Sifat Fisik Pati Ganyong (Canna edulis Kerr.) Termodifikasi dan Penambahan Gum Xanthan untuk Rerotian (Physical Characteristics of Modified Canna edulis Kerr. Starch and Gum Xanthan for Bakeries)

Modification of Canna starch through heat-moisture treatment (HMT) and gum xanthan (GX) treatment was conducted to improve the disadvantage of natural Canna starch in order to expand its usage in food industry, especially for bakery products. The research was arranged in a factorial randomized complete block design with three factors (temperature, incubation time, and GX concentrations) and three replications for each factor. The modified Canna starch by HMT possessed water content of 15 % as well as combination of temperature (80 °C and 100 °C), periods (8 and 16 hours) and concentration of GX (0; 0.5; 1; 1.5 and 2 %). The observed variables were the swelling power, water solubility index, water absorption index, baking expantion, and bulk density of modified Canna starch. The result showed that the modification of Canna starch by temperature, time of HMT and concentration GX produced modified starch with physical properties that significantly differ among treatments and natural starch. Modified Canna starch by treatments of 80 °C, 8 hours, and 1 % xanthan gum concentration showed had swelling power 16.90 ± 0.48 g/g, water solubility index 10.28 ± 0.25 %, water absorption index 112.58 ± 0.38 %, baking expantion 0.94 ± 0.11 mL/g and bulk density 0.73 ± 0.026 g/mL which alike with wheat flour so that it can be further developed as wheat flour substitute on bakery products. ABSTRAK Penelitian modifikasi pati ganyong melalui perlakuan heat-moisture-treatment (HMT) dan penambahan gum xanthan (GX) dilakukan untuk memperbaiki kelemahan pati ganyong alami sehingga menjadi luas aplikasinya dalam industri pangan terutama produk rerotian. Penelitian menggunakan rancangan acak kelompok faktorial dengan 3 perlakukan dan 3 ulangan. Perlakuan yang diberikan adalah waktu (8 dan 16 jam), suhu (80 °C dan 100 °C), kadar air 15 % dan konsentrasi gum xanthan (0, 0,5; 1; 1,5; 2 %). Data dianalisis dengan sidik ragam (ANOVA) pada α = 0,05, dilanjutkan dengan uji BNJ (α = 0,05). Parameter yang diamati swelling power (SP), indeks kelarutan dalam air (IKA), indeks absobsi air (IAA), derajat pengembangan (DP), dan densitas kamba (DK) pati ganyong termodifikasi. Hasil penelitian menunjukkan bahwa modifikasi pati ganyong dengan kombinasi perlakuan suhu dan waktu HMT serta konsentrasi GX menghasilkan pati termodifikasi dengan sifat fisik yang berbeda nyata antar perlakuan maupun pati alaminya. Modifikasi pati ganyong dengan HMT pada suhu 80 °C, waktu 8 jam, kadar air pati 15 % dan konsentrasi gum xanthan 1 % dapat menghasilkan pati ganyong yang sifat fisiknya mendekati tepung terigu kadar protein sedang dan berbeda dengan pati ganyong alami. Sifat fisik pati ganyong termodifikasi tersebut adalah SP 16,90 ± 0,48 g/g, IKA 10,28 ± 0,25 %, IAA 112,58 ± 0,38 %, DP 0,94 ± 0,11 mL/g, dan DK 0,73 ± 0,026 g/mL. Kata kunci: Pati ganyong; gum xanthan; HMT; modifikasi; sifat fisi