Cinnamyl Isobutyrate Decreases Plasma Glucose Levels and Total Energy Intake from a Standardized Breakfast: A Randomized,Crossover Intervention

1 Scope

Cinnamon is associated with anti‐obesity effects, regulating food intake, improving plasma glucose levels and lipid profiles in vivo. In the present study, the impact of cinnamyl isobutyrate (CIB), one constituent of cinnamon, on ad libitum food intake from a standardized breakfast and outcome measures of hormonal regulation of appetite were investigated.

2 Methods and results

In this randomized, short‐term crossover intervention study, a 75 g per 300 mL glucose solution solely (control) or supplemented with 0.45 mg CIB was administered to 26 healthy volunteers. Prior to and 2 h after receiving control or CIB treatment, subjective hunger perceptions were rated using a visual analog scale. Food intake from a standardized breakfast was assessed 2 h after treatments. Plasma peptide YY_3–36, glucagon‐like‐peptide1, ghrelin, and serotonin as well as plasma glucose and insulin were measured in blood samples drawn at fasting and 15, 30, 60, 90, and 120 min after treatment. CIB administration decreased total energy intake and delta area under curve plasma glucose by 4.64 ± 3.51% and 49.3 ± 18.5% compared to control treatment, respectively.

3 Conclusions

CIB, administered at a 0.45 mg bolus in 75 g glucose–water solution, decreased ad libitum energy intake from a standardized breakfast and postprandial plasma glucose levels.     

The Influence of Dietary Habits and Meat Consumption on Plasma 3‐Methylhistidine—A Potential Marker for Muscle Protein Turnover

1 Scope

3‐Methylhistidine (3‐MH) as a potential biomarker for muscle protein turnover is influenced by meat intake but data on the impact of meat on plasma 3‐MH are scarce. We determined the association of plasma 3‐MH, 1‐methylhistidine (1‐MH), and creatinine with dietary habits and assessed the impact of a single white meat intervention during a meat‐free period.

2 Methods and results

Plasma 3‐MH, 1‐MH, and creatinine concentrations of healthy young omnivores (n = 19) and vegetarians (n = 16) were analyzed together with data on anthropometry, body composition, grip strength, and nutrition. After baseline measurements omnivores adhered to a meat‐free diet for 6 days and received a defined administration of chicken breast on day four. At baseline, omnivores had higher plasma 3‐MH and 1‐MH concentrations than vegetarians. White meat administration led to a slight increase in plasma 3‐MH in omnivores. The elevated 3‐MH concentrations significantly declined within 24 h after white meat intake.

3 Conclusion

1‐MH concentrations in plasma seem to be suitable to display (white) meat consumption and its influence on 3‐MH plasma concentration. 3‐MH in plasma may be used as a biomarker for muscle protein turnover if subjects have not consumed meat in the previous 24 h.     

The Effects of a Beef‐Based Meal Compared to a Calorie Matched Bean‐Based Meal on Appetite and Food Intake

Protein and fiber have strong satiety‐inducing potential. Beef is a high quality, protein‐rich food. Beans contain moderate levels of protein as well as fiber. To determine the effects of a high protein meal (beef) compared to a moderate protein, high fiber meal (beans) on subjective appetite and energy intake at a subsequent meal twenty‐eight adults, 14 men (ages 24 ± 5 y, BMI 23 ± 2 kg/m²) and 14 women (ages 25 ± 5 y, BMI 22 ± 2 kg/m²) consumed 2 test lunches containing a “meatloaf” made from either beef or beans. The beef meal provided 26 g of protein and 3 g of fiber while the bean meal provided 17 g of protein and 12 g of fiber. An ad libitum snack was given 3 h after the test meal. Visual analogue scales were used to assess hunger, satiety, fullness, and prospective food intake. Gastrointestinal (GI) tolerance was assessed over 24 h. No difference between the beef and bean was observed for appetite ratings over 3 h, food intake at the subsequent meal (632 ± 75 kcal compared with 611 ± 75 kcal, respectively), or sum of GI score (2.2 ± 0.5 compared with 2.9 ± 0.5, respectively). Gas and bloating were reported more often after the bean meal than the beef meal (2.0 ± 0.4 compared with 1.3 ± 0.4, P value 0.057). A beef‐based meal with high protein and a bean‐based meal with moderate protein and high fiber produced similar satiety, while the bean‐based meal resulting in higher, yet moderate, gas and bloating.     

