Blueberry fiber pectin, xyloglucan and anthocyanin structure and function

Authors: Hotchkiss, Arland; Chau, Hoa - Rose; Strahan, Gary; Nunez, Alberto; Simon, Stefanie; White, Andre; Yadav, Madhav; DIENG, SENGHANE - Ingredion, Inc; HIRSCH, JULIE - Ingredion, Inc

Submitted to: Food Hydrocolloids
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/21/2020
Publication Date: 12/28/2020
Citation: Hotchkiss, A.T., Chau, H.K., Strahan, G.D., Nunez, A., Simon, S., White, A.K., Yadav, M.P., Dieng, S., Hirsch, J. 2020. Blueberry fiber pectin, xyloglucan and anthocyanin structure and function. Food Hydrocolloids. https://doi.org/10.1016/j.foodhyd.2020.106572.
DOI: https://doi.org/10.1016/j.foodhyd.2020.106572

Interpretive Summary: Blueberry is considered a healthy food consumed fresh, in salads, baked or in dairy products, yet more data is needed to support health claims for this fruit. The structural composition of blueberry fiber remaining after commercial juice processing was determined using several sophisticated analytical methods which revealed greater detail than previously possible. Health-promoting carbohydrates, anthocyanins, protein and low fat were present. Some of these compounds are known to promote the growth of health-beneficial human gut bacteria while blueberry pectin fragments may prevent chronic diseases. This information will be useful to understand the structure-function relationships for the multiple health benefits of blueberry and provide more value for this specialty crop.

Technical Abstract: Blueberry dietary fiber polysaccharides and anthocyanins in the pomace remaining after commercial juice extraction were characterized. Water soluble and insoluble fractions were produced from blueberry pomace and their structure determined. Blueberry dietary fiber was largely insoluble (46.2% vs. 14.6% soluble dietary fiber) consisting of pectin and xyloglucan polysaccharides, anthocyanins, 9% protein, 5% fat as well as free fructose and glucose. Methyl-esterified and acetylated rhamnogalacturonan I oligosaccharides with a 4,5-unsaturated function at the non-reducing end was detected, presumably produced by commercial pectinase (lyase) treatment during juice clarification. Microwave-assisted extraction of blueberry pectin at pH 2, 10 min, 80°C was had high molar mass (1072 kDa) with viscosity dependent upon the molar mass. a random coil shape was detected for blueberry pectin and blueberry pomace fractions. Xyloglucan oligosaccharide side chain structures included XG, C or T, XX, XU or XS, XL, and XL. Malvidin 3-arabinoside and peonidin 3-glucoside were the most abundant anthocyanins detetected in blueberry pomace. Blueberry anthocyanins strongly adhered to the fiber and were not removed by water extraction. These structural properties suggest that blueberry pomace may function as an antioxidant, emulsion stabilizer, thickening agent and prebiotic food ingredient based on previously published literature.