Pati sesuai untuk bahan baku pembuatan edible film (pelapis yang dapat dimakan), namun mudah sobek (getas), sehingga perlu penambahan plasticizer. Penelitian ini dilaksanakan di Laboratorium Kimia dan Teknologi Pangan Balitkabi, Malang, pada bulan Maret-Juli 2009 dengan tujuan untuk membuat edible film dari empat jenis pati umbi-umbian dengan penambahan plasticizer. Percobaan disusun menggunakan rancangan acak lengkap faktorial dengan tiga ulangan. Faktor I adalah jenis pati (pati ubi kayu, ganyong, ubi jalar, dan garut) dan faktor II adalah jenis plasticizer (gliserol dan sorbitol, masing-masing dengan konsentrasi 2% v/b pati). Pengamatan meliputi sifat kimia dan fisik pati dan sifat fisik edible film. Hasil penelitian menunjukkan bahwa interaksi jenis pati dengan jenis plasticizer berpengaruh nyata terhadap tingkat kecerahan, kekuatan peregangan (tensile strength), dan pemanjangan (elongasi) edible film, tetapi tidak berpengaruhterhadap ketebalannya. Pati garut dan ubi kayu yang derajat putihnya paling tinggi menghasilkan edible film dengan tingkat kecerahan (L*) paling tinggi. Ketebalan edible film sama untuk semua perlakuan dan relatif tipis dengan kisaran 0,02-0,03 mm. Pati garut yang ditambah sorbitol atau gliserol menghasilkan edible film dengan kekuatan peregangan dan pemanjangan yang paling tinggi (masingmasing 1,7 N dan 2,6% serta 1,5 N dan 2,6%) serta memiliki sifat fisik yang paling baik, diikuti oleh pati ubi jalar baik yang ditambah sorbitol maupun gliserol.
Physical Characteristics of Edible Films Derived from Tuber Crop Starches with Addition of Plasticizers. Starch is suitable for edible film, although the film produced is brittle. A study on preparation of edible film from starches of four tuber crops with the addition of plasticizers was conducted at the Chemical and Food Technology Laboratory, of the Indonesian Legumes and Tuber Crops Research Institute (ILETRI), Malang, from March to July 2009. The trial was arranged in a randomized complete design with three replications. The first factors were four difference tuber crops (cassava, edible canna, sweet potato, and arrowroot) and the second factors were two kind of plasticizers (glycerol and sorbitol, each at a concentration of 2% v/w starch). Observations were done on chemical and physical properties of the starches as well as physical characteristics of the edible film produced. Results showed that the interactions between starches and plasticizers significantly influenced colour, tensile strength, and elongation of the edible film. However, the effect of plasticizer on thickness of the edible film was not significant. Arrowroot and cassava starches that have the highest whiteness levels produced edible films with the highest brightness values (L*). Edible films from the four tuber crops starches had similar thickness (0.02-0.03 mm). The arrowroot starch added with either sorbitol or glycerol produced edible films with the highest values of tensile strengh and elongation (1.7 N and 2.6%, and 1.5 N and 2.6%, respectively), indicating for good physical performances of edible films. These characters were followed by starch of sweet potato that was treated with sorbitol or glycerol.
