基于Sobel算子的金相图边缘提取新算法

针对传统Sobel算法存在定位不精确、提取边缘不连续等不足,提出在传统Sobel算子模板基础上增加了45°和135°两个模板,提高了边缘定位的精度;采用局部梯度均值作为阈值对梯度图像进行局部梯度筛选,然后进行边缘提取及细化。实验证明,算法获取的图像边缘与传统Sobel算法相比,具有定位准确、边缘连续性好、噪声少等优点,在金相图片处理中有一定的实用性。     

SEPARATION OF TOCOPHEROLS AND TOCOTRIENOLS FROM PALM FATTY ACID DISTILLATE USING HYDROLYSIS-NEUTRALIZATION-ADSORPTION CHROMATOGRAPHY METHOD

Vitamin E from palm fatty acid distillate (PFAD) was concentrated in this study by removing the extraneous matters, especially free fatty acids (FFA) and acylglycerols. Original PFAD used in this study contained 85 and 13.7% of FFA and acylglycerols, respectively. Acylglycerols in PFAD were first hydrolyzed using commercially available immobilized Candida antarctica lipase at 60C for 6 h. The fatty acids liberated, together with the existing FFA were then removed by neutralization. Hydrolysis followed by neutralization step concentrated vitamin E from an initial amount of 0.37 to 4.32%. Hydrolysis was an important step as without hydrolysis, neutralization could only concentrate vitamin E to 1.80%. Oil extracted from hydrolyzed and neutralized PFAD was then subjected to a normal-phase silica adsorption chromatography. The column was first eluted with hexane followed by isopropanol. A large amount of acylglycerols was removed during the first elution, while vitamin E was desorbed by isopropanol, with a recovery of >90%. Vitamin E concentration after hydrolysis, neutralization and adsorption chromatography was 15.2%. The method described in this study offers an alternative for the existing separation methods. It could be applied as one of a series of steps in producing high-purity vitamin E concentrates.     

EFFECT OF DEGUMMING PROCESS ON CHROMATOGRAPHIC SEPARATION OF CAROTENES FROM CRUDE AND DEGUMMED PALM OIL

Carotene from crude palm oil (CPO) and degummed palm oil (DPO) was separated using synthetic polymer adsorption chromatography. Diaion HP-20 adsorbent was used for reverse-phase chromatography and column temperature was kept at 50C. Both 2-propanol and n-hexane were used as the first and the second eluting solvents, respectively. Phosphoric acid was used to remove the minor components in CPO in the degumming process. The turbidity of DPO was lower than that of CPO and the retention time in the column for DPO was shorter (21.3 min) compared to CPO (29 min) due to the removal of the minor components by phosphoric acid. Degumming process caused a reduction of 1.67 mg of total carotene content and 55.67 ppm of carotene concentration in CPO. This is probably due to the removal of carotenoids during the degumming process. After column chromatography, carotene recovery for CPO was 30.23% and 54.82% for the first and second fractions, respectively. On the other hand, carotene recovery for DPO was 33.91% for the first fraction and 46.25% for the second fraction. This indicated that the separation of carotene in CPO was more efficient than DPO in the column chromatography due to the longer retention time in the column.     

QUALITY ASSESSMENT OF FARMED BLACK TIGER SHRIMP (PENAEUS MONODON) IN SUPPLY CHAIN: ORGANOLEPTIC EVALUATION

Organoleptic quality of the farmed shrimp ( Penaeus monodon ) throughout the supply chain was investigated under two conditions – normal practices using no ice and under experimental conditions using ice at the ratio of 1:1 (ice : shrimp). Overall, organoleptic acceptability score ranged between highly acceptable and moderately acceptable (shrimp farm  =  8.8, depot  =  5.47, commission agent  =  6.67 and processing plant  =  6.33 in a scale of 10) for shrimp under normal practices and a relatively better score and quality of shrimp under experimental conditions as judged by the organoleptic evaluation. The overall organoleptic score between the two experiments did not differ significantly ( P ≤  0.05).

PRACTICAL APPLICATIONS

From the moment the shrimp is caught, the deterioration process starts and its quality is affected. The most frequent problem is temperature fluctuation in raw materials due to (1) mishandling after harvest, (2) lengthy transportation times to processing plants or (3) manual processing where shrimp are kept for several hours waiting under each stakeholder supply chain. These result in uncertainty of the shelf life and lower quality products. A score sheet is prepared based on well-defined characteristic changes (appearance, flavor, odor and texture) that occur in the deteriorative process of shrimp. Demerit points are assigned to attributes and the resulting scores prescribe overall acceptable quality. Considering food safety, organoleptic evaluation is one of the most often used simple methods for assessing freshness and quality in the fish and shrimp inspection services, and routinely applicable on all levels of marketing from harvesting to the processing plants.     

单边荷载预应力巨型框架结构设计与施工

石景山庄室内游泳池扩建工程为珠海市石景山庄的附属配套工程。本工程三面环山,一面临水,风景优美,临水面1侧为达到最佳视觉效果,设置1榀跨度40m的预应力巨型框架,梁顶标高为7．60m。屋盖平面呈弧形,其结构布置如图1所示。在巨型框架的内侧布置12根次梁,其中8根跨度12．6～15．0m的预应力次梁,梁顶标高为7．10m。