Potato starch,gut flora and caecal size in the chick

The effects upon caecal size of feeding chicks with diets containing raw or autoclaved potato starch were tested in both germ-free and conventional environments. Raw, but not autoclaved, potato starch produced enlarged caeca but the effect was less than that reported with rats. The gut flora had no effect on the enlargement. In one trial the chicks eating raw potato starch grew less well. The caecal concentrations of hexosamines were estimated as a measure of mucin content and were higher in germ-free environments than in conventional chicks and higher in chicks given raw, rather than autoclaved potato starch. The possible relevance of this work to caecal size in germ-free and conventional rodents is discussed.     

Metabolism of quercetin and rutin by the pig caecal microflora prepared by freeze-preservation

Several studies confirm a protection of cardiovascular diseases and certain forms of cancer by dietary flavonoid intake. The bioavailability of flavonoids is influenced by the metabolism of the microflora in the intestine. Using a new in vitro model system the deglycosylation of the flavonol rutin and the degradation of its aglycone quercetin were investigated by using fresh pig caecal inocula in comparison to inocula prepared before by freeze-preservation between 6 wk and 5 months. The incubation experiments led to the same pattern of phenolic degradation products in comparable amounts in both preparations using HPLC-DAD and GC-flame ionization detection (GC-FID) or GC-MS detection within 24-48 h of incubation. With the preservation of the microbial vitality and the metabolic efficiency by freeze-preparation over several months the experimental design of microbial metabolism studies will be independent in time and locality.     

The effect of yoghurt on the growth,lactose-utilizing gut organisms and β-glucuronidase activity of caecal contents of a lactose-fed,lactase-deficient animal

The chicken, which has no endogenous lactase, was assessed as a possible model for studies on lactose intolerance. The ability of yoghurt to reverse changes induced by lactose was examined. In the caecum lactose had little effect on the viable counts of three groups of organisms which utilize lactose and no effect on the water content. It suppressed body weight, induced gas formation in the caecum and slightly lowered caecum pH. None of these effects was reversed by yoghurt.The β-glucuronidase activity of the caecal contents was slightly reduced by lactose and markedly reduced in chickens receiving lactose and yoghurt. The additional effect of yoghurt also occurred with yoghurt which had been heated to kill the bacteria and inactivate the lactase. The suppression of β-glucuronidase activity was also achieved by supplements of yoghurt alone.     

Diet-induced changes in alginate- and laminaran-fermenting bacterial levels in the caecal contents of rats

Brown algae contain soluble polysaccharides, such as alginic acid, fucoidan and laminaran. To assess the induction of dietary fiber-fermenting bacteria in the intestine, rats were fed diet containing no dietary fiber (control) or 2% w/w of the polysaccharides for 2 weeks. The levels of dietary fiber-fermenting bacteria in caecal contents were determined using decimal dilution culture containing 1% w/v of the fibers. Caecal microbiota in the rats was analyzed using polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE). In the culture method, 4–9 log viable cells/g caecal content of alginate-fermenting bacteria was detected in rats fed alginate, while this was not detected in rats fed the control diet. Although laminaran-fermenting bacteria were detected in control rats (4–9 log viable cells/g), the level observed in rats fed laminaran was 8 or 9 log viable cells/g. On the other hand, fucoidan-fermenting bacteria were not detected in rats fed fucoidan. DGGE analysis showed laminaran administration increased the diversity of bacterial bands. Clostridium spp. and Parabacteroides distasonis were detected as typical species in rats fed alginate and laminaran. The results indicate that the intake of soluble fermentable fibers in edible brown algae can alter the intestinal microbiota and its fermentation capacity.     

