近红外光谱法快速鉴别涪陵榨菜品牌的研究

提出了一种基于近红外漫反射光谱技术快速鉴别涪陵榨菜品牌的方法。应用近红外漫反射光谱技术对市场上6种典型品牌涪陵榨菜提取光谱,并对获得的原始光谱数据进行平滑、一阶导数以及矢量归一化等预处理后,采用因子法计算样品间的光谱距离,通过ward’salgorithm方法进行聚类分析。并与判别分析的实验结果进行了对比,结果显示聚类分析和判别分析对6种涪陵榨菜品牌均能很好地鉴别。     

Variation in glycoalkaloid concentration of potato tubers harvested from mature plants

Individual tubers from mature plants of cultivars Pentland Dell and Estima were harvested from experimental plots in two successive years and analysed for α‐solanine, α‐chaconine and total glycoalkaloid concentration (α‐solanine and α‐chaconine combined) using high‐performance liquid chromatography. Mean tuber glycoalkaloid concentration per plant was strongly affected by genotype and was much higher in plants of Pentland Dell (10.0 and 16.3 mg per 100 g fresh weight in 1994 and 1995, respectively) than Estima (4.0 and 4.3 mg per 100 g fresh weight in 1994 and 1995, respectively). The variation between plants in mean tuber glycoalkaloid concentration, expressed as coefficient of variation, was similar for the two cultivars in both years. Variation within plants was higher for cultivar Pentland Dell than Estima for both years but it was statistically significant only in 1995. Tuber position within a plant had no effect on glycoalkaloid concentrations in tubers of similar size. An inverse relationship between total glycoalkaloid concentration and tuber fresh weight of individual tubers was found for both cultivars and small tubers of Pentland Dell (20–40 g fresh weight) exceeded the safety limit of 20 mg per 100 g fresh weight. The pattern of glycoalkaloid accumulation differed between genotypes and appeared related to tuber growth. The implications of these results in terms of food safety are discussed. © 1999 Society of Chemical Industry     

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.     

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。     

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。     

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。     

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.     

Cold storage,reconditioning potential and chip processing quality of spring potato (Solanum tuberosum L. cv. Hermes) tubers in response to differential nitrogen fertilisation

BACKGROUND: Crop management has been implicated in tuber sugar accumulation and potato processing quality. However, reports on potato postharvest behaviour, tuber composition and processing quality in response to crop nitrogen (N) fertilisation have been sparse and inconclusive. In this study, chipping potato cv. Hermes was treated with four preplanting N rates (0, 100, 200 and 300 kg ha^?1) to evaluate the effect of N fertilisation on sugar accumulation profiles and processing quality at harvest, after cold storage at 4.5 °C for up to 200 days and after reconditioning at 16 °C for 10–30 days. RESULTS: Preharvest leaf petiole analysis and tuber nitrate analysis at harvest confirmed crop response to N rates. At harvest, tuber specific gravity decreased marginally beyond 200 kg N ha^?1. Chip colour as well as tuber sucrose and reducing sugar (RS) content was unaffected by N fertilisation rate. During cold storage and reconditioning, tuber fresh weight loss and sprout growth were unaffected by N rate, while its effect on tuber sugar levels was either statistically or practically insignificant. Tuber sucrose and RS contents correlated highly with chip colour (r = ? 0.729, P <0.001 and r = ?0.791, P <0.001 respectively). Importantly, postharvest chip colour was also unaffected by N rate, though it declined markedly with the onset of cold storage and improved significantly throughout reconditioning. Differences in chip colour between years were limited but potentially critical in meeting the commercial standard. CONCLUSION: Completion of physiological crop senescence of the spring potato crop under Mediterranean climatic conditions seems to mitigate the potential interference of preplanting N fertilisation with tuber maturation and subsequently cold storage performance, reconditioning potential and processing quality. Copyright © 2009 Society of Chemical Industry     

腌渍菊芋的质地分析与感官评价研究

利用质构分析仪对腌渍菊芋进行TPA(texture profile analysis)质地剖面分析。通过此实验,将腌渍菊芋抽象的质地特性具体化、数字化。同时对其进行了感官评价,并进一步研究了感官评价和质构分析仪测定结果的相关性。为利用仪器分析代替感官评价测定腌渍菊芋的质地品质提供了理论依据。