Study on Extraction of Effective Aroma Components from Formula Tobacco by the Supercritical CO2 Extraction Method and Its Aroma Composition

[Objectives]This study was conducted to improve the sensory quality and industrial availability of tobacco extracts.[Methods]The L9(34)design was adopted to carried out an extraction experiment,in which formula tobacco was extracted using supercritical CO2,and the extract was concentrated by vacuum distillation.Through sensory evaluation and chemical analysis,the function determination and chemical composition analysis of the tobacco extracts were carried out,and the optimal supercritical fluid extraction process was finally determined.[Results]The obtained optimal supercritical fluid extraction conditions were as follows:extraction temperature 55℃,extraction pressure 25 MPa,CO2 flow rate of 20 L/h,and entrainer of 95%ethanol.The tobacco extract obtained under the optimal conditions endowed the cigarettes with full and delicate aroma,less irritation and clean aftertaste and made the flavor of the cigarettes overall coordinated and softer,so the sensory quality was significantly improved.[Conclusions]The tobacco extract obtained by the supercritical CO2 extraction method from formula tobacco can effectively improve the quality of cigarettes.

Noninvasive Quantitative Detection Methods of Liver Fat Content in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease(NAFLD)ranges from simple steatosis to NAFLD-related liver cirrhosis and is a main cause of chronic liver diseases.Patients with nonalcoholic steatohe-patitis and fibrosis are at a great risk of the progression to cirrhosis or hepatocellular carcinoma,both of which are tightly associated with liver-related mortality.Liver biopsy is still the gold standard for the diagnosis of NAFLD,but some defects,such as serious complications,sampling error and variability in histologic evaluation among pathologists,remain problematic.Therefore,noninvasive,repeatable and accurate diagnostic methods are urgently needed.Ultrasonography is a well-established and lower-cost imaging technique for the diagnosis of hepatic steatosis,especially suitable for population census,but limited by its low sensitivity to diagnose mild steatosis and being highly operator-dependent.Computed tomography also lacks the sensitivity to detect mild steatosis and small changes in fat content,and presents a potential radiation hazard.Controlled attenuation parameter based on the FibroScan?technology is a promising tool for noninvasive semiquantita-tive assessment of liver fat content,but the accuracy rate de-pends on the operator's expertise and is affected by age,width of the intercostal space,skin capsular distance and body mass index.Magnetic resonance imaging and magnetic resonance spectroscopy are regarded as the most accurate quantitative methods for measuring liver fat content in clinical practice,especially for longitudinal follow up of NAFLD patients.In this review,we mainly introduce the current imaging methods that are in use for evaluation of liver fat content and we discuss the advantages and disadvantages of each method.

The Genetics of Clinical Liver Diseases: Insight into the TM6SF2 E167K Variant

The transmembrane 6 superfamily member 2(TM6SF2)gene E167K variant(rs58542926)was identified by exome-wide as-sociation study as a nonsynonymous single nucleotide poly-morphism associated with nonalcoholic fatty liver disease.The TM6SF2 E167K variant features a C-to-T substitution at nucleotide 499,encoding a glutamate with lysine change at codon 167(E167K).TM6SF2 is markedly expressed in the liver,small intestine and kidney,and has been proposed as an im-portant risk factor for diseases associated with lipid metabo-lism.Subsequently,multifunctional studies of the TM6SF2 E167K variant have been carried out in a spectrum of liver dis-eases,such as nonalcoholic fatty liver disease,nonalcoholic steatohepatitis,fibrosis,cirrhosis,and viral hepatitis.This re-view summarizes the research status of the TM6SF2 E167K variant in different liver diseases and specific populations,and discusses the potential mechanisms of the TM6SF2 E167K var-iant's role in the progression of various liver diseases.