Suji (.) leaves are a prominent source of chlorophyll and well-known for their ability to produce green color for food ingredients. However, chlorophyll is suspectible to color degradation at high temperature. Color degradation occurred because loses magnesium in its ring and it can be avoided by adding zinc. The aim of this work was to investigate the combined effect of independent variables on chlorophyll extraction process using ZnCl as a stabilizer. Suji leaves were blanched with boiling water for 2 min, Zn-chlorophyll synthesis was done by varying concentration of ZnCl, Zn-chlorophyll extraction with ethanol, and UV-Vis spectrophotometry analysis of the final extracted solutions. A full three-level factorial design under response surface methodology was used to obtain the optimum condition of extraction process. The experimental data were analyzed by analysis of variance and fitted with second order polynomial equation. The coefficient of determination (R) was found to be 81.99%. The optimum operating conditions were obtained at pH 7, ZnCl concentration of 700 ppm and temperature of 85 °C with desirability value of 1.0000. At the optimum conditions, the total chlorophyll content (TCC) was found to be 47.2975 mg/100 g fresh weight.

A B S T R A C TEfforts to substitute synthetic dyes on fabrics for natural dyes are currently increasing. Research and innovation are extremely needed to support those attempts so that the quality of natural dyes is more competitive than synthetic dyes. This study aims to optimize the dyeing parameters of cotton fabrics using natural dye extracts derived from the barks of Tegeran (Cudrania javanensis), Merbau (Intsia bijuga), Tingi (Ceriops tagal), and Jambal (Peltophorum pterocarpum), as well as Jolawe (Terminalia bellirica) fruit peel. Varied dyeing parameters included dye concentration, dyeing time and temperature, and material to liquor ratio (MLR). The fixative solutions used were alum, lime, and iron (II) sulfate. The optimized parameters were based on the values of color depth and evenness, measured colorimetrically. Furthermore, the obtained results of the dyeing process under optimized conditions were analyzed for color quality by measuring color coordinates as well as the values of color strength (K/S), washing fastness, and light fastness. The results showed that the optimal dyeing conditions for all natural dye extracts used were the code A extract concentrations (0.0113 g/mL of Tegeran; 0.0115 g/mL of Merbau; 0.0204 g/mL of Jambal; and 0.0582 g/mL of Jolawe), dyeing at 28°C, dyeing time of 30 minutes, and the MLR of 1:30. The resulting color variations were brown, gray, and golden yellow for the Tegeran extract with alum fixative. The highest K/S value was 5.56 for the fabric dyed in Tegeran extract with iron (II) sulfate fixative solution. The washing fastness values for Merbau, Tingi, Jambal, and Jolawe were 3-4 (fairly good) to 4-5 (excellent). Meanwhile, the light fastness values for all dyes were between 4 (good) and 5 (excellent). Overall, the standard procedure for cotton fabric dyeing that meets the minimum standards for textile products is obtained.Keywords: cotton fabric; color quality; natural dyes; optimization; standard procedure for dyeingA B S T R A KUsaha substitusi penggunaan pewarna sintetis pada kain dengan pewarna alami semakin meningkat belakangan ini. Hal ini perlu didukung dengan penelitian dan inovasi agar kualitas pewarna alami lebih kompetitif terhadap pewarna sintetis. Penelitian ini bertujuan untuk mengoptimalkan parameter pewarnaan kain katun dengan ekstrak pewarna alami dari kulit kayu Tegeran (Cudrania javanensis), Merbau (Intsia bijuga), Tingi (Ceriops tagal), Jambal (Peltophorum pterocarpum), dan kulit buah Jolawe (Terminalia bellirica). Parameter pewarnaan yang divariasikan antara lain konsentrasi pewarna, waktu dan suhu pewarnaan, serta rasio kain dengan volume larutan fiksator. Larutan fiksator yang digunakan adalah tawas, kapur, dan tunjung. Paramater terikat yang dioptimasikan didasarkan pada nilai ketuaan dan kerataan warna yang diukur secara kolorimetri. Selanjutnya hasil pewarnaan dengan kondisi yang teroptimasi dianalisis kualitas warna melalui pengukuran koordinat warna, nilai kekuatan warna(K/S), dan nilai tahan luntur terhadap pencucian dan cahaya. Hasil menunjukkan bahwa parameter pewarnaan yang optimal untuk semua ekstrak pewarna alami yang digunakan adalah pada konsentrasi ekstrak dengan kode A (0,0113 g/mL Tegeran; 0,0115 g/mL Merbau; 0,0204 g/mL Jambal; dan 0,0582 g/mL Jolawe), pewarnaan pada suhu kamar, waktu pewarnaan 30 menit, dan rasio kain dengan volume larutan fiksator 1:30. Variasi warna yang dihasilkan adalah warna cokelat, abu-abu, dan kuning emas untuk ekstrak tegeran dengan fiksator tawas. Nilai K/S tertinggi sebesar 5,56 untuk kain yang diwarnai dengan ekstrak Tegeran dengan larutan fiksator tunjung. Nilai uji kelunturan terhadap pencucian untuk Merbau, Tingi, Jambal, dan Jolawe adalah 3-4 (cukup baik) sampai dengan 4-5 (sangat baik). Nilai kelunturan terhadap cahaya untuk semua jenis pewarna adalah antara 4 (baik) sampai dengan 5 (sangat baik). Secara keseluruhan, didapatkan prosedur standar pewarnaan kain katun yang memenuhi standar minimum produk tekstil.Kata kunci: kain katun; kualitas warna; optimasi; pewarna alami; standar pewarnaan

