The sandwich technique for quick and efficient application of negative pressure wound therapy to the feet and hands: a case report.

INTRODUCTION: NPWT is a surgical dressing that combines polyurethane foam with the subsequent application of continuous or intermittent negative pressure. NPWT facilitates granulation tissue production by macrostrain, microstrain and, if desired, fluid instillation. Sealing the polyurethane foam over the wound bed is achieved using acrylic drapes; however, this can be difficult to use in some anatomic sites. Failure to achieve an effective seal can necessitate additional supplies, which has led to increased innovation in developing a more effective NPWT seal over the target wound bed. Obtaining an effective pressure seal on the feet or hands can be difficult because these anatomic sites have distinct curvature for each digit, with multiple interdigital web spaces and independent mobility. In this case report, the authors propose a technique to apply either an acrylic drape or combination acrylic and soft silicone drape utilizing the "sandwich technique" to seal NPWT foam quickly and efficiently to the feet or hands.

Check-if-apply approach for consumers and utilities to communicate about drinking water aesthetics quality.

Globally, consumers judge their drinking water through its aesthetic qualities because tastes, odors, and appearances are readily detectable by untrained consumers. Consumer feedback is critical to the water industry for efficient resolution of aesthetic water quality issues, although consumer descriptions of taste and odor issues can sometimes be unfocused or confusing. A user-friendly approach can facilitate consumer communications to utilities in the challenging task of describing drinking water taste and odor issues. The purpose of this study was to develop a list of taste and odor descriptors and test a novel "check-if-apply" approach to describe drinking water quality. The final list contained 28 individual and/or groups of descriptors. 75 participants tested water samples impacted by various tastants or odorants: duplicate samples of chloraminated tap water, tap water with heptanal, tap water with 2-methylisoborneol (MIB), tap water with NaCl, bottled water, and bottled water with CuSO4. Participants used a 9-point hedonic scale (1 = 'dislike extremely'; 9 = 'like extremely') to rate overall liking of each sample, and they used the check-if-apply list to describe the taste or odor. Participants also answered a brief questionnaire and used a 5-point scale (1 = 'very difficult'; 5 = 'very easy') to evaluate their experience using the check-if-apply list. Significant differences were observed in acceptability and sensory profile of samples (p-value <0.05). Tap water with MIB had the lowest acceptability mean score (3.43 ± 1.74), while flavorless bottled water had the highest acceptability mean score (6.23 ± 1.47). 'Salty', 'metallic', 'chemical' and 'musty/earthy' were the dominant descriptors for NaCl, CuSO4, heptanal, and MIB, respectively. Most participants (81%) found the check-if-apply list as 'somewhat easy' to 'very easy' to use (mean = 3.44 ± 1.07) and suggested it as a user-friendly lexicon for consumers and utilities to communicate about water quality.

Flavor compounds in Vine Tea (Ampelopsis grossedentata) infusions.

Vine tea (Ampelopsis grossedentata) is a tea traditionally used in Chinese herbal medicine that is rich in the natural antioxidant dihydromyricetin (ampelopsin). In addition to its multiple health benefits, vine tea extracts and dihydromyricetin have been suggested as potential natural antioxidants for food applications, such as soybean oil and meat products. However, there is still little information available on vine tea chemistry, and in particular the volatile profile and sensory characteristics, which can affect product acceptability and restrict its use as a natural antioxidant. The objective of this exploratory study was to identify potential volatile components present in vine tea in order to support further research and applications in the food industry. Vine tea infusions brewed from commercial samples were characterized by acidic pH values and a dark, reddish-yellow color. Twenty-one volatile compounds were identified as potential flavor components of vine tea, including aldehydes and ketones. Further studies are suggested to quantify the volatile compounds and understand their importance to vine tea's aroma profile. Sensory studies are also suggested to access consumer's acceptability of vine tea and products containing vine tea as an ingredient.

The Facial Action Coding System for Characterization of Human Affective Response to Consumer Product-Based Stimuli: A Systematic Review.

