Efficacy of Antimicrobials Extracted from Organic Pecan Shell for Inhibiting the Growth of Listeria spp.

Growers and processors of USDA certified organic foods are in need of suitable organic antimicrobials. The purpose of the research reported here was to develop and test natural antimicrobials derived from an all‐natural by‐product, organic pecan shells. Unroasted and roasted organic pecan shells were subjected to solvent free extraction to produce antimicrobials that were tested against Listeria spp. and L. monocytogenes serotypes to determine the minimum inhibitory concentrations (MIC) of antimicrobials. The effectiveness of pecan shell extracts were further tested using a poultry skin model system and the growth inhibition of the Listeria cells adhered onto the skin model were quantified. The solvent free extracts of pecan shells inhibited Listeria strains at MICs as low as 0.38%. The antimicrobial effectiveness tests on a poultry skin model exhibited nearly a 2 log reduction of the inoculated cocktail mix of Listeria strains when extracts of pecan shell powder were used. The extracts also produced greater than a 4 log reduction of the indigenous spoilage bacteria on the chicken skin. Thus, the pecan shell extracts may prove to be very effective alternative antimicrobials against food pathogens and supplement the demand for effective natural antimicrobials for use in organic meat processing.     

Whole-chain traceability,is it possible to trace your hamburger to a particular steer,a U. S. perspective

Traceability through the entire food supply chain from conception to consumption is a pressing need for the food industry, consumers and government regulators. A robust, whole-chain traceability system is needed that will effectively address food quality, food safety and food defense issues by providing real-time, transparent and reliable information from beef production through slaughter and distribution to the consumer. Traceability is an expanding part of the food safety continuum that minimizes the risk of foodborne diseases, assures quality and cold-chain integrity. Traceability can be a positive competitive marketing edge for beef producers who can verify specific quality attributes such as humane production or grass fed or Certified Organic. In this review we address the benefits as well as the remaining issues for whole-chain traceability in the beef industry, with particular focus on ground beef for the markets in the United States.     

Detection of bacterial endotoxin in food: New planar interdigital sensors based approach

Food poisoning caused by endotoxins or Lipopolysaccharide (LPS) are associated with Gram-negative bacteria. Two major food-borne pathogens, Escherichia coli and Salmonella are examples of Gram-negative bacteria which cause a large number of outbreaks of food poisoning. New types of planar interdigital sensors have been fabricated with different coating materials to assess their response to endotoxins. A carboxyl-functional polymer, APTES (3-Aminopropyltriethoxysilane) and Thionine were chosen to be coated onto FR4 interdigital sensors. The chosen coating materials have carboxylic or amine functional groups, which were optimized to be stable in water. All coated sensors were immobilized with PmB (Polymyxin B) which has specific binding properties to LPS. The sensors were tested with different concentrations of LPS O111:B4, ranging from 0.1 to 1000 μg/ml. Analyses of sensors’ performance were based on the impedance spectroscopy method. The impedance spectra were modeled using a constant phase-element (CPE) equivalent circuit, and a principal component analysis (PCA) was used for data classification. Sensor coated with APTES has shown better selectivity for LPS detection. The experiments were repeated by coating APTES and immobilizing PmB to a new improve designed of novel interdigital sensors (thin film silicon based sensors). These sensors were observed to have better sensitivity and selectivity to the target biomolecules of LPS. Further experiments were conducted to study the effect of different coating thickness on sensor sensitivity, selectivity and stability. Different food samples contaminated with endotoxin were also tested to verify that the interdigital sensing approach is able to be used for endotoxin detection.     

Genoprotective Effects of Essential Oil Compounds Against Oxidative and Methylated DNA Damage in Human Colon Cancer Cells

Essential oils (EO) are widely used in foods as flavoring and preservative agents. Many of the biological activities of EO have been attributed to major essential oil compounds (EOC) but their direct interaction with colonic epithelial cells and their genotoxic and genoprotective effects are not well established. In this study, the cytotoxicity and genotoxicity of EOC including nerolidol, thymol, geraniol, methylisoeugenol, eugenol, linalool, and a commercial blend (Agolin) were determined. Furthermore, the genoprotective effects of EOC against oxidative and methylating damage were assessed using the comet assay in HT‐29 colorectal adenocarcinoma cells. The majority of EOC were cytotoxic to HT‐29 cells at or above 250 ppm after 24 hr exposure. At noncytotoxic doses, none of the EOC was genotoxic in the comet assay. Genoprotection against oxidative DNA damage was observed for nerolidol (at 62.5 ppm), thymol (at 12.5 ppm), geraniol, and methylisoeugenol (both at 125 ppm), as well as linalool and Agolin (both at 250 ppm). Thymol was the most protective compound against oxidative DNA damage and geraniol (at 125 ppm) also protected cells against methylating DNA damage. This study highlights the potential of EOC such as thymol to protect the colonic epithelium against oxidative DNA damage and geraniol against methylating DNA damage. Further in vivo studies are needed to confirm these findings for safety and efficacy to exploit their potential pharmaceutical or nutraceutical uses for colonic health.     