A dose–response evaluation of freeze‐dried strawberries independent of fiber content on metabolic indices in abdominally obese individuals with insulin resistance in a randomized,single‐blinded,diet‐controlled crossover trial

Scope : This study evaluated the dose–response relationship of strawberries, an anthocyanin‐rich fruit, on postprandial glucose and insulin concentrations in individuals with insulin resistance (IR), including changes in plasma anthocyanins, markers of oxidative stress, and inflammation. Methods and Results : In a randomized controlled, four‐arm, dose–response, crossover trial, 21 adults with IR consumed a high‐carbohydrate, high‐fat meal with one of four beverages containing 0 g freeze‐dried whole strawberry powder (0g FDS, control), 10, 20, or 40 g FDS, controlled for fiber. Blood was collected at 0 min and at 30 min intervals postmeal until 2 h, then hourly until 6 h. Postmeal insulin concentrations (6 h) were significantly reduced after the 40‐g FDS beverage compared to other beverages (p < 0.05). Postmeal 6 h glucose concentrations were not different, although mean insulin:glucose ratio was significantly different among beverages (p < 0.05). Pelargonidin‐glucuronide was inversely associated with mean insulin concentrations after the 20 and 40 g FDS (p < 0.05). Oxidized low‐density lipoprotein was reduced after 20 g FDS (p < 0.05) and IL‐6 was not different among treatments. Strawberry intake reduced the insulin demand to manage postmeal glucose in obese individuals with IR, which was related to plasma anthocyanin/pelargonidin concentrations. Conclusion : The data support a role of strawberries in improving insulin sensitivity in people with IR.     

In vivo effect of oat cereal β‐glucan on metabolic indexes and satiety‐related hormones in diet‐induced obesity C57‐Bl mice

This study explored the dose‐dependent effect of oat cereal β‐glucan on improving metabolic indexes of obesity mice. C57‐Bl mice were randomized to chow diet (N) group and high fat diet group and other three doses of oat β‐glucan groups (low β‐glucan, medium β‐glucan, and high β‐glucan). Energy intake, glucose, lipids, and appetite related hormones were tested. Dose‐dependent relation was observed on oat β‐glucan doses and body weight change, average energy intake, total cholesterol, HDL cholesterol, plasma neural peptide Y, arcuate neural peptide Y mRNA, and arcuate neural peptide Y receptor 2 mRNA level. Oat β‐glucan helped to increase plasma peptide Y‐Y and intestine peptide Y‐Y expression in obesity mice.     

Theobromine Does Not Affect Fasting and Postprandial HDL Cholesterol Efflux Capacity,While It Decreases Fasting miR‐92a Levels in Humans

Scope

Chocolate consumption lowers cardiovascular disease risk, which might be attributed to the methylxanthine theobromine. These effects may be mediated through effects on HDL‐mediated cholesterol efflux, which may be affected by microRNA (miRNA) levels in the HDL particles. Therefore, the aim of this study is to investigate effects of theobromine consumption on fasting and postprandial cholesterol efflux and miRNAs levels.

