Analysis and comparison of bacterial communities in two types of ‘wheat Qu’, the starter culture of Shaoxing rice wine,using nested PCR‐DGGE

Shaoxing rice wine, manufactured in Shaoxing region of Zhejiang Province, is the best‐known Chinese rice wine. In the current study, the bacterial communities associated with two types of ‘wheat Qu’, the Shaoxing rice wine starter cultures, were identified and compared using nested PCR–denaturing gradient gel electrophoresis analysis. DNA sequencing of the highly variable V3 or V9 regions of the 16S rRNA genes obtained from PCR–DGGE fingerprints identified common species related to Saccharopolyspora hordei, S. rectivirgula, Bacillus subtilis, B. amyloliquefaciens and so on. Some sequences associated with a particular type were also identified. For example, Clavibacter michiganensis and Saccharopolyspora sp. were found in the machine‐ but not in the human‐made type, while Curtobacterium plantarum, Thermoactinomyces intermedius, T. vulqaris, B. licheniformis and Bacillus sp. were found in human‐ but not in machine‐made type of wheat Qu. The information gathered from the present research enriches the present knowledge of Shaoxing rice wine‐related bacteria, and will also facilitate the long‐term objective of selecting bacterial combinations to be used as starter cultures that will more tightly regulate the fermentation process, as well as improve the quality and safety of wheat Qu. Copyright © 2012 The Institute of Brewing & Distilling     

Solid‐phase extraction and spectrophotometric determination of Allura Red (E129) in foodstuff,soft drink,syrup and energy drink samples: a comparison study

Amberlite XAD‐7 and XAD‐8 resins were used as adsorbents for preconcentration and determination of Allura Red (AR) food dye in aqueous medium. The effects of pH, sample volume, sample and eluent flow rates on the extraction of AR were optimised. The determination of dye was performed at 506.0 nm using spectrophotometry. Interference effects of matrix ions and some dyes were also investigated under optimised conditions. The methods permitted low detection limits which were 1.2 and 0.6 μg L^?1 for XAD‐7 and XAD‐8, respectively. Adsorption behaviours were investigated by adsorption isotherms and zero charge pH experiments. Validations of the method were performed by determination of AR contents in some foodstuffs. AR contents of liquid samples were found between 58 and 440 μg mL^?1. AR concentrations of solid samples were between 416 and 432 μg g^?1. The XAD‐7 and XAD‐8 resins presented a fast and reliable potential to determine AR dye in real samples.