Effect of pectin on plasma lipids and caecal enzyme activity in rutin‐supplemented mice

BACKGROUND: Few previous reports have considered the effects of dietary fibre on the plasma lipids and caecal enzyme activity of mice fed a rutin‐supplemented diet. This investigation studied the effects of pectin on the plasma lipids and caecal enzyme activities of mice fed a diet supplemented with the quercetin glycoside rutin. RESULTS: Male mice were randomly divided into two groups and fed either a pectin–rutin (PR) diet or a cellulose–rutin (CR) diet for 14 days. Plasma cholesterol and triglyceride concentrations and caecal β‐glucosidase and β‐glucuronidase activities were measured. The plasma cholesterol and triglyceride concentrations were significantly higher in the CR diet group, as were the caecal β‐glucosidase and β‐glucuronidase activities. The caecal β‐glucuronidase/β‐glucosidase activity ratio was significantly higher in the PR diet group, indicating differences in the metabolic activity of the intestinal flora. CONCLUSION: The PR diet greatly affected the caecal enzyme activities. A pectin diet supplemented with the quercetin glycoside rutin might affect the lipid metabolism and metabolic activity of the intestinal flora. The plasma lipid‐lowering effects of the PR diet might have been partially caused by the metabolic actions of the intestinal gut flora. Copyright © 2009 Society of Chemical Industry     

Effects of particle size reduction of insoluble fibres by micron technology on various caecal and faecal indices

BACKGROUND: Previous findings demonstrated that particle size reduction of insoluble fibre materials (i.e. starfruit insoluble fibre‐rich fraction and cellulose) to micro‐sizes effectively enhanced their physicochemical properties, which provided clues to their physiological functions. The aim of the present study was to investigate the effects of particle size reduction of these insoluble fibres by micron technology on indices of bowel health. RESULTS: Feeding of the micronised fibres (9.68–14.3 µm), especially those prepared by high‐pressure micronisation, effectively (P < 0.05) improved various caecal and faecal indices, such as decreasing the caecal ammonia concentration (by 20.0–30.0%), increasing the faecal output (135–150%) and moisture content (143–157%) and lowering the activities of undesired β‐D ‐glucosidase (by 39.2–43.6%) and β‐D ‐glucuronidase (by 71.4–77.5%) in faeces of hamsters. Relationships between physicochemical properties and physiological functions of the micronised fibres were considered. The results also demonstrated that the type, processing and related particle size of insoluble fibres were important factors affecting their physicochemical properties and physiological functions. CONCLUSION: The consumption of micronised insoluble fibres at 5% level might exert a favourable effect on improving various caecal and faecal indices. The results of this study provide some hints on potential applications of micron technology in the food industry. Copyright © 2007 Society of Chemical Industry     

Some factors influencing caecal enlargement induced by raw potato starch in the rat

The phenomenon of caecal enlargement in rats fed raw potato starch as their sole dietary carbohydrate source is examined. The caeca of experimental animals were enlarged 800–1700%. They contained undigested starch, an increased number of micro-organisms and a lower concentration of ions and were of lower pH (5·5) than those of control animals (pH 7·0).Duodenal contents had a lower specific activity of amylase expressed either as whole duodenal contents or on the basis of duodenal protein which was also depressed. This suggests that the potato starch either: (a) contains an inhibitor of pancreatic amylase, (b) lacks an amylase activating or stabilising factor or (c) causes changes in the duodenal secretions.The resistance of potato starch to pancreatic amylase, together with the lower level of amylase in the duodenum, results in undigested starch reaching the caecum and there probably acting as a substrate for the caecal microflora. The mechanism whereby these events result in caecal enlargement is still unclear.     

Evaluation of commercial microbial hydrocolloids concerning their effects on plasma lipids and caecal formation of SCFA in mice

Exopolysaccharides (EPS) are excreted by microorganisms into the surrounding environment and have been shown to have various physiological effects and are commonly used as food additives due to their rheological properties. Four commercially available microbial EPS with different polymeric structures and composition were tested in LDL receptor knock-out mice to investigate their effect on blood cholesterol, lipoproteins and caecal formation of SCFA. After four weeks on a Western diet supplemented with 4% EPS there were significant increases in caecal content and caecal tissue weight for the EPS groups compared to the control. The total pool of caecal short chain fatty acids was increased when mice were fed scleroglucan, xanthan and dextran. There were no differences in plasma cholesterol levels on the experimental diets compared to the control. Plasma triglycerides did not differ between groups. The results indicate that EPS supplementation to a Western diet may help in maintaining a healthy intestinal environment.     

