Enzymatic pretreatments of rice bran, using commercial carbohydrases to improve nitrogen extractability, were investigated. The pretreatment used a response surface method which included the variations in concentration of Viscozyme L (0–120 FBG unit) and Celluclast 1.5L (0–360 NC unit), time of incubation (1–5 h) and pH (3·8–5·4). The experiments were conducted at two different temperatures, 40 and 50°C. At 40°C, the maximum nitrogen extraction predicted by the model was obtained when the Viscozyme–Celluclast mixture at pH 3·8 with incubation time of 5 h was applied, giving an extracted N of 51%. At the process temperature of 50°C, the model predicted that the use of Viscozyme alone, under similar conditions, would have a most significant effect in increasing the efficacy of the nitrogen extraction, producing a 57% extracted N. This enzymatic pretreatment method improved the nitrogen extractability of rice bran at the neutral pH. © 1997 SCI.

No abstract

This study aims to determine the effect of substitution of gadung tuber flour on the organoleptic characteristics and physicochemical properties of white bread. This study used a completely randomized design (CRD) consisting of five treatments (wheat flour:gadung tuber flour) = 100:0 (A1), 90:10 (A2), 80:20 (A3), and 70:30 (A4) . The results show that the organoleptic assessments of aroma, taste, and texture were very significant but the effect on the product’s color was not significantly different. The selected treatment was the sample with the substitution of 90% wheat flour and 10% gadung tuber flour (A1) with average scores of color, texture, aroma, and taste reached 4.00 (like), 4.00 (like), 4.00 (like), 4.00 (like), respectively. The physical analysis shows that the selected sample had a volume of development of 18.97%. Meanwhile, the chemical analysis shows that the sample had 31.26% water, 1.25% ash, 11.504% protein, 8.02% fat, 47.94% carbohydrate, and HCN content of 19.44 ppm. Based on the results of the research, white bread products with the substitution of 90% wheat flour and 10% gadung tuber flour (A1) can be accepted (preferred) by the panelists and met the national standard, with the ash content that exceeds the national standard.Keywords: Bread from Gadung, organoleptic, physical, chemical.ABSTRAKPenelitian ini bertujuan untuk mengetahui pengaruh substitusi tepung umbi gadung terhadap karakteristik organoleptik dan sifat fisiko kimia roti tawar. Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) yang terdiri atas lima perlakuan (tepung terigu : tepung umbi gadung) = 100 : 0 (A1), 90 : 10 (A2), 80 : 20 (A3), 70 :30 (A4). Hasil penelitian menunjukkan bahwa penilaian organoleptik aroma, rasa, dan tekstur berbeda sangat nyata serta berbeda tidak nyata pada warna dan perlakuan terpilih terdapat pada substitusi tepung terigu 90% dan tepung umbi gadung 10% (A1) dengan rerata warna sebesar 4,00 (suka), tekstur 4,00 (suka), aroma 4,00 (suka), rasa 4,00 (suka), analisis fisik yaitu nilai volume pengembangan 18,97 %, analisis kimia yaitu kadar air sebesar 31,26 %, kadar abu sebesar 1,25 %, kadar protein sebesar 11,504 %, kadar lemak sebesar 8,02 %, kadar karbohidrat sebesar 47,94 % dan kadar HCN sebesar 19,44 ppm. Berdasarkan hasil penelitian produk roti tawar dengan substitusi tepung terigu 90% dan tepung umbi gadung 10% (A1) dapat diterima (disukai) oleh panelis dan telah memenuhi standar SNI terkecuali pada kadar abu memiliki kadar yang melebihi standar SNI.Kata kunci: : Roti tawar dari Ubi Gadung, organoleptik, fisik, kimia

