韭菜挥发油主要成份的气相色谱／质谱分析

韭菜是我国最常见的蔬菜之一，有特别的嗅味和很高的药用价值，本文用气相色谱和质谱联用的方法分析了韭菜挥发油中的主要成份，检出了二甲基二硫醚，甲基丙烯基二硫醚和二丙烯基三硫醚等２３种化合物。     

Determination of chlorfenapyr in leek grown under greenhouse conditions with GC-μECD and confirmation by mass spectrometry

A simple analytical method was developed for the determination of chlorfenapyr residues in leeks grown under greenhouse conditions. Residues were extracted by salting out, analyzed by gas chromatography with microelectron-capture detection, and confirmed via gas chromatography-mass spectrometry. The calibration curves were found to be linear with correlation coefficients (r(2) ) in excess of 0.998. The limits of detection and quantification were 0.0015 and 0.005 mg kg(-1) , respectively. For validation purposes, recovery studies were carried out at low and high levels. Yield recovery rates were 87.27-89.64% with a relative standard deviation <6%. A maximum of 0.32 mg kg(-1) of chlorfenapyr residue was detected in leek sample sprayed three times at 7 day intervals until 7 days prior to harvest. The results of this study suggest that chlorfenapyr is acceptable for application in/on leeks under the recommended dosage regimen.     

Pasta Enriched with Dried and Powdered Leek: Physicochemical Properties and Changes during Cooking

Food enrichment is commonly applied to increase the pro-health and dietary value of final products. This study aimed to evaluate how green leek powder (GL) added to semolina influenced the physicochemical, sensory, and cooking characteristics of the pasta. The pasta was prepared by partially substituting semolina with 0, 1, 2, 3, 4, and 5 g/100 g of GL. Then, the pasta samples were assessed for color, cooking properties, sensory features, mechanical properties, total phenolic content (TPC), and antioxidant activity (AA). The results indicated that GL significantly decreased the lightness and increased the yellowness of cooked pasta. The total color difference between the control pasta and enriched pasta samples ranged from 2.54 to 6.89 and 5.60 to 11.06 (for uncooked and cooked pasta, respectively). The addition of GL also caused an increase in the optimal cooking time and cooking loss. Moreover, a significant increase in stretching force was observed in cooked pasta. Sensory evaluation revealed that substitution of semolina with up to 2 g/100 g GL did not affect the smell, taste, and color of pasta. Most importantly, GL-enriched pasta was characterized by higher TPC and higher AA compared to the control samples. In summary, our results recommend partial replacement of semolina by GL (up to 3 g/100 g) in pasta production.