No abstract

Salted Otolithes ruber with 80 (±5) g weight on dry basis were dried in the blast electric oven using different temperature (20, 30, 40 and 50°C) until the humidity fell down to 0.6 from 1.23 on dry basis. Drying processes were completed between 20-48h. In this study, experiment values were compared with predicted values obtained from twenty thin layer drying theoretical/ semi-empirical/ empirical equations. Models whose coefficient of correlation (R2) values are highest were chosen to be the best models. According to this, Midillis Model was defined as the most suitable model in which predicted value is closest to experimental data for 20°C level, Weibulls model was for 30°C level, Weibull distributions model was for 40°C level and Alibas model was for 50°C level.

The article mainly investigated the effect of modified atmosphere packaging (MAP) on quality characters of sturgeon caviar during storage at 0 °C . MAP tested included MAP1 (100%CO2), MAP2 (70%CO2+30%N2), MAP3 (50%CO2+50%N2), MAP4 (30%CO2+70%N2) and MAP5 (100%N2). In order to let gas mixture interact with caver samples, the caviar directly exposed to modified atmosphere in MAP groups, and the control group (AIR) is prepackaged in tins and maintained in the air. Color properties, biochemical analyses (the volatile basic nitrogen values (TVB-N), the thiobarbituric acid values (TBA )) of sturgeon caviar were recorded before packaging (day 0) and after 1, 3 and 5 months of storage. The results showed that the MAP treatments in the study may delay the protein deterioration to some extend and MAP4 group exposed a little advantage to L*. but MAP treatments didn’t show an positive effects on the a*, b*and TBA.

The flame atomic absorption method was applied to determine aluminum in jellyfish. The optimum detecting conditions were determined through many experiments. It established a nitric oxide-acetylene flame atomic absorption method to detect aluminum content in jellyfish that a good linear relationship is obtained in concentration range and correlation coefficient r2=0.9996. There are no significant differences in results after jellyfish samples were digested by three pretreatment methods. The detection limit of this method is 3.5 mg/L, the relative standard deviations are less than 5%, and the recovery is in the range of 88.50~104.20%. The test shows that: both the precision and accuracy accord with the demands, so this instrument analytical method could apply to research on quantitative detection of aluminum in jellyfish.

To make sure the abundance of Tilapias blood resources in China can be utilized more scientificly and effectively, the extraction conditions of heme from Tilapias blood by enzymatic hydrolysis were studied in this paper. The optimal hydrolysis conditions of protamex have been fixed by the single factor and the orthogonal experiments: The optimum temperature of 40°C, optimum pH of 8.0, substrate concentration (S) was 6%, enzyme/substrate (E/S) was 8000U/g, hydrolysis time (T) was 2 hours. Followed by the heat treatment, acid precipitation and vacuum freeze drying could get the heme at last, which yield was 80.9%, purity was 28.2%. This technology is simple and practical, low production cost and suitable for industrialized production, which is not only reduce environmental pollution, but also increase the economic efficiency of enterprises effectively. This research could provide theoretical evidence for making the best use of Tilapias blood resources.