Effect Of Flaxseed Gum Or Tamarind Gum On Properties Of Waxy Rice Starch

Starch based food pasting in machining process,Starch contributes to the viscosity and special mouth-feel of Starch based food products.Gelatinized starch is easy to age during cold storage and transportation process.Aging has bad effect on food quality and shelf life.Hydrophilic colloid can regulate properties of starch by interaction.In order to better understand the application of Hydrophilic colloid in starch processing,this paper studied the effect of flaxseed gum(FG)or tamarind gum(TG)on properties of waxy rice starch.The effects of flaxseed/tamarind gum(0.1%-0.5%)on pasting properties,enthalpy properties and texture properties of waxy rice starch were investigated by Rapid Viscosity Analyzer(RVA),Differential Scanning Calorimetry(DSC),Texture Profile Analyzer(TPA).With the addition of flaxseed/tamarind gum,the peak viscosity,final viscosity and gelatinization temperature increased.Setback and breakdown value decline.The hardness of starch gradually decreased,Elasticity and cohesiveness increased.The gelatinization enthalpy was increased with the addition of flaxseed/tamarind gum.Tamarind gum has a greater influence on pasting properties,enthalpy properties and texture properties of waxy rice starchThe result of rheological properties shows the total starch gels were weak gels,the storage modulus was always higher than the loss;flaxseed/tamarind gum increased tan? value of starch gels,the gels tend to a more fluid-like behavior.The effect of tamarind gum was highly greater than that of flaxseed gum.Waxy rice starch(WRS)gels subjected to repeated freezing and thawing tend to decrease in quality.To improve the the freeze-thaw stability of waxy rice starch gel,the effect of flaxseed gum(FG)and tamarind gum(TG)on syneresis,retrogadation,crystallinity,molecular structure,microstructure and texture properties of waxy rice starch was investigated.Waxy rice starch gels containing 0–0.5% flaxseed/tamarind gum were treated to 7 freeze–thaw cycles.The result showed that flaxseed/tamarind gum effectively reduced the % syneresis.Differential scanning calorimetry showed that flaxseed/tamarind gum significantly reduced the retrogradation enthalpy and retarded waxy rice starch gel retrogradation induced by freeze–thaw treatment.X-ray diffraction results showed that crystallinity of waxy rice starch gels decreased from 13.56% to 9.29% with the addition of 0.5% flaxseed gum.The crystallinity of waxy rice starch gels decreased to 8.92% with the addition of 0.5% tamarind gum.It showed that the flaxseed/tamarind gum inhibited the recrystallization of the starch gel.Fourier transform infrared spectroscopy suggested that the hydroxyl stretching vibration peak of waxy rice starch gel had a large displacement.Flaxseed/tamarind gum enhanced intermolecular hydrogen bonding interaction.But there were not the formation of new groups.Scanning electron micrographs of freeze–thaw gels showed that smaller pore size and a thicker surrounding matrix corresponded with increasing flaxseed/tamarind gum concentration.The hardness of starch gradually decreased,Elasticity and cohesiveness increased.The result showed that flaxseed/tamarind gum was an effective agent for preserving the quality of freeze–thawed waxy rice starch gels and inhibited the retrogradation of waxy rice starch gel.