The formation and supramolecular structures of inclusion complexes between amylose and lycopene (amylose-lycopene complexes, ALCs) were investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, and ¹³C CP/MAS nuclear magnetic resonance (NMR). The results showed that the complex index of amylose to lycopene in ALCs was (17.10 ± 0.01)%, indicating that lycopene could enter the spiral cavity of starch to form a complex. ALCs exhibited a type Ⅱ composite structure consisting of spherical Ⅴ-shaped sub-microcrystals with a crystallinity of (65.32 ± 0.22)% and a T₀ of (106.72 ± 0.63) ℃ . Moreover, no characteristic absorption of lycopene at 960 cm^-1 was observed, indicating complexation between the host and guest molecules. Furthermore, the structural components of ALCs were ranked as follows: double helix > amorphous form > Ⅴ-shaped single helix. Among them, the proportions of double and Ⅴ-shaped single helix structures in ALCs were (55.95 ± 3.25)% and (17.84 ± 0.96)%, respectively. These results indicated that amylose can include and twine around lycopene to form a thermally stable composite structure. This study provides a theoretical basis for expanding the prospective pharmaceutical and nutraceutical applications of lycopene as a functional pigment.

In order to explore the effects of bound and free phenols from wheat bran on the gut microbiota during in vitro gastrointestinal digestion and colonic fermentation, this study conducted in vitro fermentation of bound and free phenols using fecal filtrates and evaluated changes in the antioxidant activity of the fermentation broth, the production of short-chain fatty acids (SCFAs) was determined by gas chromatography-mass spectrometry (GC-MS), and the changes in microbial community structure and abundance in fermentation broth were analyzed by 16S rRNA gene high-throughput sequencing. The results showed that compared with free phenols, the addition of bound phenols significantly improved the antioxidant activity of the fermentation broth and increased the production of SCFAs. The results of in vitro fecal fermentation showed that the addition of bound or free phenols reduced the relative abundance of the harmful bacterium Escherichia coli. Moreover, compared with free phenols, bound phenols significantly increased the relative abundance of beneficial bacteria (such as Bacteroides and Bifidobacterium). In summary, wheat bran bound phenols significantly improved the antioxidant capacity of the fermentation broth, promoted the production of SCFAs, and regulated the diversity of the gut microbiota, thereby being beneficial to human intestinal health.