Study And Application Of Koreeb(Dactyloctenium Aegyptium) Seeds Flour In Kisra Bread Product

Koreeb(Dactyloctenium aegyptium)seeds are uncultivated cereal grains,which utilized as a famine food in some African countries such as Sudan and Chad.Koreeb seeds flour(KSF)is a source of carbohydrate,protein and some phytochemicals.This research was conducted to investigate the best preprocessing methods apply in koreeb seeds to achieve high nutritive value and antioxidant activity,and to utilize its flour in the production of a kisra bread,in addition to investigate the bioavailability of bioactive compounds of this product.Firstly,proximate composition,amino acids,sugars,minerals and vitamins contents of the KSF prepared with different preprocessing methods(blanching,roasting,cooking,fermentation,malting and soaking)were studied.The results of these parameters revealed that,the purity index,moisture content,one thousand seeds weight and bulk density of koreeb seeds were found to be around 78%,9.9%,0.25 g(4000 caryopses per gram),and 1.23 g/mL,respectively.Also the results showed that,among different preprocessing methods the fermentation significantly increased the protein content and water absorption capacity by 7.32% and 7.77%,respectively,whereas reduced the bulk density by 15.5% and improved the lightness of KSF.The malting process alone improved the water-soluble vitamins(vitamin C and B-vitamins)content and increased lysine value by 4.48%.Calcium(Ca)was the dominant mineral in all preprocessed KSF samples and the roasted sample revealed the highest Ca content.Overall,the results indicated that in comparison with various methods performed,fermentation could improve the nutritive quality and functional properties of koreeb seeds.Secondly,this work evaluated the effects of different fermentation time(0-72 h)on rheological and thermal properties of the dough and physicochemical characteristics of kisra bread prepared from the KSF.The pH of the fermented kisra dough decreased,whereas titratable acidity increased.In addition,fermentation time exhibited a significant decrease in rheological moduli(G' and G'')and an increase in rheological tangent(?).Gelatinization temperature and degree of starch gelatinization increased,while enthalpy decreased.An increase of protein content and in vitro protein digestibility(IVPD)was observed in kisra breads.Fermented kisra breads exhibited the highest acceptability scores in sensory evaluation,especially the sample fermented for 36 h compared to the control.The X-ray diffractograms of stored kisra breads showed the B-type structure with the presence of peaks at 13.5°,17.5°,and 26.5° 2?.Moreover,all samples exhibited a peak centered at 20° 2?,which reflects V-type crystal structure of the amylose-lipid complex.Overall,the fermentation process enhanced the nutritional,sensorial,and health attributes of kisra breads.Thirdly,the effects of different fermentation time(0–72 h)on the composition of the antinutrients,phytic acid(PA),oxalic acid(OA)and tannins and on the bioavailability of iron(Fe),zinc(Zn),and calcium(Ca)of kisra bread from Koreeb seeds was studied.The results of the study revealed that PA,OA,and tannins content decreased significantly(P<0.05)whereas the amount of total Fe,Zn,and Ca was increased with the fermentation time.Fifty-four-hour fermentation resulted in maximum reduction of PA(26.9%),while 72 h fermentation recorded a maximum reduction of OA and tannins by 80.9 and 46.5%,respectively.The increase in fermentation time decreased the molar ratios of PA/Fe,PA/Zn,PA/Ca and OA/Ca of fermented kisra bread,therefore,fermentation enhanced the bioavailability of minerals(Fe,Zn and Ca).This fermented kisra bread could be a source of easily available minerals for individuals suffering from digestive disorders,as well as used as a functional food in general.Fourthly,the results of koreeb kisra breads fortified with different level of apple pomace flour(APF)(2-17%)submitted to an in vitro digestion for antioxidants bioavailability,demonstrated that the total phenolic contents and antioxidant capacity of kisra breads were increased markedly due to an increase the amount of APF added.The highest content of TPC was found in simulated gastric digestion extracts from 22.49 mg/g(control)to 37.99 mg/g DW(17% APF),whereas the antioxidant activity of fortified kisra breads was significantly higher than the activity of the control.Both Simulated gastric digestion and chemical extraction overestimates the ability to ABTS and FRAP,while,the simulated gastric extract underestimates the ability to DPPH inhibition.Fortified kisra breads with up to 8% APF gave satisfactory results.Therefore,fortified kisra bread could provide the health of consumers.Finally,the effect of extraction conditions on phenolic compounds and antioxidant properties of KSF,revealed that,the best extraction conditions were 80 mL methanol/g,1.00% HCl,180 min and 60 °C,as well as the results of TPC,TFC and DPPH were 32.38 mg GAE/g,20.88 mg QE/g and 82.22%,respectively.Therefore,KSF can be applied in functional foods and medicine related products for its health benefits.