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BACKGROUND: Berry pomaces obtained after commercial juice production contain phytochemicals which may find use as antioxidants, food additives and biomedical products. Oil extraction from seeds provides additional value but the availability of phytochemicals before and after oil extraction is not well established. OBJECTIVE: This pilot study defines the content and composition of phytochemicals from raspberry and black currant pomaces after extraction with water-ethanol mixes, but also before and after milling/ oil extraction. METHODS: The total phenol (TPC), total anthocyanin (TAC) and antioxidant content of extracts was assessed. Their phytochemical composition was studied using liquid chromatography-mass spectrometry (LC-MSn). RESULTS: TPC and TAC increased with increasing % ethanol. Anthocyanins were major components in blackcurrant pomace and were more readily extracted than total phenols. Total oil content and composition was not influenced by solvent pre-extraction. Milling/ oil extraction markedly increased TPC from raspberry but not from blackcurrant pomace. LC-MSn confirmed characteristic phytochemical compositions and that increasing % ethanol increased yield of certain components. Milling increased specific ellagitannins, proanthocyanins and triterpenoids from raspberry. CONCLUSIONS: Milling/ oil extraction increased the yield and phytochemical diversity of extracts from raspberry but not from blackcurrant pomace which suggests that the phytochemicals from blackcurrant pomace are largely available on the pomace surfaces.

Honey is known to have antimicrobial, immunomodulatory and wound healing properties. The biological properties of honey have been attributed to phytochemicals derived from their source plants and research has focused on identifying the bioactive phytochemicals with therapeutic potential. In this study, we determined the ability of 5 honeys from Kazakhstan and manuka honey to stimulate TNF-α and TGF-β production by human keratinocytes. TNF-α and TGF-β levels increased over time in honey treated and untreated keratinocytes, whereas cells treated with sugar solutions that matched those of the honeys had reduced levels of both cytokines. This suggests that the non-sugar phytochemical components of the honeys may have prevented this decrease. Analysis by LC-MS confirmed that the honeys contained a diverse range of phytochemicals. Some phytochemicals e.g. pinobanksin and vanillin were present at different levels across the honey types, whereas other components, e.g. dicarboxylic acids and their glycosides, were abundant in all honeys.

In this work, Hydrophilic Interaction Liquid Chromatography – Mass Spectrometry (HILIC-MS) was applied to assess the metabolic profiles of different tissues and industrially relevant co-products of alginate extraction from Laminaria hyperborea samples obtained in different seasons. This is the first metabolomic analysis in L. hyperborea and it allowed the putative identification of 59 metabolites using positive and negative mode MS data, predicted exact mass data and matching with database and literature searches. Another 16 components were detected but these could not be identified as yet. The metabolites ranged from known and abundant components (e.g., iodide, mannitol and various betaines) to components not previously noted in this species. The levels of these components varied between tissues and co-products with some metabolites seemingly specific to certain samples. The components also varied between winter and summer samples, perhaps reflecting seasonality in their biosynthesis and accumulation in the tissues and co-products.Therefore, the method can be used to survey the seasonal metabolomic variation across the full year and thereby track when components of potential specific commercial interest were maximally accumulated and help plan the most efficient exploitation of the harvested biomass. The method could also define variation in components in L. hyperborea from different locations or potential biotopes of this species. This initial work extends our ability to understand the phenotype of seaweeds whilst also identifying new components and new commercial opportunities.

