Utilization of Hyperspectral Imaging with Chemometrics to Assess Beef Maturity.

There is a growing demand from consumers for more assurance in premium food products such as beef and especially steak. The quality of beef steak is primarily dictated by the maturation which ultimately influences its taste and flavor. These enhanced qualities have resulted in steak becoming a premium product that consumers are willing to pay a premium price for. A challenge, however, is analyzing the maturity of beef by traditional analytical techniques. Hyperspectral imaging (HSI) is a methodology that is gaining traction mainly due to miniaturization, improved optics, and software. In this study, HSI was applied to wet aged beef supplied at various stages of maturity, with spectral data generated using a portable hyperspectral camera. Two trials were conducted over a five-month period: (i) proof of principle and (ii) a bespoke sampling trial for the industry. With the support of industry participation, all samples were sourced from a highly reputable UK/Ireland supplier. To enhance data interpretation, the spectral data collected were combined with multivariate analysis. A range of chemometric models were generated using unsupervised and supervised methods to determine the maturity of the beef, and external validation was performed. The external validation showed good accuracy for "unknown samples" tested against the model set and ranged from 74 to 100% for the different stages of maturity (20, 30, and 40 days old). This study demonstrated that HSI can detect different maturity timepoints for beef samples, which could play an important role in solving some of the challenges that the industry faces with ensuring the authenticity of their products. This is the first time that portable HSI has been coupled with chemometric modeling for assessing the maturity of beef, and it can serve as a model for other food authenticity and quality applications.

Spoilage markers for freshwater fish: A comprehensive workflow for non-targeted analysis of VOCs using DHS-GC-HRMS.

Changes of volatile organic compounds (VOCs) patterns during 6 days of storage at +4 °C were investigated in different freshwater fish species, namely carp and trout, using dynamic headspace gas chromatography time-of-flight mass spectrometry (DHS-GC-TOFMS). DHS parameters were systematically optimized to establish optimum extraction and pre-concentration of VOCs. Moreover, different sample preparation methods were tested: mincing with a manual meat grinder, as well as mincing plus homogenization with a handheld homogenizer both without and with water addition. The addition of water during sample preparation led to pronounced changes of the volatile profiles, depending on the molecular structure and lipophilicity of the analytes, resulting in losses of up to 98 % of more lipophilic compounds (logP > 3). The optimized method was applied to trout and carp. Trout samples of different storage days were compared using univariate (Mann-Whitney U test, fold change calculation) and multivariate (OPLS-DA) statistics. 37 potential spoilage markers were selected; for 11 compounds identity could be confirmed via measurement of authentic standards and 10 compounds were identified by library spectrum match. 22 compounds were also found to be statistically significant spoilage markers in carp. Merging results of the different statistical approaches, the list of 37 compounds could be narrowed down to the 14 most suitable for trout spoilage assessment. This study comprises a systematic evaluation of the capabilities of DHS-GC coupled to high-resolution (HR) MS for studying spoilage in different freshwater fish species, including a comprehensive data evaluation workflow.

Determination of Background Concentrations of Ag, Pd, Pt and Au in Highly Mineralized Ground Waters at Sub-ng L-1 Concentrations by Online Matrix Separation/Pre-Concentration Coupled to ICP-SFMS.

Though not regulated in directives such as the Water Framework Directive of the European Union, the investigation of geogenic background concentrations of certain elements such as precious metals is of increasing interest, in particular for the early detection of a potential environmental pollution due to the increased use in various industrial and technological applications and in medicine. However, the precise and accurate quantification of precious metals in natural waters is challenging due to the complex matrices and the ultra-low concentrations in the (sub-) ng L-1 range. A methodological approach, based on matrix separation and pre-concentration on the strong anion exchange resin TEVA® Resin in an online mode directly coupled to ICP-SFMS, has been developed for the determination of Ag, Pt, Pd and Au in ground water. Membrane desolvation sample introduction was used to reduce oxide-based spectral interferences, which complicate the quantification of these metals with high accuracy. To overcome errors arising from matrix effects-in particular, the highly varying major ion composition of the investigated ground water samples-an isotope dilution analysis and quantification based on standard additions, respectively, were performed. The method allowed to process four samples per hour in a fully automated mode. With a sample volume of only 8 mL, enrichment factors of 6-9 could be achieved, yielding detection limits <1 ng L-1. Validation of the trueness was performed based on the reference samples. This method has been used for the analysis of the total concentrations of Ag, Pt, Pd and Au in highly mineralized ground waters collected from springs located in important geological fault zones of Austria's territory. Concentrations ranges of 0.21-64.2 ng L-1 for Ag, 0.65-6.26 ng L-1 for Pd, 0.07-1.55 ng L-1 for Pt and 0.26-1.95 ng L-1 for Au were found.

Decision making under risk and under ambiguity in depressed suicide attempters, depressed non-attempters and healthy controls.

BACKGROUND: A number of neuropsychological alterations have been found in patients who have attempted suicide. Most studies investigating decision making (DM) abilities in suicide attempters so far have used one single DM task and included patients with a lifetime history of suicide attempts. These studies have yielded conflicting results. METHOD: In this study, currently depressed in-patients who had a recent suicide attempt (within the last six months) (n = 21), depressed in-patients without a lifetime history of suicide attempts (n = 31) and a healthy control group (n = 26) were assessed with two tasks for the assessment of DM. The Game of Dice Task (GDT) measures DM under risk and the Iowa Gambling Task (IGT) DM under ambiguity. Further, depression severity, impulsiveness and suicidal intent of the current suicide attempt were assessed. RESULTS: Both depressed groups differed from controls with respect to marital and partnership status, smoking, impulsiveness and psychiatric family history. In terms of DM, IGT scores did not differ significantly between groups. However, suicide attempters made significantly more risky decisions as assessed with the GDT than both control groups (p < 0.05 for pairwise comparisons, p = 0.065 for overall comparison of the 3 groups). LIMITATIONS: The available tasks assess DM under laboratory conditions which may not reflect the emotional status of suicidal individuals. No general cognitive assessment was included. CONCLUSIONS: Depressed suicide attempters differed with regard to DM under risk but not DM under ambiguity. When studying DM it appears crucial to take varying aspects of DM into account.

Executive Dysfunctions Predict Self-Restricted Driving Habits in Elderly People with or without Alzheimer's Dementia.

Introduction The purpose of this study was to elucidate the impact of specific cognitive functions on self-restricted driving habits in healthy elderly drivers and patients suffering from mild cognitive impairment (MCI) and Alzheimer's dementia (AD). Method Our study population included 35 cognitively healthy controls, 10 MCI patients, and 16 patients with AD. All participants completed a neuropsychological examination and a self-reported questionnaire assessing driving habits and patterns. Results In challenging driving conditions, patients with MCI or AD showed significantly more driving self-restriction than healthy subjects (effect size d=1.06, p=0.007). Ordinal regression analysis across the entire group revealed that deficits in executive functions and reaction had a higher impact on driving restriction (p=0.002) than deficits in memory functions (p=0.570). Additionally, our data showed that 40% of patients with mild to moderate AD still drive in challenging conditions. Discussion Our results illustrate that elderly individuals use self-imposed driving restrictions as compensatory strategies. These restrictions increase with cognitive decline mainly in the field of executive functions, but they do not change once patients convert from MCI to AD.