*2.7. Storage Stability*

The stability of lutein was represented by the retention of lutein in the microfluidic noodle at each storage day 1, 2, 3, 4, 5, 6 and 7 under 4 ◦C as compared to the initial added lutein content. The storage stability was calculated as follows:

$$Stability(\%) = \frac{100 \times \text{C}\_{sample}}{\text{C}\_{initial}} \tag{1}$$

where *Csample* is the remaining lutein content in the microfluidic noodle samples at each storage day, and *Cintial* corresponds to the initial added lutein content.

#### *2.8. Bioaccessibility, Release and Micellarization of Lutein*

The fraction of lutein solubilized in the mixed micelles phase after passing through the simulated in vitro digestion was taken to be bioaccessibility and was calculated as follows:

$$Bioaccessibility(\%) = \frac{100 \times \mathbb{C}\_{micches}}{\mathbb{C}\_{initial}} \tag{2}$$

The release rate was determined as the lutein content in the digesta released from the initial food matrix and was calculated as follows:

$$Relase(\%) = \frac{100 \times \mathbb{C}\_{digesta}}{\mathbb{C}\_{initial}} \tag{3}$$

The micellarization rate was determined as transfer of lutein from the digesta to the mixed micelles and was calculated as follows:

$$\text{Micellarization}(\%) = \frac{100 \times \text{C}\_{\text{miccells}}}{\text{C}\_{\text{diçesta}}} \tag{4}$$

where *Cmicelles* is lutein content in the micellar fraction, *Cdigesta* is lutein content in the digesta, and *Cintial* is the initial added lutein content in the microfluidic noodle. All the determinations of lutein bioaccessibility, release and micellarization were conducted on day 1.

A schematic representation of the stability, bioaccessibility, release and micellarization of lutein are shown in Figure 2.

**Figure 2.** A schematic representation of the stability, bioaccessibility, release and micellarization of lutein.