Methods and results

Thirty overweight and 14 obese healthy men and women participated in this randomized, double‐blind crossover study. Participants consumed 500 mg d^?1 of theobromine or placebo for 4 weeks. ABCA1‐mediated cholesterol efflux was measured using J774 macrophages. MiRNAs levels (miR‐92a, miR‐223, miR‐135a*) were quantified in apolipoprotein B‐depleted serum. Theobromine consumption did not affect fasting and postprandial cholesterol efflux. Fasting miR‐223 and miR‐135a levels were unchanged, while miR‐92a levels were decreased (?0.21; p < 0.05). The high‐fat meal increased postprandial cholesterol efflux capacity (+4.3 percentage points; p ≤ 0.001), miR‐92a (+1.21; p < 0.001), and miR‐223 (+1.79; p < 0.001) levels, while a trend was found for miR‐135a (+1.08; p = 0.06).

Conclusion

Theobromine did not improve fasting and postprandial ABCA1‐mediated cholesterol efflux capacity, but decreased fasting miR‐92a levels. High‐fat meal intake increased postprandial cholesterol efflux and the three selected miRNAs levels.

     

In Vitro Fermentation Behavior of Isomalto/Malto‐Polysaccharides Using Human Fecal Inoculum Indicates Prebiotic Potential

1 Scope

This study characterize intestinal fermentation of isomalto/malto‐polysaccharides (IMMPs), by monitoring degradation of IMMPs, production of short chain fatty acids (SCFAs), lactic acid, and succinic acid as well as enzyme activity and microbiota composition.

2 Methods and results

IMMP‐94 (94% α‐(1→6) glycosidic linkages), IMMP‐96, IMMP‐27, and IMMP‐dig27 (IMMP‐27 after removal of digestible starch segments) are fermented batchwise in vitro using human fecal inoculum. Fermentation digesta samples are taken for analysis in time up till 48 h. The fermentation of α‐(1→6) glycosidic linkages in IMMP‐94, IMMP‐96, and IMMP‐dig27 starts after 12 h and finishes within 48 h. IMMP‐27 fermentation starts directly after inoculation utilizing α‐(1→4) linked glucosyl residues; however, the utilization of α‐(1→6) linked glucoses is delayed and start only after the depletion of α‐(1→4) linked glucose moieties. SCFAs are produced in high amounts with acetic acid and succinic acid being the major products next to propionic acid and butyric acid. The polysaccharide fraction is degraded into isomalto‐oligosaccharides (IMOs) mainly by extracellular enzymes. The smaller IMOs are further degraded by cell‐associated enzymes. Overall microbial diversity and the relative abundance of Bifidobacterium and Lactobacillus, significantly increase during the fermentation of IMMPs.

3 Conclusion

IMMP containing segments of α‐(1→6) linked glucose units are slowly fermentable fibers with prebiotic potential.     

The Effects of Whole Grain High‐Amylose Maize Flour as a Source of Resistant Starch on Blood Glucose,Satiety, and Food Intake in Young Men

The objective of this study was to determine the dose response effect of whole grain high‐amylose maize (HAM) flour as a source of resistant starch (RS) on blood glucose, appetite and short‐term food intake. In a repeated‐measures crossover trial, healthy men (n = 30, 22.9 ± 0.6 y, BMI of 22.6 ± 0.3 kg/m²) were randomly assigned to consume 1 of 3 cookies once a week for 3 wk. Cookies were control (100% wheat flour), low‐dose (63% wheat flour,37% HAM flour), and high‐dose (33% wheat flour, 67% HAM flour) providing 53.5, 43.5, and 36.3 g of available carbohydrate, respectively. Ad libitum food intake was measured 120 min at a pizza meal, blood glucose and subjective appetite were measured after consumption of the cookie (0 to 120 min) and after the pizza meal (140 to 200 min). Blood glucose concentrations were lower at 30 and 45 min after high‐dose treatment, and at 120 min after both high‐ and low‐dose treatments compared to control (P < 0.05). Blood glucose AUC before the pizza meal (0 to 120 min) was 44% and 14% lower, and higher by 43% and 41% after the pizza meal (140 to 200 min) compared with control. Yet despite the higher response following the meal, cumulative AUC (0 to 200 min) was still 22% lower after the high‐dose treatment (P < 0.05). All treatments equally suppressed subjective appetite and there was no effect on food intake. In conclusion, HAM flour as a source of RS and incorporated into a cookie was associated with better glycemic control in young men.     

