Use of fermented milling by-products as functional ingredient to develop a low-glycaemic index bread

Selected Lactobacillus plantarum DSM 32248 and Lactobacillus rossiae DSM 32249, isolated and identified from wheat germ, were used to ferment a milling by-products mixture. Lactic acid bacteria metabolisms improved the functional properties of wheat bran and germ, which are considered important sources of functional compounds. Wheat breads were manufactured using 15% (w/w) of fermented (and unfermented) milling by-products, and compared to baker’s yeast wheat bread manufactured without the addition of milling by-products. The use of the fermented ingredient improved the biochemical, functional, nutritional, textural, and sensory features of wheat bread, showing better performances compared to the solely use of wheat flour. Protein digestibility, nutritional indexes, and the rate of starch hydrolysis markedly improved using fermented milling by-products as ingredient. Enriched bread was also characterized by high content of dietary fibre and low glycaemic index determined in vivo.This study exploited the potential of fermented milling by products as functional ingredient. According to the Regulations the bread made under this study conditions can be defined as “high fibre content” and “low glycaemic index”. A number of advantages encouraged the manufacture of novel and healthy and functional leavened baked goods.     

Antibacterial activity of oxytetracycline on microbial ecology of Nile tilapia (Oreochromis niloticus) gastrointestinal tract under laboratory condition

The antibacterial effect of oxytetracycline (OTC) on bacterial load, pathogen and possible development of antibiotic resistance in intestinal flora of apparently healthy Nile tilapia (Oreochromis niloticus) was investigated under laboratory condition. OTC, a broad spectrum approved antibiotic widely used in aquaculture, was fed to Nile tilapia through medicated diet at a rate of 2 g/ kg of feed for consecutive 7 days in treatment 1 (T₁) and 30 days in treatment 2 (T₂). Changes in physico‐chemical parameters of water were also recorded where pH and dissolved oxygen influenced bacterial load and coliform count respectively. At the start of the experiment, initial bacterial load in fish intestine was 1.61 ± 2.25 × 10¹⁰ cfu/g, which after OTC treatment decreased significantly (p < .05) to 3.06 ± 2.08 × 10⁸ cfu/g on day 7 and 3.45 ± 4.46 × 10⁷ cfu/g on day 30 when compared with the control group. Among the 10 bacterial genera identified in the intestine, 4 potential public health concern bacteria viz., Salmonella, Escherichia, Enterobacter and Staphylococcaus were predominant. There was a sharp increase in bacterial load on day 18 in T₂ that may be attributed to the development of antibiotic resistance in intestinal bacteria. Antibiotic susceptibility test for isolates against seven antibiotics: amoxycillin, ciprofloxacin, co‐trimoxazole, erythromycin, gentamicin, nitrofurantoin and tetracycline using disc diffusion method revealed significantly increased resistance of Gram‐negative rods (p < .05) that possibly caused increased frequency of OTC‐resistant microorganisms. In conclusion, short‐ and long‐term exposure to OTC treatment affected the distribution of bacterial genera including pathogens in the Nile tilapia gastrointestinal tract and concomitantly influenced their antimicrobial resistance.     

低血糖生成指数燕麦颗粒牛奶的开发及测试

低血糖生成指数膳食对人体的血糖水平影响较小,有助于人体健康状况的改善、糖尿病的预防以及糖尿病患者的血糖控制。本文从燕麦和牛奶这两种原料入手,加入维生素、矿物质、膳食纤维等营养元素,开发了一款营养价值高、风味独特的燕麦颗粒牛奶。通过单因素试验、正交试验,确定最优方案为:淀粉添加量1.6%、麦芽糖醇添加量4.0%、燕麦颗粒添加量3.0%。此时燕麦颗粒牛奶具有独特的谷物与牛奶的香气,香醇适口,且稳定性良好。本研究对于开发糖尿病患者适用的乳制品,以及推动我国乳品行业向健康方向发展具有重要的现实意义。     