Effects of dietary inclusion of xylooligo‐ saccharides,arabinoxylooligosaccha‐ rides and soluble arabinoxylan on the microbial composition of caecal contents of chickens

BACKGROUND: Arabinoxylan (AX)‐derived preparations have raised particular interest by the suggestion that they exert prebiotic properties. Therefore an in vivo experiment was conducted to study the effects of xylooligosaccharides (XOS), arabinoxylooligosaccharides (AXOS) and soluble AX (S‐AX) on several groups of gut bacteria of chickens. Chickens were fed a control diet or the same diet supplemented with 2.5 g kg^?1 of XOS (average degree of polymerisation (avDP) of 3, average degree of arabinose substitution (avDS) of 0.09), wheat bran‐derived AXOS (avDP 9, avDS 0.34) or wheat endosperm alkali‐solubilised AX (S‐AX, avDP > 6000, avDS 0.5). RESULTS: All treatment groups showed an increase in the number of caecal bifidobacteria after 2 weeks of feeding (P < 0.05), while the treatments did not impact numbers of Enterobacteriaceae and aerobic lactobacilli in the caeca relative to the control. XOS led to a tremendous increase in caecal bifidobacteria counts (10⁸ g^?1 for the XOS treatment versus 10³ g^?1 for the control treatment) after only 1 week of supplementation, while AXOS and S‐AX led to similar strong increases in bifidobacteria counts after 2 weeks of supplementation. Addition of S‐AX to the diet, but not of AXOS or XOS, led to a significantly decreased (P < 0.05) body weight gain after 2 weeks of feeding relative to animals on the control diet, consistent with its known viscosity‐related antinutritive effects in chickens. CONCLUSION: Similar to XOS, AXOS selectively stimulate the presence of bifidobacteria in the caeca of chickens, establishing their bifidogenic effect as a first indicator for prebiotic potential. Copyright © 2008 Society of Chemical Industry     

Analysis of caecal microbiota in rats fed with genetically modified rice by real-time quantitative PCR

The effect of genetically modified rice (GMR) on bacterial communities in caecal content was analyzed in a 90-d feeding rat model. A total of 12 groups of rats, which included male and female, were fed with the basal diets containing 30%, 50%, 70% GMR (B(1), B(2), B(3)) or 30%, 50%, 70% non-GMR (D(1), D(2), D(3)). The structure of intestinal microflora was estimated by real-time quantitative PCR (RQ-PCR) based on genus-specific 16s rDNA primers. SYBR Green was used for accurate detection and quantification of 6 kinds of major bacteria shared by humans and rats. According to RQ-PCR, the genome copies of Lactobacillus group from the cecum of male rats fed with 70% non-GMR was higher than those fed with 70% GMR and the relative abundance of Lactobacillus group also higher for group D. This result was in contrast with the E. coli subgroup, which was more numerous in proportion of group B, except D(2) and B(2) for male rats. The Clostridium perfringens subgroup was numerically more abundant in group D than group B of the same level, also except D(2) and B(2) for male rats. These results suggested that GMR had a complex effect on caecal microflora that may be related to the health of the host.     

Composition of the caecal microflora, faecal bile acids and serum proteins of rats fed turmeric (Curcuma longa L.) and its alcoholic extract

Wistar strain albino rats were fed turmeric (Curcuma longa L.) powder (100 mg rat⁻¹ day⁻¹) and its alcoholic extract (20 mg rat⁻¹ day⁻¹). The caecal contents were analysed after 3 months and 2 years. Colony counts of lactobacilli and total aerobes were decreased and of coliforms, total anaerobes and Clostridium perfringens were increased in the caecal contents of rats fed turmeric and its alcoholic extract for 3 months. A similar trend was also observed after 2 years feeding, except that the coliform count apparently decreased. Concomitantly faecal deoxycholic acid was increased and serum globulins were decreased as compared to those of rats fed a control diet.     

