The global prevalence of type 2 diabetes is increasing rapidly; consequently there is great need for new and novel therapeutic options. Gynostemma pentaphyllum (GP) is a traditional medicinal plant, mainly present in Southeast Asian countries, that has been reported to exert antidiabetic effects, by stimulating insulin secretion. The specific compound responsible for this effect is however as yet unidentified. Screening for discovery and identification of bioactive compounds of an herbal GP extract, was performed in isolated pancreatic islets from spontaneously diabetic Goto-Kakizaki (GK) rats, a model of type 2 diabetes, and from non-diabetic control Wistar rats. From this herbal extract 27 dammarane-type saponins, including two novel compounds, were isolated and their structure was elucidated by mass spectrometry and NMR spectroscopy. One of the dammarane-type triterpenoid showed a glucose-dependent insulin secretion activity. This compound, gylongiposide I, displays unique abilities to stimulate insulin release at high glucose levels (16.7 mM), but limited effects at a low glucose concentration (3.3 mM). Further studies on this compound, also in vivo, are warranted with the aim of developing a novel anti-diabetic therapeutic with glucose-dependent insulinogenic effect.

Saffron, the dried red stigmas of Crocus sativus L. is the world's most expensive spice. The expense of Saffron has led to greater incidences of fraudulent practice within this market. The importation and rebranding of cheaper growing regions to be passed off as regions of higher quality is one such practice. Analytical techniques have been reported in literature for rapid detection of these fraud issues. These techniques can be affected by post harvest processing, therefore more confirmatory techniques with direct links to the environment should also be considered. Trace element concentrations and stable isotopic ratios are investigated in this study to differentiate the geographic origins of Saffron grown in Khorasan Province, Iran and the La Mancha region of Spain. Statistical analysis of the data using Linear Discriminate Analysis (LDA) resulted in a classification model which could determine saffron from each origin, suggesting this is a feasible confirmatory approach for origin verification of Saffron.

Membrane lipids, including sphingolipids and glycerol-phospholipids, are essential in maintaining the skin's barrier function in mammals, but their composition in fish skin and their response to diets have not been evaluated. This study investigated the impacts of reducing dietary eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on membrane lipids in the skin of Atlantic salmon through a 26 week feeding regime supplying different levels (0-2.0% of dry mass) of EPA/DHA. Ceramide, glucosylceramide, sphingomyelin, sphingosine, and sphinganine in salmon skin were analyzed for the first time. Higher concentrations of glucosylceramide and sphingomyelin and higher ratios of glucosylceramide/ceramide and sphingomyelin/ceramide were detected in the deficient group, indicating interruptions in sphingolipidomics. Changes in the glycerol-phospholipid profile in fish skin caused by reducing dietary EPA and DHA were observed. There were no dietary impacts on epidermal thickness and mucus-cell density, but the changes in the phospholipid profile suggest that low dietary EPA and DHA may interrupt the barrier function of fish skin.

During the last decade there has been an ongoing controversy regarding the extent to which nitrogen fertilization can increase carbon sequestration and net ecosystem production in forest ecosystems. The debate is complicated by the fact that increased nitrogen availability caused by nitrogen deposition has coincided with increasing atmospheric carbon dioxide concentrations. The latter could further stimulate primary production but also result in increased allocation of carbon to root exudates, which could potentially ‘prime’ the decomposition of soil organic matter. Here we show that increased input of labile carbon to forest soil caused a decoupling of soil carbon and nitrogen cycling, which was manifested as a reduction in respiration of soil organic matter that coincided with a substantial increase in gross nitrogen mineralization. An estimate of the magnitude of the effect demonstrates that the decoupling could potentially result in an increase in net ecosystem production by up to 51 kg C ha−1 day−1 in nitrogen fertilized stands during peak summer. Even if the effect is several times lower on an annual basis, the results still suggest that nitrogen fertilization can have a much stronger influence on net ecosystem production than can be expected from a direct stimulation of primary production alone.

