Effect Of Ethanol Extract Of Chuanminshen Violaceum Sheh Et Shen On Common Physicochemical Parameters And Infrared Spectral Properties Of Frying Oil

Chuanminshen Violaceum Sheh et Shen(C.Violaceum)is a tonic from Sichuan province,which polysaccharides,volatile oils and phenolic substances have strong antioxidant properties and have potential application in quality control of frying oils.Active substance of C.Violaceum was ultrasonically extract with 80% ethanol,and 0.07% ethanol extract of C.Violaceum was added to soybean oil,palm oil and rapeseed oil,respectively.To investigate effects of ethanol extract of C.Violaceum on the quality of three vegetable oils frying at 180 °C for 36 h.Changes of common and short-chain fatty acid(SCFA)were analyzed by gas chromatography-mass spectrometry(GC-MS),and acid value(AV),carbonyl value(CV)and total polar component(TPC)content of frying oil were observed by combined with FTIR technology.The main research results are as follows:(1)The ethanol extract of C.Violaceum has strong antioxidant activity.Within the mass concentration of 5-25 mg/m L,the clearance rates of DPPH and ABTS free radicals were 39.39%-95.52% and 22.73%-74.41%,respectively.The absorbance of iron ion reduction ability ranged from 0.14 to 0.26;the total phenol and total flavonoid content were 6.63 mg GAE/g and 14.01 mg RT/g,respectively.(2)Adding the ethanol extract of C.Violaceum to the soybean,palm and rapeseed oil fried with chicken breast meat and potato,respectively,the acid value decreased by 4.8%,28.94%,12.55%,0.47%,12.40% and 4.26%,respectively;the carbonyl value decreased by 33.91%,37.44%,-5.37%,10.50%,39.59% and 42.25%,respectively;the TPC decreased by 2.63%,7.02%,-3.05%,-2.15%,-7.02% and-0.66%,respectively.The ethanol extract of C.Violaceum had significantly inhibitory effect on the acid value of soybean oil fried with potato,palm oil and rapeseed oil fried with chicken breast meat(P<0.05);it had significantly inhibitory effect on the carbonyl value of soybean and rapeseed oil fried with chicken breast meat and potato(P<0.05),respectively;it had little effect on TPC.(3)The reduction content of linoleic acid(C18:2)of soybean oil fried with chicken breast meat and potato was: no addition > TBHQ> ethanol extract of C.Violaceum;the reduction content of linolenic acid(C18:3)was: no addition> ethanol extract of C.Violaceum > TBHQ.The reduction content of C18:2 of palm oil was: no addition(potato)> TBHQ(potato)> ethanol extract of C.Violaceum(potato)> no addition(chicken breast meat)> ethanol extract of C.Violaceum(chicken breast meat)> TBHQ(chicken breast meat).The reduction content of C18:2 of rapeseed oil was: no addition(potato)> ethanol extract of C.Violaceum(potato)> no addition(chicken breast meat)> TBHQ(potato)> ethanol extract of C.Violaceum(chicken breast meat)> TBHQ(chicken breast meat).The octanoic acid(C7:0)content of soybean oil,palm oil and rapeseed oil fried with chicken breast meat and potato was reduced by 62.5%,14.29%,22.22%,23.80%,-18.75% and 50%,respectively;the nonanoic acid(C8:0)content was reduced by 52%,47.91%,41.67%,63.23%,-44.44% and 74.79%,respectively.(4)FTIR-partial least squares(PLS)analyzed AV,CV and TPC of soybean oil,and optimized prediction model to get the best pretreatment method that was first derivative combined with multiple scattering correction(D1-MSC).The cross-validation root mean square error(RMSECV),predicted root mean square error(RMSEP),and the determination coefficient of validation set(R~2(val-y))of acid value models were 0.1895,0.1375,and 0.9363,respectively;RMSECV,RMSEP,and R~2(val-y)of carbonyl value models were 7.0502,21.1122,and 0.9394,respectively;RMSECV,RMSEP,and R~2(val-y)of TPC models were 3.9198,3.3896,and 0.8717,respectively.Similarly,the palm oil and rapeseed oil spectral data were all based on D1-MSC,and a better prediction model was obtained.In summary,addition of the ethanol extract of C.Violaceum has obvious effects on soybean and rapeseed oil(P<0.05),and the antioxidant effect in palm oil was not obvious.It has little effect on the TPC of frying oil and has significant inhibitory effect on the formation of SCFA(P<0.05);overall its antioxidant activity is weaker than TBHQ.SCFA was introduced as an auxiliary index,and FTIR-PLS was used as a rapid analysis technique to evaluate the quality change of frying oil and the effect of ethanol extract of C.Violaceum on the quality of frying oil.The results showed that the ethanol extract of C.Violaceum had a protective effect on the thermal stability of frying oil,and provided a theoretical basis in frying oil.