Molecular and microbiological analysis of caecal microbiota in rats fed with diets supplemented either with prebiotics or probiotics

The potential health-improving effects of both a prebiotic and a probiotic infant formula have been evaluated in a rat model. Two groups of 10 rats were fed with either prebiotics containing fructo-oligosaccharides or probiotics containing viable Bifidobacterium lactis and Streptococcus thermophilus. The composition of their caecal microbiota was analyzed both by classical plate count of the main bacterial groups and by PCR amplification of a V3 fragment of 16S rRNA genes and denaturing gradient gel electrophoresis (DGGE). Both diets induced a significant reduction of clostridia and Bacteroides spp. compared to a control diet, whereas prebiotics were also able to reduce the number of coliforms and to increase the presence of bifidobacteria. DGGE analysis showed a significant increase of 16S rRNA gene fragments in rats fed with either probotics or prebiotics. Nineteen bands were sequenced and most of them showed similarity to cultured bacteria. Detection of Bifidobacterium spp. by this technique using genus-specific primers only permitted these bacteria to be detected in prebiotics-fed rats, whereas the use of Lactobacillus group-specific primers gave similar results in rats fed with any diet, in agreement with the plate count results.     

Effects of ingestion of a green seaweed,Ulva lactuca,upon caecal and colonic mucosas in the germ‐free rat and in the heteroxenic rat harbouring a human bacterial flora

Effect of ingestion of green seaweed, Ulva lactuca, (70 g kg⁻¹) during a 6‐week period on caecal and colonic mucosas was studied in germ‐free (GF) rats and in heteroxenic (HE) rats harbouring a human bacterial flora (GF rats associated with a human flora). The pH and sulphide concentration of the caecal contents, crypt morphometry, mitotic index and mucin types in the caecal and distal colonic mucosas were determined. In the GF caecum, Ulva strongly increased crypt depth and mucin‐containing cells irrespective of the mucin type studied (neutral, acidic or sulphated) compared to the control diet but had no significant effect on mitotic index. The crypt depth and mucin‐containing cells in the caecum were higher in HE than in GF control rats. They were slightly but significantly increased by Ulva. In the distal colon mucosa of GF rats, Ulva decreased crypt depth and cell number as well as sulphomucin‐containing cells. Conversely, in the HE rats, it increased crypt depth and reduced the number of neutral mucin‐containing cells. These results show that Ulva lactuca exerts an intrinsic effect on mucosal morphometry and on mucin biosynthesis in GF rats. No pathological alteration was observed in the mucosas and no significant modification of the mitotic index or sulphide production was observed in HE rats. © 1999 Society of Chemical Industry     

Water-, oil-, and soil-repellent treatment of textiles,artificial leather,and leather

Several products are on the market to realize water-, oil-, and soil-repellent properties on textiles or textile-related materials. To make an adequate and fast rating of repellent properties of finished textiles, different drop tests according to AATCC and ISO standards are commonly used. For evaluation of the repellent properties of solid substrates against different liquids often contact angle measurements are performed. The aim of the work presented here is to determine and evaluate the repellent effects gained by the application of three different finishing agents on three different substrates, such as polyester fabric, artificial leather, and leather. The main questions are at that point: It is possible to gain similar repellent effects with the same finishing product applied on different substrates? Do the different testing methods lead to comparable results? Is there a relation to the repellency against everyday consumer products as red wine, ice tea, or coffee? This article should help the reader to evaluate different testing methods and the influence on common substrates.     

Polyphenols, Anthocyanins, Ascorbic Acid, and Radical Scavenging Activity of Rubus, Ribes, and Aronia

ABSTRACT: Total polyphenols, total anthocyanins, and reduced ascorbic acid were evaluated in berries belonging to the genera Rubus, Ribes, and Aronia by means of spectrophotometric and high-performance liquid chromatography (HPLC) techniques. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of the fruit extracts was tested. Total polyphenols ranged from 140.6 to 888.5 mg/100 g fresh weight (FW), total anthocyanins ranged from 22.0 to 460.5 mg/100 g FW, and reduced ascorbic acid ranged from 12.4 to 153.8 mg/ 100 g FW. The average EC50 values for Aronia melanocarpa, Ribes nigrum, Ribes rubrum, Rubus fruticosus, and Rubus idaeus were 1.8, 2.8, 5.3, 6.4, and 8.2 mg FW, respectively. The results indicate that the fruits tested are good sources of natural antioxidants.     

