Effects Of Two Processing Methods On The Physical Properties,Anthocyanin Structure And Anti-inflammatory Activities Of Black Grains

There are many types of black grains,which are rich in nutrients,and have significantly higher nutrient content than similar light-colored grains.However,they have the disadvantages of inconvenience in eating,difficult to preserve,and rough taste.Drum drying and extrusion are two common grain processing methods.In this study,black rye,black rice and black beans were extruded and drum-dried,respectively.The physicochemical properties,dissolution characteristics,powder flowability,rheological characteristics and storage stability were investigated.Black rice was selected to study the effects of drum-dried and extruded on the structure,bioactive component content,antioxidant activity and anti-inflammatory activity in vitro of anthocyanin extracts.The results are shown as follows:1.The extruded and drum-dried treatment significantly decreased the lipid starch and anthocyanin contents of three grains but significantly improved the solubility.While the protein content and liquidity did not change significantly.During the 50-day accelerated storage,the fatty acid value and peroxide value of three drum-dried andextruded processed black grains were lower than unprocessed persistently.The carbonyl value changes were in a dynamic equilibrium state.The types of volatile components in three black grains did not change significantly after drum-dried and extruded processing.Compared with day 0,the relative content of limonene in the volatile flavor components of black grains increased significantly after 50 days of accelerated storage,and most of the remaining alkanes were reduced,the species of aldehydes are reduced,the species and relative content of aromatic substances are increased.The results of the accelerated storage experiment show that both drum dried and extruded processing could improve the quality deterioration of grains due to oil oxidation during storage,and improve the storage stability of grains.2.This study identified the phytochemical constituents of three anthocyanin-rich extracts from raw(BRAE),drum-dried(D-BRAE)and extruded black rice(E-BRAE)using UPLC-LTQ-Orbitrap-MS2.A total of 9 compounds were tentatively identified:Syringic acid;Protocatechuic acid;Cyanidin 3,5-diglucoside;Cyanidin-3-glucoside;peonidin-3-glucoside;cyanidin;vanillic acid;delphinidin-3-glucoside;Gingerglycolipid B.Cyanidin-3-glucoside was the main anthocyanin in BRAEs(27.45±0.38 mg C3G/g DW,17.70±0.41 mg C3G/g DW and 7.45±0.12 mg C3G/g DW,respectively).Compared with BRAE,the content of C3G was significantly reduced in D-BRAE and E-BRAE(reduced 35.52%and 72.86%,respectively),the P3G also decreased directly(reduced 34.16%and 59.01%,respectively).And the content of protocatechuic acid increased significantly in E-BRAE(increased 3.1-fold),and increased slightly in D-BRAE(increased 14.29%);and the cyanidin was found in D-BRAE and E-BRAE while BRAE not.The TPC(138.82±4.21 mg GAE/g DW)and TAC(121.79±8.28 mg C3G/100 g DW)of BRAE were significantly higher than D-BRAE and E-BRAE,while the TAC/TPC/TFC of E-BRAE were significantly higher than D-BRAE.The antioxidant capacity of DPPH,ABTS,FRAP of D-BRAE and E-BRAE was significantly reduced compared with BRAE,and the antioxidant capacity of D-BRAE was lower than E-BRAE.3.One μg/mL LPS was used to stimulate RAW264.7 cells to establish a model of cell inflammation.Three concentrations of 50,200,and 400 μg/mL were selected to study the anti-inflammatory effects of BRAE,D-BRAE,and E-BRAE.BRAE,D-BRAE,and E-BRAE significantly inhibited the secretion of inflammatory mediators(NO,PGE2)and their related proteins(iNOS,COX-2)and their mRNA expression in RAW264.7 cells induced by LPS;significantly reduced inflammation Factors TNF-α,IL-6,IL-1β secretion and mRNA expression;significantly down-regulate the phosphorylation of MAPK,NF-κB related proteins(JNK,ERK,IκBα,p65)and reduce NF-Nuclear transfer effect of κB p65.The unprocessed and two processing methods of black rice anthocyanin extract had good anti-inflammatory function in RAW264.7 cells stimulated by LPS.The two processing treatments of roller drying and extrusion puffing did not significantly inhibit the black rice anthocyanin extract.Anti-inflammatory activity.Squeezing treatment significantly enhanced the inhibitory effect of black rice anthocyanins on the phosphorylation of inflammatory signaling pathways(MAPK,NF-κB)related proteins(JNK,ERK,IκBα,p65).