Effect Of Three Amino Acids On The Sensory Qualities And Reactive Carbonyl Species In Cookies

Bakery foods are favorite foods for the consumers and have developed rapidly in recent years in China.However,the harmful substances produced during baking,such as reactive carbonyl compounds,dangers human health.In this paper,different levels of L-cysteine hydrochloride(0、0.3、0.6、1.0、1.5 g/kg),L-serine(0、0.2、0.4、0.67、1.0 g/kg)and L-alanine(0、0.17、0.34、0.57、0.85 g/kg)were incorporated the dough to prepare cookies and investigate their effects on the sensory quality of cookies,the inhibition effect of reactive carbonyl compounds;the cell cytotoxicity the water extracts of cookies was also investigated.The main conclusions are as follows.1.Effects of three amino acids on the sensory quality and flavors of cookiesThe addition of the three amino acids did not affect the moisture content of the cookies.L-cysteine hydrochloride and L-serine slightly decreased the p H value,while L-alanine showed no influence.L-alanine had little effect on the color of the cookie surface,and there was no significant change.The addition of L-serine resulted in a darker cookie surface,while the addition of L-cysteine hydrochloride gradually lightened the cookie surface.Meanwhile,L-serine and L-cysteine hydrochloride made the cookie crispier,while L-alanine made the cookie softer.Through sensory evaluation experiments,it was finally concluded that L-alanine had no effect on the sensory quality of cookies,L-serine could improve the taste of cookies,and L-cysteine hydrochloride had the highest improvement on the overall quality of cookies,its sensory evaluation score was significantly higher than that of L-alanine and L-serine.GC-MS results showed that: the addition of L-cysteine hydrochloride increased the content of volatile aldehydes,alcohols,pyrazines and esters in the cookies,and decreased the content of most ketones except furanone.The addition of L-alanine and L-serine increased the types and contents of volatile flavor substances in the cookies,which can give cookies a richer flavor.2.Effects of three amino acids on the content of carbonyl compounds in cookiesThe addition of three amino acids markedly reduced the content of 5-hydroxymethylfurfural(HMF),3-deoxyglucuronide(3-DG),glyoxal(GO),acetone aldehyde(MGO)and fluorescent advanced glycation end products(AGEs)in the cookies in a dose-response relationships.At the highest addition levels,L-cysteine hydrochloride decreased 5-HMF,3-DG,GO and MGO by 82.95%、62.73%、46.27%、36.59%,L-serine decreased them by 84.8%、37.3%、41.4%、16.5%,and L-alanine decreased them by 69.0%、51.4%、42.1%、15.5% respectively.Moreover,the content of fluorescent AGEs derived from the reactive carbonyl compounds in the cookies was also significantly reduced by the addition of the three amino acids.This confirms that L-cysteine hydrochloride,L-serine,and L-alanine can not only reduce the endogenous contaminants in cookies,but also inhibit protein oxidation and improve the safety of baked goods.3.Effect of water extracts of cookies on cytotoxicityTwo types of cells,human gastric mucosal epithelial cells(GES-1)and human clonal colon adenocarcinoma cells(Caco-2),were selected for the toxicity assay of the water extract of cookies.Compared with the control,the extracts showed growth-promoting effects on GES-1 and Caco-2 cells after he addition of L-cysteine hydrochloride,Lserine,and L-alanine.At the highest addition level,the cell viability of GES-1 cells treated by the water extracts of the cookies added with L-cysteine hydrochloride,Lserine,and L-alanine cookie was 22.3%,26.4%,and 15.1% higher than the control group.The addition of amino acids also influenced the cell viability in Caco-2 cells.At the highest addition level,Caco-2 cell viability increased by 48.9%,20.0% and 9.6%,respectively,compared with the control group.