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  • Author: Li Gao x
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Open access

Dadji Stéphane Serge Bonny, Xin Li, Zheng Li, Meng Li, Manting Du, Lingling Gao and Dequan Zhang

Abstract

The objective of this study was to investigate the colour stability and lipid oxidation of beef under different packaging methods. The muscles longissimus lumborum were randomly packed in vacuum or modified atmosphere packaging (MAP, 80% O2, 20% CO2). Both packages were aged at 4°C for 7, 14 and 21 days. After each ageing time, samples were displayed in a refrigerator for 2, 4 and 6 days. Colour stability, lipid oxidation and their correlation were determined. Beef under vacuum packaging showed higher a* values on 7, 14, and 21 days of ageing and lower L* values on 14 and 21 days of ageing than beef in MAP (p<0.05). Lower a* values were observed in the samples packed in MAP, then displayed compared to samples packed in vacuum, then displayed after 21 days of ageing time on day 2, 4 and 6 of the display period (p<0.05). Thiobarbituric acid reactive substances (TBARS) increased significantly in MAP compared to vacuum during 7, 14, and 21 days of ageing (p<0.05). An increase of TBARS was also observed during display after 14 and 21 days of ageing in samples packed in MAP, then displayed. Furthermore, a significant difference (p<0.05) was observed between samples packed in MAP and vacuum in peroxide value on 14 days of ageing. Lipid oxidation was observed mainly in the samples packed in MAP compared to vacuum, and positively correlated with results on colour stability.

Open access

Qianqian Song, Wei Zhang, Fen Wu, Ningying Xu, Jinzhi Zhang, Mingshu Xu, Haihong Li, Zhujun Han and Haixia Gao

Abstract

The coding sequences (CDS) of TFAM and TFB2M genes from Jiaxing Black Pig (JBP) were first time obtained by RT-PCR and DNA-seq in the present study. Sequence analyses showed that the TFAM gene contains a 741-bp CDS region encoding 246 amino acids sharing a 100% homology with the sequence on NCBI, while TFB2M gene contains a CDS region of 1176 bp encoding 391 amino acids with two missense mutations. The results of quantitative Real-Time PCR for TFAM and TFB2M revealed that transcripts of the genes were both presented at highest levels in spleen tissue followed by liver tissue, while least levels in longissimus dorsi muscle (LDM), and obviously higher levels in two adipose tissues than those in LDM tissue(P<0.01). Meantime, a total of forty-two JBPs were employed in this experiment to investigate the effect of these two genes on the carcass, meat quality traits and flavor substances such as fatty acids, intramuscular fat (IMF) in LDM. With expectation, some strong correlations of gene expression abundance of TFAM and TFB2M mRNA in particular tissues such as liver and LDM with carcass and meat quality traits including marbling score, as well as the content of saturated fatty acid (SFA), in JBP were found.

Open access

Yong Zhang, S. G. Zhang, L.W. Qi, B. Liu, J. M. Gao, C. B. Chen, X. L. Li and Wenqin Song

Abstract

The chromosome microdissection, cloning and painting technology has evolved into an efficient tool for genomic research. Application of these techniques has rarely been applied for forest plants, largely due to the difficulty of chromosome preparation. The present study was performed to establish a method for single chromosome microdissection, cloning and painting in forest plants using poplar (Populus tremula) as a model. An individual chromosome 1 was microdissected from the metaphase spreads of poplar root-tip cells with fine glass needle controlled by a micromanipulator. The dissected chromosome was amplified in vitro by the Sau3A linker adaptor mediated PCR (LA-PCR) technique, by which 200bp to 3,000bp smear DNA fragments were obtained. Then, the second round PCR products from the single chromosome 1 were cloned into T-easy vectors to generate a DNA library of the chromosome 1. Approximately 3 x 105 recombinant clones were obtained. The second round PCR products were used as a complex probe mixture for fluorescent in situ hybridization (FISH) on the metaphase spreads of poplar. Hybridization signals were observed, mainly, along the entire chromosome 1, at the same time, signals were also present on telomeric and centromeric regions of other chromosomes. Therefore, this research suggests that chromosome microdissection, cloning and painting of the single small chromosome in forest plants are feasible.