Volatile Organic Compounds (VOCs) Produced by Levilactobacillus brevis WLP672 Fermentation in Defined Media Supplemented with Different Amino Acids

Fermentation by lactic acid bacteria (LAB) is a promising approach to meet the increasing demand for meat or dairy plant-based analogues with realistic flavours. However, a detailed understanding of the impact of the substrate, fermentation conditions, and bacterial strains on the volatile organic compounds (VOCs) produced during fermentation is lacking. As a first step, the current study used a defined medium (DM) supplemented with the amino acids L-leucine (Leu), L-isoleucine (Ile), L-phenylalanine (Phe), L-threonine (Thr), L-methionine (Met), or L-glutamic acid (Glu) separately or combined to determine their impact on the VOCs produced by Levilactobacillus brevis WLP672 (LB672). VOCs were measured using headspace solid-phase microextraction (HS-SPME) gas chromatography-mass spectrometry (GC-MS). VOCs associated with the specific amino acids added included: benzaldehyde, phenylethyl alcohol, and benzyl alcohol with added Phe; methanethiol, methional, and dimethyl disulphide with added Met; 3-methyl butanol with added Leu; and 2-methyl butanol with added Ile. This research demonstrated that fermentation by LB672 of a DM supplemented with different amino acids separately or combined resulted in the formation of a range of dairy- and meat-related VOCs and provides information on how plant-based fermentations could be manipulated to generate desirable flavours.

The Physical and Structural Effects of 1-MCP on Four Different Apple Cultivars during Storage

The impact of the ethylene inhibitor, 1-methylcyclopropene (1-MCP), on four apple cultivars (Braeburn, Fuji, Jazz and Golden Delicious) over 150 days of storage at 2 °C was assessed. Proton transfer reaction quadrupole mass spectrometry (PTR-QUAD-MS) was used to monitor changes in VOC composition, while texture analysis and X-ray microcomputer tomography (µ-CT) scanning were used to study microstructural changes. The application of 1-MCP on apples reduced VOC emissions, concurrently maintaining a firmer texture compared to the untreated apples at each time point. The µ-CT scanning revealed how changes in specific morphological characteristics such as anisotropy, connectivity and porosity, size and shape, as well as the interconnectivity of intracellular spaces (IS) influenced texture even when porosity was similar. Additionally, this study showed that the porosity and connectivity of IS were associated with VOC emission and increased simultaneously. This study highlights how the morphological parameters of an apple can help explain their ripening process during long-term storage and how their microstructure can influence the release of VOCs.

Online monitoring of higher alcohols and esters throughout beer fermentation by commercial Saccharomyces cerevisiae and Saccharomyces pastorianus yeast

Higher alcohols and esters are among the predominant classes of volatile organic compounds (VOCs) that influence the quality of beer. The concentrations of these compounds are determined through a specific yeast strain selection and fermentation conditions. The effect of yeast strains on the formation of higher alcohols and esters throughout fermentations (at 20°C) was investigated. Flavour-relevant esters (ethyl acetate, isoamyl acetate, ethyl hexanoate and ethyl octanoate) and higher alcohols (isoamyl alcohol, isobutyl alcohol and phenylethyl alcohol) were monitored throughout the fermentation using proton transfer reaction-time of flight-mass spectrometry (PTR-ToF-MS) coupled with an automated sampling system for continuous measurements. Compound identification was confirmed by analysis of samples using gas chromatography-mass spectrometry (GC-MS). Results demonstrated the specific time points where variation in higher alcohol and ester generation between yeast strains occurred. In particular, the concentrations of isoamyl acetate, ethyl octanoate and isoamyl alcohol between yeast strains were significantly different over the first 2 days of fermentation; whereas, after Day 3, no significant differences were observed. The two Saccharomyces pastorianus strains produced comparable concentrations of the key higher alcohols and esters. However, the key higher alcohol and ester concentrations varied greatly between the two S. cerevisiae strains. The use of PTR-ToF-MS to rapidly measure multiple yeast strains provides new insights on fermentation for brewers to modify the sensory profile and optimise quality.

