| Alpinia oxyphylla Miq.mainly grows in the south of China.It is a medicinal and edible plant.Commonly,Alpinia oxyphylla is used to alleviate gastralgia,diarrhea,ulceration,diuresis,aging and dementia,which mainly contains flavonoids,sesquiterpenes and diarylheptanoids.The fruit of Alpinia oxyphylla Miq.is widely used in food,drug,health products and other industries.However,there are few researches focused on other parts of Alpinia oxyphylla Miq..The main results were showed as follows:The nutrient components of different parts of Alpinia oxyphylla Miq.were analyzed and compared with the stemBT,leafBT,pericarpBT,seedBT,and peduncleBT of Alpinia oxyphylla Miq.in Baoting(BT),and the stemQZ and leafQZ of Alpinia oxyphylla Miq.in Qiongzhong(QZ),Hainan.Fresh samples were used for analyzing routine nutrient components and vitamins content.The water contents of pericarpBT and peduncleBT were the highest,up to 80%.The total sugar content of seedBT was the highest(35.48 g/100 g).The fats content in seedBT was the highest(2.43 g/100 g).The pigment and the crude fiber in leaf BT were the highest(0.369 g/100 g,15.77 g/100 g,respectively).The contents of VBs,VC,VA and VE in leaf QZ were 12.97 mg/100 g,13.04 mg/100 g,0.901 mg/100 g and 43.76 mg/100 g,respectively.The contents of VB2,VBe and VE in leaf BT were 0.47 mg/100 g,12.32 mg/100 g and 5.81 mg/100 g,respectively,which were significantly higher than those in other parts in the same origin.Besides VB3 and VC,the vitamins content of pericarpBT was higher than those in seedBT.The contents of mineral elements in Alpinia oxyphylla Miq.are rich.The contents of Ca,Mg and Fe in leaf QZ were the highest,then the contents of K and Mg in pericarp81 and the contents of Zn in stemBT were higher than those in other parts in the same origin.And the contents of heavy metals were lower than the national standards in all samples.The linoleic acid contents in ste1BT and peduncle81 were 16.53%and 19.02%respectively,which accounted respectively for 56.1%and 58.2%of the total unsaturated fatty acids.The composition of fatty acids of stemBT was relatively uniform and accorded with the index of healthy vegetable oils.In addition to the traditional edible part of Alpinia oxyphylla,the stem 0il,leaf and pericarp all have nutritional value.The leaves of Alpinia oxyphylla Miq.was selected for further study based on the highest content of total flavonoids compared to other parts.The extraction rate of total flavonoids from the leaves of Alpinia oxyphylla Miq.(TFL),DPPH free radical(1,1-diphenyl-2-picrylhydrazyl radical,DPPH.)and ABTS free radical(2,2,-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid radical,ABTS+·)scavenging capacity,ferric reducing antioxidant power(FRAP)were used as criteria to optimize microwave extraction process using orthogonal method.The optimum extraction process of TFL was obtained as follows:50%ethanol as extraction solvent,liquid-material ratio of 20 mL/g,extraction temperature of 70?,extraction cycle of 3.Five groups of validation experiments showed that the TFL extraction rate was 28.24%(RSD=0.487%),And its extract has excellent antioxidant abilities.The TFL powder was obtained by decompression concentration and freeze-dried of the above extracts.Four antioxidant tests were used to evaluate the antioxidant capacity of TFL:the 50%inhibiting concentration(IC50)of TFL on DPPH??ABTS+*and superoxide anion radical(O2-·)were 6.56 ?g/mL,71.28 ?g/mL and 1.308 mg/mL,respectively.FRAP,DPPH·and O2-·scavenging capacity of TFL were similar to those of VC,which were far superior to those of positive control butylated hydroxytoluene(BHT).High Performance Liquid Chromatography(HPLC)was used to determine the content of Chrysin and tectochrysin in TFL,which were 0.0896 mg/g and 1.8020 mg/g,respectively.Fourier Transform Infrared Spectrum(FTIR),thermogravimetric(TG),differential scanning calorimetry(DSC)and mineral