卷烟中锂、铬、镍、铜、砷、硒、钼、镉、铊和铅含量分析

采用微波消解-电感耦合等离子体质谱法测定了41个牌号烤烟型卷烟和雪茄烟样品烟丝中的锂、铬、镍、铜、砷、硒、钼、镉、铊和铅含量,并按照类型和价位对卷烟中这10种有害元素含量进行了统计分析。结果发现:①卷烟中锂和铜的含量较高,铊的含量很低,铬、镍、镉、铅、砷、硒和钼7种元素的平均含量为0.55～4.42μg/g;②雪茄烟中铬、镍、砷、钼、镉、铊和铅的含量一般高于烤烟型卷烟,而硒元素的含量则相反,但差别较小;烤烟型卷烟中锂和铜的含量与雪茄烟没有显著差异;③高档卷烟中的锂、镍、镉、铊和铬含量较低,而砷、铅的含量较高;不同价位卷烟的铜、硒和钼含量差异不显著。     

Optimization of extraction conditions of total phenolics, antioxidant activities, and anthocyanin of oregano, thyme, terebinth, and pomegranate

The purpose of this study was to evaluate the total phenolic extracts and antioxidant activity and anthocyanins of varieties of the investigated plants. These plants include oregano, thyme, terebinth, and pomegranate. The optimum extraction conditions including temperature and solvent of the extraction process itself were investigated. Total phenolic and anthocyanin extracts were examined according to Folin-Ciocalteu assay and Rabino and Mancinelli method, respectively. The effect of different extracting solvents and temperatures on extracts of phenolic compounds and anthocyanins were studied. Plant samples were evaluated for their antioxidant chemical activity by 2, 2-diphenyl-1-picrylhydrazl assay, to determine their potential as a source of natural antioxidant. Results showed that all tested plants exhibited appreciable amounts of phenolic compounds. The methanolic extract (60 °C) of sour pomegranate peel contained the highest phenolic extract (4952.4 mg/100 g of dry weight). Terebinth green seed had the lowest phenolic extract (599.4 mg/100 g of dry weight). Anthocyanins ranged between 3.5 (terebinth red seed) and 0.2 mg/100 g of dry material (thyme). Significant effect of different extracting solvents and temperatures on total phenolics and anthocyanin extracts were found. The methanol and 60 °C of extraction conditions found to be the best for extracting phenolic compounds. The distilled water and 60 °C extraction conditions found to be the best for extracting anthocyanin.     

The levels of zinc, copper, manganese, selenium, chromium, nickel, cobalt, and aluminium in the meat, liver and kidney of swedish pigs and cattle

The levels of zinc, copper, manganese, selenium, chromium, nickel, cobalt, and aluminium were determined in samples of meat, liver and kidney from pigs and cattle from Swedish slaughterhouses. The results have been compared with those reported from other investigations carried out in recent years. For zinc, copper, manganese and selenium, the mean levels found in the different tissues were very similar to those reported in previous studies. The mean levels of chromium and nickel were found to be in the range less than 0.010-0.015 mg/kg, regardless of the type of tissue. Cobalt levels ranged from 0.001 to 0.043 mg/kg, the highest levels being in the liver samples. The mean levels of aluminium were between 0.024 and 0.068 mg/kg. Tissues from cattle contained approximately twice as much aluminium as tissues from pigs. Analytical quality assurance was carried out by analysing standard reference materials. A great effort was made to minimize and check contamination. This may partly explain the fact that the levels of chromium, nickel, and aluminium found in the present study are among the lowest reported.