Different preparation methods affect the phenolic profiles and antioxidant properties of Qingke barley foods

Abstract

Background and objectives Barley is rich in bioactive compounds and can prevent some chronic diseases. With the increasing health awareness of the consumers, Qingke barley has been widely consumed in China in the Qingke barley fresh noodles (QBFN), Qingke barley dried noodles (QBDN), Qingke barley bread (QBB), and Qingke barley Chinese steamed bread (QBSB) forms. Preparation methods affect the phenolic profiles, content, and antioxidant capacity of these products. In this work, phenolic profiles and antioxidant activities of the above products were evaluated, and the effects of different preparation methods on the release of phenolic compounds were explained from the perspective of the destruction of the protein–phenol interaction by molecular docking method. Findings The main free phenols in these products were gallic acid, ferulic acid, and phloroglucinol, while the main bound phenols were syringic acid, epicatechin, and quercetin. The different preparation methods altered the free and bound phenolic compounds’ contents in different degrees. Compared with the mixed flour, the finished products showed fairly higher DPPH. Scavenging and reduction capacity, and QBB, QBSB showed a higher antioxidant capacity than the QBFN and QBDN. Molecular docking results predicted that phenols and proteins in these products form phenol–protein complexes bounded by hydrogen and hydrophobic bonds. Different preparation methods would breakdown these bonds, resulting in the release of phenolic compounds. Conclusion Different preparation methods changed the phenolic compounds content and antioxidant capacity in different degrees, QBB and QBSB have higher level of phenolic content and better antioxidant capacity than QBFN and QBDN. Different preparation methods may breakdown hydrogen and hydrophobic bonds between protein and phenolic compounds by different degrees, resulting in the release of phenolic compounds.

Prediction of DPP‐IV inhibitory potentials of polyphenols existed in Qingke barley fresh noodles: In vitro and in silico analyses

“…This work may provide new research ideas for developing new food originating bioactive compounds using in vitro and in silico methods. acid, chlorogenic acid, vanillic acid, syringic acid, p-coumaric acid, rutin, ferulic acid, naringin, epicatechin, o-coumaric acid, quercetin, naringenin, kaempferol in Qingke barley fresh noodles (Figure S1, has been published) (Tuersuntuoheti et al, 2021). According to previous studies, we hypothesized that these phenolic compounds also could reduce the blood sugar level by inhibiting DPP-IV activity.…”

“…Most studies attribute the hypoglycemic function of barley to β‐glucan, besides β‐glucan, there are abundant polyphenols in barley. In our previous research, we found that there were 14 kinds of phenolic compounds, including gallic acid, protocatechuic acid, chlorogenic acid, vanillic acid, syringic acid, p‐coumaric acid, rutin, ferulic acid, naringin, epicatechin, o‐coumaric acid, quercetin, naringenin, kaempferol in Qingke barley fresh noodles (Figure S1, has been published) (Tuersuntuoheti et al, 2021). According to previous studies, we hypothesized that these phenolic compounds also could reduce the blood sugar level by inhibiting DPP‐IV activity.…”

“…Qingke barley fresh noodles were prepared according to the methods described in our previous research (Tuersuntuoheti et al, 2019), and its 14 kinds of phenolic compounds were quantified by HPLC (Waters 600E, Delta 600 pump, Waters, Milford). The specific methods were also described in our previous research (Tuersuntuoheti et al, 2021).…”

A functional bread produced by supplementing wheat flour with high β‐glucan hull‐less barley flour

“…The bound phenols interact with macromolecules such as starch, protein, and lipid by covalent and noncovalent bonds (hydrogen bonds, hydrophobic, van der Waals forces, ionic interactions, etc.). The interactions are destroyed under certain conditions, such as alkaline/acid hydrolysis, fermentation, and heating, resulting in the release of more phenolics from the food matrix (Acosta‐Estrada et al, 2014; Tuersuntuoheti et al, 2021). As expected, the majority of phenolics were in the bound form.…”

Effects of coarse cereals on dough and Chinese steamed bread – a review

“…Besides, many kinds of cereal contain higher levels of phytochemicals than wheat, especially polyphenols ( 14 ). Polyphenols can scavenge free radicals in the body to achieve the effect of antioxidants ( 33 ), polyphenols can also play a role in lowering blood pressure, blood lipids, and cholesterol, it has a preventive effect on cardiovascular and cerebrovascular diseases and atherosclerosis ( 34 – 36 ). These polyphenols may also promote the slow digestion of starch by inhibiting digestive enzymes ( 37 ).…”