Recovery of Polyphenols from Brewer’s Spent Grains

peer-reviewedThe recovery of antioxidant polyphenols from light, dark and mix brewer’s spent grain (BSG) using conventional maceration, microwave and ultrasound assisted extraction was investigated. Total polyphenols were measured in the crude (60% acetone), liquor extracts (saponified with 0.75% NaOH) and in their acidified ethyl acetate (EtOAc) partitioned fractions both by spectrophotometry involving Folin–Ciocalteu reagent and liquid-chromatography-tandem mass spectrometry (LC-MS/MS) methods. Irrespective of the extraction methods used, saponification of BSG yielded higher polyphenols than in the crude extracts. The EtOAc fractionations yielded the highest total phenolic content (TPC) ranging from 3.01 ± 0.19 to 4.71 ± 0.28 mg gallic acid equivalent per g of BSG dry weight. The corresponding total polyphenols quantified by LC-MS/MS ranged from 549.9 ± 41.5 to 2741.1 ± 5.2 µg/g of BSG dry weight. Microwave and ultrasound with the parameters and equipment used did not improve the total polyphenol yield when compared to the conventional maceration method. Furthermore, the spectrophotometric quantification of the liquors overestimated the TPC, while the LC-MS/MS quantification gave a closer representation of the total polyphenols in all the extracts. The total polyphenols were in the following order in the EtOAc fractions: BSG light > BSG Mix > BSG dark, and thus suggested BSG light as a sustainable, low cost source of natural antioxidants that may be tapped for applications in food and phytopharmaceutical industries

Little Higgs after the little one

At the LHC, the Littlest Higgs Model with $T$-parity is characterised by various production channels. If the $T$-odd quarks are heavier than the exotic partners of the $W$ and the $Z$, then associated production can be as important as the pair-production of the former. Studying both, we look for final states comprising at least one lepton, jets and missing transverse energy. We consider all the SM processes that could conspire to contribute as background to our signals, and perform a full detector level simulation of the signal and background to estimate the discovery potential at the current run as well as at the scheduled upgrade of the LHC. We also show that, for one of the channels, the reconstruction of two tagged $b$-jets at the Higgs mass $(M_h = 125~{\rm GeV})$ provides us with an unambiguous hint for this model.Comment: 22 pages, 3 captioned figures, 8 Tables; minor modifications, version published in JHE

A note on the effectiveness of selenium supplementation of Irish-grown Allium crops.

peer-reviewedThis study is funded by the Department of Agriculture and Food through the Network and Team Building Initiative of the Food Institutional Research Measure (FIRM Reference Number 06/NITARFC6).Onions and other Allium crops contain high levels of dietary phenolics and, unlike many other crops, accumulate the beneficial mineral selenium. Selenium-enhanced Allium crops are of interest both from a public good perspective and as a market positioning strategy for growers. Field trials were carried out to i) identify onion and scallion varieties that contain high levels of health-promoting phenolic and flavonoid compounds as potential targets for selenium supplementation and ii) investigate selenium supplementation in the widely-grown commercial onion variety ‘Hyskin’ at different application rates of nitrogen fertilizer. Levels of selenium in onion bulbs were significantly increased from 0.5–5.9 μg/g dry weight (DW) to 40.6–70.0 μg/g DW.Department of Agriculture, Food and the Marin

Client Selection in Federated Learning under Imperfections in Environment

Federated learning promises an elegant solution for learning global models across distributed and privacy-protected datasets. However, challenges related to skewed data distribution, limited computational and communication resources, data poisoning, and free riding clients affect the performance of federated learning. Selection of the best clients for each round of learning is critical in alleviating these problems. We propose a novel sampling method named the irrelevance sampling technique. Our method is founded on defining a novel irrelevance score that incorporates the client characteristics in a single floating value, which can elegantly classify the client into three numerical sign defined pools for easy sampling. It is a computationally inexpensive, intuitive and privacy preserving sampling technique that selects a subset of clients based on quality and quantity of data on edge devices. It achieves 50–80% faster convergence even in highly skewed data distribution in the presence of free riders based on lack of data and severe class imbalance under both Independent and Identically Distributed (IID) and Non-IID conditions. It shows good performance on practical application datasets

The Effect of High Pressure Processing on Polyphenol Oxidase Activity, Phytochemicals and Proximate Composition of Irish Potato Cultivars

peer-reviewedPolyphenol oxidase (PPO) activity, proximate composition, and phytochemicals were determined in four common Irish potato cultivars following a high pressure processing (HPP) at 600 MPa for 3 min. PPO activity was significantly (p < 0.05) lower in all HPP treated samples, while the overall proximate composition was not affected. The total phenolic content was significantly higher in the HPP treated samples. Chlorogenic acid levels significantly decreased with simultaneous increase of caffeic acid and p-coumaric acid levels upon HPP treatment. No significant changes were observed in rutin and ferulic acid levels, although their levels varied, depending on the potato cultivars, while the levels of cytotoxic glycoalkaloids (α-solanine and α-chaconine) remained unaltered

