Escherichia coli O157:H7 has become an important problem for human health in the United States. Scientific studies indicate cattle herds as primary reservoirs of E. coli O157:H7. To diagnose this pathogen, proper isolation and identification methods are crucial. From five different culture media, CT-SMAC and CHROMagar O157 results analyzed simultaneously were the best option for an effective detection of environmental E. coli O157. Despite extensive research at feedlots and dairy farms, there is limited information available on the prevalence of E. coli O157:H7 at cow/calf operations. From 28 small-scale cow/calf operations in the state of Louisiana, we observed an 8% prevalence of this pathogen, with no significant difference between fecal matter, water, and swabs from surfaces as a source of contamination. In a different context but also important for the state of Louisiana, hot sauce has become a large industry with more than 35 brands available in the market. Production of hot pepper sauce may require fermentation of red hot pepper mash in barrels from 2 weeks to 3 years. Physicochemical and microbiological changes during mash natural fermentation were studied over a period of 18 months. A significant reduction of pH was observed, which had a reverse correlation with production of lactic acid. There were minor changes in color of mash. Aroma was analyzed based on six volatile compounds which had a significant increase during the first 60 days of fermentation. We observed four stages during the fermentation of the mash, where LAB and yeast were the main microorganisms isolated, presenting a symbiotic association that stopped at 18 months of fermentation. As part of the fermentation process, 7% of red hot chili pepper mash will develop undesired changes in color, texture, and aroma. Bacillus firmus, Bacillus pumilus, Brevibacillus laterosporus, Enterococcus avium, and Aerococcus viridans were isolated from spoiled mash. When fresh pepper mash was inoculated with this isolates, spoilage of mash was produced after 60 days of storage at 35°C. These microorganisms were also isolated from naturally fermented not spoiled pepper mash. In conclusion, to prevent loses due to spoilage of the mash, fermentation should be stopped after 18 months.

Lignocellulosic biomass is a promising renewable resource for the production of biofuels and biochemicals. Energycane is considered a lignocellulosic biomass characterized by its high fiber content and cold tolerance. It can be planted on marginal land and does not need to compete with the food supply. Wet storage in combination with sodium hydroxide (NaOH) or white-rot fungi was applied to energycane bagasse to preserve the lignocellulosic polymeric sugars (cellulose and hemicellulose) during short-term storage (60 days) and to make them accessible for conversion into biofuels and biochemicals. Alkaline-assisted wet storage was successful in preserving the biomass by minimizing microbial degradation, increasing lignin degradation, preventing cellulose degradation, and enhancing sugar digestibility. Four sodium hydroxide loadings (0, 5, 7.5, and 10 g NaOH/kg dry matter) at two moisture contents (45% and 75%) were applied to energycane bagasse. Higher loadings of sodium hydroxide and lower moisture content resulted in less cellulose degradation and greater lignin degradation. Higher moisture content (75%) resulted in higher sugar digestibility. Sodium hydroxide loading of 10% wt. at a moisture content of 45% was the optimal condition that preserved the most glucan (40%), degraded the most lignin (67%) and hemicellulose (48%), and resulted in 69% cellulose digestibility and 43% hemicellulose digestibility during the 60 days storage of energycane bagasse. Fungal-assisted wet storage using white-rot fungus, Ceriporiopsis subvermispora, was also successful in preserving the biomass by inhibiting microbial growth, increasing lignin degradation, preventing cellulose degradation, and enhancing sugar digestibility. At 75% moisture, fungal-assisted storage of energycane bagasse resulted in 44% lignin degradation and 2% cellulose loss as compared to 14% and 31% from untreated samples, respectively. The majority of lignin degradation occurred after 10 days, and no significant difference (p > 0.05) was observed in fungal treated samples after 50 days. Cellulose digestibility (67%) and hemicellulose digestibility (34%) of white-rot fungus treated samples were higher than untreated samples (38% and 20%, respectively). This study indicated that sodium hydroxide and white-rot fungal assisted wet storage were efficient in preserving glucan, removing lignin and increasing sugar digestibility of energycane bagasse.