培养条件对pTrxAR质粒在E.coliGI724中孕育量的影响

硫氧还融合表达系统是Invitrogon公司近年来发展的以E .coli硫氧还蛋白作为融合伴侣的融合表达系统。其重组质粒的诱导表达需在E .coliGI系列菌株中进行。本文对载体质粒pTrxFus及其携带编码hARLBD基因的重组质粒pTrxAR在E .coliG1 72 4株中的质粒孕育量与生长培养条件的关系进行了研究。结果表明 ,菌株在平板RM培养基上的活化生长时间及菌体液体培养时的温度对其质粒孕育量影响极大 ,其次为液体培养基中Ampicillin浓度。菌体在35℃ ,1 0 0ug/mlTrp的诱导条件下 ,其重组质粒在数小时内迅速丢失。通过菌体质粒的提取、测定 ,可为优化使用该表达体系表达hARLBD片段的表达条件提供理论指导。     

GIS支持下的典型油菜地土壤养分 特性空间变异研究

采用地理信息系统及地统计学方法,分析了典型油菜地土壤 pH 值、有机质、全氮、速效磷、速效钾和有 效硼等养分的空间变异规律,并绘制养分空间分布图,为油菜地精细管理与有效施肥提供理论依据。 结果表明院5种 养分的变异系数均在 16. 88% ~65. 42% 之间,属于中等程度的变异。全氮和速效钾的块金系数小于 0. 25,具有强烈的空 间相关性;pH 值和其他 3种养分则具有中等程度的空间相关性。 经过半方差函数分析,采用高斯模型、指数模型、球 状模型和线性模型对养分参数进行拟合,并利用 GS+与 Ar cGI S 绘制养分分布图,结果表明,研究区土壤理化性状存 在明显的空间差异,总体表现在西南区域的有机质、全氮、有效磷、速效钾和有效硼等各个养分的含量都较高,具备 很好的油菜种植生产条件,东北部区域养分含量普遍较低,其主要影响因素为结构性和人为随机性因素。     

Acute stress alters the intestinal lining of Atlantic salmon, Salmo salar L.: An electron microscopical study

Groups of Atlantic salmon (Salmo salar L.) in feeding (guts filled with faeces) or fasted (three days of diet deprivation) states were subjected to 15 minutes of acute stress. Blood samples and intestinal tissue were collected and prepared for chemical and ultrastructural analyses at intervals post stress until 53 h of recovery. Subjecting fish to acute stress led to significant alterations of the ultrastructure of the enterocytes lining the gastrointestinal tract (GI tract). The most notable effect was substantial damage to the intercellular junctional complexes in midgut regions. These effects appeared within the first hour after stress, were maintained for at least 12 h and were more pronounced in fed than fasted fish. In contrast, hindgut was influenced less by stress and damage was rarely observed. Stress also influenced fish intestinal microbiota. Adherent bacteria decreased in both midgut and hindgut of stressed fish, and this was accompanied by a significant increase in the bacterial contents of faeces. It is suggested that this was due to the sloughing off of mucus eliminating existing microflora and allowing remaining bacteria (also pathogenic) in the gut lumen to colonize the surface of the enterocytes. Although blood haematocrit and plasma cortisol increased following stress, the response appeared to be greater in fasted fish. There were also significant differences in carbohydrate metabolism. While liver glycogen stores were depleted in fasted fish following the mobilization of glucose into plasma, liver glycogen was never depleted in fed fish. As a consequence, plasma glucose levels remained high for more than 12 h of recovery. In fed fish, plasma lactate was also higher than in fasted salmon, and the clearance rate appeared slower. Acute stress induced oxidative stress, as measured through plasma malondialdehyde, but the effect was marginal and nonsignificant. This revised version was published online in July 2006 with corrections to the Cover Date.     

