Colorflex cx2379

The color parameters of the ASBS, LSBS and CSBS samples from the barracuda skin were obtained using the established procedure [30 (link)]. All samples were tested under a colorimeter (ColorFlex CX2379; HunterLab, Reston, VA, USA). The attributes designed in the present study were L*, representing the lightness value; a*, reflecting the redness value; and b*, depicting the yellowness value.

The color parameter of pepsin-solubilized collagen from lizardfish skin, bone and scales was measured based on the procedure from a previous study [60 (link)]. We used a ColorFlex CX2379 (HunterLab, Reston, VA, USA) to measure the color attributes that are L* (lightness/brightness), a* (redness/greenness) and b* (yellowness/blueness). In addition, the whiteness index (WI) was also measured using the following equation from Briones and Aguilera [61 (link)]: $${\mathrm{WI}=100-\left[\right(100-\mathrm{L}}^{*}{)}^2+({\mathrm{a}}^{*2}){+(\mathrm{b}}^{*2}{)]}^{0.5}$$

The yield of parrotfish scale collagens was stipulated according to the formula described by Matmaroh et al. [24 (link)] $\begin{array}{c}\mathrm{Y}\mathrm{i}\mathrm{e}\mathrm{l}\mathrm{d}\left(\%\right)=\frac{\mathrm{W}\mathrm{e}\mathrm{i}\mathrm{g}\mathrm{h}\mathrm{t}\mathrm{o}\mathrm{f}\mathrm{d}\mathrm{i}\mathrm{e}\mathrm{d}\mathrm{c}\mathrm{o}\mathrm{l}\mathrm{l}\mathrm{a}\mathrm{g}\mathrm{e}\mathrm{n}\left(ASC\wedge PSC\right)}{\mathrm{W}\mathrm{e}\mathrm{i}\mathrm{g}\mathrm{h}\mathrm{t}\mathrm{o}\mathrm{f}\mathrm{i}\mathrm{n}\mathrm{i}\mathrm{t}\mathrm{i}\mathrm{a}\mathrm{l}\mathrm{d}\mathrm{r}\mathrm{y}\mathrm{p}\mathrm{a}\mathrm{r}\mathrm{r}\mathrm{o}\mathrm{t}\mathrm{f}\mathrm{i}\mathrm{s}\mathrm{h}\mathrm{s}\mathrm{c}\mathrm{a}\mathrm{l}\mathrm{e}}\times 100\text{.}\end{array}$
Colour attributes for ASC-PFS and PSC-PFS were assessed through a colorimeter instrument (ColorFlex CX2379, HunterLab, Galveston, TX, USA), as described in a previous study [25 (link)]. The differences in the color test were presented in the CIELAB or CIE 1976 L^∗a^∗b^∗ colour space, where L^∗ is the lightness or brightness, a^∗ is the redness (from green to red), and b^∗ is the yellowness (from blue to yellow). For whiteness index (WI), both ASC and PSC from the parrotfish scales were determined using a formula stated by Ishamri et al. [27 (link)] $\begin{array}{c}WI={\left.{\left[\left(100-L^{\ast }\right.\right]}^2+\left({a^{\ast }}^2\right)+\left({b^{\ast }}^2\right)\right]}^{0.5}\text{.}\end{array}$

Colour analysis of extracted collagens was performed according to the method described by Huda et al. [7 (link)] using with a colorimeter (ColorFlex CX2379, HunterLab, Galveston, TX, USA). Attributes of color tested include lightness (L*), redness (a*), and yellowness (b*). Whiteness index (WI) was calculated based on the study of Briones and Anguilera [63 (link)] using the following equation: $${\mathrm{WI}=100 - \left[\right(100 - L*)}^2+({a*}^2){+(b*}^2{\left)\right]}^{0.5}$$