Highlights • The response to nitrogen of 4 winter oat varieties in three field trials was analysed. • A novel high-resolution method was developed to profile metabolite changes. • Conditions that enhance yield do not necessarily result in higher nutritional value. • Choice of variety is of equally high importance as the nitrogen levels applied., Oats (Avena sativa L.) are a healthy food, being high in dietary fibre (e.g. β-glucans), antioxidants, minerals, and vitamins. Understanding the effect of variety and crop management on nutritional quality is important. The response of four oat varieties to increased nitrogen levels was investigated across multiple locations and years with respect to yield, grain quality and metabolites (assessed via GC- and LC- MS). A novel high-resolution UHPLC-PDA-MS/MS method was developed, providing improved metabolite enrichment, resolution, and identification. The combined phenotyping approach revealed that, amino acid levels were increased by nitrogen supplementation, as were total protein and nitrogen containing lipid levels, whereas health-beneficial avenanthramides were decreased. Although nitrogen addition significantly increased grain yield and β-glucan content, supporting increasing the total nitrogen levels recommended within agricultural guidelines, oat varietal choice as well as negative impacts upon health beneficial secondary metabolites and the environmental burdens associated with nitrogen fertilisation, require further consideration.

Cichorium intybus L. has recently gained major attention due to large quantities of health-promoting compounds in its roots, such as inulin and sesquiterpene lactones (SLs). Chicory is the main dietary source of SLs, which have underexplored bioactive potential. In this study, we assessed the capacity of SLs to permeate the intestinal barrier to become physiologically available, using in silico predictions and in vitro studies with the well-established cell model of the human intestinal mucosa (differentiated Caco-2 cells). The potential of SLs to modulate inflammatory responses through modulation of the nuclear factor of activated T-cells (NFAT) pathway was also evaluated, using a yeast reporter system. Lactucopicrin was revealed as the most permeable chicory SL in the intestinal barrier model, but it had low anti-inflammatory potential. The SL with the highest anti-inflammatory potential was 11&beta, 13-dihydrolactucin, which inhibited up to 54% of Calcineurin-responsive zinc finger (Crz1) activation, concomitantly with the impairment of the nuclear accumulation of Crz1, the yeast orthologue of human NFAT.

In some growing environments blueberry (Vaccimium corymbosum L.) yields exhibit excessive annual variation associated with poor photosynthetic performance. The purpose of this study was to determine how photosynthesis may be affected by demand and to define the mechanisms underpinning photosynthetic plasticity. Manipulation of source-sink ratios revealed that yields were maintained following 50 % defoliation. This was associated with an adaptive increase in photosynthetic capacity mediated via changes in stomatal physiology, photosynthetic electron transport and CO2 assimilation. Transcripts encoding enzymes of the Calvin-Benson cycle including the Rubisco large subunit, Rubisco activase, phosphoribulokinase and plastid-localised glyceraldehyde phosphate dehydrogenase 3 were more abundant in leaves from partially defoliated plants relative to control plants. Short-term 13CO2 labelling experiments suggested that partial defoliation did not incur an assimilation penalty although the accumulation of sugars and starch in some organs was reduced. Metabolite profiles of leaves from partially defoliated plants exhibited some differences from those of control leaves, however, no changes in the diurnal content of leaf sugar and starch were observed between treatments. The data highlights the mechanisms by which blueberry leaves adapt to increased demand and demonstrate that photosynthetic plasticity can compensate for significant loss of the photosynthetic area.

