Influence of the chemical structure on the thermal degradation of the glucosinolates in broccoli sprouts

Glucosinolates are secondary plant metabolites occurring in Brassica vegetables. Food processing significantly reduces glucosinolate content, among other things due to thermal degradation. As there is only little information about thermal glucosinolate breakdown, the influence of the chemical structure as well as the influence of different pH to thermal degradation of individual glucosinolates was studied by analysing desulphoglucosinolates with HPLC-DAD. Thermal degradation was forced by heating broccoli sprouts at 130 °C in dry medium, whereas the influence of the pH was studied by cooking at 100 °C in aqueous medium. Within each group of glucosinolates differences in thermal degradation were revealed. Within the sulphur containing aliphatic glucosinolates the oxidative state of the sulphur atom as well as the side chain length influenced the reactivity. Among the indole glucosinolates great differences in stability were observed. A hydroxyl function in the side chain generally seems to destabilise glucosinolates. Glucosinolates were most stable towards thermal treatment in neutral and slightly acidic medium, whereas they degraded more rapidly in basic medium.     

The effect of temperature and radiation on flavonol aglycones and flavonol glycosides of kale (Brassica oleracea var. sabellica)

The winter crop kale has a complex profile of different glycosylated and acylated flavonol glycosides which may be affected by global warming. To the best of our knowledge, compound–climate relationships for flavonol aglycones and flavonol glycosides were established for the first time. The investigated 10 major flavonol glycosides responded structure-dependent in the investigated temperature range between 0 and 12 °C and the photosynthetic active radiation range between 4 and 20 mol m⁻² d⁻¹, e.g. the decrease in temperature led to an increase in sinapic acid monoacylated and diacylated quercetin glycosides, while the sinapic acid monoacylated kaempferol glycosides showed a maximum at 4.5 °C. Furthermore, the hydroxycinnamic acid residues and the different number of glucose moieties in the 7-O position affected the response of kaempferol triglucosides. Consequently, global warming would result in lower concentrations of antioxidant-relevant quercetin glycosides in winter crops, suggesting a production at e.g. higher altitudes due to lower temperature.     

Predictors of high-risk alcohol consumption in young offenders on community orders: Policy and treatment implications.

The present study examined the relationship between a set of individual and contextual variables and high-risk alcohol use among young offenders placed on community orders in New South Wales, Australia. Participants (n = 777) were compared on a set of factors known to be strong predictors of high-risk alcohol use among adolescents. The authors assessed the strength of the relationship between gender, age, ethnicity, geographical region of residence, school attendance, father absence, history of childhood trauma, and the presence of severe conduct disorder on weekly levels of alcohol use. Living in rural locations, not currently attending school, being female, and not having been raised with a biological father present were associated with significantly increased odds of alcohol abuse. Father absence was a more important risk factor for rural young offenders, but school dropout was associated with more hazardous drinking among young offenders in urban areas. Accordingly, the authors suggest family-focused intervention programs for young offenders living in rural areas and school-based programs for vulnerable young people living in urban areas, although programs should consider including both factors for both groups if feasible and warranted. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Long-term sweat collection using salt-impregnated pads

To facilitate a study of the pharmacokinetics of drugs dissolved in sweat, a technique was devised for collecting sweat at a steady rate over an 8-day period. Three normal subjects each wore 4 absorbent pads applied to their skin under waterproof dressings for 8 days. The absorbent pads were either plain cotton or cotton impregnated with sodium chloride crystals. Each pad (3 cm x 3 cm) was applied to an area of skin (2 cm x 2 cm) defined by an adhesive template, and was removed daily, weighed, and replaced, to determine progressive uptake of sweat. Sweat uptake by plain cotton pads reached a plateau value within 2 to 3 days and did not significantly increase thereafter; in contrast, uptake by the salt-impregnated pads continued at a steady rate for the full 8 days of the study (mean rate 0.79 mg/cm2/hr, SD = 0.16, N = 6). This effect may be related to an osmotic gradient across the skin, but the physiologic mechanisms are not completely clear. This appears to be a convenient tool for the collection of sweat over long periods at a steady rate.     

Effect of cholesterol and cholestyramine feeding and of fasting on sterol synthesis in the liver, lleum, and lung of the guinea pig

The effects of feeding diest containing either cholesterol (0.24% w/w) or cholestyramine (2.5% w/w) and of fasting on sterol synthesis in the liver, ileum, and lung of both male and female guinea pigs have been studied by measuring the incorporation by tissue slices of 14C-labeled acetate into total digitoninpredipitable sterols. Cholesterol feeding significantly decreased (P less than 0.05) sterol synthesis in the liver, ileum, and lung of the males and in the ileum of females. Cholestyramine feeding stimulated the rate of hepatic sterol synthesis 13-fold but did not significantly affect sterologenesis in the ileum. Sterol synthesis in the lung was significantly increased (P less than 0.05) but to a much lesser extent than in the liver. Fatty acid synthesis in the liver, ileum, and lung was not significantly affected by either cholesterol or cholestyramine feeding. In guinea pigs fasted for 24 hr, sterol synthesis was inhibited in all three tissues, the most pronounced effect occurring in the liver. Only in the lung was fatty acid synthesis significantly decreased (P less than 0.001) by fasting. Cholesterol feeding resulted in increased concentrations of cholesterol in the plasma and liver. Cholestyramine feeding reduced plasma cholesterol concentration by 81% in females and by 64% in males. However, it did not significantly change the tissue cholesterol concentrations. Fasting resulted in a significant increase (P less than 0.05) in plasma cholesterol concentration but did not effect the concentration of cholesterol in the tissues. It was concluded that in the normal guinea pig, the feedback inhibition produced by both cholesterol and also possibly by bile acids suppresses sterol synthesis in the liver to very low rates compared to those in the small intestine, where sterologenesis is not only less sensitive to the cholesterol negative feedback system than that in the liver, but also is not subject to regulation by the bile acid negative feedback system.