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Two winter wheat cultivars with different drought tolerance were selected to investigate the effects of source-sink regulation on the vegetative organs water soluble carbohydrates (WSC) content and 1000-grain mass (TGM) of wheat under drought stress (DS) and well watered (WW) conditions. Sink-cutting increased the WSC content of different vegetative organs significantly, and promoted the relative transportation of the WSC positively; while source-cutting caused opposite responses. The effects of source-sink regulation on the WSC content and its relative transportation amount (TA) and transportation rate (TR) were significantly higher under DS and sink-cutting than under WW and source-cutting, for drought-resistant cultivar (Longjian 19) than for drought-sensitive Q9086, and for peduncle internode and PedI than for penultimate internode and PenI. Under source-cutting, the superior organs of Longjian 19 in the TR of total WSC were sheath, PedI, and PenI, which also contributed to the fructan TR of the two cultivars, while those of Q9086 were the PenI and the third internode from top (ThiI). Source-cutting decreased the TGM of Longjian 19 and Q9086 significantly, with the decrement being 27.3% and 31.7% under DS and 25.3% and 12.1% under WW, respectively. The correlation coefficients of the WSC content and its TA and TR and the TGM were significantly higher under sink-cutting than under source-cutting, and also, under DS than under WW. There existed a higher correlation coefficient (r2 > 0.900) of the TGM and the total WSC and fructan contents in different vegetative organs. The vegetative organs with closer correlation between their WSC content and its TA and TR and the TGM were mainly sheath and PedI. Under DS, the traits associated with the total WSC content had a higher correlation with TGM; under WW, the traits associated with sucrose and glucan contents generally showed a higher correlation with TGM. It was suggested that the effects of source-sink regulation on the WSC content of vegetative organs and the TGM were significantly affected by soil water environment, wheat genotype, and vegetative organs location.

Objective: The HPAEC-PAD method for polydextrose determination was developed based on AOAC 2000.11., Methods: This method included water extraction, centrifugal ultrafiltration, mulienzyme hydrolysis, and anion exchange chromatography detection. The polydextrose was elated by a gradient program of 0.15 mol/L NaOH and 0.5mol/L sodium acetate in 0.15 mol/L NaOH on a CarboPAC TM PA 1 column, then detected by a gold electrode with pulse amperometric detection mold. The inject volume was 20 microl., Results: The LOD and LOQ of this method were 1.69 microg/g, 5.47 microg/g, respectively. The repeatability and reproducibility were excellent, ranging from 2.10% to 6.62%. The average recovery of polydextrose in various food matrix were 92.4%-104.4%., Conclusion: This method could be used for polydextrose determination in foods.

Truffles, which belong to ascomycetes, are rare wild growing edible mushrooms; their fruit body contains high nutritive value composition, and their polysaccharide constituents have potential medical applications. In the present paper, Fourier transform infrared (FTIR) spectroscopy was used for obtaining vibrational spectra of mushrooms of truffles growing in mountains of Yunnan province, southwest China. The results show that the mushrooms exhibit characteristic spectra. The two strongest absorption bands appear at about 1 077 and 1 042 cm(-1), respectively. The spectra exhibit complicated patterns between 1200 and 750 cm(-1), which may be used as fingerprints to discriminate different species of truffles. Great changes were also found between mold and healthy truffles, showing major differences observed in the bands of protein. In addition, some vibrational-spectrum differences were observed among the same species of truffles from different growing areas. It is showed that FTIR can provide valuable information about the chemical constituents of intact truffles prior to any extraction method is used.

Carboxymethyl pachyman gives a red color when treated with phenol and concentrated sulfuric acid. The reaction is sensitive and the color is stable. Based on this reaction, a colorimetric method has been developed to analyse carboxymethyl pachyman, and some factors that affect the determination were discussed.