Surveillance of the quality of turmeric powders from city markets of India on the basis of curcumin content and the presence of extraneous colours

Curcumin, the principal curcuminoid of turmeric, is responsible for its yellow colour and serves as a measure of turmeric quality. The Prevention of Food Adulteration (PFA) Act of India allows only Curcuma longa L. for the production of turmeric powder and prohibits addition of any foreign matter/artificial colour, but it does not specify a minimum curcumin content. The present surveillance was undertaken to study the quality of loose versus branded turmeric powders vis-à-vis curcumin content and the presence of unwarranted extraneous colours from city markets in India using a newly developed two-dimensional high-performance thin-layer chromatography (2D-HPTLC) method. The results show that curcumin content in branded samples ranged from 2.2% to 3.7%, while non-branded samples had from 0.3% to 2.6%. Though none of the branded turmeric powders contained artificial colours, 17% of loose powders showed the presence of extraneous colour metanil yellow, in the range 1.0–8.5 mg g^?1, which may pose health threats. Low curcumin content in the analysed samples may be due to mixing of other curcuma species or their curcumin-depleted matrices and foreign starches as cheaper alternatives. This is supported by the fact that major Indian turmeric trade types are known to possess curcumin contents ranging from 2.1% to 8.6%, with an average of 4.8%. There is thus an urgent need to prescribe realistic curcumin limits for turmeric powder, otherwise there is no obligation on the part of traders to stick to any minimum levels and consumers will keep on getting this nutrient-depleted household spice.     

A study of antioxidant properties of some varieties of grapes (Vitis vinifera L.)

Grapes (Vitis vinifera L.) are a major fruit crop in the world. Grapes seem to confer health benefits due to their antioxidant activity. We have evaluated the antioxidant potential of 11 grapes varieties from India and nearby Asian countries. The assays employed involve different levels of antioxidant action like ferric reducing antioxidant power, radical scavenging by 1,1-diphenyl-2-picrylhydrazyl, ferrylmyoglobin/2,2'-azobis-3-ethylbenzthiazoline-6-sulfonic acid, oxygen radical absorbance capacity (ORAC), and inhibition of lipid peroxidation. The total phenolic and flavonoids contents were also estimated. Our study indicates that cv. Mango is the most potent followed by Sharad Seedless. Ethanolic extracts were found to be more effective than aqueous extracts. Cv. Sharad Seedless, Mango, and Manikchaman also had high ORAC values. Their HPLC analysis showed the presence of various antioxidant polyphenols. In conclusion our studies identified some varieties of grapes with high antioxidant activities and showed that their high antioxidant potential may be due to their phenolic and flavonoid contents.     

Study of glasses/glass-ceramics in the SrO-ZnO-SiO2 system as high temperature sealant for SOFC applications

Glasses having composition (in wt.%) 51SrO-9ZnO-(40−x)SiO₂ (SZS), where x represents the additives like B₂O₃, Al₂O₃, V₂O₅, and Cr₂O₃, were prepared by melt-quench method and transformed into glass-ceramics by controlled crystallization based on differential thermal analysis (DTA) data. Glasses and glass-ceramics were characterized using dilatometry, X-ray diffraction (XRD), microhardness, and Raman spectroscopy. XRD revealed that glass-ceramics are composed of mainly Sr₂ZnSi₂O₇ and SrSiO₃ crystalline phases along with residual glassy phase. Raman spectroscopy showed that main constitutes of the glass network are the Q¹ and Q² silicate structural units. With the addition of B₂O₃ and other additives silicate glass network depolymerizes and concentration of Q¹ structural units increases at the expense of Q² units. Formation of phases during crystallization depends on the presence of different silicate structural units in the glass matrix. B₂O₃ goes into the glass network as triangular (BO₃) borate structural units and at higher concentration of B₂O₃, only a part of the B₂O₃ forms tetragonal (BO₄) structural units. Investigated glasses and glass-ceramics have thermal expansion coefficient (TEC) in the range of 105-120 × 10⁻⁷/°C which matches with TEC of other cell components. B₂O₃ containing SZS glasses show good adhesion/bonding with YSZ and Crofer 22 APU. Elemental line scans indicate that interdiffusion of Fe, Cr and Si across interface is responsible for good bonding with Crofer 22 APU and interdiffusion of Sr, Si, Y and Zr is responsible for good bonding with YSZ.     

On the analysis of the electrochemical spark machining process

The electrochemical spark machining (ECSM) process has been proved as a potential process for machining of low machinability high-strength electrically non-conducting materials, but the mechanism of material removal during the process, by and large, is not yet understood. In the present work, the electrochemical discharge is modelled as a phenomenon similar to that which occurs in arc discharge valves. This phenomenon is used to explain various experimental results, on the basis of circuit and arc discharge valve characteristics. The spark energy and the approximate order of hydrogen gas bubble diameter are computed by the proposed valve theory. Material removal rate is evaluated by modelling the problem as a 3-D unsteady state heat conduction problem. The problem is solved by the finite element method to compute the temperature distribution which is post-processed for estimating material removal per spark, overcut obtained in the machined cavity, and attainable maximum penetration depth. The conclusion drawn is that the application of valve theory to the ECSM process seems to be realistic. Estimated material removal rate, overcut and maximum penetration depth show a good agreement with experimental findings.     

