Optimasi Formula Roti dengan Substitusi Tepung Ubi Jalar Ungu (Ipomoea batatas L.) menggunakan D-Optimal Mixture Design.

Abstract

Ubi jalar ungu merupakan salah satu komoditas pertanian dengan tingkat produktivitas yang cukup tinggi dengan produksi mencapai 2.416 ton dan terdapat kandungan antosianin yang cukup tinggi, namun hingga saat ini pemanfaatannya dalam bentuk produk olahan masih terbatas dan belum banyak dijumpai di pasaran. Salah satu produk pangan yang banyak dikembangkan oleh industri saat ini adalah roti. Seiring dengan meningkatnya kesadaran masyarakat terhadap pangan bergizi, kini mulai banyak dilakukan inovasi dalam pembuatan roti melalui substitusi bahan baku, salah satunya menggunakan tepung ubi jalar ungu. Penelitian ini bertujuan menentukan formulasi optimum untuk pembuatan roti substitusi tepung ubi ungu berdasarkan pengujian sensori hedonik dan sifat fisik sebagai parameter untuk mempertimbangkan pemilihan formula, serta membandingkan formula optimum dengan produk komersial untuk mengetahui posisi produk terhadap pasar. Formulasi menggunakan variabel bebas yaitu tepung terigu dan tepung ubi jalar ungu komersial. Optimasi dilakukan dengan mengukur respon dari 15 formula yang dirancang menggunakan Design Expert 13.0®. Berdasarkan hasil optimasi diperoleh 2 formula terbaik dengan komposisi tepung ubi jalar ungu 2-7%. Berdasarkan uji ranking produk formula optimal tidak terdapat perbedaan yang signifikan terhadap produk komersial sehingga dapat bersaing di pasaran. Selain itu, formula optimal memiliki kadar air sebesar 20,31%, kadar abu 1,36%, protein 2,47%, lemak 15,07%, dan karbohidrat 60,80%.

Purple sweet potato is one of the agricultural commodities with relatively high productivity, reaching 2,416 tons, and contains a considerable amount of anthocyanins. However, its utilization in processed food products remains limited and is not widely available in the market. One of the food products that is currently being extensively developed by the industry is bread. Along with increasing public awareness of nutritious foods, various innovations have been introduced in bread production through the substitution of raw materials, one of which is the use of purple sweet potato flour. This study aimed to determine the optimum formulation of bread substituted with purple sweet potato flour based on hedonic sensory evaluation and physical characteristics as parameters for formula selection, as well as to compare the optimum formula with a commercial product to determine its market competitiveness. The formulation employed wheat flour and commercial purple sweet potato flour as independent variables. Optimization was carried out by measuring the responses of 15 formulations designed using Design-Expert® 13.0 software. Based on the optimization results, two optimum formulations were obtained containing 2-7% purple sweet potato flour, respectively. The ranking test indicated that there was no significant difference between the optimum formulations and the commercial product, suggesting that the developed bread has the potential to compete in the market. Furthermore, the optimum formulation contained 20,31% moisture, 1,36% ash, 2,47% protein, 15,07% fat, and 60,80% carbohydrate.