13 kinds of amino acid were calculated by CNDO method (Complete Neglect of Differential Overlap method), and relationship analysis was done between molecular structure of amino acid and sweet taste. It was found that sweet taste was significantly related to α-H, carbonyl of amino acid and one of amino-H (P<0. 01). It was supposed that the sweet taste response was intermolecular hydrogen bonding between amino acid and taste bud receptor site. The sweet unit of amino acid was α-H, carbonyl-O and one hydrogen atom of NH3+ group. The taste bud receptor site was AH (hydrogen provider) and B (hydrogen acceptor). The strength of the hydrogen bond between H of NH3+ group and the 3rd receptor site of taste bud resolved in the intensity of sweetness.

The effects of main factors. invoving pH value, lightshine, temperature, oxygen and microbe,and the interaction between them were investigated for the stability of chlorophyll in fresh spinach juice, The results show that to remarkable character of all effect factors on stability of chlorophyll,lightshine occupies first place, microbe and oxygen come second, while pH value and temperture are not notable. The interaction between microbe and oxygen is intense, and the interaction between the other factors may be negligible.

This paper was on the preparation of alkali -insoluble glucan by the discarded brewer’s yeast autolysed beforehand. The alkali extraction method and the enzyme-alkali extraction method were carried out. The effects of the amount of NaOH and protease added, the extraction time, the concentration of NaOH on extracting glucan were studied in detail. Quantitative and qualitative analyses were carried out on the final preducts, and the results shew that 9(1 - 3) -D-glucan was the major component of the preducts.

 A study on mod population in mineral water was carried out. Colony counts of sampleswire detemined on rose-bangel agar plates incubated at 27℃ - 7166 strains was isolated and identified. Cephalosporium. Aspergillus and Cladosporium were these genus found most frequentiy in both tyPe of samples, and others of 24 genus were isolated less frequently. Although these mold has sometimes been isolated from polluted springs, but products were usually polluted with mold from the filling-bottle process.