A comparative study of thermal and hydraulic autofrettage

Thermal autofrettage is a potential process to generate beneficial compressive residual stresses at and around the inner wall of a thickwalled cylinder for increasing its pressure carrying capacity. Due to its simplicity and inexpensive arrangement, it can compete with the conventional hydraulic autofrettage process. In this work, a comparative study of the thermal autofrettage and the hydraulic autofrettage is carried out. As the thermal autofrettage does not require hydraulic power pack, the process is more economical than the hydraulic autofrettage. The thermal autofrettage process is also studied for the thick-walled cylindrical vessels subjected to high thermal gradient with or without pressure and is compared with the hydraulic autofrettage. Comparison shows that for cylinders subjected to high thermal gradient without pressure, the thermal autofrettage is superior to the hydraulic autofrettage.     

The effects of diet, ad libitum overfeeding, and moderate dietary restriction on the rodent bioassay: the uncontrolled variable in safety assessment

Ad libitum (AL) overfeeding is the most significant, uncontrolled variable affecting the outcome of the current rodent bioassay. There is a highly significant correlation between AL food consumption, the resultant obesity and body weight, and low 2-yr survival in rodents. AL feeding of diets with lowered protein, metabolizable energy (ME), and increased fiber does not improve survival. Only dietary restriction (DR) of all diets tested significantly improves survival and delays the onset of spontaneous degenerative disease (i.e., nephropathy and cardiomyopathy) and diet-related tumors. Moderate DR results in an incidence of spontaneous tumors similar to AL-fed rats, but the tumors are found incidentally and do not cause early mortality. There is a decreased age-adjusted incidence of pituitary and mammary gland tumors in moderate DR-fed rats, but tumor growth time is similar between AL and DR rats with only a delay in tumor onset time seen in DR-fed groups. Moderate DR does not significantly alter drug-metabolizing enzyme activities nor the toxicologic response to 5 pharmaceuticals tested at maximum tolerated doses (MTDs). However, moderate DR-fed rats did require much higher doses of 4 additional pharmaceutical compounds before classical MTDs were produced. Toxicokinetic studies of 2 of these compounds demonstrated equal or higher steady-state systemic exposures to parent drug and metabolites in moderate DR-fed rats. Markers of oxidative stress (lipid peroxidation, protein oxidation) are decreased and cytoprotective anti-oxidant markers are preserved in moderate DR-fed rats. But moderate DR does not delay reproductive senescence in female rats. Only marked DR delays reproductive senescence compared to AL and moderate DR-fed female rats. These and other data indicate that moderate DR is the most appropriate method of dietary control for the rodent bioassay when used to assess pharmaceuticals for human safety and compounds for risk assessment.     

Correlates of peak expiratory flow rate: a study of sand stone quarry workers in desert

BACKGROUND: Pulmonary infections continue to be a major cause of morbidity and mortality in patients with sickle cell disease (SCD). METHODS: In this study cell-mediated immunity in vitro was evaluated in 62 SCD patients (62 steady state and 16 with acute pneumonia) and compared with 44 normal controls (30 healthy and 14 with acute pneumonia). Lymphocyte blastogenic responses to phytohemagglutinin, tetanus toxoid and Candida albicans antigen were assessed in all subjects. In addition production of tumor necrosis factor, alpha- and gamma-interferon (IFN) were assayed. RESULTS: The results revealed comparable blastogenic responses to all three stimuli in all subjects except SCD patients with pneumonia. This group showed poor responses to all stimuli. The mean counts per minute were decreased 65 to 90% when compared with the other patients. Cytokine production of IFN-alpha and TNF was equivalent in all subjects. Conversely IFN-gamma production in both SCD groups, steady state (35 +/- 6 U/ml) and SCD with pneumonia (14 +/- 6 U/ml), was significantly decreased when compared with those in normal healthy controls (65 +/- 14 U/ml) and with pneumonia (48 +/- 17 U/ml). On analysis of individual titers 15 of 62 (24%) steady state and 10 of 16 (63%) SCD patients with pneumonia were deficient in IFN-gamma production in vitro. CONCLUSIONS: Acute pulmonary infections seem to have a profound effect on cell-mediated immunity in SCD. IFN-gamma deficiency, along with quantitative and qualitative T cell abnormalities, may represent significant factors to explain the frequent and severe infections seen in SCD.     

APPLICATION OF NORMAL AND DERIVATIVE ULTRAVIOLET ABSORPTION SPECTROSCOPY FOR THK DETERMINATION OF AROMATIC HYDROCARBONS IN GAS OILS

Ultraviolet absorption spectroscopy, has an immense potential for characterization of aromatic hydrocarbons in distillate petroleum fractions. The second derivative ultraviolet spectroscopy has improved the understanding of complex aromatic structures, such as polynuclear aromatics, which are present in gas oil fractions. Normal and second derivative ultraviolet spectroscopy of gas oils and their separated fractions are discussed in detail and conclusions are drawn regarding mono-di-and polynuclear aromatics in various gas oils.