Penambahan Asam Asetat dan Fumarat untuk Mempertahankan Kualitas Pikel Ubi Jalar Kuning Pasca Fermentasi - Neti Yuliana; Siti Nurdjanah; Maya Sari (Faculty of Agricultural Technology, Universitas Gadjah Mada, Yogyakarta, Indonesia, 2014)
The objective of this investigation was to determine the ability of fumaric acid, acetic acid and their combinations, as organic acid preservatives to maintain the quality of fermented sweet potatoes pickle during 6 weeks of storage at room temperature, as well as to compare with sodium benzoate. Acetic acid (1, 1.5 and 2%), fumaric acid (0.1, 0.15 and 0.2%), and their combinations, were used as treatments in this investigation. As controls, sodium benzoate and without preservatives additions were also conducted. The best treatment for maintaining the quality of fermented yellow sweet potatoes pickle was combination of acetic acid 1% and fumaric acid 0.2%,which has a total mold, yeast, non lactic acid bacteria and lactic acid bacteria, each <30 colonies/ml, total acid 1.34%, pH 3.18 and the total soluble solids 2.07 brix. The pickle was described as somewhat pale orange color and acidic aroma with the acceptance rates 87%. In term of sensory acceptabilitty, however, fumaric acids treatment was better than either single acetic acid or combination of acetic-fumaric acids. The results indicated that acetic, fumaric acid and their combination treatments were able to keep the sweet potatoes pickle quality, therefore, these preservative could serve as an alternative substitution for the use of sodium benzoate.ABSTRAKTujuan penelitian ini adalah untuk mengetahui dan membandingkan kemampuan asam fumarat, asam asetat dan kombinasinya sebagai pengawet untuk mempertahan kualitas pikel ubi jalar kuning pasca fermentasi yang disimpan pada suhu ruang selama 6 minggu; dan juga membandingkannya dengan pengawet asam benzoat. Perlakuan terdiri dari konsentrasi asam asetat 1; 1,5 dan 2%; konsentrasi asam fumarat 0,1; 0,15 dan 0,2%, dan kombinasi keduanya. Perlakuan dengan asam benzoat dan tanpa pengawet juga disiapkan sebagai kontrol. Perlakuan terbaik diperoleh dari kombinasai asam asetat 1% dan fumarat 0,2%, dengan karakteristik kualitas sebagai berikut: total kapang, khamir, bakteri bukan asam laktat, dan bakteri asam laktat masing masing <30 koloni/ml, total asam 1,35%, pH 3,18 dan total padatan terlarut 2,07o brix, warna orange pucat, beraroma asam dengan tingkat penerimaan panelis 87%. Berdasarkan penerimaan sensoris, perlakuan asam fumarat lebih baik daripada asam asetat ataupun kombinasai asam asetat-fumarat. Hasil penelitian menunjukkan bahwa asam asetat, fumarat dan kombinasi keduanya dapat mempertahankan kualitas pikel ubi jalar kuning yang berpotensi menjadi alternatif pengganti pengawet benzoat.