Four-week coffee consumption affects energy intake,satiety regulation,body fat,and protects DNA integrity

Recent epidemiological studies suggest that coffee, one of the most widely consumed beverages worldwide, may reduce risks of degenerative diseases such as diabetes type 2, cardiovascular disease and certain types of cancer. These effects have partly been ascribed to coffee's antioxidant and body weight-reducing capacities. To explore the mechanisms involved, effects of coffee consumption on body weight/composition, food intake, satiety markers (serotonin and ghrelin) and DNA integrity were monitored in a four-week double-blind randomized crossover intervention study with 84 healthy subjects. Subjects consumed two different coffee blends (study blend, SB, and market blend, MB), with similar caffeine contents but substantially differing contents of chlorogenic acids and N-methylpyridinium. The consumption of both coffees (3 × 250 mL per day) was associated with a decrease in body fat over the whole study period (p < 0.001), which was more pronounced with SB. During intervention with MB, plasma serotonin levels increased (p < 0.001) whereas plasma ghrelin levels decreased (p < 0.001) relative to levels recorded during the preceding washout period. Consumption of both coffee blends was associated with DNA-protective effects (p < 0.001). These findings suggest that regular coffee consumption may provide health benefits in terms of reducing energy intake and body fat, regulating satiety and protecting DNA integrity.     

Probiotics Affect One‐Carbon Metabolites and Catecholamines in a Genetic Rat Model of Depression

1 Scope

Probiotics may influence one‐carbon (C1) metabolism, neurotransmitters, liver function markers, or behavior.

2 Methods and results

Male adult Flinders Sensitive Line rats (model of depression, FSL; n = 22) received Lactobacillus helveticus R0052 and Bifidobacterium longum R0175 (10⁹ or 10¹⁰ colony‐forming units per day) or vehicle for 10 weeks. The controls, Flinders Resistant Line rats (FRL, n = 8), only received vehicle. C1‐related metabolites were measured in plasma, urine, and different tissues. Monoamine concentrations were measured in plasma, hippocampus, and prefrontal cortex. Vehicle‐treated FSL rats had higher plasma concentrations of betaine, choline, and dimethylglycine, but lower plasma homocysteine and liver S‐adenosylmethionine (SAM) than FRLs. FSL rats receiving high‐dose probiotics had lower plasma betaine and higher liver SAM compared to vehicle‐treated FSL rats. FSLs had higher concentrations of norepinephrine, dopamine, and serotonin than FRLs across various brain regions. Probiotics decreased plasma dopamine in FSLs in a dose‐dependent manner. There were no detectable changes in liver function markers or behavior.

3 Conclusions

Probiotics reduced the flow of methyl groups via betaine, increased liver SAM, and decreased plasma dopamine and norepinephrine. Since these changes in methylation and catecholamine pathways are known to be involved in several diseases, future investigation of the effect of probiotics is warranted.     

Short-term appetite-reducing effects of a low-fat dairy product enriched with protein and fibre

The objectives of this work were to investigate short-term appetite-reducing effects of an innovative low-fat yogurt enriched with protein (8 g/serving) and fibre (2.6–2.9 g/serving). Two studies were conducted using randomised cross-over designs. Healthy women consumed a mid-morning snack consisting of either the test or the control yogurt product (Study 1, n = 24: iso-energetic, not iso-weight conditions; Study 2, n = 121: iso-weight, not iso-energetic conditions) under laboratory conditions. Subjective appetite ratings (of hunger, fullness, desire to eat and prospective consumption) were recorded throughout the morning; sensory and hedonic ratings were also collected. In Study 2, two hours after consumption of the dairy snack, subsequent food intake at lunch was also measured. The test product reduced subjective appetite compared to the control (all ratings, P < 0.05). Energy intake at lunch was reduced by 274 kJ after the test compared to the control (P < 0.001). These two studies demonstrated that a low-fat dairy product enriched with protein and fibre can significantly reduce short-term appetite.     

