Mohamad G. Abiad

Green synthesis of curcumin conjugated nanosilver for the applications in nucleic acid sensing and anti-bacterial activity.

Silver nanoparticles (Ag NPs) are often synthesized by chemical and physical methods. Natural and non-toxic molecules are recently being replaced for nanoparticles preparation. In this paper we have used curcumin, which interacts with Ag+ and subsequently synthesizes silver nanoparticles. Further continuation of the reaction often makes aggregation and forms dark brown/black silver oxide. Presence of glycerol in the reaction mixture gives mono-disperse curcumin conjugated Ag NPs, which can be made stable by capping with polyvinylpyrolidone (PVP). XRD data confirm that curcumin conjugated Ag NPs are crystalline in nature with a mean crystalline size of 13.27 nm. The Ag NPs are spherical and in the range of 10-50 nm though their hydrodynamic radius is found to be higher, ∼294 nm, due to polyvinylpyrolidone capping and aggregation of nanoparticles in solution. The production of curcumin conjugated Ag NPs follows first order kinetics and the effect of curcumin concentration during formation of Ag NPs indicates a linear enhancement in the production of Ag NPs with an increase in concentration of curcumin. These curcumin conjugated silver nanoparticles show anti-bacterial activity and can successfully determine nucleic acid (DNA and RNA) in the concentration range 100-1000 ng/mL with a linear regression coefficient >0.997 using Resonance Rayleigh Scattering spectra.

The global economic and regulatory determinants of household food waste generation: A cross-country analysis

Food is generally wasted all along the supply chain, with an estimated loss of 35percent generated at the consumer level. Consequently, household food waste constitutes a sizable proportion of the total waste generated throughout the food supply chain. Yet such wastes vary drastically between developed and developing countries. Using data collected from 44 countries with various income levels, this paper investigates the impact of legislation and economic incentives on household food waste generation. The obtained results indicate that well-defined regulations, policies and strategies are more effective than fiscal measures in mitigating household food waste generation.

Encapsulation of curcumin in cyclodextrin-metal organic frameworks: Dissociation of loaded CD-MOFs enhances stability of curcumin.

Curcumin has been successfully encapsulated in cyclodextrin-metal organic frameworks (CD-MOFs) without altering their crystallinity. The interaction between curcumin and CD-MOFs is strong through hydrogen bond type interaction between the OH group of cyclodextrin of CD-MOFs and the phenolic hydroxyl group of the curcumin. Interestingly, dissolving the curcumin loaded CD-MOFs crystals in water results in formation of a unique complex between curcumin, γCD and potassium cations. In fact, the initial interaction between curcumin and CD-MOF is crucial for the formation of the latter. This new complex formed in alkaline media at pH 11.5 has maximum absorbance at 520nm and emittance at 600nm. Most importantly, the stability of curcumin in this complex was enhanced by at least 3 orders of magnitude compared to free curcumin and curcumin:γ-CD at pH 11.5. These results suggest a promising benign system of CD-MOFs, which can be used to store and stabilize curcumin for food applications.

Assessment of Thermal Transitions by Dynamic Mechanical Analysis (DMA) Using a Novel Disposable Powder Holder

Foods and pharmaceuticals materials are exposed to various environmental conditions during processing and while in storage; therefore, stability and quality are key attributes of concern. The properties of foods and pharmaceutical materials that define their quality are affected by conditions such as temperature, humidity and time. Glass transition is considered a key material property to understand how these external conditions affect the stability and quality of foods and pharmaceuticals. Thus, investigating the thermo-mechanical properties of these materials as well as characterizing the glass transition temperature have a great interest not only in the food industry, but also extend to the pharmaceutical and polymer industries. The aim of this study was to design and test a new disposable powder holder that allows the use of a dynamic mechanical analysis (DMA) instrument to test and characterize loose powder samples. The disposable aluminum powder holder was designed and constructed to be used in the single cantilever configuration on a TA Instruments RSA III DMA. Three different powder samples – Felodipine, polyethylene-oxide (MW 900 kDa) and HPMC (E4M) – were used for validation. The use of this powder holder allows the detection of different thermal changes of powder samples without compacting and when large sample size is necessary for detection and/or interpretation.