To characterize human emotions, researchers have increasingly utilized Automatic Facial Expression Analysis (AFEA), which automates the Facial Action Coding System (FACS) and translates the facial muscular positioning into the basic universal emotions. There is broad interest in the application of FACS for assessing consumer expressions as an indication of emotions to consumer product-stimuli. However, the translation of FACS to characterization of emotions is elusive in the literature. The aim of this systematic review is to give an overview of how FACS has been used to investigate human emotional behavior to consumer product-based stimuli. The search was limited to studies published in English after 1978, conducted on humans, using FACS or its action units to investigate affect, where emotional response is elicited by consumer product-based stimuli evoking at least one of the five senses. The search resulted in an initial total of 1,935 records, of which 55 studies were extracted and categorized based on the outcomes of interest including (i) method of FACS implementation; (ii) purpose of study; (iii) consumer product-based stimuli used; and (iv) measures of affect validation. Most studies implemented FACS manually (73%) to develop products and/or software (20%) and used consumer product-based stimuli that had known and/or defined capacity to evoke a particular affective response, such as films and/or movie clips (20%); minimal attention was paid to consumer products with low levels of emotional competence or with unknown affective impact. The vast majority of studies (53%) did not validate FACS-determined affect and, of the validation measures that were used, most tended to be discontinuous in nature and only captured affect as it holistically related to an experience. This review illuminated some inconsistencies in how FACS is carried out as well as how emotional response is inferred from facial muscle activation. This may prompt researchers to consider measuring the total consumer experience by employing a variety of methodologies in addition to FACS and its emotion-based interpretation guide. Such strategies may better conceptualize consumers' experience with products of low, unknown, and/or undefined capacity to evoke an affective response such as product prototypes, line extensions, etc.

Interaction effect of LED color temperatures and light-protective additive packaging on photo-oxidation in milk displayed in retail dairy case.

Effect of varied LED color temperatures on photo-oxidation in 2% fat milk and protection efficiency of packaging with and without light-protective additives (LPA) under different color temperatures was firstly evaluated. Riboflavin (Rb) is one of the critical photo-sensitizers in 2% milk when exposed to LED light. Higher color temperature with higher relative intensity of Rb absorbance region resulted in lower Rb and vitamin A retention, lower dissolved oxygen content, and higher TBARS value in milk packaged with non-LPA packaging. Yellow pigmented packaging that completely blocked the Rb absorbance region of all three LED color temperatures successfully reduced the rate of degradation of milk nutrients and flavor. TiO2-added packaging partially block the destructive light wavelength; higher level of TiO2 provided a longer protection on milk freshness. Combination of appropriate LED color temperature and LPA-packaging provided a cost-effective solution for minimizing photo-oxidation in retail dairy case.

Grape pomace and its secondary waste management: Biochar production for a broad range of lead (Pb) removal from water.

Grape pomace (GP) management has been a challenge worldwide. We have previously demonstrated a biorefinery process to recover oil and polyphenols, and produce biofuels from GP sequentially, although over 50% of GP solid waste remains post-processing. To approach zero solid waste during GP processing, herein a pyrolysis process was designed for converting GP and its secondary processing wastes to biochars, which were then evaluated for lead (Pb) adsorption from water. GP lignin pyrolyzed at 700 °C (GPL2700 biochar) with specific surface area of 485 m2/g showed the highest Pb adsorption capacity, and achieved 66.5% of Pb removal from an initially high concentration of 300 mg/L within 30 min. At low initial Pb concentrations (50-3000 µg/L), GPL2700 biochar could reduce Pb concentrations to 0.208-77.2 µg/L. In addition, experimental and modeling results revealed that both physisorption and chemisorption mechanisms were involved in the adsorption process of GPL2700 biochar.

Compositional Characterization of Different Industrial White and Red Grape Pomaces in Virginia and the Potential Valorization of the Major Components.

To better evaluate potential uses for grape pomace (GP) waste, a comprehensive chemical composition analysis of GP in Virginia was conducted. Eight commercial white and red pomace samples (cv. Viognier, Vidal Blanc, Niagara, Petit Manseng, Petit Verdot, Merlot, Cabernet Franc, and Chambourcin) obtained from different wineries in Virginia, USA were used. For extractives, GPs contained 2.89%-4.66% titratable acids, 4.32%-6.60% ash, 4.62%-12.5% lipids with linoleic acid being the predominant (59.0%-70.9%) fatty acid, 10.4-64.8 g total phenolic content (gallic acid equivalents)/kg GP, 2.09-53.3 g glucose/kg GP, 3.79-52.9 g fructose/kg GP, and trace sucrose. As for non-extractives, GPs contained 25.2%-44.5% lignin, 8.04%-12.7% glucan, 4.42%-7.05% xylan, and trace amounts of galactan, arabinan, and mannan (less than 3% in total). Potential usages of these components were further examined to provide information on better valorization of GP. Considering the valuable extractives (e.g., polyphenols and oil) and non-extractives (e.g., lignin), designing a biorefinery process aiming at fully recover and/or utilize these components is of future significance.