element analysis showed that TFL were stable below 210?.Based on the content of polysaccharides,the seed and pericarp of Alpinia oxyphylla Miq.were selected.A Box-Behnken design was used to optimize the extraction of polysaccharides from the seed and pericarp.The results showed that the optimum extraction conditions of polysaccharide from seed(PS)were pH 4,liquid-material ratio 35 mL/g,enzymatic hydrolysis time 2.5 h,extraction time 2.5 h.The optimum extraction conditions of polysaccharide from pericarp(PP)were pH 4,liquid-material 35 mL/g,enzymatic hydrolysis time 1.5 h,extraction time 2.0 h.The extraction rates of PS and PP were(10.40±0.14)%,(6.21±0.14)%,which were close to the theoretical predicted value.The optimized model of polysaccharide extraction was reliable.After purification,the yields of PS and PP were 4.67%and 4.12%,respectively.Three kinds of antioxidant tests showed that the DPPH·scavenging IC50 values of PS and PP were 2.455 mg/mL and 0.17 mg/mL,respectively.The scavenging rates of ABTS+·were 12.36%and 92.47%when the concentration of PS and PP was 3 mg/mL.The FRAP were 52.67 ypmoI/L and 756.77?mol/L,respectively.The antioxidant ability of PP was better than that of PS.The results of FTIR,TG,DSC,scanning electron microscopy(SEM)and macroscopical state showed that there were differences between the two polysaccharides from these two parts.The monosaccharide content of PS and PP were different.The Glucose content of PS was the highest,while the Galacturonic Acid content of PP was the highest.The molar ratio of main monosaccharides in PS is Mannose:Rhamnose:Glucosamine:Galacturonic Acid:Glucose:Galactose:Xylose:Arabinose:Fucose=1:3.18:0.83:5.47:98.34:9.62:24.60:17.51:1.45.The molar ratio of main monosaccharides in PP is Mannuronic Acid:Mannose:Rhamnose:Glucosamine:Glucuronic Acid:Galacturonic Acid:Glucose:Galactose:Xylose:Arabinose:Fucose=5.06:1:1.64:1.08:1.81:91.17:5.43:636:12.22:12.23:0.86.Two kinds of polysaccharides,PP-70 and PP-80,were purified by fractional precipitation with ethanol.The molecular weights of PP-70 and PP-80 were about 65 KDa and 55 Kda,respectively.The antioxidant capacity of these two polysaccharides were better than that of PP.The chemical constituents of five parts were analyzed by HPLC-MS.Compounds 1,2,3 and 6 were identified as nootkatone,tectochrysin,Chrysin,oxyphyllone D or oxyphyllone G,And unknown compounds 4,5 and 7 had molecular weights of 636,384 and 546,respectively,which needed to be further determined.The contents and the types of chemical constituents in five parts of Alpinia oxyphylla Miq.were quite different.The ethanol extracts of different parts were extracted by four different polar extraction segments:Petroleum ether(PE),ethyl acetate(EA),n-butanol(nBA),water(W).The results of DPPH·,ABTS4 scavenging capacity and FRAP indicated that the antioxidant capacity of nBA and EA segments in stem,leaf and peduncle were stronger than that of the extracted segments of seed and pericarp.The draft food safety standard includes two parts of Alpinia oxyphylla Miq.:seed and pericarp.According to the test results,the water content of seed and pericarp were limited to ?10.0 g/100 g and ?6.0 g/100 g,respectively.The ash contents were limited to ?5.0 g/100 g and ?8.0 g/100 g,respectively.The volatile oil contents were limited to?0.7 mL/100 g.The protocatechuic acid contents were limited to?35.000?g/g,?25.000 ?g/g,respectively.The nootkatone contents were limited to>2.4000 mg/g,>0.1800 mg/g,respectively.According to the content of four antinutrient factors(oxalic acid,phytic acid,tannins and trypsin in-hibitor activity),the results suggested that the raw materials of seed and pericarp should be treated by hot water immersion.Heavy metals,pesticide residues,microbial examination and other requirements meet the corresponding national food safety standards. |
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