This study aimed to determine the effect of yellow sweet potato flour and carrot flour substitution on the organoleptic characteristics and nutritional value of biscuits. This study used a completely randomized design (CRD) with five treatments K0 (0% yellow sweet potato flour: 0% carrot flour: 100% wheat flour), K1 (75% yellow sweet potato flour: 5% carrot flour: 20% wheat flour ), K2 (70% yellow sweet potato flour: 10% carrot flour: 20% wheat flour), K3 (65% yellow sweet potato flour: 15% carrot flour: 20% wheat flour), and K4 (60% yellow sweet potato flour: 20% carrot flour: 20% wheat flour). Data were analyzed using analysis of variances (ANOVA). The results show that the substitution treatment of yellow sweet potato flour and carrot flour had a very significant effect on the organoleptic improvement of color, aroma, and taste. The most preferred treatment was the K1 treatment with preference values of color, aroma, texture, and taste reached 4.12 (very like), 4.40 (very like), 3.95 (like), and 4.07 (very like), respectively. The selected treatment had 4.66% water, 2.16% ash, 15.91% fat, 5.44% protein, 71.83% carbohydrate, and 2.15 mg/g β- carotene. Based on the SNI 01-2973-1992 standard, the yellow sweet potato flour and carrot flour biscuit products met the quality standards on water, fat, and carbohydrate contents.Keywords: yellow sweet potato flour, carrot flour, wheat flour, biscuits.ABSTRAKPenelitian ini bertujuan untuk menentukan pengaruh substitusi tepung ubi jalar kuning dan tepung wortel terhadap karakteristik organoleptik dan nilai gizi biskuit. Penelitian ini menggunakan rancangan acak lengkap (RAL) dengan lima perlakuan K0 (Tepung ubi jalar kuning 0% : tepung wortel 0% : Tepung terigu 100%), K1 (Tepung ubi jalar kuning 75% : tepung wortel 5% : tepung terigu 20%), K2 (Tepung ubi jalar kuning 70% : tepung wortel 10% : tepung terigu 20%), K3 (Tepung ubi jalar kuning 65% : tepung wortel 15% : tepung terigu 20%), K4 (Tepung ubi jalar kuning 60% : tepung wortel 20% : tepung terigu 20%).. Data dianalisis menggunakan analysis of variances (ANOVA). Hasil penelitian menunjukkan bahwa perlakuan substitusi tepung ubi jalar kuning dan tepung wortel berpengaruh sangat nyata terhadap peningkatan organoleptik warna, aroma dan rasa. Perlakuan terpilih diperoleh dari perlakuan K1 dengan nilai kesukaan terhadap warna sebesar 4,12 (sangat suka), aroma sebesar 4,40 (sangat suka), tekstur sebesar 3,95 (suka) dan rasa sebesar 4,07 (sangat suka). Perlakuan terpilih memiliki nilai kimia biskuit yaitu kadar air sebesar 4,66%, kadar abu sebesar 2,16%, kadar lemak sebesar 15,91%, kadar protein sebesar 5,44%, kadar karbohidrat sebesar 71,83% dan kadar β-karoten sebesar 2,15 mg/g. Berdasarkan standar mutu SNI 01-2973-1992 bahwa produk biskuit tepung ubi jalar kuning dan tepung wortel telah memenuhi standar mutu SNI pada kadar air, kadar lemak dan kadar karbohidrat.Kata kunci: tepung ubi jalar kuning, tepung wortel, tepung terigu, biskuit.

Research on the transformation of Oil Palm Empty Fruit Bunches (OPEFB) through pretreatment process using ionic liquid triethylammonium hydrogen sulphate (IL [TEA][HSO4]) was completed. The stages of the transformation process carried out were the synthesis of IL with the one-spot method, optimization of IL composition and pretreatment temperature, and IL recovery. The success of the IL synthesis stage was analyzed by FTIR, H-NMR and TGA. Based on the results obtained, it showed that IL [TEA][HSO4] was successfully synthesized. This was indicated by the presence of IR absorption at 1/λ = 2814.97 cm−1, 1401.07 cm−1, 1233.30 cm−1 and 847.92 cm−1 which were functional groups for NH, CH3, CN and SO2, respectively. These results were supported by H-NMR data at δ (ppm) = 1.217–1.236 (N–CH2–CH3), 3.005–3.023 (–H), 3.427–3.445 (N–H+) and 3.867 (N+H3). The TGA results showed that the melting point and decomposition temperature of the IL were 49 °C and 274.3 °C, respectively. Based on pretreatment optimization, it showed that the best IL composition for cellulose production was 85 wt%. Meanwhile, temperature optimization showed that the best temperature was 120 °C. In these two optimum conditions, the cellulose content was obtained at 45.84 wt%. Testing of IL [TEA][HSO4] recovery performance for reuse has shown promising results. During the pretreatment process, IL [TEA][HSO4] recovery effectively increased the cellulose content of OPEFB to 29.13 wt% and decreased the lignin content to 32.57%. The success of the recovery process is indicated by the increasing density properties of IL [TEA][HSO4]. This increase occurs when using a temperature of 80–100 °C. The overall conditions obtained from this work suggest that IL [TEA][HSO4] was effective during the transformation process of OPEFB into cellulose. This shows the potential of IL [TEA][HSO4] in the future in the renewable energy sector.