Study on the chemical composition of sorghum flour as wheat flour substitute

English. The objectives of study were; (a) to evaluate chemical composition of sorghum flour of ten varieties/line and (b) to determine the critical substitution level of wheat flour (baking test). The study carried out in Laboratory of Food Processing and Chemistry, Research Institute of Maize and Other Cereals, Maros and Laboratory of Chemistry, Institute for Research and Development of Agro-Based Industry, Bogor, during the period of January-October 1999. The experiment design was completely randomized with three replications. Treatment consisted of 10 sorghum varieties/line and wheat flour as control. Parameter analyzed were moisture, ash, protein, fat, crude fiber and starch content. Chemical composition of UPCA-S1 and Isiap Dorado was moisture 10.81 percent and 10.84 percent, ash 0.68 percent and 0.62 percent, protein 6.98 percent and 7.90 percent, fat 1.27 percent and 1.19 percent, crude fiber 0.90 percent and 0.78 percent and starch 82.59 percent and 82.10 percent. Amino acid content of Isiap Dorado is better than UPCA-S1. Several amino acid contents of the sorghum flour were very low compared with wheat flour. They were glutamic acid 1.587 percent:3.826 percent, proline 0.292 percent:1.514 percent, arginine 0.315 percent:0.725 percent and phenylalanine 0.272 percent. Leucine and alanine in sorghum were higher then in wheat flour i.e. 1.39 percent:0.88 percent and 0.85 percent:0.48 percent respectively. The organoleptic test of bread in terms of color, taste, flavour and texture showed that substitution at 20 percent with sorghum flour closely resembled to wheat bread alone. Panelists responses were still acceptable at 30 percent, substitution at 40 percent level showed a lower response, especially in terms of taste, while color and flavour were accepted. At 50 percent substitution level, the taste of bread could not be accepted.

English. Penelitian bertujuan untuk mengevaluasi komposisi kimia tepung sorgum beberapa varietas/galur dan mengetahui tingkat substitusi terhadap terigu pada pembuatan roti tawar. Penelitian dilaksanakan di Laboratorium Pengolahan Pangan dan Kimia Balai Penelitian Tanaman Jagung dan Serealia lain, Maros, dan Laboratorium Kimia Balai Besar Hasil Industri Pertanian, Bogor, sejak Januari sampai Oktober 1999. Penelitian menggunakan rancangan acak lengkap dengan 10 varietas/galur sorgum dan terigu (kontrol) sebagai perlakuan masing-masing tiga ulangan. Tahap penelitian adalah analisis kadar air, abu, protein, lemak, serat kasar, dan pati tepung 10 varietas/galur sorgum dan terigu. Tahap berikutnya analisis asam-asam amino dari dua varietas sorgum terpilih, kemudian pembuatan roti tawar dengan 11 formula. Dari komposisi kimia 10 varietas/galur sorgum, UPCA-S1 (memiliki kadar air 10,84 persen, abu 0,68 persen, protein 6,98 persen, lemak 1,27 persen, pati 82,59 persen, serat kasar 0,90 persen), dan Isiap Dorado (kadar air 10,84 persen, abu 0,6 persen, protein 7,90 persen, lemak 1,19 persen, pati 82,10 persen, serat kasar 0,78 persen) terpilih untuk diteliti kandungan asam aminonya dan dibuat roti. Asam amino tepung sorgum yang kadarnya rendah adalah glutamat 1,587 persen, protein 0,292 persen, arginin 0,315 persen, dan fenilalanin 0.272 persen, sedangkan terigu mengandung glutamat 3,826 persen, prolin 1,514 persen, arginin 0,725 persen, dan fenilalanin 0,614 persen. Asam amino tepung sorgum yang lebih tinggi dibanding terigu adalah leusin dan alanin. Roti yang terbuat dari 80 persen terigu dan 20 persen tepung sorgum mendapat nilai yang hampir sama dengan roti yang terbuat dari 100 persen terigu.