Microbial transglutaminase (MTGase) has been shown to effectively induce soymilk with a certain level of solid content to form filled tofu. The gel formation of this kind of tofu and the influence of reaction parameters on the properties of formed tofu were investigated by dynamic oscillatory and/or large-strain rheological measurements. The gelation process and the development of the mechanical moduli (especially the storage modulus, G0) of this kind of tofu were highly dependent upon the incubation temperature. Textural property analysis (TPA) results showed that many TPA parameters of this kind of tofu, including gel hardness, gumminess, springiness and cohesiveness, were also affected by the applied enzyme amount, the pH of soymilk and the presence of NaCl, especially for gel hardness. In addition, the additional heating and cooling treatment could significantly improve the gel strength of tofu, induced by MTGase at lower temperatures (e.g. 25 and 37 1C). These results suggested that a new kind of tofu with good quality could be produced using the enzymatic cross-linking technique, by the combination with the thermal treatment.

Spirulina platensis was batch cultivated in a novel 3.5 l magnetic air-lift photobioreactor with external-loop on which 0–0.55 T electromagnetic field (EMF) was imposed to investigate the EMF effects on the algal growth and nutrition composition. At the same time, the correlative mechanism was discussed mainly based on C, N, P uptake. It was found that, EMF has double-side effects on S. Platens is cultivation depend on EMF intensity. 0.25 T EMF stress was found to be suitable for the algal cultivation enhancement increasing the maximum cell dry weight by 22% in a time period two days less than that of the control at 35 C and 2521mol photons m2 S1. In addition, the nutritional composition of S. platens is was improved in both essential amino acids such as histidine and trace elements Ni, Sr, Cu, Mg, Fe, Mn, Ca, Co and V. It was suggested it was possible to optimize the cultivation process of S. platens is by imposing suitable weak EMF which may enhance the nutrition assimilation e.g. C, N, P and minerals by S. platens is.

The influence of nine small organic molecules on the phosphorescence properties of cyclodextrin (CD)/1-naphthol/1,2- dibromoethane (DBE) and CD/2-naphthol/DBE ternary inclusion complexes are examined by means of room temperature phosphorescence (RTP) measurements. It was demonstrated that the rigidity of -CD/naphthol inclusion complex, RTP intensity and lifetime could be enhanced when different small organic molecules (less than 1% v/v) were added respectively; the analytical characters of two kinds of naphthols in host–guest stabilized-RTP were improved. The linear range of 1-naphthol become broad in the presence of n-propanol, methanol, ethanol or 2-propanol and its detection limitwas reduced from 4×10−6 to 7.5×10−8 mol l−1 in the presence of 0.6% (v/v) methanol. Likewise, for 2-naphthol, the detection limit was reduced from 2.0 × 10−6 to 2.8×10−7 mol l−1 and to 8.1 × 10−7 mol l−1 after 0.5% (v/v) glycol and 0.2% (v/v) 2-propanol being added, respectively.

The bioeffects of selenium on the growth of Spirulina platensis and the selenium distribution were investigated. S. platensis was batch cultured in Zarrouk medium containing increasing concentrations of sodium selenite. The biotransformation characteristic of selenium was analysed by the determination of the detailed selenium distribution forms. At 35 C, 315.2 lEm2 s1, sodium selenite concentrations below 400 mg l1 were found to stimulate algal growth, especially in the range of 0.5–40 mg l1. However, above 500 mg l1 sodium selenite was toxic to this alga with the toxicity being related to the sulfite level in the medium. S. platensis was found to resist higher selenite by reducing toxic Se(IV) to nonsoluble Se(0). Selenium was accumulated efficiently in S. platensis during cultivation with accumulated selenium increasing with selenite concentration in the medium. It was demonstrated that inorganic selenite could be transformed into organic forms through binding with protein, lipids and polysaccharides and other cell components. The organic selenium accounted for 85.1% of the total accumulated selenium and was comprised of 25.2% water-soluble protein-bound, 10.6% lipids-bound and 2.1% polysaccharides-bound selenium. Among the organic fractions lipid possessed the strongest ability to accumulate Se (6.47 mg kg1). The 14.9% inorganic selenium in S. platensis was composed of Se(IV) (13.7%) and Se(VI) (1.2%).