This chapter reviews the application of stable isotope ratio measurements to verify the authenticity of dairy products such as milk and cheese using a conventional batch approach. It presents an alternative using a predictive model to reduce the data burden and, hence lower some of the barriers to those wishing to use isotope ratio analysis as an authentication tool for dairy products. A high-profile international case was the addition of melamine to milk powder, which was later incorporated into infant formula. The major constituents of milk are water, lactose, protein, and fat, which typically comprise 87", 4.6", 3.3" and 4.0" of the total milk composition, respectively. Conventional stable isotopes methods have, however, proved unable to distinguish the origin of adulterated dairy products once they are incorporated into mixtures. The importance of milk in the human diet and especially its use as an ingredient in infant formula makes it a target for deliberate contamination for pecuniary gain.

Traceability of dairy products is an important issue for the dairy industry. Empirical studies have demonstrated the utility of stable isotope measurements on milk for verification of origin. However, various drivers influence the isotopic composition of a food stuff, such as rainfall levels or food supplements. Relationships between the isotopic composition (δ2H, δ18O, δ13C and δ15N) of milk fatty acids, the water component of the milk, and feed and farm water from 18 New Zealand dairy farms were studied. Significant relationships between the isotopic composition of milk and both farm water and feed fatty acids were observed. Measurement of both diet and drinking water from each dairy farm enabled the underlying environmental correlations to milk fatty acids to be explored by analysis of their respective δ2H values. Development of this technology may provide a diagnostic tool for determining type and the origin of dietary feed utilised in milk production.

Hydrogen isotope ratios (delta H-2) have become a tool for food traceability and authentication of agricultural products. The principle is that the isotopic composition of the produce is influenced by environmental and biological factors and hence exhibits a spatial differentiation of delta H-2. This study investigates the variation in delta H-2 values of New Zealand milk, both in the bulk powder and individual fatty acids extracted from milk samples from dairy factories across New Zealand. Multivariate statistical analyses were used to test for relationships between delta H-2 of bulk milk powder, milk fatty acid and geographical location. Milk powder samples from different regions of New Zealand were found to exhibit patterns in isotopic composition similar to the corresponding regional precipitation associated with their origin.A model of delta H-2 in precipitation was developed based on measurements between 2007 and 2010 at 51 stations across New Zealand (Frew and Van Hale, 2011). The model uses multiple linear regressions to predict daily delta H-2 from 2 geographic and 5 rain-weighted climate variables from the 5 x 5 km New Zealand Virtual Climate Station Network (VCSN). To approximate collection radius for a drying facility the modelled values were aggregated within a 50 km radius of each dairy factory and compared to observed delta H-2 values of precipitation and bulk milk powder. Daily delta H-2 predictions for the period from August to December for the area surrounding the sample collection sites were highly correlated with the delta H-2 values of bulk milk powder. Therefore the delta H-2 value of milk fatty acids demonstrates promise as a tool for determining the provenance of milk powders and products where milk powder is an ingredient. Separation of milk powder origin to geographic sub-regions within New Zealand was achieved. Hydrogen isotope measurements could be used to complement traditional tracking systems in verifying point of origin. (C) 2012 Elsevier Ltd. All rights reserved.

The aim of this study was to investigate the correlation of δ²H and δ¹³C of bulk milk powder and milk powder fatty acids to their production region. A total of 46 milk powder samples from across New Zealand were collected and analyzed. Principal component analysis (PCA) showed that the δ²H and δ¹³C of four fatty acids (C4:0, C14:0, C16:0, C18:1) and bulk milk powder were found to be correlated with regional production area. Linear discriminant analysis (LDA) models were prepared using different combinations of bulk and fatty acid δ²H and δ¹³C. All models were effective in discriminating samples from the North and South Islands. The LDA model using just fatty acid δ²H and δ¹³C provided the best separation. Therefore, the isotopic composition of the aforementioned fatty acids can be utilized as a good biomarker in milk powder that conveys reliable isotopic information to track milk powders to their regional origin.