Clinical and Vitamin Response to a Short‐Term Multi‐Micronutrient Intervention in Brazilian Children and Teens: From Population Data to Interindividual Responses

Scope

Micronutrients are in small amounts in foods, act in concert, and require variable amounts of time to see changes in health and risk for disease. These first principles are incorporated into an intervention study designed to develop new experimental strategies for setting target recommendations for food bioactives for populations and individuals.

Methods and results

A 6‐week multivitamin/mineral intervention is conducted in 9–13 year olds. Participants (136) are (i) their own control (n‐of‐1); (ii) monitored for compliance; (iii) measured for 36 circulating vitamin forms, 30 clinical, anthropometric, and food intake parameters at baseline, post intervention, and following a 6‐week washout; and (iv) had their ancestry accounted for as modifier of vitamin baseline or response. The same intervention is repeated the following year (135 participants). Most vitamins respond positively and many clinical parameters change in directions consistent with improved metabolic health to the intervention. Baseline levels of any metabolite predict its own response to the intervention. Elastic net penalized regression models are identified, and significantly predict response to intervention on the basis of multiple vitamin/clinical baseline measures.

Conclusions

The study design, computational methods, and results are a step toward developing recommendations for optimizing vitamin levels and health parameters for individuals.

     

An After‐School Snack of Raisins Lowers Cumulative Food Intake in Young Children

Snacks are an important part of children's dietary intake, but the role of dried fruit on energy intake in children is unknown. Therefore, the effect of ad libitum consumption of an after‐school snack of raisins, grapes, potato chips, and chocolate chip cookies on appetite and energy intake in twenty‐six 8‐ to 11‐y‐old normal‐weight (15th to 85th percentile) children was examined. On 4 separate weekdays, 1 wk apart, children (11 M, 15 F) were given a standardized breakfast, morning snack (apple), and a standardized lunch. After school, children randomly received 1 of 4 ad libitum snacks and were instructed to eat until “comfortably full.” Appetite was measured before and 15, 30, and 45 min after snack consumption. Children consumed the least calories from raisins and grapes and the most from cookies (P < 0.001). However, weight of raisins consumed was similar to potato chips (about 75 g) and lower compared to grapes and cookies (P < 0.009). Raisins and grapes led to lower cumulative food intake (breakfast + morning snack + lunch + after‐school snack) (P < 0.001), while the cookies increased cumulative food intake (P < 0.001) compared to the other snacks. Grapes lowered appetite compared to all other snacks (P < 0.001) when expressed as a change in appetite per kilocalorie of the snack. Ad libitum consumption of raisins has potential as an after‐school snack to achieve low snack intake prior to dinner, similar to grapes, compared to potato chips, and cookies in children 8 to 11 y old.     

Egg White Ovotransferrin‐Derived ACE Inhibitory Peptide Ameliorates Angiotensin II‐Stimulated Insulin Resistance in Skeletal Muscle Cells

1 Scope

The renin‐angiotensin system (RAS) is a major contributor to the development of insulin resistance and its related complications. Egg white ovotransferrin‐derived tripeptides, IRW (Ile‐Arg‐Trp), IQW (Ile‐Gln‐Trp), or LKP (Leu‐Lys‐Pro) are previously identified as the inhibitors of angiotensin‐converting enzyme (ACE), a key enzyme in the RAS. This study aims at determining whether these peptides are effective in improving insulin resistance, and their mechanisms of action, in a rat derived skeletal muscle cell line (L6 cells).

