Polyphenols, particularly anthocyanins, are linked to metabolic health benefits, driving growth in anthocyanin-based supplements extracted from various food sources (1). However, whether these extracts provide greater bioavailability compared to whole foods, which comprises a complex food matrix, remains unclear. Emerging evidence suggests that food matrix components may significantly influence polyphenol stability, particularly that of anthocyanins, affecting their overall bioavailability - including bioaccessibility during digestion, intestinal absorption, and subsequent bioactivity. (2,3). This study investigated the impact of food matrix on polyphenol and anthocyanin bioaccessibility and intestinal barrier outcomes using acai berry, a rich anthocyanin source in three forms: freeze-dried powder, crude extract, and purified anthocyanin extract. Freeze-dried powder represented whole fruit, crude extract represented fruit juice without insoluble fibre, and purified extract represented supplements with a complete lack of food matrix. Total polyphenol content (TPC) and anthocyanins (ACN) were quantified across standardized INFOGEST digestion phases using Folin-Ciocalteu and pH-differential methods, respectively. Antioxidant capacity was assessed via DPPH radical scavenging assay. Intestinal absorption-related parameters were examined in Caco-2 monolayers exposed to intestinal digests, including transepithelial electrical resistance (TEER) and FITC–dextran transport. Bioaccessibility data were analysed by two-way ANOVA with Tukey’s post-hoc test (n = 3, p < 0.05). Intestinal bioaccessible TPC was comparable between whole fruit (30.91 ± 1.08 mg GAE/g; 58% bioaccessibility) and crude extract (30.99 ± 1.33 mg GAE/g; 58%), but significantly lower in pure extract (22.77 ± 1.62 mg GAE/g; 43%, p < 0.0001). The ACN bioaccessibility demonstrated clear food matrix protection: whole fruit achieved the highest levels (6.30 ± 0.12 mg C3G/g, 44%), crude extract showed intermediate retention (4.59 ± 1.02 mg C3G/g, 32%), while pure extract exhibited significantly reduced bioaccessibility (1.74 ± 0.26 mg C3G/g, 12%, p < 0.001) compared to both whole fruit and crude extract. Antioxidant capacity in intestinal digests was highest in whole fruit (63.4 ± 4.0% inhibition), comparable to crude extract (62.0 ± 0.04%, p > 0.05), but significantly higher than pure extract (58.5 ± 1.2%, p = 0.0041). It was also evident that the digestive environment, including enzymatic activity and pH conditions, plays a critical role in modulating polyphenol bioavailability. Preliminary intestinal barrier function assessment revealed that digested whole fruit enhanced the TEER compared to crude and pure extract. These findings demonstrate that the presence of food matrix components significantly preserves anthocyanin stability during digestion and enhance intestinal barrier function. Incorporation of natural food matrices or designing matrix-mimicking delivery systems may be key to enhancing the bioavailability and functional properties of anthocyanin-rich nutraceuticals such as acai.