Celiac disease (CD) is a chronic immune-mediated disease of the small intestine caused by the ingestion of gluten. Gluten presents to the intestine largely intact where it is deamidated by Transglutaminase-2 (TG2), increasing affinity for Human Leukocyte Antigen DQ2 (HLA-DQ2) and forming a complex that elicits an inflammatory response ultimately leading to villous atrophy. The only current treatment is strict adherence to a gluten-free diet, though TG2 inhibition is an attractive therapy due its central role in CD pathogenesis. Cocoa contains procyanidin-B2, theobromine and caffeine and may be capable of inhibiting TG2-induced intestinal inflammation and reduce CD symptoms. Procyanidin-B2 rich cocoa extracts reduced TG2 levels by up to 77% in vitro using Caco-2 cells. Significant TG2 inhibition was seen when cocoa extracts contained at least 8.5 μM procyanidin-B2 (p<0.05). Other CD inflammatory biomarkers including COX-2 and IL-15 were also significantly decreased in the presence of cocoa extracts. Serum cytokines IL-6, IL-8 and IL-1β are commonly used to monitor CD and were analyzed using ELISA to confirm the inhibition of inflammatory biomarkers. This study shows promising results for use of a bioactive-rich cocoa product as a dietary inhibitor of TG2 that can be used with wheat-based products as an alternative therapy in CD.

Juglone, a naphthoquinone found in Juglandaceae family, which includes black walnut, European walnut, and butter nut possess various biological activities. The anti-cancer properties of juglone has been reported; however, the effect of juglone in pancreatic cancer (PC) has not been elucidated yet. PC is an aggressive lethal, highly metastatic disease associated with poor prognosis and high mortality rate. PC is usually diagnosed in advanced stage and chemotherapy is provided as a first line of treatment. The de novo chemoresistance that develops with chemotherapeutic treatment creates a critical need for identification of novel therapeutic agents for effectively targeting the disease. The effects of juglone on PC cell proliferation, level of reactive oxygen species (ROS) production, and expression of various oncogenic signal transduction molecules in MIA Paca-2, pancreatic carcinoma cells were investigated. The major findings indicate that treatment with juglone dose dependently suppressed the in vitro proliferation and induced cell death of rapidly dividing human PC cells with an IC50 value of 5 μM at 24 h. Long-term colonies forming ability of PC cells was also significantly inhibited. The molecular mechanisms behind juglone-induced apoptosis of PC cells indicated activation of caspase-3, cleavage of PARP, upregulation of Bax, down regulation of Akt, ERK, HER-2, Cox-2, and Bcl-2 and very high production of ROS leading to chromatin condensation, DNA damage and cell death. Changes in morphological features of cell treated with juglone were obtained by confocal microscopy using Hoechst staining, which specified apoptotic features in treated cells. The results also revealed the anti-angiogenic and anti-metastatic potential of juglone. PC cell migration and invasion was significantly reduced with juglone treatment and the potential of endothelial cells to form tubes was also limited when treated with juglone. Key angiogenic regulators such as HIF-1α and VEGF were also downregulated with juglone treatment. Taken together, our data suggest that of ROS-inducing agent juglone could provide a novel therapeutic approach for PC treatment.

Chitosan (CH) is a biopolymer obtained from the deacetylation of chitin, a polysaccharide present in the exoskeleton of crustaceans and cell walls of fungi. Application of CH may be limited by its water-insolubility. It can be dissolved in acids and forms relatively high viscosity solutions. CH solutions have antioxidant and antimicrobial properties. CH penetration into shrimp may be facilitated by vacuum tumbling with low viscosity chitosan-sodium tripolyphosphate (CH-TPP) nanoparticle or water-soluble chitosan (WSC) solutions. It is expected that this would reduce lipid oxidation and microbial loads. In this study, CH-TPP and WSC solutions were developed and applied to shrimp, and the quality characteristics during frozen storage were evaluated. This research was conducted in two separate studies. In the first study, four treatment solutions were prepared: (1) a 1% acetic acid (AA) solution, (2) a CH in AA solution, (3) a sodium tripolyphosphate (TPP) in AA solution, and (4) a CH-TPP in AA solution. The solutions were sonicated and then sheared in an ultra-homogenizer to reduce particle size. In the second study, WSC was produced by enzymatic hydrolysis. Two treatment solutions were prepared: (1) a 0.1 M AA solution and (2) a WSC in distilled water (DW) solution. In both studies, fresh shrimp meat was separately vacuum tumbled with the solutions, cryogenically frozen, and evaluated for quality characteristics under frozen storage. Fresh shrimp meat tumbled with DW and fresh shrimp meat without tumbling (NT) were used as controls. Shrimp treated with CH, CH-TPP, and WSC had lower aerobic plate counts (APC) compared to other treatments after 120 days of storage at -20 °C. However, only the WSC treatment decreased yeast and mold counts (YMC) in the shrimp. CH, CH-TPP, and WSC treatments could aid in retention of color, texture, and moisture content of shrimp. Additionally, CH, CH-TPP, and WSC treatments produced the highest reduction in lipid oxidation compared to other treatments. This research indicated that CH, CH-TPP, and WSC solutions, combined with vacuum tumbling, can be effective at reducing APC and lipid oxidation in shrimp during frozen storage. As WSC can be dissolved in water, it may have greater application potential in seafood than CH or CH-TPP.

