Thermal degradation of corn starch based biodegradable plastic plates and determination of kinetic parameters by isoconversional methods using thermogravimetric analyzer

Oil shortage and awareness of environment pollution leads to the extensive use of biodegradable starch-based materials against synthetic plastics. The accumulated wastes of these plastics takes more time for natural recycling and the process is complex. Therefore the best option of recycling would be to convert these polymers into a source of energy by pyrolysis. So to understand the pyrolytic behaviour, kinetics of such waste plastics is studied by using thermogravimetric analysis at different heating rates of 10 °C, 20 °C, 40 °C, 60 °C, 80 °C and 100 °C in nitrogen atmosphere followed by characterization of the pyrolysis products. The kinetic parameters are obtained for two major stages of decomposition in two different temperature ranges 250–620 °C and 620–855 °C by iso-conversional methods such as Friedman, Coats-Redfern, FWO and Kissinger methods. The regression coefficient data (>0.9) of kinetic plots obtained for different methods best fits to the kinetic equation. Empirical formula of the compound is determined by ultimate analysis is CH_2.214S_0.0018O_0.6910. Proximate analysis gives the idea of volatile component which is74.33%. The range of average value of activation energy is 120.7013 kJ/mol to 140.7707 kJ/mol for the biodegradable plastic plate with different conversion (0.1–0.6) and (0.1–0.3) respectively at two different temperatures. The pyrolysis products obtained using a semi-batch reactor are characterized to know their composition and other properties.     

Contamination of some foodstuffs marketed in Italy by fatty acid esters of monochloropropanediols and glycidol

ABSTRACT

Fatty acid esters of 3-monochloropropanediol (3-MCPD), 2-MCPD and glycidol (Gly) are food-processing contaminants that cause concerns about possible adverse health effects. The present study evaluates the contamination levels of the three ester classes in 130 samples of foodstuffs marketed in Italy covering 10 food categories, namely margarines, oils, roasted coffee, breakfast cereals, salted crackers, cookies, infant biscuits, rusks, breads and potato crisps. The analytical method employed is a so-called indirect method that entails MCPD/glycidol cleavage from their esterified forms, cleanup, derivatisation and GC-MS analysis. The MCPDs and glycidol concentrations (from esters) were found to be equal or a little higher than the levels reported in previous studies conducted in other European countries and described in the literature. 3-MCPD was the predominant compound in all foodstuffs analysed with the exception for rusks where Gly levels were slightly higher. Considering the sum of MCPD and Gly esters, the most contaminated foodstuffs were seed oils, followed by margarines and cookies, whereas roasted coffee, bread, rusks, cornflakes and infant biscuits were less contaminated with MCPDs and Gly concentrations often below LOQ or LOD values. Refined olive oil, potato chips and salted crackers showed contamination levels intermediate between the two above groups. The results of this study also confirm that the use of palm oil as an ingredient or frying medium is an important cause of increase of the levels of MCPD and Gly esters, especially in salted crackers, rusks and potato crisps. Finally, the Italian intake of 3-MCPD due to the various foods analysed has been calculated and related to TDI. The MoE for Gly was also estimated.     

Optimization of process parameters and catalytic pyrolysis of Cascabela thevetia seeds over low-cost catalysts towards renewable fuel production

The present study deals with the optimization of process parameters and thermocatalytic pyrolysis of Cascabela thevetia (CT) seeds in a semi-batch cylindrical-shaped reactor. Response surface methodology (RSM) was employed for the optimization of process variables, while commercial catalysts CaO and Al₂O₃ were used for catalytic pyrolysis. From results, it was concluded that 525 °C temperature, 75 °C min⁻¹ heating rate, and 75 mL min⁻¹ flow of nitrogen yielded maximum pyrolytic liquid (45.26 wt%) while with the attendance of catalysts at 20 wt% increased the yield of pyrolytic liquid (49.12 wt% and 46.87 wt% for CaO and Al₂O₃ respectively). Optimization outcomes displayed that linear and quadratic terms of utilized factors were more noteworthy while interaction effects between the factors were not significant. Further, characterization of pyrolytic oil established that utilization of catalysts expressively enhanced its properties by reducing viscosity and boosted the calorific value. FTIR examination of pyrolytic oil showed that the attendance of phenols, ethers, alcohols, ketones, alkanes, acids, etc., while ¹H NMR results supported the FTIR results. GC-MS analysis showed a substantial reduction of phenols and oxygen-rich products and boost the development of alcohol and aldehydes in pyrolytic oil with the introduction of catalysts. These parameters indicate improved properties of pyrolytic oil, which intensified its bioenergy capabilities.     