Comparison of Common Analytical Methods for the Quantification of Total Polyphenols and Flavanols in Fruit Juices and Ciders.

Multiple analytical methods are used for quantification of total polyphenols and total flavanols in fruit juices and beverages. Four methods were evaluated in this study: Folin-Ciocalteu (F-C), Lowenthal permanganate (L-P), 4-dimethylaminocinnamaldehyde (DMAC), and the bovine serum albumin (BSA) precipitation method. Method validation parameters, including working range, limit of detection, limit of quantitation, precision (repeatability), accuracy, and specificity, were assessed and compared. The F-C method was not specific to polyphenols, and the L-P method had the widest working range but lacked accuracy. The DMAC method was the most specific to flavanols, and the BSA method was not suitable for quantification of smaller flavanols, such as catechin and epicatechin. Quantitative performance was evaluated using commercial fruit juice samples (n = 14), apple juice samples of different cultivars (n = 22), and commercial ciders (n = 17). In general, the L-P titration method and DMAC method resulted in higher quantitative values than the F-C method and BSA precipitation method, respectively. However, ratios of results obtained by the L-P and F-C method ranged from 1 to 28, and ratios of results obtained by the DMAC and BSA precipitation method ranged from <1 to 280. This tremendous variation is likely due to variation in polyphenol composition and sample matrix. This information provides perspective for comparison of results obtained through these different methods, and a basis for choosing the most appropriate analytical method for quantification of polyphenols to address a specific research question when working with commercial fruit juice, apple juice from different apple cultivars, and commercial ciders. PRACTICAL APPLICATION: This study compared results obtained when four common polyphenol quantification methods were applied to a diverse selection of fruit juices and beverages with distinct polyphenol composition and sample matrix. The matrix and polyphenol composition of the samples significantly influenced the results. Our findings can help manufacturers of fruit-based products choose the most appropriate analytical method for polyphenol quantification as part of a quality assurance program or to convey information on dietary polyphenol content to consumers. An assessment of analytical method validation parameters is provided for each of the four methods, which will help users of these methods to understand their limitations.

Trace minerals in tilapia fillets: Status in the United States marketplace and selenium supplementation strategy for improving consumer's health.

This goal of this study was to highlight the importance of minerals in the diet of fish for meeting micronutrient requirements in the human diet. First arsenic, calcium, cadmium, copper, iron, molybdenum, magnesium, manganese, sodium, phosphorus, potassium, selenium, and zinc concentrations of twelve commercially available tilapia samples were measured. The nutritional value of fillets in regard to their mineral content were assessed to establish potential health benefits or risks for consumers. The health benefit value of selenium was also calculated. Positive health benefit values indicate that tilapia fillets in the United States marketplace of this study do not pose health risks associated with mercury exposures. Selenium was the trace mineral of interest. After the market study, a seven-week fish feeding trial was conducted to study the influence of organic versus inorganic dietary selenium on Nile tilapia (Oreochromis niloticus). Fish were fed two different diets enriched with the same concentration (0.01g kg-1) of selenium in form of inorganic (sodium selenite) or organic (seleno-L-methionine) selenium in triplicate groups. There were no significant differences between growth and biometrics of fish fed different diets (p>0.05). At the end of trial twelve fish from each treatment were collected. Fillets of fish fed organic selenium had selenium concentrations of 0.55 ± 0.01 µg g-1 which were significantly (p<0.05) higher than fish fed inorganic selenium at levels of 0.22 ± 0.008 µg g-1 or fish samples from the marketplace with a selenium level of 0.2 ± 0.03 µg g-1. Fish fed organic selenium also had significantly higher (p<0.05) plasma and kidney selenium in comparison to fish fed inorganic selenium. No significant differences (p>0.05) were observed in glutathione peroxidase activities in either the plasma or liver of Nile tilapia in the different treatment groups. This study shows that organic selenium is a better option for production of Nile tilapia fillets rich in selenium.

Lignin-Based Biopolymeric Active Packaging System for Oil Products.

