Time filter

Source Type

Tan G.-L.,Zhongshan Institute for Food and Drug Control | Tan G.-L.,China Institute of Metrology | Liu Y.,China Institute of Metrology | Li X.-L.,Zhongshan Torch Polytechnic | And 2 more authors.
Modern Food Science and Technology | Year: 2015

A loop-mediated isothermal amplification (LAMP) method was established to detect the presences of animal-derived ingredients in edible vegetable oils and hogwash oils. Two outer primers (F3 and B3) and two inner primers (FIP and BIP) were designed based on the mitochondrial Cytb genes of pig, cattle, chicken, and duck. The inner primers FIP/BIP, betaine, Mg2+, and other reaction parameters were optimized, and the amplified products were detected with real-time fluorescence LAMP. The specificity and sensitivity of the method were evaluated. The results showed that the optimal conditions were 0.2 µmol/L outer primers (F3 and B3), 1.6 µmol/L inner primers (FIP and BIP), 0.8 μmol/L loop primers (FLP and BLP), 1 mol/L betaine, 6 mmol/L Mg2+, 1.6 mmol/L dNTPs, and a reaction temperature of 63℃. Under the optimal conditions, the best amplification was achieved for the abovementioned four animal-derived ingredients. With this improved LAMP approach, the animal-derived ingredients in mixed oils containing 1% of animal oils and 5% of hogwash oils could be detected. This method exhibits a very high specificity and sensitivity for pig-, cattle-, chicken-, and duck-derived ingredients, can be applied in the detection of animal-derived ingredients in oils, and provides a technical support for identification of oils and hogwash oils. © 2015, South China University of Technology. All right reserved.

Lan Q.-X.,Shenzhen Academy of Metrology Quality Inspection | Chen X.-J.,Shenzhen Academy of Metrology Quality Inspection | Yan Q.-Y.,Shenzhen Academy of Metrology Quality Inspection | Chen J.,Shenzhen Academy of Metrology Quality Inspection | And 6 more authors.
Journal of Pure and Applied Microbiology | Year: 2014

A high nitrite content ginger paste was found during the 26th Universiade. This study aimed to explore the reason behind this phenomenon. Kluyvera cryocrescens and Kluyvera ascorbata were isolated from the ginger paste. Both the two strains increased steadily if the pH was 5.0, 6.0 or 7.0. Under pH 4.0 conditions, strains reduced sharply. Compared these data we can find that the best pH for K.cryocrescens propagation was pH 6.0, and as for K.ascorbata was pH 5.0. Also Kluyvera strains can grow well if the NaCl concentration weas 0.5%, 1.0% or 2.0%, they not survival if the NaCl concentration reached 5%. The ginger paste provided suitable pH and temperature for Kluyvera propagation when it was stored at 8°C. Nitrite concentration in most of ginger slices sample reached a peak value when the bacterial concentration of Kluyvera reached 108 CFU/g. In this study, it is confirmed that Kluyvera played a major role in reducing nitrate to nitrite in the ginger paste.

PubMed | Shenzhen Academy of Metrology & Quality Inspection
Type: Journal Article | Journal: Journal of AOAC International | Year: 2013

A discrimination method based on polyalcohol determination was developed for authenticity of protected geographical indication (PGI) vinegars-Shanxi extra aged vinegar (SVs) in China. Six polyalcohols in vinegars including erythritol, arabitol, xylitol, inositol, mannitol, and sorbitol were selected as the PGI discriminators. GC/MS was used to analyze the polyalcohols in the SVs, Zhenjiang vinegars (ZVs), Kazuo aged vinegars (KVs), and other non-geographical indication protected vinegars (NVs). SVs can be distinguished from KVs by the chemical markers mannitol and sorbitol, although the production processes for both types of vinegars are similar. Principal component analysis (PCA) was used to distinguish SVs from ZVs and NVs. The differences among the three kinds of vinegars shown by PCA results may be due to the higher erythritol content in SVs, and the inositol and mannitol in ZVs. This study also found that the amount of polyalcohols in Chinese vinegars increases with the acidity value only, regardless of the aging time. The overall results indicated that the polyalcohols can be practicable discriminators for SV discrimination.

Loading Shenzhen Academy of Metrology & Quality Inspection collaborators
Loading Shenzhen Academy of Metrology & Quality Inspection collaborators