Research On The Effects Of Whole Wheat Flour On The Quality And Oil Content Of Sachima

Refined wheat flour (RWF) in the recipe for Sachima dry mix was replaced with wholewheat flour (WWF) at different levels. The effects of WWF on the properties of the doughand the quality of Sachima were investigated. A kind of WWF Sachima with highernutritional value and lower oil content was developed, and the mechanisms of WWF onreducing oil content of fried Sachima sticks were studied.The effects of WWF on the properties of the Sachima dough were studied. Thedevelopment time (DDT), dough stability time (DST), farinograph quality number (FQN) anddough extensibility decreased significantly with adding WWF (P<0.05), while the waterabsorption (WA), the degree of softening (DS) and the values of resistance to a certainextension increased. Furthermore, the dynamic rheological properties were weakened byadding WWF with lower storage modulus (G’) and lower loss modulus (G’’).The effects of WWF on the quality of fried Sachima sticks were also investigated. WWFenhanced the puncture force and breaking force of fried Sachima sticks and darkened thesurface color with lower L*and higher a*values. The ΔE increased significantly comparedwith the control (P<0.05). The puffing quality was negatively affected by WWF with adecreased specific volume. The surface oil content (SUOC) increased with the increasinglevel of WWF substitution, while the structure oil content (SOC) decreased significantly(P<0.05). Then, the total oil content (TOC) was reduced by24.48%with a WWF substitutionlevel of75%, compared with the control. On the other hand, the sensory quality of finalSachima products was negatively affected by adding WWF.The optimal formula and deep-frying process of WWF Sachima were obtained asfollows: WWF,50g; gluten powder,20g; RWF,30g (WWF:gluten:RWF=5:2:3); fresh egg,65g; baking powder,1.0g; and ammonium bicarbonate,0.5g. Sachima dough was fried at160°C for80s. Based on the optimal process parameters, the WWF fried Sachima sticks gotthe best quality: specific volume,5.03cm3/g; breaking force,512g; TOC,31.70%; finalproducts’ sensory score,73.44.The nutritional quality and volatile flavor compounds of commercial Sachima, controlSachima and WWF Sachima were determined respectively. The results indicated that theWWF Sachima had higher protein and fiber content and better antioxidant capacity. Thelevels of aroma components such as aldehydes and pyrazine in WWF Sachima were alsohigher than commercial and control Sachima. As a result, the utilization of WWF in Sachimadry mix could improve the nutritional value and flavor quality of the final products.Finally, the mechanisms of WWF on reducing oil content of fried Sachima sticks wasdiscussed. The puffing capacity during deep-frying was weakened by adding WWF, while thebreaking force was enhanced. The kinetic coefficients of moisture and oil transfer (kmand ko)decreased significantly by substituted with WWF. It can be attributed to the enhancedwater-binding capacity in Sachima dough with decreased spin-spin relaxation time (T2) ofwater molecules and increased gelatinization temperature (Toand Tp) of starch by addingWWF. The total signal intensity of oil and the area ratio of the first oil signal peak (T24) decreased with the increasing amount of WWF, along with the crystallization enthalpies (ΔHc)of fried Sachima sticks. Furthermore, WWF can partially substitute RWF to produce lower oilcontent Sachima, which had a compact surface and dense structure with fewer and smallervoids.