Antioxidant activity of enzymatically modified soybean protein film with two different forms of added lignin (alkali lignin and lignosulfonate) was investigated using two stimulated food systems involving direct and indirect contact with soybean oil and fish fatty acid ethyl ester (FAEE). For the direct system, control and lignin-doped films were added to oil vials which were stored at dark under 40 °C whereas for indirect, films were used to cover oil-containing glass vials stored under standard commercial lighting conditions. Autoxidation of oil samples in the direct contact system was determined by peroxide value (PV), color, headspace oxygen, and volatile compounds, while for the indirect contact system photoxidation was determined by using PV and color. For the direct contact system with soybean oil, the PV was significantly lower during storage for both lignins used compared to the control (packaging system without lignin film). There was not a significant effect of lignin on the color of the oils (P > 0.05). Modified films tested in this study did not have a significant effect on headspace oxygen contents of oil samples; however, it resulted in reduced volatile compounds for both soybean oil and fish oil samples. Based on our observation, soybean protein films with lignin showed a greater impact on soybean oil than fish oil, possibly because of high initial oxidation levels in the fish oil. Enzymatic modified soy protein films with lignin are alternative active packaging materials for highly sensitive to oxidation by radical and UV light. PRACTICAL APPLICATION: Plastic packaging materials require the use of petroleum oil and are not biodegradable. Packaging materials made from renewable, biodegradable biopolymers are of great interest but often suffer from performance problems, such as weak mechanical properties compared to petroleum-based plastics. Applying modified biopolymeric film with lignin in the inner layer of food packaging system improved some aspects of their performance during storage, not only by preventing the migration of chemical compounds from the package to the food but also by radical scavenging activity and UV-blocking ability of the packaging system.

Flavanol supplementation protects against obesity-associated increases in systemic interleukin-6 levels without inhibiting body mass gain in mice fed a high-fat diet.

Weight gain and obesity are associated with increased levels of proinflammatory cytokines. Studies have demonstrated the ability of dietary flavanols to reduce the severity of metabolic derangements due to high-fat (HF) feeding. The degree of polymerization of the flavanols appears to play a role in determining the extent of these protective effects. This study evaluated the preventative effects of grape seed and pine bark flavanol supplementation, with significantly different flavanol degree of polymerization, in the context of an HF diet. For 13 weeks, mice were given 35 mg/kg body weight per day grape seed or pine bark as part of an HF diet and compared to mice fed a low-fat diet and control HF diet. All flavanol-supplemented groups and the HF control incurred significantly higher weight gain compared to the lean control, and the grape seed group gained significantly more weight than the HF control. Increased weight gain of treatment groups was likely caused by hyperphagia. Despite lack of improvements to weight gain and glycemic control, it was observed that all flavanol treatment groups were able to significantly reduce interleukin-6 compared to HF control. The grape seed group, which gained the most weight overall, also exhibited the lowest levels of interleukin-6 compared to other groups. Overall, low-dose flavanol extract supplementation, regardless of mean degrees of polymerization, blunted cytokine production despite increased weight gain. This obesity-independent effect suggests flavanols may be used as complementary interventions to ameliorate increased inflammatory tone in the contexts of obesity and diabetes. Furthermore, flavanol-induced hyperphagia may have use for attenuation of cachexia.

Efficacy of light-protective additive packaging in protecting milk freshness in a retail dairy case with LED lighting at different light intensities.

Light emitting diodes (LED) are rapidly developing as dominant lighting systems in dairy retail cases. Bright light is typically chosen to best exhibit milk products. However, high intensity LED lighting may create high potential for detrimental oxidation and destroying milk freshness. In this study, we investigated the interaction between LED light intensity, exposure time, and packaging material on limiting milk oxidation and protecting milk freshness and vitamins. Within 4 h of LED light exposure at an intensity as low as 1068 lx, light-induced oxidation occurred on 2% milkfat milk with commercial packaging including glass and translucent high-density polyethylene (HDPE) bottles. Higher light intensity (>4094 lx) and longer light exposure time (>24 h) rapidly increased the oxidation rate in milk. Polyethylene terephthalate (PET) packaging with lower oxygen permeability rate effectively reduced (P < 0.05) vitamin A degradation under low light intensity within 24 h. A combination of light-protective additive (TiO2) and oxygen barrier material (PET) successfully reduced (P < .05) the loss of dissolved oxygen and riboflavin, and decreased the formation of final oxidation products in milk, as measured by thiobarbituric reactive substances (TBARS), when exposed to high light intensity within 24 h. Lower LED light intensity in retail case was preferred by 50% of participants in a visual acceptance test; consumers are willing to consider pigmented packaging with limited visibility. Results of this study provides guidance for dairy industry in choosing appropriate LED lighting conditions and packaging to adequately display the milk products as well as minimize the degradation of milk nutrients and flavor.