Effect of Drying Methods on the Steroidal Alkaloid Content of Potato Peels, Shoots and Berries

peer-reviewedThe present study has found that dried potato samples yielded significantly higher levels of steroidal alkaloids such as α-solanine and α-chaconine than the corresponding fresh samples, as determined by the UPLC-MS/MS technique. Among the drying techniques used, air drying had the highest effect on steroidal alkaloid contents, followed by freeze drying and vacuum oven drying. There was no significant difference between the freeze dried and vacuum oven dried samples in their α-chaconine contents. However, freeze dried potato shoots and berries had significantly higher α-solanine contents (825 µg/g dry weight (DW) in shoots and 2453 µg/g DW in berries) than the vacuum oven dried ones (325 µg/g dry weight (DW) in shoots and 2080 µg/g DW in berries). The kinetics of steroidal alkaloid contents of potato shoots during air drying were monitored over a period of 21 days. Both α-solanine and α-chaconine content increased to their maximum values, 875 µg/g DW and 3385 µg/g DW, respectively, after 7 days of drying. The steroidal alkaloid contents of the shoots decreased significantly at day 9, and then remained unchanged until day 21. In line with the potato shoots, air dried potato tuber peels also had higher steroidal alkaloid content than the freeze dried and vacuum oven dried samples. However, a significant decrease of steroidal alkaloid content was observed in air dried potato berries, possibly due to degradation during slicing of the whole berries prior to air drying. Remarkable variation in steroidal alkaloid contents among different tissue types of potato plants was observed with the potato flowers having the highest content.This study has been carried out with the financial support from the Potato Peel project funded under the Food Institutional Research Measure (FIRM, 11F/050; NovTechIng) by the Irish Department of Agriculture, Food and Marine

Qualitative and Quantitative Analysis of Polyphenols in Lamiaceae Plants—A Review

peer-reviewedLamiaceae species are promising potential sources of natural antioxidants, owing to their high polyphenol content. In addition, increasing scientific and epidemiological evidence have associated consumption of foods rich in polyphenols with health benefits such as decreased risk of cardiovascular diseases mediated through anti-inflammatory effects. The complex and diverse nature of polyphenols and the huge variation in their levels in commonly consumed herbs make their analysis challenging. Innovative robust analytical tools are constantly developing to meet these challenges. In this review, we present advances in the state of the art for the identification and quantification of polyphenols in Lamiaceae species. Novel chromatographic techniques that have been employed in the past decades are discussed, ranging from ultra-high-pressure liquid chromatography to hyphenated spectroscopic methods, whereas performance characteristics such as selectivity and specificity are also summarized

Apple Pomace as a Potential Ingredient for the Development of New Functional Foods

Extruded snacks and baked scones were formulated with increasing levels (0-30%) of apple pomace (AP). The incorporation of up to 20% of AP in extruded snacks and in baked scones does not change significantly (pβ-carotene/linoleic acid system) increased when compared to the products to which no AP was added. Chlorogenic acid and quercetin were the major phenolic compounds found in the products. Loss of phenolic compounds during heat treatment occurred, however the DPPH radical scavenging activity of final products was not affected

Observations on the water distribution and extractable sugar content in carrot slices after pulsed electric field treatment

peer-reviewedThe impact of pulsed electric field (PEF) processing conditions on the distribution of water in carrot tissue and extractability of soluble sugars from carrot slices was studied. Time domain NMR relaxometry was used to investigate the water proton mobility in PEF-treated carrot samples. Three distinct transverse relaxation peaks were observed in untreated carrots. After PEF treatment only two slightly-overlapping peaks were found; these were attributed to water present in the cytoplasm and vacuole of carrot xylem and phloem tissues. This post-treatment observation indicated an increase in water permeability of tissues and/or a loss of integrity in the tonoplast. In general, the stronger the electric field applied, the lower the area representing transverse relaxation (T2) values irrespective of treatment duration. Moreover an increase in sucrose, β- and α-glucose and fructose concentrations of carrot slice extracts after PEF treatment suggested increases in both cell wall and vacuole permeability as a result of exposure to pulsed electric fields.The authors acknowledge financial support from the Irish Phytochemical Food Network (IPFN) project funded under the Food Institutional Research Measure (FIRM, 06/TNI/AFRC6) of the Irish Department of Agriculture, Food and Marine. Dr. Aguiló-Aguayo thanks Generalitat of Catalonia for the postdoctoral grant Beatriu de Pinós (BP-DGR2010). E. Balagueró thanks the Lifelong Learning Programme for the internship grant Leonardo da Vinci MOTIVA3 (201 1-1-ES1-LEO02-34225)

Dark Matter and Collider Searches in S3S_3-Symmetric 2HDM with Vector Like Leptons

We study the $S_3$-symmetric two Higgs doublet model by adding two generations of vector like leptons (VLL) which are odd under a discrete $Z_2$ symmetry. The lightest neutral component of the VLL acts as a dark matter (DM) whereas the full VLL set belongs to a dark sector with no mixings allowed with the standard model fermions. We analyse the model in light of dark matter and collider searches. We show that the DM is compatible with the current relic density data as well as satisfying all direct and indirect dark matter search constraints. We choose some representative points in the model parameter space allowed by all aforementioned dark matter constraints and present a detailed collider analysis of multi-lepton signal viz. the mono-lepton, di-lepton, tri-lepton and four-lepton along with missing transverse energy in the final state using both the cut-based analysis and multivariate analysis respectively at the high luminosity 14 TeV LHC run.Comment: 51 Pages, 10 Captioned figures and 20 Tables, minor changes made in the manuscript, version accepted for publication in The European Physical Journal C journa