Use of pesticide has become part of modern day agricultural practice. Some pesticides can remain in the environment for decades and contaminate surface water that is used for irrigation of produce. Two studies were conducted- first to examine possible pesticide residue in surface water and some fruits, vegetables and cereals in Louisiana; and second was to alleviate possible pesticide residues in the water using zeolite filtration. Samples of 8 foods (tomato, corn, rice, blueberry, cucumber, cabbage, wheat and melon) and 35 surface waters were studied using a QuEChERS extraction method for food samples and an EPA method for the water samples. Gas chromatography-mass spectrometry was used to analyze water and food samples. Alleviation of pesticide residues was attempted for 10 water samples using a natural zeolite filtration. One water sample was filtered through a surfactant (HDTMA-Cl)-modified-zeolite. Eighteen pesticides were detected in the surface water samples and 5 in the food samples. Pesticides detected were below FDA limit but 0.18 ppm cypermethrin found in tomato was 90 % close to the FDA limit (0.2 ppm). Alleviation was achieved in 9 water samples out of 10 samples that were filtered through zeolite. The highest removal of pesticides from water with zeolite was 100 % in bifenthrin in CLC sample, followed by 99.1 % in atrazine in the same sample. Minimum reduction of 10.9 % was in metolachlor in sample BRH. Further reduction of pesticide residues up to 50 % was recorded in the SMZ treatment as the concentrations of 4 out of 8 pesticide residues were reduced. This study suggests the need to intermittently monitor pesticide contamination in our food and water.

The use of beans in the human diet provides an excellent source of dietary fiber and has potential for lowering glycemic load. Prepared meals with high levels of dietary fiber and low glycemic loads were found to be rare in a market survey of nine stores with various price points in the greater Baton Rouge area. The majority of the prepared meals found fell into low or medium fiber categories with medium to high glycemic loads. This indicates a need to increase the fiber level and decrease the glycemic load in popular foods. The purpose of this research is to accomplish these changes in prepared meals by substituting a portion of the standard pasta flour with bean flour. Various mixtures of pinto bean, navy bean, black bean, enriched semolina, and 00 flours (a high-gluten red spring wheat flour) were tested using a standard Rapid Visco Analysis method and the visco-elastic properties were compared with the control flour. The addition of navy bean four to the control flour was found to produce a composite flour with a similar texture at 25%, 30%, and 50% substitution levels. A calculated proximate analysis was performed on three ravioli produced: a control, a 50%, and a 75% navy bean ravioli. A 14% DV and a 21% DV increase in dietary fiber were predicted for the 50% and 75% navy bean ravioli, respectively. A seven and a ten gram decrease in glycemic load were predicted for the 50% and the 75% navy bean ravioli. The three ravioli types were also subjected to a sensory study with 103 participants. It was found that the color, texture, aroma, appearance, and liking preferences were not significantly changed by the substitution of navy bean flour at a 50% substitution level (α = 0.05). These characteristics of commercially available frozen pasta meals were also measured with a blind consumer survey of consumers ages 65 and older. The predominant unsatisfactory characteristics found were texture and color. In comparison, the texture and color were not significantly altered by the 50% substitution of navy bean flour in the ravioli sensory study.