Production of omega-3 enriched tilapia through the dietary use of algae meal or fish oil: Improved nutrient value of fillet and offal.

The goal of this project was to increase the nutrient value of fillets, by-product muscle, and offal of aquacultured tilapia. A diet that includes seafood with a high omega-3 (n-3) fatty acid content, more specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are known to have numerous health benefits for consumers. Improved nutrient value of the offal may also attract new market opportunities for the aquaculture industry. Tilapia were cultured on different experimental feeds that contained various levels of n-3 fatty acids from either fish oil (FO) or algae meal (AM) that were used to replace corn oil. The experimental diets included a control (corn oil 6.3%), FO1%, FO3%, FO5%, AM1.75%, AM5.26%, and AM8.77%. All diets were formulated to be isocaloric, isonitrogenous, and isolipid. Three hundred and fifty tilapia with an initial mean weight of 158±2 g were cultured in a recirculating aquaculture system (seven diets replicated at the tank level, 14 tanks, 25 fish per tank). For all of the production performance data, no differences (P>0.05) were observed between the experimental groups which included survival (overall mean ± standard error, 99.4±0.3%), growth per week (45.4±1.0 g/wk), food conversion ratio (1.32±0.03), fillet yield (44.4±0.2%), hepatosomatic index (1.61±0.02), viscerosomatic index (2.86±0.06), and mesenteric fat index (0.97±0.04). Fillet and rib meat tissues were collected at weeks four and eight, and liver and mesenteric fat tissues were collected at week eight. Fatty acids were extracted, methylated and identified with gas chromatography-mass spectrometry. All tissues had improved fatty acid profiles (higher n-3, lower n-6, n-6:n-3) with increasing levels of FO and AM in the diet. For example, the best diet for significantly (P<0.05) improving the lipid profile in tilapia fillets at week eight was diet AM8.77%. In the fillet, total n-3 was increased (control versus AM8.77%) from 151.2±19.0 to 438.7±14.2 mg per 4 ounce (113 g) serving and n-6:n-3 ratio was improved from 5.19±0.76 to 1.29±0.03.

Evaluation of Enzymatically Modified Soy Protein Isolate Film Forming Solution and Film at Different Manufacturing Conditions.

The effects of transglutaminase on soy protein isolate (SPI) film forming solution and films were investigated by rheological behavior and physicochemical properties based on different manufacturing conditions (enzyme treatments, enzyme incubation times, and protein denaturation temperatures). Enzymatic crosslinking reaction and changes in molecular weight distribution were confirmed by viscosity measurement and SDS-PAGE, respectively, compared to 2 controls: the nonenzyme treated and the deactivated enzyme treated. Films treated with both the enzyme and the deactivated enzyme showed significant increase in tensile strength (TS), percent elongation (%E), and initial contact angle of films compared to the nonenzyme control film due to the bulk stabilizers in the commercial enzyme. Water absorption property, protein solubility, Fourier transform infrared (FTIR) and X-ray diffraction (XRD) spectroscopy revealed that enzyme treated SPI film matrix in the molecular structure level, resulted in the changes in physicochemical properties. Based on our observation, the enzymatic treatment at appropriate conditions is a practical and feasible way to control the physical properties of protein based biopolymeric film for many different scientific and industrial areas. PRACTICAL APPLICATION: Enzymes can make bridges selectively among different amino acids in the structure of protein matrix. Therefore, protein network is changed after enzyme treatment. The behavior of biopolymeric materials is dependent on the network structure to be suitable in different applications such as bioplastics applied in food and pharmaceutical products. In the current research, transglutaminase, as an enzyme, applied in soy protein matrix in different types of forms, activated and deactivated, and different preparation conditions to investigate its effects on different properties of the new bioplastic film.

Binding of volatile aroma compounds to can linings with different polymeric characteristics.

