikan pindang dengan perlakuan terbaik. Hasil penelitian menunjukkan bahwa penggunaan ekstrak daun jambu sebagai larutan perebus pada pemindangan ikan tongkol mampu menghambat peningkatan kadar TBA dan menekan oksidasi asam lemak tidak jenuh, tetapi tidak mampu menghambat peningkatan kadar TVB dan pertumbuhan mikroorganisme selama penyimpanan pada suhu ruang. Meskipun penggunaan ekstrak daun jambu menyebabkan warna pindang cenderung menjadi lebih gelap (kecoklatan), pindang tongkol yang direbus dengan ekstrak daun jambu mempunyai intensitas bau dan rasa tengik yang sangat rendah dan tekstur yang lebih baik bila dibanding kontrol. Perlakuan ekstrak daun jambu yang paling efektif sebagai pengawet pindang tongkol dengan nilai sensori terbaik adalah perlakuan ekstra