Maturity assignment based on histology‐validated macroscopic criteria: Tackling the stock decline of the Mediterranean swordfish (Xiphias gladius)

1. Effective stock assessment relies on the evaluation of the reproductive potential of a population, but this is often achieved using fast, inexpensive, and inaccurate macroscopic indicators of gonadal maturity. Indeed, this approach suffers from high error rates as a result of misclassification and operator errors. Although histology is considered the gold standard to assign reproductive stages, it represents a time‐consuming and expensive method. Therefore, cost‐effective approaches are currently needed to assess the species‐specific reproductive potential and define the correct size at first maturity (L₅₀).
2. In the present study a histology‐calibrated method based on the gonadal index (GI) was developed to assign maturity stages to the overfished Mediterranean swordfish (Xiphias gladius), supported by histological classification of gonadal development, an estimation of L₅₀, and an analysis of the reproductive output of this species.
3. The performance of this new method had an overall agreement of 90% with histological data, and the L₅₀ calculated by the GI‐based method compared with histology analysis was not statistically different (p > 0.05). Moreover, in order to apply this method without bias, a thorough validation of the relationship between length and gonad weight was carried out and the suitability of the GI to compare individuals of different size and maturity stages was confirmed.
4. The present findings provide a comprehensive picture of the patterns characterizing Mediterranean swordfish reproduction and a promising method to assign maturity stages based on a macroscopic indicator. This method has the potential to be extensively applied during routine fish sampling activities in the field because of its simple requirements.

     

The effects of season, temperature and initial gonad condition on roe enhancement of the sea urchin Evechinus chloroticus

A series of 10-week experiments were repeated during the austral autumn, winter, spring and summer to investigate the seasonal effects, independent of seasonal temperature variation, on roe development (enhancement) of Evechinus chloroticus over a 12-month period and whether this differed among urchins with different initial gonad index (GI) values. E. chloroticus collected from wild populations with high and low initial GI values were caught and held in either ambient or constant ( 14.7 °C) seawater temperatures. The study has shown that, given a suitable roe enhancement diet, it is possible to significantly increase the GI of urchins throughout the year and that a seasonal effect on both the final GI and increase in GI, is primarily caused by seasonal variation in temperature. There are also significant effects from other factors, such as the initial condition of the animals prior to the trial and the reproductive stage of the urchins, but these are not as significant as the effects of temperature. The results indicate that it would be possible to increase the productivity of sea urchins by capturing them in cooler water and enhancing them at a site with relatively warmer water. The initial condition (GI) of the urchins plays an important role in gonad production with animals taken in low initial GI condition producing significantly larger increases in GI throughout each of the four seasons, than those with a high initial GI value. The urchins from the two populations developed through the stages of the reproductive cycle at a similar rate despite different final GI values and rates of increase in GI in both the temperature and population treatments, indicating that the differences in gonad production are related to environmental effects rather than the reproductive stage of the urchins. The exception to this occurred in the autumn samples where lower GI values and increase in GI were found during this season compared to in other seasons for the constant temperature treatment.

There is an overabundance of low GI urchins in the coastal waters of New Zealand and these animals are relatively easily found and fished on snorkel compared to high GI animals for which fishing pressure is much higher. It would appear to be more economic to fish and enhance low GI animals in New Zealand due to their relative abundance, ease of access and higher productivity during enhancement.     

超干燥保存的烟草种子活力变化规律研究

本文是在烟草种子超干燥保存技术研究取得初步成功的基础上，对1993－1994年采收并经过超干燥处理的4份烟草种子分别在原干燥器内继续保存2年和4年后进行的种子活力跟踪试验。并对种子发芽势、发芽率和发芽指数等指标作方差分析和多重比较。结果为：2年后不同干燥剂间种子的发芽势、发芽率和发芽指数差异显著，其中，各处理的种子活力排列为：硅胶＞硅胶＞生石灰＞生石灰；2：1＞1：1＞3：1＞4：1；牛津3号＞其它品种。4年后，烟草种子的发芽指数硅胶＞硅胶＋生石灰＞生石灰。万良烟＞其它品种，比例间无显著差异。对种子的含水量、发芽势、发芽率、发芽指数和活力指数相关矩阵进行分析，结果为含水量与发芽指数和活力指数之间，发芽势与发芽指数之间，发芽指数与活力指数之间差异显著，种子含水量对种子活力贡献最大，其次为发芽率，发芽势、发芽指数。几项指标间的相互关系可用多元方程表示：Y＝0．496507＋0．136777X1＋0．000567X2－0．007197X3－0．000201X4。方程可信度达93．12％。该试验为长期，安全保存烟草种子和延长超干燥烟草种子保存寿命提供理论依据及配套措施。