Flavor compounds have been shown to interact with packaging materials either by scalping, the movement of flavorings from the food product to the package, or by flavor release, movement of flavorings from the package to the food. Work has elucidated the parameters important for the scalping of flavor compounds to polyolefin packaging materials, but very little work has been conducted examining the scalping of flavor compounds by can lining materials. Can linings composed of three different polymers, polyolefin, acrylic, epoxy, were studied for binding of volatile flavor compounds (octanal, nonanal, decanal, eugenol, d-limonene) at room temperature over a 2-week period. Solid phase microextraction (SPME) was used with gas chromatography mass spectrometry to identify and quantify volatile compounds. Flavor compounds were studied at concentrations around 4-1,000 ppb. Fourier transform infrared spectroscopy was used to verify can lining polymer chemistry. Almost complete binding of all five of the volatile compounds studied was observed over 9-14 days at room temperature for each of the can lining chemistries. The number of time data points limited our ability to determine the order and rate constants of binding. This model system appears to be a valuable for investigating flavor binding of polymeric can lining materials.

Free amino nitrogen concentration correlates to total yeast assimilable nitrogen concentration in apple juice.

Yeast assimilable nitrogen (YAN) is essential for yeast growth and metabolism during apple (Malus x domestica Borkh.) cider fermentation. YAN concentration and composition can impact cider fermentation kinetics and the formation of volatile aroma compounds by yeast. The YAN concentration and composition of apples grown in Virginia, USA over the course of two seasons was determined through analysis of both free amino nitrogen (FAN) and ammonium ion concentration. FAN was the largest fraction of YAN, with a mean value of 51 mg N L-1 FAN compared to 9 mg N L-1 ammonium. Observed YAN values ranged from nine to 249 mg N L-1, with a mean value of 59 mg N L-1. Ninety-four percent of all samples analyzed in this study contained <140 mg N L-1 YAN, a concentration generally considered the minimum level needed in grape-based wines for yeast to fully utilize all of the fermentable sugars. FAN concentration was correlated with total YAN concentration, but ammonium concentration was not. Likewise, there was no correlation between FAN and ammonium concentration.

Utilization of Lignin in Biopolymeric Packaging Films.

Lignin is a byproduct of agricultural industries and only has limited applications. In this study, lignin was investigated for use in sustainable biopolymeric packaging film. Alkali lignin (AL) and lignosulfonate (LSS) were added to enzymatically modified soy protein isolate (SPI) biopolymeric film with different concentrations with the goal of improvement of film physical and functional properties. A radical scavenging activity test revealed that films containing LSS had values 28 and 6% higher than control and AL-based films, respectively; AL itself (not in films) had significantly higher radical scavenging activity than LSS. This indicates the activity of lignin is affected by interaction with SPI. The higher compatibility between LSS and enzymatically modified SPI resulted in a positive effect on surface smoothness, water absorption, and mechanical properties of LSS-based films. Films containing AL showed a high light absorption range in the UV region, and this UV-blocking ability increased with increasing level of lignin. Deconvoluted Fourier transform infrared spectra confirmed that the addition of lignin resulted in some changes in the secondary structure of the protein matrix, which were aligned with X-ray diffraction results. The addition of lignin improved tensile strength (TS) and thermal stability of films compared to the lignin-free control. This improvement in TS and thermal stability was probably a result of new intermolecular interactions between lignin and SPI. Water vapor permeability of the films containing lignin decreased to 50% of the control because lignin played a role as a filler in the matrix. On the basis of our observations, the incorporation of lignin into biopolymeric film is capable of providing additional benefits and solutions to various industries, such as food, packaging, agriculture, and pharmaceuticals.

Evaluation of peanut skin and grape seed extracts to inhibit growth of foodborne pathogens.

