Effect of in vitro gastrointestinal digestion on phenolic compounds and antioxidant properties of soluble and insoluble dietary fibers derived from hulless barley

Abstract

In this study, the bioaccessibility and antioxidant activity of phenolic compounds in insoluble dietary fiber (IDF) and soluble dietary fiber (SDF) derived from hulless barley were evaluated by an in vitro gastrointestinal (GI) digestion model. The total phenolic and flavonoid contents, as well as antioxidant activity of phenolic compounds in IDF and SDF following GI digestion were studied. The results obtained showed an increase in total phenolic and flavonoid contents, as well antioxidant activity compared with undigested extracts. Moreover, the bioaccessibility indexes of phenolic compounds in IDF and SDF were 490.90 ± 3.10% and 1608.79 ± 40.63% respectively, after GI digestion. Similarly, the bioaccessibility indexes of flavonoids in IDF and SDF were 179.20 ± 15.16% and 814.36 ± 26.31%, respectively. Based on our findings, individual phenolic compounds show different stability in the digestion process. The content of ferulic acid has different trends in IDF and SDF during GI digestion. This study could provide a scientific basis for hulless barley DF as valuable food additives. Practical Application Hulless barley is a unique cereal with potential health benefits due to high dietary fiber (DF) content and phenolic compounds. Phenolic compounds could be linked to DF through chemical bonds. Phenolic compounds in DF can be slowly and continuously released under acidic, alkaline, and enzymatic conditions by in vitro gastrointestinal digestion, which could maintain a higher phenolic concentration in the bloodstream and be beneficial for human health. This study could provide a scientific basis for hulless barley DF as valuable food additives.

Bioaccessibility and Oxidative Stability of Omega-3 Fatty Acids in Supplements, Sardines and Enriched Eggs Studied Using a Static In Vitro Gastrointestinal Model

“…where C a and C b are the amounts of each PUFA before and after digestion [48]. BI was calculated for PUFAs that were present in the sample before digestion (C a > 0).…”

UPLC–Q–TOF–MS/MS Analysis of Phenolic Compounds from the Fruit of Cephalostachyum fuchsianum Gamble and Their Antioxidant and Cytoprotective Activities

“…The total phenolic content (TPC) was determined by the Folin-Ciocalteu colorimetric method, as described by Zhu [10] and Li [9]. Briefly, an appropriate amount of the sample was placed in a clean centrifugal tube, then 0.5 mL of 2 mol/L Folin-Ciocalteu reagent was added and mixed.…”

“…The TEAC assay was performed according to the procedure of Li [9] and Zhu [10], with minor modifications. ABTS solution was made by mixing 7 mmol/L ABTS working solution and potassium persulfate (2.45 mmol/L) in a volume ratio of 1:1.…”

“…The FRAP assay of the CFG extract was estimated according to Li's [9] and Zhu's [10] procedures. Methanol was used as blank, and ferrous sulfate was used as a standard reference.…”

“…The HPSA was carried out following the method of Zhu [10] and Li [9]. In short, CFG extract (0.6 mL) was mixed with 0.9 mL H 2 O 2 (400 mmol/L) and 1.5 mL of sodium phosphate buffer (45 mmol/L, pH 7.4).…”