Sifat Fisiko-Kimia, Mikrobiologi dan Organoleptik Roti Tawar Sourdough Tersubstitusi dengan Tepung Umbi Kimpul (Xanthosoma sagittifolium) SIFAT FISIKO-KIMIA DAN ORGANOLEPTIK ROTI TAWAR TERSUBSTITUSI TEPUNG UMBI KIMPUL (Xanthosoma sagittifolium) DENGAN PENGGUNAAN SOURDOUGH

Abstract

      Tepung umbi kimpul (Xanthosoma sagittifolium) mengandung serat pangan tinggi dan berpotensi menjadi substitusi tepung terigu dalam pembuatan roti tawar. Roti sourdough difermentasi secara alami tanpa tambahan starter. Penelitian ini bertujuan untuk mengetahui sifat fisiko-kimia dan organoleptik dari roti tawar sourdough tersubstitusi tepung umbi kimpul dengan perbedaan formulasi. Penelitian dilakukan menggunakan Rancangan Acak Lengkap (RAL) dengan satu faktor, yaitu perbandingan tepung umbi kimpul: tepung terigu sebesar 0 persen:100 persen, 10 persen:90 persen, 20 persen:80 persen dan 30 persen:70 persen. Parameter yang dianalisis adalah kadar air, kadar abu, kadar protein, kadar lemak, dan karbohidrat, ukuran pori-pori, tekstur, warna, volume pengembangan, angka lempeng total (ALT), dan total kapang serta
parameter organoleptik berupa penerimaan sensori atribut rasa, aroma, warna, aftertaste, dan keseluruhan. Hasil penelitian menunjukkan substitusi tepung umbi kimpul dalam roti tawar sourdough memberikan pengaruh nyata pada semua parameter pengujian. Makin tinggi konsentrasi tepung umbi kimpul, warna makin gelap, tekstur makin keras, meningkatkan kadar air, menurunkan kadar protein dan abu, menurunkan ukuran pori dan volume pengembangan. Total kapang dan ALT pada roti sourdough memenuhi kriteria SNI 8371:2018. Roti tawar sourdough dengan substitusi tepung umbi kimpul substitusi hingga 30 persen masih memenuhi kriteria SNI 8371:2018, namun secara penerimaan organoleptik substitusi dilakukan hingga 10 persen.

           “Kimpul” tuber flour which is high in dietary fibre has a potential as a substitute for wheat flour in white bread production. Sourdough bread is naturally fermented. This study aimed to determine the physicochemical and organoleptic properties of sourdough bread substituted with “kimpul” tuber flour in different formulations. This research used a completely randomized design (CRD) with one factor. The percentages of “kimpul” tuber flour to wheat flour are 0 percent:100 percent, 10 percent:90 percent, 20 percent:80 percent, and 30 percent:70 percent. Parameters analyzed were chemical properties, including moisture content, ash content, protein content, fat content, and carbohydrate content; Physical parameters were pore sizes, texture, colour, and swelling volume. The hedonic organoleptic parameters were taste,
aroma, color, after-taste attributes, and overall acceptability. Higher concentration of “kimpul” tuber flour resulted in darker color, increased hardness and water content, reduced the ash and protein content, decreased the size of pores and organoleptic acceptability. The TPC and mold indicate that the sourdough was at a safe level and met the criteria of SNI 8371:2018. While kimpul tuber flour substitution up to 30% complied with SNI 8371:2018 standards, sourdough bread with up to 10% substitution showed comparable sensory acceptability to the non-substituted version.