Peanut skin extract (PSE) and grape seed extract (GSE) are derived from waste products in the wine and peanut industries, respectively. Both have high concentrations of polyphenols, known to possess antioxidant and antimicrobial properties. PSE primarily contains "A-type" procyanidins, while GSE primarily contains "B-type" procyanidins. These differ structurally, but are both isomers of epicatechin dimers. The objective of this study was to evaluate the antimicrobial effects of PSE containing A-type procyanidins and GSE containing B-type procyanidins against select foodborne pathogens (Listeria monocytogenes, Escherichia coli O157:H7, and Salmonella Typhimurium). The minimum inhibitory concentration (MIC) of the two extracts on L. monocytogenes, E. coli O157:H7, and S. Typhimurium was determined using the pour plate method. GSE had a significantly lower MIC (p ≤ .05) than PSE for L. monocytogenes (GSE = 60.6 ppm, PSE > 68.2 ppm) and S. Typhimurium (GSE = 45.7 ppm, PSE = 60.6 ppm), but no difference in inhibition of E. coli O157:H7. Since GSE contributed to greater inhibition, GSE extract was fractionated into monomer-rich (consisting primarily of catechins, epicatechins, and epicatechin gallates) and oligomer-rich (consisting of dimers, trimers, tetramers, up to decamers) components. Growth curves of all three pathogens in the presence of full extract, monomer and oligomer fractions were compared separately. None of the extracts inhibited S. Typhimurium growth. Generally, the extract containing greater oligomer components inhibited growth of L. monocytogenes and E. coli O157:H7 when compared to the control. Results indicate that an extract with type B procyanidins higher in oligomers may have greater antimicrobial properties.

Monomeric cocoa catechins enhance ß-cell function by increasing mitochondrial respiration.

A hallmark of type 2 diabetes (T2D) is ß-cell dysfunction and the eventual loss of functional ß-cell mass. Therefore, mechanisms that improve or preserve ß-cell function could be used to improve the quality of life of individuals with T2D. Studies have shown that monomeric, oligomeric and polymeric cocoa flavanols have different effects on obesity, insulin resistance and glucose tolerance. We hypothesized that these cocoa flavanols may have beneficial effects on ß-cell function. INS-1 832/13-derived ß-cells and primary rat islets cultured with a monomeric catechin-rich cocoa flavanol fraction demonstrated enhanced glucose-stimulated insulin secretion, while cells cultured with total cocoa extract and with oligomeric or polymeric procyanidin-rich fraction demonstrated no improvement. The increased glucose-stimulated insulin secretion in the presence of the monomeric catechin-rich fraction corresponded with enhanced mitochondrial respiration, suggesting improvements in ß-cell fuel utilization. Mitochondrial complex III, IV and V components are up-regulated after culture with the monomer-rich fraction, corresponding with increased cellular ATP production. The monomer-rich fraction improved cellular redox state and increased glutathione concentration, which corresponds with nuclear factor, erythroid 2 like 2 (Nrf2) nuclear localization and expression of Nrf2 target genes including nuclear respiratory factor 1 (Nrf1) and GA binding protein transcription factor alpha subunit (GABPA), essential genes for increasing mitochondrial function. We propose a model by which monomeric cocoa catechins improve the cellular redox state, resulting in Nrf2 nuclear migration and up-regulation of genes critical for mitochondrial respiration, glucose-stimulated insulin secretion and ultimately improved ß-cell function. These results suggest a mechanism by which monomeric cocoa catechins exert their effects as an effective complementary strategy to benefit T2D patients.

Flavanol concentrations do not predict dipeptidyl peptidase-IV inhibitory activities of four cocoas with different processing histories.

Cocoa and its constituent bioactives (particularly flavanols) have reported anti-diabetic and anti-obesity activities. One potential mechanism of action is inhibition of dipeptidyl peptidase-IV (DPP4), the enzyme that inactivates incretin hormones such as glucagon-like peptide-1 and gastric inhibitory peptide. The objective of this study was to determine the DPP4 inhibitory activities of cocoas with different processing histories, and identify processing factors and bioactive compounds that predict DPP4 inhibition. IC25 values (µg mL-1) were 4.82 for Diprotin A (positive control), 2135 for fermented bean extract, 1585 for unfermented bean extract, 2871 for unfermented liquor extract, and 1076 for fermented liquor extract This suggests mild inhibitory activity. Surprisingly, protein binding activity, total polyphenol, total flavanol, individual flavanol and complex fermentation/roasting product levels were all positively correlated to IC25 concentrations (greater levels correspond to less potent inhibition). For the representative samples studied, fermentation appeared to improve inhibition. This study suggests that cocoa may possess mild DPP4 inhibitory activity, and that processing steps such as fermentation may actually enhance activity. Furthermore, this activity and the variation between samples were not easily explainable by traditional putative bioactives in cocoa. The compounds driving this activity, and the associated mechanism(s) by which this inhibition occurs, remain to be elucidated.