Introduction Blackcurrant (Ribes nigrum L.) is an excellent example of a “super fruit” with potential health benefits. Both genotype and cultivation environment are known to affect the chemical composition of blackcurrant, especially ascorbic acid and various phenolic compounds. Environmental conditions, like temperature, solar radiation and precipitation can also have significant impact on fruit chemical composition. The relevance of the study is further accentuated by the predicted and ongoing changes in global climate. Objectives The aim of the present study was to provide new knowledge and a deeper understanding of the effects of post flowering environmental conditions, namely temperature and day length, on fruit quality and chemical composition of blackcurrant using an untargeted high performance liquid chromatography–photo diode array–mass spectrometry (HPLC–PDA–MS) metabolomics approach. Methods A phytotron experiment with cultivation of single-stemmed potted plants of blackcurrant cv. Narve Viking was conducted using constant temperatures of 12, 18 or 24 °C and three different photoperiods (short day, short day with night interruption, and natural summer daylight conditions). Plants were also grown under ambient outdoor conditions. Ripe berries were analysed using an untargeted HPLC–PDA–MS metabolomics approach to detect the presence and concentration of molecules as affected by controlled climatic factors. Results The untargeted metabolomics dataset contained a total of 7274 deconvolved retention time-m/z pairs across both electrospray ionisation (ESI) positive and negative polarities, from which 549 metabolites were identified or minimally annotated based upon accurate mass MS. Conventional principal component analysis (PCA) in combination with the Friedman significance test were applied to first identify which metabolites responded to temperature in a linear fashion. Multi-block hierarchical PCA in combination with the Friedman significance test was secondly applied to identify metabolites that were responsive to different day length conditions. Temperature had significant effect on a total of 365 metabolites representing a diverse range of chemical classes. It was observed that ripening of the blackcurrant berries under ambient conditions, compared to controlled conditions, resulted in an increased accumulation of 34 annotated metabolites, mainly anthocyanins and flavonoids. 18 metabolites were found to be regulated differentially under the different daylength conditions. Moreover, based upon the most abundant anthocyanins, a comparison between targeted and untargeted analyses, revealed a close convergence of the two analytical methods. Therefore, the study not just illustrates the value of non-targeted metabolomics approaches with respect to the huge diversity and numbers of significantly changed metabolites detected (and which would be missed by conventional targeted analyses), but also shows the validity of the non-targeted approach with respect to its precision compared to targeted analyses. Conclusions Blackcurrant maturation under controlled ambient conditions revealed a number of insightful relationships between environment and chemical composition of the fruit. A prominent reduction of the most abundant anthocyanins under the highest temperature treatments indicated that blackcurrant berries in general may accumulate lower total anthocyanins in years with extreme hot summer conditions. HPLC–PDA–MS metabolomics is an excellent method for broad analysis of chemical composition of berries rich in phenolic compounds. Moreover, the experiment in controlled phytotron conditions provided additional knowledge concerning plant interactions with the environment. Electronic supplementary material The online version of this article (10.1007/s11306-018-1462-5) contains supplementary material, which is available to authorized users.

Anthocyanin content of potato tubers is a trait that is attracting increasing attention as the potential nutritional benefits of this class of compound become apparent. However, our understanding of potato tuber anthocyanin accumulation is not complete. The aim of this study was to use a potato microarray to investigate gene expression patterns associated with the accumulation of purple tuber anthocyanins. The advanced potato selections, CO97216-3P/PW and CO97227-2P/PW, developed by conventional breeding procedures, produced tubers with incomplete expression of tuber flesh pigmentation. This feature permits sampling pigmented and non-pigmented tissues from the same tubers, in essence, isolating the factors responsible for pigmentation from confounding genetic, environmental, and developmental effects. An examination of the transcriptome, coupled with metabolite data from purple pigmented sectors and from non-pigmented sectors of the same tuber, was undertaken to identify these genes whose expression correlated with elevated or altered polyphenol composition. Combined with a similar study using eight other conventional cultivars and advanced selections with different pigmentation, it was possible to produce a refined list of only 27 genes that were consistently differentially expressed in purple tuber tissues compared with white. Within this list are several new candidate genes that are likely to impact on tuber anthocyanin accumulation, including a gene encoding a novel single domain MYB transcription factor.

Plant polyphenolics continue to be the focus of attention with regard to their putative impact on human health. An increasing and ageing human population means that the focus on nutrition and nutritional enhancement or optimisation of our foodstuffs is paramount. Using the raspberry as a model, we have shown how modern metabolic profiling approaches can be used to identify the changes in the level of beneficial polyphenolics in fruit breeding segregating populations and how the level of these components is determined by genetic and/or environmental control. Interestingly, the vitamin C content appeared to be significantly influenced by environment (growth conditions) whilst the content of the polyphenols such as cyanidin, pelargonidin and quercetin glycosides appeared much more tightly regulated, suggesting a rigorous genetic control. Preliminary metabolic profiling showed that the fruit polyphenolic profiles divided into two gross groups segregating on the basis of relative levels of cyanidin-3-sophoroside and cyanidin-3-rutinoside, compounds implicated as conferring human health benefits.