Norovirus (NoV) is the principal cause of viral gastroenteritis in the United States. It has been linked to filter-feeding molluscan shellfish, that bioaccumulate the virus from contaminated surrounding waters. The consumption of raw or undercooked contaminated oysters may result in acute gastroenteritis. We investigated the occurrence of NoV GI and GII and microbial indicators of fecal contamination in oysters and harvesting water from areas along the Louisiana Gulf Coast. We developed a filtration and concentration method for the detection of NoV from oyster harvesting waters. Lastly, this body of work compares commonly used molecular techniques (RT-PCR) and a commercial enzyme immunoassay for the detection of NoV. One oyster sample was positive for norovirus GII at 3.5 ± 0.2 log10 genomic equivalent copies/g digestive tissues, however the surrounding water tested negative for NoV. Zeolite granules were used for the filtration of norovirus-seeded waters. Beef Extract (10%) in McIlvaines buffer was the optimal elution buffer resulting in an average percent recovery of 41.76 + 0.07 (p<0.05). Artificial and environmental waters with 20ppt salt had an observed average percent recovery of 40.79 + 0.19 and 18.95 + 0.24, respectively which was significantly higher than 0, 5, 10, 15, and 25ppt (p<0.05). The observed percent recoveries for artificial and environmental waters were 44.03 + 0.20 and 34.36 + 0.02, respectively. The percent recovery for artificial and environmental water using TaqMan® Fast Virus 1-Step RT-qPCR was 38.85% + 0.27 and 19.77% + 0.07, respectively. In comparison, SuperScript® III Platinum One-Step qRT-PCR exhibited an average percent recovery of 11.12% + 0.183 and 15.55% + 0.225 for artificial and environmental waters. The EIA assay assay was not sensitive enough to detect NoV in the elution samples despite RT-qPCR methods quantifying the virus concentration between 104 and 105 genomic copies/ml. As such, it is not an effective method for the detection of NoV from environmental water matrices without RT-qPCR as a secondary validation method. This body of work provides an effective method to detect norovirus in oyster harvesting waters. Our results emphasize the need for regular monitoring of pathogenic viruses in oyster harvesting areas to reduce viral gastroenteritis incidences.

Clostridium difficile (C. difficile) is regarded as the major cause of infectious diarrhea in humans after antimicrobial treatment. C. difficile has been reported to be widely isolated from food animals and meat. The main purpose of this study was to characterize C. difficile isolates from retail fresh vegetable (lettuce), test the antibiotic-resistance property using five common clinical-selected antibiotics (metronidazole, vancomycin, clindamycin, erythromycin, and cefotaxime). Lettuces (grown in California, Arkansas, and Louisiana) were purchased from retail stores. Toxigenic C. difficile was isolated from 13.8% (41/297) of the lettuce samples. Among the toxigenic isolates, 82.9% (34/41) only produce toxin B, and 17.1% (7/41) produced both toxin A and toxin B. Under the treatment of the five antibiotics, the virulence C. difficile isolates were identified as having antibiotic resistance to metronidazole, vancomycin, and erythromycin. The present study reports the highest toxigenic C. difficile yield rate from varieties of retail vegetables (lettuce) in the USA. The antibiotic resistance to metronidazole, vancomycin, and erythromycin of the isolated C. difficle from varieties of retail lettuces could lead to public health concerns.

Whole grain (WG) and fat content of the diet have been previously shown to affect intestinal fermentation and phenotype conferred by highamylose maize starch (HAM), a form of fermentable dietary fiber. The current study was designed to compare rodent gut health following consumption of whole grain and nonwhole grain prebiotics on moderate fat (MF) and high fat (HF) diets using a 2x2x2 factorial design. MF and HF diets were prepared to contain the following diet sources: (1) control starch with no WG or RS [CON], (2) whole grain waxy corn flour with low RS [WWG], (3) purified HAM resistant starch (RS) [HAMRS], and (4) WG HAM flour rich in resistant starch (WG+RS) [HMWG]. The eight diet conditions were fed to Sprague Dawley rats for six weeks (n = 12 per group). After euthanasia, blood, cecal contents and cecal epithelial cells were collected and gastrointestinal (GI) tract portions and fat pad (retroperitoneal, perirenal, and epididymal) weights recorded. The presence of purified RS2 resulted in greater fermentation as part of the RS*WG interaction whereas no WG with high RS had the lowest pH of cecal contents. There was a main effect of RS with the high RS groups having the lowest abdominal fat percent of body weight. The presence of WG resulted in consistency of fermentation as groups with WG had similar levels of short chain fatty acids with MF and HF diets as reflected by WG*FAT. No RS*FAT effect was observed because of the WG consistency. Also, a greater butyrate production with WG was demonstrated by RS*WG. Results were primarily driven by two major effects, reflected by the presence of and lack of some significant differences. Purified RS fermented better on MF than HF diets. Diets with RS+WG show similar fermentation on both types of diets. These effects may be driven by RS1 vs. RS2 as high RS2 ferments better with MF diets, but presence of RS1 may ferment better with HF diets.