The Studies On The Rice Antistaling Agent Of Lipid-based

In this thesis, the emulsion rice antistaling agent was prepared mainly from palmoil, soybean phospholipid powder, sucrose esters, trehalose, etc. Then spraying itonto the surface of rice to investigate the impact of the concentration gradient and thecoating dosage of the antistaling agent on physical and chemical indexes of rice in theaccelerated aging process, and to explore the effect of different conditions on physicaland chemical properties and texture quality during storage with simulating differentstorage temperature and humidity conditions. And then the optimal ingredients ofantistaling agent and the maximize preservation effect of the concentration, dosageand the storage temperature and humidity was determined.1.The research use the lipid composition of palm oil、powder phospholipids、preservative ingredients such as trehalose、tea polyphenol, and emulsifiers suchasspan-60、tween-80、sucrose ester as raw material, and then mix them together byadopting the method of emulsification process in order to prepare a antistaling agentconforming to the emulsion properties of, the best ratio was determined asfollows:40%palm oil,6%lecithin,3%span-60,0.5%tween-80,5%trehalose,4%teapolyphenols,0.2%sucrose ester,and others was water.2.The impact of different storage conditions such as temperature conditions of25℃、30℃、35℃and humidity conditions of45%,65%,85%to the effect of riceantistaling agent was investigated in. And the results show that fatty acid value,peroxide value and total acidity is lower than the control group after using the ricefresh-keeping agent.(a): The antistaling agent had high inhibition capacity to riceageing at two and four times dilution multiples, while the mildew proof ability ofantistaling agent is not outstanding.(b): Taking the multiple physical and chemicalindicators into account in accelerated aging process, the optimal dosage in which the antistaling agent of preservation effect played best was1:150.(c): The antistalingagent play a different effect on rice as temperature change by comprehensiveevaluation. comprehensive physical and chemical indicators of rice under differenttemperature change, antistaling agent has no significant effect on rice at25℃, andhigh temperature can also limit the ability of preservative rice to keep good storagequality, namely, antistaling agent at30℃can play a better effect to slow the riceageing.(d). Under different humidity conditions, antistaling agent can keep moisturecontent of rice in an appropriate range, and the antistaling agent in different humiditystorage environment play a different function to rice.In consideration of the fatty acidvalue, peroxide value and total acidity, effect of antistaling agent at85%humidity wasmore obvious than45%and65%humidity, but bacteriostatic effect was moreapparent at65%humidity.3.The coating rice was analyzed by X-T21Texture Analyser by changing thestorage conditions. the results indicated that the antistaling agent had the biggestfresh-keeping influence on the viscosity of rice/hardness value at30℃during onemonth storage: after30days storage, the viscosity/hardness value of coating groupand control group changed from0.0592before storage to0.050、0.037respectively,and viscosity/hardness value of coating group was35.13%higher than the controlgroup.45%humidity storage played the biggest fresh-keeping effect on the viscosity/hardness value of rice: after30days storage, the viscosity/hardness of the coatinggroup and the control group values were0.056、0.039respectively, coating group was43.59%higher than the other. The antistaling agent had small effect on elasticity ofrice under different storage temperature and humidity conditions.