ABSTRAKPenelitian ini dilakukan untuk mengetahui sifat fungsional pati ubi kelapa kuning (Dioscorea alata) dan mengetahui kemampuannya sebagai pengental pada saus tomat. Penelitian dilakukan dalam 2 tahapan yaitu ekstraksi pati saus tomat menggunakan rancangan acak lengkap dengan 5 taraf konsentrasi pati (0, 1, 2, 3, dan 4% b/b) dan 4 kali ulangan. Konsentrasi pati dihitung berdasarkan persentase berat pati terhadap berat bubur tomat. Analisis sifat fungsional pati menunjukkan bahwa pati ubi kelapa kuning memiliki kemampuan sebagai pengental namun masih memiliki nilai setback yang cukup tinggi. Konsentrasi pati ubi kelapa kuning berpengaruh nyata terhadap kekentalan, sineresis saus tomat, dan nilai a* saus tomat namun tidak berpengaruh nyata terhadap kadar air, total padatan terlarut, nilai L* dan nilai b* saus tomat. Walaupun terjadi perubahan warna yang jelas dapat dilihat sineresis selama penyimpanan selama 1 minggu dan memiliki kekentalan 4,85 Poise, total padatan terlarut 44,8 o brix, nilai L* 50,75, a* 50,75, b* 51,30 dan penerimaan keseluruhan "agak suka". ABSTRACTThe aim of this research was to determine the functional properties of yellow greater yam's starch (Dioscorea alata) and its ability to acts as thickening agent for tomato sauce. This research was carried out in 2 stages: starch extraction followed by determination of its physical and functional properties and production of tomato sauce using completely randomized design with 5 levels of starch concentration and 4 replications. The levels were 0, 1, 2, 3 and 4% which was calculated from tomato pulps. Functional properties of yellow greater yam's starch showed the capability as thickening agent but had quite high setback value. The result showed that the p <0 .01) and a* value (p < 0.05) but did not affect water content, total soluble solid, L* and b* of the tomato sauce. Although creates an thickening agent in tomato sauce producing tomato sauce without syneresis during a week of storage, viscosity 4.85 Poise, total soluble solid 44.8 o brix, L* 50.75, a* 50.75, b* 51.30 and overal acceptance "rather like" to "like".