Study On Flavor Components Of Hunan Chopped Fermented Red Pepper And Construct Its Fingerprint

As a common pepper processing product in Hunan,chopped fermented red pepper is mainly made from Cayenne pepper or line peppe through fermentation,and is loved by consumers for its spicy and crisp taste.The flavor of chopped pepper includes both the flavor of pepper fruit and the unique flavor of fermented products,and the processing of chopped pepper is being transformed from traditional method to industrial mass production.In order to ensure the good flavor of chopped pepper products,it is important to study the characteristic flavor substances of traditional fermented chopped pepper and establish the fingerprint profile of related flavor substances.In this paper,we collected naturally chopped fermented red peppers from different regions of Hunan Province,examined the types and contents of free amino acids,organic acids and volatile substances in chopped fermented red peppers,combined with electronic nose,electronic tongue and sensory evaluation to select chopped fermented red pepper with good taste and strong aroma,and used fingerprinting technology to construct the fingerprint profiles of flavor substances and to establish the content range of characteristic flavor substances in high-quality chopped fermented red peppers.The purpose of this paper is to provide technical parameters for the establishment of flavor substance evaluation standards and flavor quality control of chopped fermented red pepper.The main results of this paper are as follows:1.Thirty-two fermented Cayenne peppers and thirty-one fermented line peppers were selected as the test samples,and the chopped pepper samples with good taste and strong aroma were screened by fuzzy mathematical sensory evaluation and electronic sensory evaluation.2.The content of 24 free amino acids in fermented chopped peppers was determined by high phase liquid chromatography(HPLC),and the characteristic free amino acids in fermented Cayenne peppers and fermented line peppers were obtained by principal component regression analysis,and the free amino acid fingerprints of high quality chopped peppers were constructed by screening chopped peppers with good taste and strong aroma by fuzzy mathematical sensory evaluation and electronic sensory technology,and the types and content range of characteristic free amino acids in chopped peppers with good taste and strong aroma were obtained.Fermented Cayenne pepper: Asp(0.3126 ± 0.0796 mg/g),Glu(0.5318 ± 0.0943mg/g),Asn(2.0553 ± 0.4391mg/g),Gln(1.1866 ± 0.2301 mg/g),His(0.1552 ±0.0318 mg/g),Arg(0.6832 ± 0.092 mg/g),Val(0.3949 ± 0.0669 mg/g),and Hyp(0.3092 ± 0.0724 mg/g).Fermentation line pepper: Asp(0.2625 ± 0.1326 mg/g),Glu(0.4167 ± 0.1806mg/g),Asn(0.7792 ± 0.2461 mg/g),Gln(0.497 ± 0.2123 mg/g),His(0.1049 ± 0.054mg/g),Arg(0.5354 ± 0.2391 mg/g),Val(0.2853 ± 0.09 mg/g),Nva(0.1054 ± 0.0345mg/g),and Pro(0.1008 ± 0.0649 mg/g).This can be used as a criterion for judging that chopped pepper with the characteristic free amino acid content within the above content range can be considered as a chopped pepper product with good taste and rich aroma.3.The content of 7 organic acids in chopped fermented red peppers was determined by HPLC,and the characteristic organic acids in fermented Cayenne peppers and fermented line peppers were obtained by using principal component analysis and orthogonal partial least-squares discriminant analysis(OPLS-DA),and the organic acid fingerprints of high quality chopped fermented red pepper with good taste and strong aroma were constructed by screening the chopped fermented red peppers with good taste and strong aroma by fuzzy mathematical sensory evaluation and electronic sensory technology:Fermented Cayenne pepper: Lactic acid(5.0685 ± 0.5646 mg/g),Citric aci d(9.5197 ± 0.7382 mg/g).Fermentation line pepper: Lactic acid(3.7033 ± 1.3028 mg/g).The organic acid content of chopped fermented red peppers within the above-mentioned content can be considered as a good tasting and aromatic chopped fermented red pepper product.4.GC-MS was used to detect the types and contents of volatile substances in chopped peppers with good taste and strong aroma selected by fuzzy mathematical sensory evaluation and electronic sensory technology,and the fingerprint profiles of volatile substances in high quality chopped peppers were constructed after using principal component analysis and two-way orthogonal partial least squares analysis(O2PLS)to identify the characteristic volatile substances in fermented Cayenne peppers and fermented line peppers:Fermented Cayenne pepper: Benzaldehyde(8.17 ± 2.55 μg/kg),N-butyl formate(0.68±0.24 μg/kg),Tetrahydrofuranol(4.27 ± 2.23 μg/kg),(E)-8-methyl-4-decene(1.61 ± 0.89 μg/kg),Isoamyl n-Valerate(2.36 ± 0.62 μg/kg),2-methoxy-3-isobutylpyrazine(6.37 ± 2.90 μg/kg),Hexyl 3-methylbutyrate(108.32±39.47 μg/kg),Ethyl nonanoate(9.21 ± 3.01 μg/kg),Heptyl 2-methylbutanoate(27.89± 7.22 μg/kg),Ethyl trans-4-decenoate(52.36 ± 25.16 μg/kg),Ethyl decanoate(45.50± 14.19 μg/kg),2,2-dimethyl-1-decanol(871.96 ± 284.32 μg/kg),2-butyrooctanol(6.47 ± 2.55 μg/kg),7-tetradecene(12.63 ± 7.21 μg/kg),β-Elemene(17.38 ± 7.05μg/kg),et al.Fermented line pepper: Isoamyl methacrylate(0.44 ± 0.26 μg/kg),Linalool(11.14 ± 4.54 μg/kg),2-methyl-1-octanol(3.11 ± 1.78 μg/kg),Phenylethanol(6.98 ±2.14 μg/kg),Octyl formate(4.54 ± 3.23 μg/kg),2-propyl-1-heptanol(3.86 ± 1.82μg/kg),γ-Pinoresinol(6.09 ± 2.71 μg/kg),Trans-2,4-undecaprenal(4.60 ± 1.93 μg/kg),2-hydroxy-5-methylacetophenone(5.76 ± 3.41 μg/kg),Capric acid(0.44 ± 0.25μg/kg),Ethyl trans-4-decenoate(9.14 ± 4.94 μg/kg),1-tetradecene(3.73 ± 1.90μg/kg),Lauryl alcohol(66.14 ± 29.51 μg/kg),Chlorambucil(6.23 ± 2.14 μg/kg),(+)-α-Bisvanols(2.16 ± 0.97 μg/ kg),Myristate(3.02 ± 1.73 μg/kg),et al.This can be used as a criterion for judging that chopped fermented red peppers with characteristic volatile substance content within the above content range can be recognized as chopped fermented red pepper products with good taste and strong aroma.