Exploration Of Barked Pingou Hazelnut Volatile Composition And Preparation Of Essence Process By Enzymatic Hydrolysis

Hazel is one of the most important woody fuel in China.Pingou hazelnut is hybridization between ping hazel(C.heterophylla Fisch)from China and Europe hazel(C.avellana L).Pingou hazel can resist cold environment,large nuts,the characteristics of high yield,high kernel,so it is developing rapidly in our country.Baking is an important effects in hazelnut oil fragrance,it makes peculiar flavor in hazelnut.Roasting which is produce the characteristic aroma substances not only as an important quality index of the hazelnut but also can be used as a biological safety marks in roasting process.It is used for risk assessment and quality control,through objective and measurable indicators to properly monitor the baking processing,it could adjust the sensory properties of product.In the current research of the hazelnut is mainly concentrated on Europe hazelnut.However Pingou hazelnut and Ping hazelnut have better smell than Europe hazelnut and typical characteristic aroma component in Pingou hazelnut.This research use high quality of Pingou hazelnut as the test materials,combineing with a variety of volatile aroma composition detection and analysis technique to analysis characteristics of aroma component in Pingou hazelnut.Then to find out the rule and inherent aroma component in Pingou hazelnut.To provide theory for perfection and criterion in our roasted hazelnut industrial.HS-SPME-GC-MS is used in this paper to collection,detection.quantitative analysis Pingou hazelnut aroma component and to make quantitative and qualitative analyse,principal component analysis(pca)is used to analysis determine the composition of the volatile components of the aroma and its contribution rate.Using amino acid analyzer and titration,respectively,to determine the baking process of amino acid and sugar consumption quantity and variety and simulate the Maillard reaction and oxidation experiments.Use the alkaline protease enzyme hydrolysis and flavor to the hazelnut meal.The hydrolysate is simulated by Maillard reaction,and through the HS SPME-GC-MS to analysis product.1.Using HS-SPME-GC-MS technology,according to the analysised volatile components peak area to insure the needle extraction efficiency,the optimum extraction conditions are:extraction temperature 60?,extraction time 30min,hold time 3.5min.2.Utilizes the optimum extraction conditions to analysis quantitative and qualitative of volatile components of raw Pingou hazelnut,N0.1 Pingou hazelnut,NO.2 Pingou hazelnut and NO.3 Pingou hazelnut by HS-SPME-GC-MS.The detection display that there are a few of volatile components in raw Pingou hazelnut and the characteristic aroma component pyrazine is detected in different barked Pingou hazelnut.Volatile components kinds and amount increased with the increase of roasting degree and paste Pingou hazelnut has the most aroma component.3.By calculating the OAV values and literature search,determine 11 kinds of aroma components during barking Pingou hazelnut,they are methyl pyrazine;2,5-dimethylpyrazine;3-ethyl-2,5-dimethyl-pyrazine;2-ethyl-3,5-dimethyl-pyrazine;hyacinthin;2,4-decadienal-fufur al;5-dimethyl-4-hydroxy-3-furan-ketone;2-ethylhexanol;maltol;2,3-dihydro-3,5-2-6-methyl-4 h-pyran-4-ketone.Through principal component analysis(pca),11 kinds of aroma compenents can be divided into two principal components and F value can be calculated to compare which the barked Pingou hazelnut aroma component is best.4.Using amino acid analyzer to analysis the change of free amino acid in Pingou hazelnut barked by microwave oven,the results show that Pingou hazelnut in barking process involved in maillard reaction to make aroma components is arginine,glutamic,alanine,valine,leucine and isoleulcine.5.The determination of soluble sugar by adopting the method of national standard second(titration),in the process of barking Pingou hazelnut is consumption of sugar,sugar does not directly involved in maillard reaction,hydrolysate glucose and fructose are involved in maillard reaction.6.Using the above six kinds of amino acid and two kinds of monosaccharide respectively through maillard reaction products putting into raw hazelnut oil,under the conditions of 40 ? and measuring the change of oil peroxide value.Results showed that the glucose and amino acid of maillard reaction products of oxidation resistance is superior to the combination of fructose and amino acid.In 20d,the glucose and leucine system of maillard reaction products of antioxidant is the best.At the same time,this simulation system to detect the most aldehyde and pyrazine compounds.7.By calculating the degree of hydrolysis and soluble nitrogen content on the alkaline protease and flavor enzyme hydrolysis hazelnut protein.When the concentration is 3%,the best hydrolysis conditions is the alkaline protease hydrolysis temperature is 55 ? hydrolysis time is 2.5hours,hydrolysis pH is 10.0,enzyme adding amount is 3%;flavor enzyme hydrolysis temperature is 48?,hydrolysis time is 4 hours,hydrolysis pH is 6.3,enzyme adding amount is 3%.Finally under the two kinds of enzymes,hazelnut meal enzymolysis liquid degree of hydrolysis is 28.93%.8.Add 1g glucose and fructose in hazelnut meal enzymolysis liquid,under the condition of 120? oil bath pot reaction 2 hours and volatile components production is extracted and analysised by HS-SPME-GC-MS.Simulation system detected 30 kinds of violate components,and 13 kinds of components are also detected in barked Pingou hazelnut which account for 43.44%of total violate components.