Waste utilization of blueberry pomace: Structural characterization, anti-atherosclerosis activity, mechanism of myocardial injury protection of novel polymeric compounds

Blueberry pomace is a low-value by-product that is typically discarded. It can be valorized as a renewable source of bio-functional polysaccharides. In this study, the crude blueberry pomace polysaccharides (BBPP80) significantly reduced body weight, serum lipid levels, and aortic plaque formation in an atherosclerotic mice model, indicating its lipid-lowering and anti-atherosclerotic potential. A novel neutral polysaccharide (BBPP80–2a) and an acidic polysaccharide (BBPP80–2b) were isolated and purified by graded ethanol precipitation. Both polysaccharides were primarily composed of galactose and arabinose, with homogeneous molecular weight distributions of 29.86 and 20.86 kDa, respectively. Furthermore, Structural analysis revealed some common residues including →4)-Gal p -(1→, →3)-Gal p -(1→, and →3,6)-Gal p -(1→, while BBPP80–2b additionally contained →4)-Gal p A-(1→. Scanning electron microscopy revealed their irregular sheet-like or rod-shaped morphology. Both polysaccharides were nontoxic to H9c2 cells and effectively inhibited hypoxia/reoxygenation-induced apoptosis. Mechanistically, their cardioprotective activity was associated with increased BCL-2/BAX ratio and improved phosphorylation of the PI3K/AKT/mTOR and JNK/ERK/MAPK signaling pathways. These findings suggest, for the first time, that blueberry pomace-derived polysaccharides exert potent anti-atherosclerotic activity in vivo and confer direct cardiomyocyte-protective effects in vitro through anti-apoptotic signaling modulation, underscoring the industrial potential of converting blueberry pomace waste into cardiovascular health-promoting ingredients. • Preparation of polysaccharides is an appropriate approach for the waste utilization of blueberry pomace. • Activity-oriented separation strategy of blueberry pomace polysaccharides (BBPP80) was used. • A novel acidic polysaccharide and a newly neutral polysaccharide were purified from the active fraction. • They both effectively improved H/R-induced apoptosis through BCL-2/BAX, PI3K/AKT/mTOR, and JNK/ERK/MAPK pathways. • In vivo anti-atherosclerosis and in vitro myocardial injury protection effects of BBPP80 polysaccharides were explored for the first time.