A novel method to measure the glass and melting transitions of pharmaceutical powders

A method to measure thermo-mechanical properties of pharmaceutical and polymeric powders was developed. The measurements are conducted by characterizing the materials response to applied acoustic waves. Measurements were performed using griseofulvin, felodipine and indomethacin as model drugs and polyethylene oxide (MW=200,000, 900,000, 2,000,000Da) as model polymers. The method employed measures the mechanical impedance enabled the calculation of the powder rheological and thermo-mechanical properties. Measurements attained with this new technique are compared with measurements made using differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). The new method detects the melting and glass transitions events while providing complementary information to that provided by DSC and DMA.

The effect of governance mechanisms on food safety in the supply chain: Evidence from the Lebanese dairy sector

BACKGROUND Food safety is a key public health issue worldwide. This study aims to characterise existing governance mechanisms - governance structures (GSs) and food safety management systems (FSMSs) - and analyse the alignment thereof in detecting food safety hazards, based on empirical evidence from Lebanon. RESULTS Firm-to-firm and public baseline are the dominant FSMSs applied in a large-scale, while chain-wide FSMSs are observed only in a small-scale. Most transactions involving farmers are relational and market-based in contrast to (large-scale) processors, which opt for hierarchical GSs. Large-scale processors use a combination of FSMSs and GSs to minimise food safety hazards albeit potential increase in coordination costs; this is an important feature of modern food supply chains. The econometric analysis reveals contract period, on-farm inspection and experience having significant effects in minimising food safety hazards. However, the potential to implement farm-level FSMS is influenced by formality of the contract, herd size, trading partner choice, and experience. CONCLUSION Public baseline FSMSs appear effective in controlling food safety hazards; however, this may not be viable due to the scarcity of public resources. We suggest public policies to focus on long-lasting governance mechanisms by introducing incentive schemes and farm-level FSMSs by providing loans and education to farmers.

PREVALENCE OF DIABETES IN GREATER BEIRUT AREA: WORSENING OVER TIME

OBJECTIVE The Middle East North Africa region has one of the highest rates of diabetes, both in prevalence and in rate of increase. The aim of this study was to examine the prevalence and associated risk factors of type 2 diabetes mellitus (T2D) in the adult population of Beirut. METHODS A random sample of 501 men and women aged 18 to 79 years was examined in a cross-sectional manner. The sample was then divided into 3 groups based on T2D self-report, glycosylated hemoglobin (HbA1c), and fasting glucose (no diabetes [ND], at risk for diabetes [RD], and probable diabetes [PD]). These were compared to determine the various associated risks. RESULTS The sample consisted of 64.3% women, with an average age of 45.4 ± 15 years, and a mean body mass index (BMI) of 29.4 ± 5.9 kg/m2. The subjects were predominantly from a low socio-economic status, and more than half smoked either cigarettes or a waterpipe. The percentages of the 3 groups were as follows: 41.7%, 40.3%, and 18.0% for ND, RD, and PD, respectively. Out of 90 subjects diagnosed with PD, 26 did not know they had diabetes. Independent, positively associated risk factors were age, BMI, heart rate, hypertension, triglyceride, and high-density lipoprotein cholesterol. CONCLUSION The prevalence of T2D was high in this study and seems to be increasing compared to prior diabetes reports. Overall, the whole sample had a high prevalence of cardiovascular risk factors such as smoking, obesity, and physical inactivity. However, subjects with diabetes had significantly more components of the metabolic syndrome. ABBREVIATIONS ADA = American Diabetes Association CRP = C-reactive protein DD = definite diabetes FPG = fasting plasma glucose HbA1c = glycosylated hemoglobin MENA = Middle-East North Africa ND = no diabetes PD = probable diabetes RD = at risk of diabetes T2D = type 2 diabetes mellitus TSH = thyroid-stimulating hormone.

