ABSTRACT
Natural polymer (cellulose)-based fabric was colored using an environmentally friendly natural dye extracted from Jalawe (Terminalia bellirica) in the preparation of Batik fabric, a cultural heritage of Indonesia that is recognized by United Nations Educational, Scientific and Cultural Organization (UNESCO). Despite the significant favorable properties in terms of functions, environmental, and cultural aspects, the combination between natural polymer-based fabric and natural dyes makes the Batik fabric an ideal medium for bacterial growth, leading to lower product quality. In the quest for a sustainable, environmentally friendly, rich-in-culture, yet durable textile, this study aimed at the functionalization of natural dye (ND)-colored Batik fabric with antibacterial ZnO nanoparticles (ZnO NPs) synthesized from Electric Arc Furnace Dust (EAFD) waste. An in situ immobilization process with a Chemical Bath Deposition (CBD) method was explored at a pH range from 6 to 11 at 50 °C. Characterization methods include XRD, XRF, FESEM, EDX, FT-IR, tensile strength measurement, agar diffusion testing, and a CIE L*a*b* scale measurement. The XRD and XRF results showed that pure (>98%) ZnO NPs were formed at pH 11 of the CBD process. FESEM results demonstrated that the pure ZnO NPs either precipitated at the CBD reactor or were immobilized on the cellulose fabric, exhibiting distinct morphology compared to the non-pure ZnO NPs. EDX elemental analysis before and after washing demonstrated the durability of the ZnO NPs attachment, in which 84% of the ZnO NPs remained on the fabric after two washing cycles (equal to 10 cycles of home laundering). The FT-IR spectra provided information on the chemical functional groups, demonstrating the success of the ZnO NPs immobilization on the cellulose fabric through Van der Waals or coordination bonding. Moreover, the in situ immobilization of ZnO NPs enhanced the Batik fabric's tensile strength but reduced its elongation. ZnO NP-functionalized Batik fabric that was treated at pH 10 and pH 11 showed antibacterial activity against Staphylococcus aureus. The CIE L*a*b* scale results showed that the immobilization process affects the color quality of the ND-colored Batik fabric. However, based on organoleptic observations, the color of the Batik fabric that was treated at pH 11 is still acceptable for Jalawe ND-colored Batik fabric.
ABSTRACT
Betacyanin is a red natural dye pigment widely used in food products. However, the pigment is also unstable and easily degraded by temperature during storage and food processing. This research aims to increase the stability of betacyanin obtained from dragon fruit peels using pectin as a wall medium via the coacervation method. Due to the efficiency and shell integrity, the coacervation method was selected instead of spray drying to enhance betacyanin's stability. Coacervation was conducted in a three-necked round-bottomed flask fitted with a mercury-sealed stirrer and reflux condenser. An accelerated stability test was conducted at 80 °C and 100 °C for 30 min and considered completed after obtaining a stable absorbance. Two full factorials, three-level design, for 80 °C and 100 °C, were analyzed by Response Surface Methodology using Minitab® 19. The core/wall ratio, agitation speed, and pH were the continuous variables, with temperature as the categorical variables. The models were yielded high R-square and low coefficient of variance on the validation process. Simple coacervation is selected because of a superior method such as simplicity, low-cost, high efficiency, and high shell integrity.
ABSTRACT
Suji (Pleomele angustifolia Roxb.) 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 porphyrin 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 ZnCl2 as a stabilizer. Suji leaves were blanched with boiling water for 2 min, Zn-chlorophyll synthesis was done by varying concentration of ZnCl2, 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 (R2) was found to be 81.99%. The optimum operating conditions were obtained at pH 7, ZnCl2 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.
