Adsorptive Removal Of Bad Flavor Compounds In Anchovy Enzymatic Hydrolysates

Sea food protein enzymatic technology has been promoting nowadays,however, its development is constrained by the flavor defect.This paper was done for the above question. Bad flavor compounds including bitterness and fishy odor matters were adsorptive removed by macroporous adsorption resins(MARs),adsorption process was researched,adsorption and elution conditions were determined and adsorption mechanism was preliminary studied. Details of the paper were as follows:1.Two MARs MARs XAD7HP and DA201-C in eight were selected. XAD7HP had the best adsorption of bitterness compounds,sensory score was 1.0. Moreover,DA201-C was the best MAR of fishy odor compounds adsorption,sensory score was 1.6.Different adsorption conditions such as:temperature,salt addition,pH, sample volume and velocity were compared.The adsorption process was determined, that is:anchovy enzymatic hydrolysate supernatant was dynamic adsorbed by XAD7HP and DA201-C continuously,each condition was:XAD7HP:20℃,salt addition 0%,pH6-6.5,sample volume 30BV,velocity 14.5BV/hr;DA201-C:20℃,salt addition 10%,pH4-7,sample volume 10BV,velocity 10BV/hr.The bitterness and fishy odor sensory score could keep in 2.After the adsorption process,the total nitrogen(TN) was 1.35g/100ml,and the amino acid nitrogen(AAN) was 0.66g/100ml.Component of eluent was studied taking TN elution ratio and fishy odor sensory score as indexes.Results shows:eluent containing ethanol had a better effect than diluted acid and alkali eluent, gradient ethanol eluent was the best eluent.Elution velocity was determined reguarding TN elution ratio.The final elution condition was:XAD7HP:gradient ethanol eluent(25%,50%和75%,v/v)2BV, velocity lOBV/hr; DA201-C:gradient ethanol eluent 2BV, velocity lOBV/hr.20 times adsorption and elution process was carried out, indexes of TN,AAN and sensory score were detected.Result shows:effects of MARs XAD7HP and DA201-C adsorption were descended.But this decrease was slight,after 20 times,these two MARs maintained high activities,which could be still used.2.Molecular weight(MW) of adsorbed peptide was studied.It was found that TN adsorption ratioes of MW 500-2000 and 2000-3500 were 10.21% and 11.65%.Adsorption of bitterness peptide was significant,and debittering effect was obvious.ACE inhibitory activity was detected by the improved method of HPLC, and influence of adsorption process was compared. Result shows that:change of the ACE inhibitory activity was determined by the polar of resin, which non-polar macroporous resins reduced the ACE inhibitory activity of enzymatic hydrolysate and polar and weak-polar resins could slightly improved it. The ACE inhibitory activity was decreased obviously treated by non-polar macroporous resin DA201-C,the value of IC50 increased from 9.10mg to 17.58mg.After MARs adsorption debittering and deodorization process, value of IC50 up to 16.42mg/ml,IC5o value of DA201-C and XAD7HP enlution were 8.40mg/ml和4.47mg/ml.The ACE inhibitory peptide(ACEIP) would be enriched by MARs effectively.Seven biogenic amines of anchovy enzymatic hydrolysate MARs adsorption were detected by the high performance liquid chromatography-post column derivation-fluorescence detection method(HPLC-PCD-FLD).Adsorption of seven biogenic amine was determined by the polar of resin,polar and weak-polar resins had a better effect on biogenic amine adsorption.Furthermore,composition and specific surface-area could impact the adsorption result.MARs DA201-C had a maximum adsorption of tyramine,which composed by divinylbenzene and had the largest specific surface area.MARs adsorption process could significantly reduce the content of biogenic amines.and improve safety of anchovy enzymatic hydrolysate.The content of seven biogenic amines reduced from 211.2mg/L to 113.0mg/L.Flavor compounds of anchovy hydrolysate and MARs adsorption solution were detected by solid phase microextraction-gas chromatograph-mass spectroscopy method(SPME-GC-MS). Kinds of flavor compounds reduced from 74 to 38 after adsorption process.The ion current intensity of trimethylamine (TMA) reduced from 4.51E+08 to 1.74E+07 and carbonyls reduced from 2.42E+09 to 6.94E+07and its propotion reduced from14.0% to 7.3%.Fishy odor compounds decreased obviously.Amino acids were determined by the method of pre-column derivatization-high performance liquid chromatography.Results shows:the content of amino acids was decrease 4% after MARs adorption debittering and deodorization process,which was little.Content of essential amino acids Was 38% in adsorption liquid,the component of amino acid was nutritious.Reduce of tyrosine and phenylalanine was prominent,the contents were 89% and 90% of original liquid.Flavor amino acid aspartate and glutamate had an small reduction,the content were 98% and 101% of original liquid.This indicated that MARs adorption debittering and deodorization process would improve the flavor of anchovy enzymatic hydrolysate,this progress could be applied in production of enzymatic hydrolysate flavor products.