Determination of Theanine and Catechin in <Emphasis Type="Italic">Camellia sinensis</Emphasis> (Kangra Tea) Leaves by HPTLC and NMR Techniques

Camellia sinensis is used to make special tea and also become a raw material for dietary supplements, health foods, and cosmeceuticals. Theanine (amino acid) and catechins (polyphenol) are most abundantly found in tea leaves. Theanine and catechins are also responsible for taste and flavor of tea products along with therapeutic and nutritional values. Hence, identification and quantification method for theanine and catechin has been developed using high performance thin layer chromatography (HPTLC) and NMR techniques. HPTLC method was validated for selectivity, sensitivity, accuracy, and precision. Theanine and catechin were quantified in three tea samples including randomly plucked tea leaves (HAR), authentically plucked tea leaves (HAN), and processed tea (HAT). Both theanine and catechin were found maximum in HAN as compared to HAR and HAT. The Validated HPTLC method is economical, rapid, and highly suitable for quantification of theanine and catechin. Moreover NMR studies were also used for the qualitative and quantitative estimation of theanine and catechin along with other important metabolites in C. sinensis samples.     

The food security challenge of the food-land-water nexus in India

Two of the key factors that drive agricultural growth and food production in India are access to arable land and utilizable water resources. These are examined with particular reference to their regional variation in order to make an assessment of the magnitude of the food security challenge they pose for the country. Recent official estimates of groundwater exploitation in India are compared with actual negative physical, social and economic consequences of over-exploitation, as are evident in different regions, and their implications for national food security discussed. The analyses show that the real food security and water management challenge lies in the mismatch between water availability and agricultural water demand: high demands occur in water scarce but agriculturally prosperous regions and low demands in naturally water-abundant but agriculturally backward regions. Serious groundwater depletion problems, which occur in the naturally water-scarce but surplus food-producing regions, magnify the challenge. The small area of arable land per capita is a major reason for low agricultural water demand in regions that have abundant water. Sustainability of well irrigation in the naturally water-scarce regions, which is the backbone of India??s food security, could be achieved through judicious investment in surface water projects which encourage direct irrigation and replenishment of over-exploited aquifers. Other strategies include: pro rata pricing of electricity in the farm sector; volumetric pricing of water from public irrigation systems; improving the efficiency of utilization of green water or the rainwater held in the soil profile; preventing depletion of the residual soil moisture in the field after crop harvest by reducing the fallow period; and reducing the use of water through a shift to low water consuming crops     

Evaluation of in vitro probiotic potential of phytase‐producing bacterial strain as a new probiotic candidate

Sixty‐three phytase‐producing bacterial strains were isolated from natural sources, and their probiotic potential was evaluated. Of these, only fifteen strains were selected on the basis of confirmatory plate assay. Among these, five phytase‐producing strains exhibiting potent probiotic properties were identified as Bacillus cereus P1, Bacillus subtilis P6, B. subtilis P7, Pseudomonas aeruginosa P12 and P. aeruginosa P15 on the basis of morphological, biochemical and molecular characteristics. Maximum phytase activity (2.74 EU mL^?1) with potential probiotic properties, that is more than 70% survivability at pH 2.0, up to 2.0% bile salt tolerance, sporulation efficiency of more than 80% and survival in anaerobic condition (94.31%), was revealed by B. subtilis P6 as compared to the well‐established commercial probiotic strains Lactobacillus sporogenes and Lactobacillus casei. Thus, phytase‐producing B. subtilis P6 with promising probiotic features can be used in food and animal feed applications for betterment of mankind after further validation.     

Experimental investigation on heat transfer effect of conical strip inserts in a circular tube under laminar flow

The aim of this paper is to observe the Nusselt number and friction factor behavior of the circular tube with conical strip inserts as turbulators in a laminar flow condition, using staggered and non-staggered conical strips with three different twist ratios (Y = 2, 3 and 5). The conical strip is inserted in the forward and backward direction individually compared to the flow of water which is the working fluid. The results indicate that the conical strip inserts increases the Nusselt number when compared to the plain surface tube. It is observed that the strip geometry has a major effect on the thermal performance of the circular tube. On examination of different strips for determining the enhancement of Nusselt number, the staggered conical strip with the twist ratio of Y = 3 has given a better result compared to the other two strips. Finally, correlations have been derived using regression analysis for predicting the Nusselt number and friction factor.     

Thermodynamic analysis and utilisation of wet ethanol in homogeneous charge compression ignition engine

In this study, our objective is to computationally analyse the wet ethanol operated homogeneous charge compression ignition (HCCI) engine to evaluate its first and second law efficiency and observe these results by varying effectiveness of regenerator. The paper concludes that the first and second law efficiency decreases due to the increase in the effectiveness of regenerator. This increase in effectiveness leads to an increase in the temperature of air coming out of the regenerator. It further results in increase of the fuel air mixture intake temperature which finally reduces the work output and efficiency of the engine. Furthermore, the method of exergy analysis has been applied and evaluated. This study indicates that due to domination of chemical exergy destruction in combustion reaction in these systems, maximum exergy is destroyed in HCCI engine and to a lesser extent in catalytic converter. These findings will help in the design of such system for optimum result.