2 Methods and results

Insulin resistance is induced by treating L6 cells with 1 μm angiotensin II (Ang II) for 24 h. Effects of peptides on glucose uptake are determined using glucose uptake assay, glucose transporter 4 (GLUT4) translocation by immunofluorescence, reactive oxygen species (ROS) by dihydroethidium (DHE) staining, while insulin signaling pathway, Ang II receptor (AT1R or AT2R) levels, and NADPH oxidase activation are measured using Western Blot. Only IRW treatment significantly improves insulin resistance in L6 cells via stimulation of insulin signaling. IRW decreases Ang II‐stimulated AT1R expression, ROS formation, and NADPH oxidase activation.

3 Conclusions

Of three ACE inhibitory peptides studied, only IRW improves insulin resistance in L6 cells, at least partially via reduced AT1R expression and its anti‐oxidative activity.     

Extracellular Vesicles from Hypoxic Adipocytes and Obese Subjects Reduce Insulin‐Stimulated Glucose Uptake

1 Scope

We investigate the effects of extracellular vesicles (EVs) obtained from in vitro adipocyte cell models and from obese subjects on glucose transport and insulin responsiveness.

2 Methods and results

EVs are isolated from the culture supernatant of adipocytes cultured under normoxia, hypoxia (1% oxygen), or exposed to macrophage conditioned media (15% v/v). EVs are isolated from the plasma of lean individuals and subjects with obesity. Cultured adipocytes are incubated with EVs and activation of insulin signalling cascades and insulin‐stimulated glucose transport are measured. EVs released from hypoxic adipocytes impair insulin‐stimulated 2‐deoxyglucose uptake and reduce insulin mediated phosphorylation of AKT. Insulin‐mediated phosphorylation of extracellular regulated kinases (ERK1/2) is not affected. EVs from individuals with obesity decrease insulin stimulated 2‐deoxyglucose uptake in adipocytes (p = 0.0159).

3 Conclusion

EVs released by stressed adipocytes impair insulin action in neighboring adipocytes.     

No Adverse Programming by Post‐Weaning Dietary Fructose of Body Weight,Adiposity, Glucose Tolerance,or Metabolic Flexibility

1 Scope

Metabolic programming can occur not only in the perinatal period, but also post‐weaning. This study aims to assess whether fructose, in comparison to glucose, in the post‐weaning diet programs body weight, adiposity, glucose tolerance, metabolic flexibility, and health at adult age.

2 Methods and results

Three‐week‐old male and female C57BL6/JRccHsd mice are given an intervention diet with 32 energy percent (en%) glucose or fructose for only 3 weeks. Next, all animals are switched to the same 40 en% high fat diet for 9 weeks. Neither body weight nor adiposity differs significantly between the animals fed with glucose or fructose diets at any point during the study in both sexes. Glucose tolerance in adulthood is not affected by the post‐weaning diet, nor are activity, energy expenditure, and metabolic flexibility, as measured by indirect calorimetry. At the end of the study, only in females fasting serum insulin levels and HOMA‐IR index are lower in post‐weaning fructose versus glucose diet (p = 0.02), without differences in pancreatic β‐cell mass.

3 Conclusions

Our present findings indicate no adverse programming of body weight, adiposity, glucose tolerance, and metabolic flexibility by dietary (solid) fructose in comparison to glucose in the post‐weaning diet in mice.     

In vitro and In vivo studies on intragastric soya protein–polysaccharide gels in a beverage matrix

Intragastric gelation is a mechanism whereby a consumed liquid food gels under the acidic gastric condition. It was hypothesised that intragastric gelation would result in satiety due to delayed gastric emptying. Three treatment beverages that is soya protein isolate (SPI) with λ‐carrageenan (SPI‐LC; high viscosity, gelling), guar gum (SPI‐GG; high viscosity) and no polysaccharide (SPI; low viscosity) were given to twenty participants in a randomised 3 × 3 double‐blind within‐subject crossover design trial and asked to rate their hunger and fullness scores (visual analogue scale; VAS) before and up to 60 min after consumption of the beverage. Results show that there were no significant effects on hunger, fullness and energy intake after consuming the SPI‐LC (gelling) beverage compared to the SPI‐GG beverage, but did evoke weak satiety signals up to 20 min after consumption when compared to the control (low‐viscosity) SPI beverage. Therefore, intragastric gelation does not result in satiety in this study.     

