IMPROVED STABILITY OF BUTTERFLY PEA ANTHOCYANINS 3 MD and GG at a ratio of 3/1 (w/w) were prepared in a 40% total solid form and kept in a refrigerator for complete hydrating. ENCAPSULA TION OF BP The prepa red BP extract was mixed with the prepared three biopolymeric wall systems with ratio between the anthocyanins extract and wall of 1/4 and 1/5, with or without acidifi ed condition to pH 2 using 1.5 N HCl. The mixtures were mixed (100 rpm, 20 min) and lyophilized (13–15). The obtained dried solid particles were grounded and sieved (30 mesh) to give a smaller size less than 600 μm. TOTAL ANTH OCYANIN (TAC) ANALYSIS TAC was as sessed by means of a pH differential method modifi ed from Wrolstad (16) in KCl (0.2 M, pH 1.0) and C2H3O2Na (1 M, pH 4.5). Absorbance of the sample (10 mg in 1 ml of deionized (DI) water) in each buffer was recorded at 520 and 700 nm using a microplate reader (ASYS, Biochrome UVM340, Cambridge, UK). TAC was calculated with the extinction coeffi cient for cyanidin-3-glucoside as Absorbance = (A520nm–A700nm)pH1.0 - (A520nm–A700nm)pH 4.5 and expressed a s mg cyanidin-3-glucoside equivalent per gram sample (mg Cyn-3-glu/g sample). The assay was undertaken in triplicates. COLOR PARAMETE R ANALYSIS Colorimetric a nalysis of the samples (0.5 g) was performed using CR-400 Chroma Meter (Konica Minolta, Tokyo, Japan) for L*, a*, b*, C*, and h in triplicates. ACCELERATED ST ABILITY TEST The accelerate d stability test using high temperature and low temperature for seven cycles (heating 45°C, 24 h and cooling 4°C, 24 h) was undertaken (4). TAC and color were reas- sessed, and reduction (%) of these parameters was calculated. PARTICLE SIZE AN ALYSIS Particle size di stribution (PSD) of the selected biopolymeric wall–encapsulated BP ex- tract was examined. The encapsulated system (0.2 g) in DI water (10 ml) was analyzed by Mastersizer 2000 (Malvern, Cambridge, UK) using the wet method. STATISTICAL ANAL YSIS Data are present ed as the mean ± SD. Statistical analysis was performed using the SPSS program version 16.0 for Windows (IBM, New York, NY). The parameters were com- pared and analyzed using one-sample t-test and analysis of variance test with a signifi - cance level of p 0.05.
JOURNAL OF COSMETIC SCIENCE 4 RESULTS AND DISCU SSION PREPARATION OF BP EXTRACT AND BIOPOLYERMIC WALLS BP extract was pr epared to be encapsulated in the bipolymeric walls. The anthocyanin extract was quality controlled to 15° brix giving a dark blue color, and some amount of the extract was lyophilized to be used as the reference BP. The macromolecules used to prepare the walls are quite different in color. MD is white, GA is pale brown, GE is pale yellow, and GG is pale beige. Nevertheless, once the macromolecules were mixed and prepared into the biopolymeric walls, their colors were indifferent by the visual assess- ment, all of them were in off-white tone as exhibited in Figure 1A. Thereafter, the exam- ined colorimetric parameters of BP, macromolecules, and biopolymeric walls were compared as shown in Table I. Color was recorded in terms of L* (0–100 black to white), a* (-60 to +60 green to red), and b* (-60 to +60 blue to yellow), as well as chroma or C*, saturation of color, in addition to h. h is one of the important values that are widely used to describe the shade of anthocyanins. These parameters were, therefore, analyzed to char- acterize the color of the studied systems. BP extract was more reddish than the biopoly- meric walls as per the bluish shade regarding a* and b*, which corresponds with h and C*. STABILIZATION OF BP EXTRACT IN BIOPOLYMERIC WALLS Stabilization of BP was challenged by encapsulation in different biopolymeric walls at the 1/4 and 1/5 ratio, with or without acidifi ed condition to pH 2. Acidifi ed condition was applied in this study as anthocyanins were reported to be better stabilized and the reddish pink color of anthocyanins will be obtained under the acidifi ed condition (15). The completely dried anthocyanin–encapsulated systems following lyophilization were sieved to control the particle size of smaller than 600 μm, which afforded the qualitative yields (82.17–95.58%). BPs encapsulated in the biopolymeric walls were purple-blue Figure 1. (A) Biopolymeric walls : MD and GA, MD and GE, and MD and GG, (B) BP extract in MD and GA, (C) MD and GE, and (D) MD and GG walls at conditions 1/4 without acidifi ed, 1/4 with acidifi ed, and 1/5 without acidifi ed, 1/5 with acidifi ed, respectively.
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