Research on the relationship between cephalosporin structure,solution clarity,and rubber closure compatibility using volatile components profile of butyl rubber closures

Objective: Establish an effective experimental strategy to determine the compatibility of rubber closures for drugs.

Significance: Various types of rubber closures with different compositions are available for drug packaging. Many additives of rubber closures can be released from rubber closures and may affect the quality of drugs and pose a risk to human health. In this study, we aimed to determine the relationship between cephalosporin structure, solution clarity, and rubber closure compatibility using volatile components profile of butyl rubber closures.

Methods: Two opposite polarity gas chromatography (GC) systems and GC-mass spectrometry (MS) were used to achieve rapid qualitative determination of the main volatile components in rubber closures. Simulated adsorption experiment was performed to investigate the adsorption of main volatile components in rubber closures by cephalosporins with different side chain structures, and to determine the effects of adsorption on solution clarity.

Results: A volatile components screening library of rubber closures was established and the structures of some volatile component were confirmed. The specific adsorption of the structure of cephalosporins on volatile components from rubber closures was studied.

Conclusion: Based on the results of this study, rubber closures with good compatibility for cephalosporins with different side chain structures can be selected rapidly. This experimental strategy not only facilitates the screening of suitable rubber closures more effectively, but also enables the quick determination of volatile components adsorbed by drugs.     

Dynamic changes in wax and cutin compounds and the relationship with water loss in 'Red Fuji' and 'Golden Delicious' apples during shelf life

Knowledge of the dynamic composition changes of combined cuticular wax and cutin in apples during their shelf life is scarce. Therefore, this issue was addressed using GC-MS analyses of the respective epidermal components in 'Red Fuji' and 'Golden Delicious' apples at 5 days intervals during the shelf life of 25 days. Water loss from the apples was also assessed. The proportion of total n-alkanes decreased in cuticular wax, whereas total acids increased gradually, and cutin monomer content significantly changed during the first 5 days. The predominant wax compound, nonacosane (C₂₉), decreased by 40.13% and 26.22% in 'Red Fuji' and 'Golden Delicious' apples, respectively. The cutin monomers 10,16-dihydroxy hexadecanoic acid (10,16-diOH C_16:0) and 9,10,18-trihydroxyoctadecanoic acid (9,10,18-triOH C_18:0) were detected only at the beginning of shelf life in apples of both cultivars. Regression analysis indicated that the rate of water loss significantly correlated with eight components. Our results expand the understanding of the dynamics of both wax and cutin compounds in postharvest apples and help to target specific compounds to maintain the quality of apples throughout their shelf life.     

Distribution of POPs,pesticides and antibiotic residues in organic honeys from different production areas

Demand for honey is increasing, especially if it is organic and if its nutritional properties are linked to untreated environments in order to guarantee quality for health. Sources of contamination of honey can be divided into environmental and apicultural. Therefore, the distribution of persistent organic pollutants, pesticides and antibiotic residues from geographical areas with different contamination sources (high anthropic impact, intensive farming, husbandry and low anthropic impact) was investigated in order to confirm the potential transfer of xenobiotics into the supply chain and to give beekeepers tools for the selection of areas dedicated to organic production. The presence of polychlorinated biphenyls, polybrominated diphenyl ether and polycyclic aromatic hydrocarbons was confirmed, not only in proximity to highly urbanised centres, where the concentrations were higher, but in all environment contexts, confirming their ubiquity. No antibiotics or neonicotinoids were detected in 95 organic honeys, demonstrating the absence of apicultural treatments and consequently the good quality of honey of different areas. These results are important due to the undefined regulatory European situation on honey antibiotic limits.     

Investigating volatile compounds’ contributions to the stale odour of green tea

This study aimed to characterise the volatiles that contribute to stale odour of green tea. Volatiles were extracted using headspace solid-phase microextraction (HS-SPME) and analysed using gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry (GC-O). Results showed that a total of ninety-six volatiles were identified by GC-MS, in which forty-four volatiles were screened out based on Principal component analysis (PCA) and orthogonal projections to latent structures–discriminant analysis (OPLS-DA), and thirty-nine volatiles had a significant variation at the level of 0.05 by analysis of variance (anova ). From GC-O analysis, fifty-four aromatic volatiles with strong aroma intensity (aroma intensity above 2) were perceived. Further investigation revealed that fifteen volatiles, including 1-octen-3-ol, benzyl alcohol, benzaldehyde, safranal, β-cyclocitral, (E,E)-3,5-octadien-2-one, (Z,E)-3,5-octadien-2-one, dimethyl adipate, dihydroactinidiolide, β-ionone, α-ionone, geranyl acetone, phenylethyl alcohol, methyl decanoate and α-terpineol were responsible for stale odour, besides the former nine compounds were only found in stored tea.