Effect of short-term storage on phenolic content,o-diphenolase and peroxidase activities of cut yam tubers (Dioscorea sp)

The effect of short-term storage on the protein, phosphorus and phenolic content as well as peroxidase and o-diphenolase activities of cut, harvested Jamaican yam (Dioscorea sp) tubers (D rotundata. D alata and D cayenensis) was studied. There was an initial increase in the total phenolic content up to the third week of storage followed by a gradual decrease to the sixth week. Phenolic content was found to be highest in D cayenensis followed by D rotundata and D alata. The activities of peroxidase (EC 1. 11. 1. 7) and o-diphenolase (EC 1. 10.3.1) increased steadily up to the third week of storage and thereafter decreased to the fifth week. The intensity and rapidity of browning in tubers when cut, correlated very closely with the tuber o-diphenolase and phenolic content levels while the onset of rotting correlated with the peroxidase activity levels in the species studied.     

复合多功能通风管道的性能及在空调系统中的应用

详细介绍了复合多功能通风管道的各种性能,并与薄钢板通风管道作了比较,指出了其在空调系系统中的推广应用具有广阔的发展前景。     

辽宁省主栽品种马铃薯块茎和马铃薯全粉的品质分析

以辽宁省主栽的11个品种马铃薯块茎为原料,采用捣碎制泥工艺生产马铃薯颗粒全粉,测定其原料品质指标(总淀粉、蛋白质、还原糖、脂肪、粗纤维和氨基酸)和颗粒全粉功能性指标(碘蓝值、透光率、冻融稳定性、持水和持油性)。结果表明:11个马铃薯品种的淀粉含量为67.9%~73.4%,其中大西洋、919淀粉含量高,早大白和克23淀粉含量低;蛋白质含量差异较大,其中富金、尤金蛋白质含量高,中5蛋白质含量最低;还原糖含量差异也较大,BQ25和大西洋含量较低,克23还原糖含量较高;脂肪含量差异不大;大西洋粗纤维含量较低,克23粗纤维含量较高。异亮氨基酸、苯丙氨基酸+酪氨酸含量11个品种均高于世界卫生组织(WHO)的“必需氨基酸模式标准”,相对其他氨基酸,33、大西洋、夏波蒂和中5的氨基酸含量较高。11种马铃薯全粉的游离淀粉率差异不大。但是透光率差异很大,919的透光率最大,BQ25和大西洋的透光率较小。富金、克23和33的析水率较高,BQ25和大西洋析水率低。11种马铃薯全粉的持水能力为7.3~8.1 g/mL,持油能力为7.6~8.6 g/mL。     

白芨-丹皮酚包合物在化妆品中的应用研究

化妆品正在形成天然化和功能化的新趋势。“组分天然化”和“回归大自然”的呼声已成为世界化妆品工业的潮流。当今国际化妆品的品位已经由天然成分所占的比例来决定,高档化妆品无一不是以其产品化学成分含量少为荣。开发中药白芨-丹皮酚包合物作为天然功能组分不仅会有很好的化妆品市场前景,同时,还将探明白芨-丹皮酚这种纯天然保湿成膜剂和抗菌剂进一步应用于医药品、日化产品甚至食品工业等领域的应用价值。     

换气包装技术与榨菜包装的改进

本文从榨菜和榨菜的变质谈起，着重介绍了换气包装技术及其工业化生产的意义和榨菜包装的改进。     

Changes of polysaccharide content and texture of potato during French fries production

The purpose of the present study was to determine the changes in non-starch polysaccharide and lignin contents of potato during French fries production and also the relationship between the texture of the finished product and half-products, as a result of processing at each stage under investigation. The samples for laboratory studies were taken from potato tubers, strips and French fries collected from nine locations of a technological line. The greatest changes in non-starch polysaccharide content and texture of potatoes resulted from blanching and frying. The texture of French fries was mainly affected by pectin and cellulose. The texture of French fries can be predicted from the measurements of the texture of potato strips after blanching.     

N,N′-alkylated Imidazolium-Derivatives Act as Quorum-Sensing Inhibitors Targeting the Pectobacterium atrosepticum-Induced Symptoms on Potato Tubers

Bacteria belonging to the Pectobacterium genus are the causative agents of the blackleg and soft-rot diseases that affect potato plants and tubers worldwide. In Pectobacterium, the expression of the virulence genes is controlled by quorum-sensing (QS) and N-acylhomoserine lactones (AHLs). In this work, we screened a chemical library of QS-inhibitors (QSIs) and AHL-analogs to find novel QSIs targeting the virulence of Pectobacterium. Four N,N′-bisalkylated imidazolium salts were identified as QSIs; they were active at the μM range. In potato tuber assays, two of them were able to decrease the severity of the symptoms provoked by P. atrosepticum. This work extends the range of the QSIs acting on the Pectobacterium-induced soft-rot disease.     

试论涪陵榨菜软实力的提升

涪陵榨菜属地理标志商标,是涪陵的重要软实力之一。认识涪陵榨菜的软实力,加大营销力度,提升涪陵榨菜的国际知名度,有利于推动涪陵榨菜健康与快速发展。文章从软实力的含义、涪陵榨菜硬实力和固有软实力的体现、提升涪陵榨菜软实力的途径与措施进行了论述。     

Digital imaging for evaluation of potato after-cooking darkening and its comparison with other methods

After‐cooking darkening (ACD) phenomenon occurs when potato tubers develop greyish dark colour after boiling, frying, or steaming. The pigment responsible for ACD is a complex of chlorogenic acid and iron, which is formed during cooking and oxidised during cooling. The evaluation of ACD is thus based either on the amount of chlorogenic acid in raw tubers or the greyish colour intensity on cooked tuber surfaces. This study introduced a new method, the digital imaging method, for evaluation of potato ACD. The comparison of this new method with visual evaluation and the measurement of chlorogenic acid using HPLC were also presented. The digital imaging method is based on the direct measurement of the degree of dark colour on cut tuber surfaces, expressed by pixel levels. The new method is faster, more reliable and simpler when compared with any methods presently used. It is particularly applicable to handling large sample numbers.     

高效液相色谱法测定马铃薯薯肉中类胡萝卜素

本实验研究了用高效液相色谱法测定马铃薯薯肉中叶黄素和玉米黄素.采用丙酮:石油醚(1:1,含0.1%BHT)混合液直接提取,用ZOBAX C18(4.6×250mm,5μm)色谱柱,乙腈:甲醇:二氯甲烷(75:20:5,含0.1%BHT)为流动相,进样量为5μ1,流速为1ml/min,柱温为25℃,在450nm下检测类胡萝卜素.研究结果表明,该法可以快速、准确地分离测定马铃薯薯肉中叶黄素和玉米黄素的含量,具有良好的线性(相关系数分别为0.9997和0.9987)和重复性,叶黄素和玉米黄素回收率分别达到92.87%和95.68%.而且本方法可有效防止类胡萝卜素氧化,因而非常适用于大批量样品的分析检测.