Effect And Mechanism Of Orange Peel Powder On Decreasing Fishy Odour Of Algal-DHA-enriched Quail Eggs

DHA eggs have become a popular product in recent years because they are rich in n-3polyunsaturated fatty acids(n-3 PUFAs).However,when the enrichment level of n-3 PUFAs is too high,it will lead to an increase in the content of trimethylamine(TMA)in eggs,resulting in a fishy odour of eggs,which seriously affects the public’s acceptance.At present,the measures to improve the flavor of eggs mainly include nutritional regulation,physical masking,chemical mechanism regulation and elimination of susceptible genotypes.Therefore,in this experiment,different medicinal and edible homologous spices were added to the DHA enriched diet of algae source.Starting from the physical masking method,combined with the breeding experiment,the method of artificial sensory evaluation was used to screen out the medicinal and edible homologous spices that had the effect of removing the fishy odour of algal-DHA-enriched quail eggs,and to explore its deodorization effect on DHA enriched quail eggs of algae source and the deodorization mechanism of DHA enriched quail eggs of algae source.In order to provide basic data and feasibility support for the production of DHA enriched quail eggs of low fishy smell algae source,and provide new ideas for the diversified development of quail industry.In order to investigate the effect of medicine and food homologous spices on the fishy odour of algal-DHA-enriched quail eggs.In this experiment,five kinds of medicinal and edible homologous spices were screened by physical masking method,breeding experiment and artificial sensory evaluation.The degree of deodorization,egg fragrance retention and taste enhancement were taken as sensory evaluation indexes.Finally,the medicinal and edible homologous spices with the effect of removing the fishy odor of algal-DHA-enriched quail eggs were selected and the optimum addition amount was determined.Firstly,the physical masking method was used to select the medicinal and edible homologous spice(orange peel powder)which had the effect of removing the fishy smell of DHA algae source for breeding test.The results showed that when the addition amount was 2.0%,the deodorization degree,egg aroma retention degree and taste enhancement degree of quail eggs enriched by algae source DHA basically reached the highest value,while when the addition amount increased to 4.0%,the egg aroma retention and taste improvement decreased.In order to verified the orange peel powder on decreasing fishy odour of algal-DHA-enriched quail eggs.In this experiment,the effects of orange peel powder on the sensory flavor of DHAenriched quail eggs and the content of TMA and DHA in egg yolk were studied.The results showed that compared with the control group,the fishy smell,fishy taste and TMA content in egg yolk of the test group I were significantly increased(P<0.01),the test group II were no significantly different(P>0.05).Compared with the control group,the DHA content in the yolk of the test group I and the test group II was significantly increased(P<0.01),while the DHA content in the yolk of the test group I and the test group II was not significantly different(P>0.05).This indicates that orange peel as a dietary additive can improve the sensory flavor of algae-derived DHA-enriched quail eggs(reducing the fishy smell and fishy taste in algae-derived DHA-enriched quail eggs),and can reduce the content of TMA in algae-DHA-enriched quail egg yolk,but has no significant effect on DHA content.In order to explore the deodorization mechanism of orange peel powder on algal-DHAenriched quail eggs,this experiment studied the effects of orange peel powder on the cecal microbial community of laying quails and the expression level of FMO3 gene in liver tissue.The same batch of quails as experiment 2 were used for experiment.(1)Metagenomic next-generation sequencing technology was used to detect and analyze the microbial diversity and species composition of the cecum of egg quail.The results showed that a total of 608 093 valid sequences were obtained.The sparse curve is relatively flat,indicating that the amount of sequencing is sufficient to reflect the species diversity of the sample.There was a significant difference in Simpson index between the control group,the experimental group II and the experimental group I(P<0.05),and there was a significant difference in Shannon-Wiener index between the experimental group II and the experimental group I(P< 0.05).At the phylum level,compared with the control group,the relative abundance of Acidobacteria in the experimental group I was significantly increased(P<0.05),while there was no significant difference in the experimental group II(P>0.05).But compared with the experimental group I,the experimental group II had a downward trend except Firmicutes,Synergistetes,Spirochaete and Deferribacteres.At the genus level,compared with the control group,the Salinispora in the experimental group I decreased significantly(P<0.05),while the Salinispora in the experimental group II increased significantly compared with the experimental group I(P<0.05).Except for Pseudomonas,the other genera in the test group II were decreased to varying degrees compared with the test group I.It is suggested that orange peel powder can inhibit the Acidobacteria producing TMA,regulate the structure of cecal microflora in egg quail,increase the abundance of beneficial bacteria and reduce the fixed value of harmful bacteria.(2)The effect of orange peel powder on the expression level of FMO3 gene in liver tissue of egg quail was studied by q PCR.The results showed that compared with the control group,the expression of FMO3 gene in liver tissue of laying quails in group I was significantly increased(P<0.05),There was no significant change in the expression of group II(P>0.05).The results showed that the expression of FMO3 gene may be related to the content of TMA in vivo.Orange peel powder inhibited the bacteria that produced TMA,reduced the content of TMA in vivo,and reduced the activity of FMO3 enzyme,resulting in the decrease of FMO3 gene expression.In conclusion,this study screened orange peel powder from several different medicinal and edible homologous spices,and then detected the deodorization effect and deodorization mechanism of orange peel powder on algal-DHA-enriched quail eggs.It was found that orange peel powder could inhibit the abundance of TMA-producing Acidobacteria,regulate the cecal flora structure of laying quails,and increase the abundance of beneficial bacteria such as Lactobacillus and Halospora.The content of TMA in egg yolk was reduced,and the fishy smell of algal-DHA-enriched quail eggs was reduced,but the content of DHA in egg yolk was not adversely affected.Studies have shown that orange peel powder has a good deodorization effect on algal-DHA-enriched quail eggs,and can be used to produce low fishy odour algal-DHA-enriched quail eggs.It provides a certain theoretical basis and scientific basis for the research and promotion of orange peel powder in the production of low fishy odour algal-DHA-enriched quail eggs,and also lays a certain foundation for the application of orange peel powder in other poultry.