Abstract Immature Litsea mollis fruits (ILMFs) are widely used as cold appetizers and seasonings in China. The free and bound volatile components of ILMFs from five distinct regions of China were determined by gas chromatography-mass spectrometry (GC-MS) combined with headspace solid phase microextraction (SPME) in the present work. The results reveal sixty six free-form volatiles and fifty two bound-form volatiles in ILMFs and terpene hydrocarbons and oxygenated terpenes are the dominate components. In addition, sixty-seven volatile compounds are found in Litsea mollis fruit for the first time. The free α-pinene, eucalyptol, linalool, α,β-citral, geraniol and citronellal, and bound β-myrcene, α-citral, geraniol, citronellal and eugenol are the major odor contributors of ILMFs. Multivariate statistical analysis indicates that the free and bound volatiles profiles of ILMFs of Fujian and Guangxi in southern China are similar and those of Yunnan and Sichuan in southwestern China are similar. The odor profiles of all of the ILMFs are floral, fruity and herbaceous.

Abstract This study optimized using a headspace solid-phase microextraction (HS-SPME) method for extracting volatile aroma compounds, terpenoids in particular, from Litsea mollis Hemsl. immature fruit (LMIF). Gas chromatography-mass spectrometry was used to separate and identify volatile terpenoids in LMIF. The types of SPME fiber coating, salt addition, and desorption time were optimized by single factor-experiments to determine the range of extraction temperature. Built on insights from the single factor-experiments, the response surface methodology was further used to optimize the extraction temperature, extraction time, and equilibrium time of HS-SPME. The results showed that the optimal HS-SPME conditions for extracting volatile terpenoids from LMIF were: 50/30 μm of DVB/CAR/PDMS SPME fiber, 2.0 g of added sodium chloride, desorption at a temperature of 250 °C for 3 min, extraction and equilibrium temperature of 46 °C, extraction time of 36 min, and equilibrium time of 20 min. Under the above conditions, the predicted value of extraction was 66.92, while the experimental value was 65.78. The prediction value matched well with the experimental value with good repeatability. The designed model was proven to be valid, which can be applied for future extraction of aroma compounds from IMIF.

Toll-like receptor 4 (TLR4) is a cell-surface receptor that activates innate and adaptive immune responses. Recognizing a broad class of pathogen-associated molecular patterns (PAMPs), TLR4 is implicated as a receptor mediating cellular activation in response to bacterial lipopolysaccharide (LPS), a cell-wall component of gram-negative bacteria, which is the principal PAMP of TLR4. TLR4 is a candidate gene for resistance to a large number of diseases. Human models, in particular, suggest TLR4 to be a candidate gene associated with resistance to sepsis, immunodeficiencies, atherosclerosis and asthma. In this study the bovine TLR4 mRNA and genomic DNA were sequenced and their gene structures were determined through alignment of the genomic DNA sequence to the mRNA sequence. Its mRNA sequence consisted of a 2526-bp open reading frame (ORF) flanked by a 470-bp 5'-untranslated region (UTR) and a 743-bp 3'-UTR; and its genomic DNA is 11,013-bp in length and includes the three exons and two introns. Thirty-one single nucleotide polymorphisms (SNPs) were detected by sequencing polymerase chain reaction (PCR) products from 15 cattle, consisting of five randomly selected individuals from Chinese Simmental, Holstein and Sanhe cattle breeds each. Sixteen of these SNPs were in coding regions (cSNP). However, the 3'-untranslated region was comparatively conservative and no SNP was found in it. The SNP (g.8664C>T) found in the Toll IL-1 receptor (TIR) domain of the bovine TLR4 gene leads to amino acid substitution from Thr (C allele) to Ile (T allele). Three hundred and ninety seven cows from Chinese Simmental, Holstein and Sanhe cattle breeds were genotyped for SNP (g.8664C>T) using the method of created restriction site PCR together with restriction fragment length polymorphism (RFLP) by Hinf I. An association study between the SNP and somatic cell score (SCS) in the three breeds showed that the SCS of individuals with a CC genotype was significantly lower than that of the TT genotype.