Anti‐glycative and anti‐inflammatory effects of caffeic acid and ellagic acid in kidney of diabetic mice

Protective effects of caffeic acid (CA) and ellagic acid (EA) in kidney of diabetic mice were examined. CA or EA at 2.5 and 5% was mixed in diet and supplied to diabetic mice for 12 wk. Results showed that the intake of CA or EA increased renal content of these compounds, alleviated body weight loss, decreased urine output, increased plasma insulin and decreased blood glucose levels at weeks 6 and 12 (p<0.05). The intake of these compounds dose dependently reduced plasma blood urea nitrogen and elevated creatinine clearance (p<0.05). CA or EA at 5% significantly decreased the levels of plasma HbA1c, urinary glycated albumin, renal carboxymethyllysine, pentosidine, sorbitol and fructose (p<0.05), and significantly diminished renal activity of aldose reductase and sorbitol dehydrogenase, as well as suppressed renal aldose reductase mRNA expression (p<0.05). CA or EA dose dependently lowered renal levels of IL‐6, IL‐1β, tumor necrosis factor (TNF)‐α and monocyte chemoattractant protein 1 (MCP‐1) (p<0.05). Furthermore, CA or EA dose dependently down‐regulated tumor necrosis factor‐α and monocyte chemoattractant protein‐1 mRNA expression in kidney (p<0.05). Based on the observed anti‐glycative and anti‐inflammatory effects, the supplement of CA or EA might be helpful for the prevention or attenuation of diabetic kidney diseases.     

Antimicrobial activities of high molecular weight water‐soluble chitosans against selected gram‐negative and gram‐positive foodborne pathogens

Antimicrobial activities of high molecular weight water‐soluble chitosans (HMWWS) against selected Gram‐negative and Gram‐positive foodborne pathogens (initial inoculation of ca. 6.5 Log CFU mL^?1) were evaluated. Chitosans with 789 kDa and/or 1017 kDa were dissolved in aspartic acid (AS) to obtain 1–4% w/v solutions. Among HMWWS, only 4% 789 kDa AS chitosan reduced E. coli counts by 2 Log CFU mL^?1 from 7.33 at 0 h to 5.16 Log CFU mL^?1 at 96 h, and they were not effective against S. Typhimurium. Depending on the concentrations, HMWWS completely inhibited V. cholerae, V. vulnificus and V. parahaemolyticus as well as B. cereus and L. monocytogenes after 48 h or 96 h of incubation. Compared with the control (no HMWWS), 2% or 3% 1017 kDa AS chitosans showed about 3 Log CFU mL^?1 lower (4.72–4.86 vs. 7.71) for S. aureus at 96 h of incubation.     

Separation‐preconcentration of Cu,Cd, Pb and Ni in various water and food samples on Sepabeads SP‐207

This study presents a solid phase extraction (SPE) procedure for preconcentration and separation of Cu(II), Cd(II), Pb(II) and Ni(II), as their diethyldithiocarbamate chelates on Sepabeads SP‐207 resin using flame atomic absorption spectrometry. The parameters, including pH, sample volume, eluent type and volume etc., were optimised. The influences of the some alkali, alkali earth and transition metal ions on the involvement of copper(II), cadmium(II), lead(II) and nickel(II) were also examined. The preconcentration factor was calculated as 50. The limit of detections of the analyte ions (k = 3, N = 21) were 0.18 μg L^?1 (Cu), 0.17 μg L^?1 (Cd), 0.55 μg L^?1 (Pb) and 1.67 μg L^?1 (Ni). GBW 07605 Tea and NRCC‐DORM‐2 Dogfish Muscle certificated reference materials were used for confirm of method. The method was successfully performed for determination of Cu(II), Cd(II), Pb(II) and Ni(II) ions in water and food samples. The relative standard deviation was found to be lower than 7%.