Analysis Of Flavor And Functional Substances In Lemon NFC Juice

Lemon is a kind of dicotyledonous citrus with rich aroma,bright color and rich nutrition.Lemon fruit and its processed products are deeply loved by consumers.Lemon NFC juice has shorter heating time and less loss of nutrients during processing,which can better maintain the composition and taste of fresh fruit.At present,domestic scholars have little research on lemon NFC juice.In this paper,the processing technology of lemon NFC juice was designed and optimized,and the relevant quality indicators were determined to verify.The volatile substances in lemon NFC juice were analyzed by SPME-GC-MS,and compared with the NFC juice drinks on the market.The functional components in lemon NFC juice were analyzed by HPLC-MS / MS,and the results were compared in the market Objective to further explore the improvement effect of lemon juice on oxidative damage of L-02 hepatocytes induced by high fat.The results are as follows:(1)The processing technology of lemon NFC juice was optimized as follows:pasteurization,high temperature sterilization,ultra-high pressure sterilization,high temperature and high pressure sterilization.Among the four sterilization methods,ultra-high pressure sterilization at 400 MPa was used for 6 times Two level plaktett Burman test showed that the main factors affecting the processing technology of lemon NFC juice were the addition of pectinase,enzymolysis temperature and homogenization pressure(P < 0.05),and the results showed that the addition of 0.1% cellulase,0.01%amylase,0.06% α-L-rhamnose and 0.04% α-L-rhamnose were the best The results of response surface analysis showed that pectinase dosage was 0.25%,enzymolysis temperature was 42 ℃,homogenization pressure was 26 MPa.According to the above factors,three times of validation test were repeated,and the results were significant.The sensory score was 94 ± 1,and the stability coefficient was 0.473 ± 0.231.(2)SPME-GC-MS was used to analyze the volatile substances in lemon NFC juice,and compared with four kinds of NFC juice drinks on the market.Twenty three volatile compounds were identified in lemon NFC juice.D-limonene,γ-Terpinene,α-terpineol and β-myrcene were highly positively correlated with the flavor of lemon NFC juice.Valencia limonene played an important role in NFC orange juice and NFC apple banana juice.β-caryophyllene,aromatic diene and Δ-Terpinene were closely related to the flavor of NFC guava mixed juice-Ocimene,3-carene,Terpinene,etc.were the main influencing components of NFC mango juice flavor.The amount of flavor compounds in NFC lemon juice produced by the above processing technology showed obvious advantages.(3)The main components of lemon juice were analyzed by high performance liquid chromatography-mass spectrometry(HPLC-MS / MS),and its antioxidant activity was studied at the cellular level.The results showed that the lemon juice mainly contained quinic acid,malic acid,citric acid and other organic acids,aspartic acid,serine and other amino acids,and Vitexin,naringin,polydatin and other flavonoids.The antioxidant activity test showed that lemon juice could improve the activity of SOD by promoting the synthesis of mitochondria and the expression of SOD2 protein,thus reducing the level of ROS in cells and effectively improving the oxidative damage of L-02 hepatocytes induced by high fat.