Effect of Spray Drying Conditions on the Physicochemical Properties and Enthalpy Relaxation of α-Lactose

The purpose of this work was to investigate the effect of different spray drying conditions on the physicochemical properties of dried lactose. Results indicated that the feed concentration and inlet temperature, as well as storage condition, influenced the thermal properties of the dried material, which were evaluated by the degree of molecular relaxation, presumably associated to different levels of molecular mobility in the sample. It was evident that higher drying temperatures decreased molecular mobility of the dried material while increasing its glass transition and crystallization temperatures. This is most likely due to the existence of states of lower mobility within the material as those with higher mobility were relaxed. The change in heat capacity at the glass transition temperature, , and the reduced crystallization temperature, , were used to compare the crystallization tendencies of the spray dried powders. It was observed that a decrease in and an increase in were associated with higher crystallization temperatures. On the other hand, the enthalpic relaxation did not change significantly with storage conditions. The findings illustrated that the initial enthalpy relaxation, which occurred during spray drying, was related to the crystallization tendencies and storage conditions.

Unraveling mean and variance heterogeneity influences of information provision on safer food purchasing decisions: A heteroscedastic mixed logit approach

Abstract The literature on information provision in stated preference surveys studying food safety has virtually ignored potential influences on variances of preference parameters (or heteroskedasticity) and has solely focused on systematic heterogeneity in their means estimates. Recently, unraveling both types of preference heterogeneity underlying consumer choices has become possible with the extension of the mixed logit (ML) model into a heteroskedastic variant (HML). In this paper, we use a HML model to analyze data from a choice experiment studying the effect of providing information related to third-party food safety certification on Lebanese food consumers’ purchasing decisions. To our knowledge, this is the first application of the model to study information provision. Results reveal that besides the expected increases in preference parameters’ mean pertaining to the food safety certificates (ISO 22000 and ServSafe®) among informed respondents, variances also significantly increased. In contrast, the price parameter variance decreased significantly. The distribution plots of certification and price preferences suggest that the HML model better captures the narrowing of the price distribution and broadening of both ServeSafe and ISO 22000 distributions. Thus, the HML model can offer useful insights into the behavioral underpinnings of consumer food safety attitudes and purchasing decisions.

Worsening of the Cardiovascular Profile in a Developing Country: The Greater Beirut Area Cardiovascular Cohort

BACKGROUND Lebanon has no established governmental noncommunicable diseases surveillance and monitoring system to permit reporting on noncommunicable diseases rates. The last World Health Organization-supported surveillance report showed worrying trends in cardiovascular disease (CVD) risk factors. OBJECTIVES A cardiovascular cohort was established to permit CVD outcomes studies in an urban sample in the Lebanese capital and the study in hand presents the baseline CVD risk factors of this cohort. METHODS A cross-sectional study was carried out including 501 Lebanese adults (64.3% women) from the Greater Beirut area using random multistage probability sampling. Interviews, physical exams, and blood withdrawal were conducted to collect information on demographic and lifestyle factors, body mass index, blood pressure, fasting blood glucose, blood lipids, as well as history of coronary artery diseases, hypertension, diabetes mellitus type 2, dyslipidemia, and stroke. Means with SD for continuous variables and frequencies and percentages for categorical variables are reported. RESULTS The prevalence CVD risk factors including obesity, smoking, diabetes mellitus type 2, hypertension, and dyslipidemia prevalence in the Greater Beirut area was higher than that reported for the general population. Important sex and age differences were also observed, whereby older participants and women had higher rates of obesity, diabetes mellitus type 2, and dyslipidemia and younger participants and men were engaged more in cigarette smoking and alcohol consumption. Interestingly, water pipe smoking was similarly prevalent among genders. CONCLUSIONS The overall prevalence of CVD risk factors in this urban population is higher than reported in the 2010 World Health Organization Stepwise Approach to Surveillance report on the Lebanese population, indicating that the urban population in the capital carries a higher burden of CVD risk. In addition, sex and age difference rates of CVD risk factors highlight the need for tailored public health measures to tackle the sex- and age-based CVD risk factors.