People use peels, stems, leaves, and fruits of plants as a natural colorant. One part of fruit peel that has potentially used as a food colorant is red dragon fruit peels. The pigments found are betacyanin, but betacyanin compounds are easily degraded by heat, pH, and light. Degradation of betacyanin forms betalamic acid compounds (yellow) and cyclo-DOPA acids (cloroless). In this work, an attempt was made to increase the stability of betacyanin pigment against temperature by adding stabilizer such as glucose, sucrose, and lactose. Betacyanin extract was obtained from extraction using water solvent at pH 6 with a ratio of 1:4 (w/v). Extract was diluted and added stabilizer at concentration 0 ppm, 100 ppm, and 150 ppm. The solution was heated in a water bath at temperature of 60 °C for 1 hour. The content of betacyanin was examined by a UV-VIS spectrophotometer at a wavelength of 534.8 nm every 15 minutes. The retention value for 150 ppm of lactose was the greatest of all the stabilizer with the value of 61.95%. Pigment betacyanin was degraded more slowly in a lactose solution. The highest half-life time increased by 24.24% for dissolution in 150 ppm lactose. Thus, lactose has the potential to increase the stability of betacyanin.

The recovery process of indigoid compounds involves enzymatic hydrolysis of indigo precursors continued by oxidation reaction to synthesize indigo pigment. The purpose of this research was to evaluate the effect of physicochemical process variables, i.e., temperature, time, and pH aeration, on indigo yield from Strobilanthes cusia leaves. Small leaf pieces were immersed in distilled water and heated at temperatures (40, 50, and 60 °C) and duration (1, 2, and 3 h). The extract was aerated at different pHs (8, 10, and 12) to form the indigo product. The indigo concentration was quantified through a visible spectrophotometer and high-performance liquid chromatography (HPLC). The optimized condition for indigo production was studied using response surface methodology (RSM). Temperature, time, and interaction between temperature and time significantly affected the indigo yield. The optimized conditions for extraction of indigo dyes were determined to be at 60 °C for 1 h and pH 8 for maximizing the indigo yield. On that condition, the indigo concentration quantified by HPLC was 1.15% (w/v) which was lower than that by the spectrophotometry. By spectrophotometric analysis, the actual indigo content of 1.68% (w/v) on that optimum condition was close to the predicted indigo content of 1.77% (w/v) using RSM.