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The aim of this study was to investigate the shelf-life and microbial community dynamics of super-chilled vacuum-packaged beef striploins imported from Australia to China after approximately five weeks of shipping time and an additional 15 weeks of storage at −1 °C ± 0.5 °C. Data analysis using a mixed model (REML) with time as the fixed effect and portion as a random effect, showed that the only beef quality trait that changed during storage was total volatile basic nitrogen (TVBN; P <.05), which reached the threshold of 15 mg/100 g between 15 and 20 weeks (including 5 weeks of transport). The total viable count (TVC) accounted for 78% of the variance in TVBN, when storage time was included in the model. Sensory scores decreased as storage time extended (P <.05), but were still acceptable at 20 weeks. After 9 weeks, Carnobacterium spp. and Lactobacillus spp. dominated alternately and then Lactobacillus became the most prevalent bacteria. An operational taxominc unit based hierarchical cluster analysis using the unweighted pair-group method with arithmetic means was performed and it was shown that the bacterial communities tended to be consistent as storage time extended. Overall indications are that beef which is safe can be imported into China from Australia and aged for extended periods. Unlabelled Image • Shelf-life of beef cuts imported from Australia to China was evaluated based on TVBN. • TVC accounted for 78% of the variance in TVBN during the storage of beef up to 20 weeks. • The sensory scores decreased as time extended, but were still acceptable at 20 weeks. • Carnobacterium spp. and Lactobacillus spp. dominated alternately after 9 weeks. • Lactobacillus became the most prevalent bacteria in the end of the storage. [ABSTRACT FROM AUTHOR]

Nucleic acid constituents are the main functional ingredients in edible fungi, therefore understanding the nucleic acid constituents of edible fungi often eaten on the table by the Chinese people is of significant value. In this study, Sichuan Provincial Center for Disease Control and Prevention collected 147 samples of edible fungi (including certain species that the Chinese often eat) from different parts of the Sichuan Basin. A new UPLC-QqQ/MS method has been developed to determine the 17 nucleic acid constituents in these 147 samples, including guanosine, adenosine, uridine, cytidine, inosine, thymidine, xanthosine dehydrate, 2′-deoxyguanosine, 2′-deoxyadenosine, 2′-deoxyuridine, 2′-deoxycytidine, 2′-deoxyinosine, guanosine 5′-monophosphate, adenosine 5′-monophosphate, uridine 5′-monophosphate, cytidine 5′-monophosphate, and inosine 5′-monophosphate. Finally, similarity assessment of the main edible fungus was performed using vectorial angle cosine method, and hierarchical cluster analysis was used to classify all the 147 samples. The results showed that some edible fungi have high similarities, especially in Lentinula edodes (Berk.) Pegler, the monogenic nucleotides content of which (55.84 ± 8.4 mg/100 g) is far greater than any other edible fungus, which is directly related to its taste. For quality control, this paper proposed to use the reference values of total nucleic acid compounds in edible fungi computed by percentile threshold method. This is the first time a comprehensive evaluation of nucleic acid constituents of different edible fungi of daily consumption was conducted for a large region, and the results is conducive to the quality evaluation and quality control of edible fungus. Unlabelled Image • Developed a new UPLC-/MS method for the determination of 17 nucleic acid constituents • The similarity was assessed by vectorial angle cosine and hierarchical cluster analysis. • The reference values of total nucleic acids in each species computed by percentile threshold method. • Can be applied for quality evaluation and quality control of edible fungus [ABSTRACT FROM AUTHOR]

Dianhong teas produced from fresh leaves of different tea cultivars (YK is Yunkang No. 10, XY is Xueya 100, CY is Changyebaihao, SS is Shishengmiao), were compared in terms of volatile compounds and descriptive sensory analysis. A total of 73 volatile compounds in 16 tea samples were tentatively identified. YK, XY, CY, and SS contained 55, 53, 49, and 51 volatile compounds, respectively. Partial least squares–discriminant analysis (PLS-DA) and hierarchical cluster analysis (HCA) were used to classify the samples, and 40 key components were selected based on variable importance in the projection. Moreover, 11 flavor attributes, namely, floral, fruity, grass/green, woody, sweet, roasty, caramel, mellow and thick, bitter, astringent, and sweet aftertaste were identified through descriptive sensory analysis (DSA). In generally, innate differences among the tea varieties significantly affected the intensities of most of the key sensory attributes of Dianhong teas possibly because of the different amounts of aroma-active and taste components in Dianhong teas. [ABSTRACT FROM AUTHOR]

• Metabolic profiles of Caoxian white and green asparagus were studied. • 114 compounds have been tentatively identified by MS/MS fragmentation pattern. • 43 of these compounds were characterized for the first time in asparagus. • PCA and HCA showed 9 metabolites decisive to discriminate these asparagus samples. China is the largest planting country of asparagus (Asparagus officinalis L.) in the world. Caoxian, as the famous asparagus township in China, enjoys a reputation for producing asparagus with high yield and good quality, due to its unique geological characteristic. In this study, a method of reverse-phase ultraperformance liquid chromatography coupled with electrospray tandem mass spectrometry (RP-UPLC-ESI-MS/MS) was established for profiling metabolites from three segments (tip, mid, and base) of 'Caoxian white and green Asparagus'. A total of 114 metabolites were identified, among them, 43 were found for the first time in this vegetable. Principal component analysis (PCA) and hierarchical cluster analysis (HCA) was applied to provide an overview of the metabolite profiles of Caoxian asparagus and to separate different segments of spears. The variables most decisive to discriminate among segments included 9 of the metabolites tentatively identified. This study will help to improve the protection of Caoxian asparagus geographical indication. [ABSTRACT FROM AUTHOR]