The Application of Biometric Approaches in Agri-Food Marketing: A Systematic Literature Review

A challenge in social marketing studies is the cognitive biases in consumers' conscious and self-reported responses. To help address this concern, biometric techniques have been developed to obtain data from consumers' implicit and non-verbal responses. A systematic literature review was conducted to explore biometric applications' role in agri-food marketing to provide an integrated overview of this topic. A total of 55 original research articles and four review articles were identified, classified, and reviewed. It was found that there is a steady growth in the number of studies applying biometric approaches, with eye-tracking being the dominant method used to investigate consumers' perceptions in the last decade. Most of the studies reviewed were conducted in Europe or the USA. Other biometric techniques used included facial expressions, heart rate, body temperature, and skin conductance. A wide range of scenarios concerning consumers' purchase and consumption behaviour for agri-food products have been investigated using biometric-based techniques, indicating their broad applicability. Our findings suggest that biometric techniques are expanding for researchers in agri-food marketing, benefiting both academia and industry.

Food Technology Neophobia Scales in cross-national context: Consumers' acceptance of food technologies between Chinese and New Zealand

An increasing number of novel food technologies have been developed to meet consumers' growing desire for safe and high-quality foods. However, consumers can be cautious of novel food technologies, and their acceptance cannot be guaranteed. Food Technology Neophobia Scales (FTNS) have been proven to be an effective tool to predict consumers' behavior toward novel food technologies in a range of individual countries, but not for cross-national contexts. To fill the gap, this study designed a survey involving 604 Chinese and 614 New Zealand respondents, investigating the influence of consumers' food technology neophobia (FTN) on their acceptance of food technologies. Chinese respondents' FTNS score (50.62) was lower than that of New Zealand respondents (55.02), which was in line with the finding that Chinese respondents' acceptance of all tested food technologies was higher than New Zealand respondents (0.34-0.86 in a Likert-7 scale). Chinese respondents' acceptance was determined by their perception of benefits, whereas New Zealand respondents were influenced by their perception of both benefits and risks. The findings conclude that FTNS is a valid tool to reflect consumers' acceptance of novel food technologies in cross-national contexts, although the influence of FTN varies among consumers from different countries. PRACTICAL APPLICATION: China has the largest food market, and New Zealand is a leading food exporter. Understanding their consumers' acceptance of and attitudes toward food technologies will help food companies implement appropriate strategies in developing and using novel technologies. Because FTNS first was constructed in 2008, it has been applied in Australia, Italy, Canada, Finland, Korea, China, Chile, Brazil, and Uganda; the findings of this study will allow these individual studies on FTNS to better connect, help food companies predict consumer acceptance of food technologies in the global market, and help them identify early adopters of novel food technologies in new food markets.

Flavour Volatiles of Fermented Vegetable and Fruit Substrates: A Review

Health, environmental and ethical concerns have resulted in a dramatic increase in demand for plant-based dairy analogues. While the volatile organic compounds (VOCs) responsible for the characteristic flavours of dairy-based products have been extensively studied, little is known about how to reproduce such flavours using only plant-based substrates. As a first step in their development, this review provides an overview of the VOCs associated with fermented (bacteria and/or fungi/yeast) vegetable and fruit substrates. Following PRISMA guidelines and using two English databases (Web of Science and Scopus), thirty-five suitable research papers were identified. The number of fermentation-derived VOCs detected ranged from 32 to 118 (across 30 papers), while 5 papers detected fewer (10 to 25). Bacteria, including lactic acid bacteria (LAB), fungi, and yeast were the micro-organisms used, with LAB being the most commonly reported. Ten studies used a single species, 21 studies used a single type (bacteria, fungi or yeast) of micro-organisms and four studies used mixed fermentation. The nature of the fermentation-derived VOCs detected (alcohols, aldehydes, esters, ketones, acids, terpenes and norisoprenoids, phenols, furans, sulphur compounds, alkenes, alkanes, and benzene derivatives) was dependent on the composition of the vegetable/fruit matrix, the micro-organisms involved, and the fermentation conditions.

A Comprehensive Review of Variability in the Thermal Resistance (D-Values) of Food-Borne Pathogens-A Challenge for Thermal Validation Trials

The thermal processing of food relies heavily on determining the right time and temperature regime required to inactivate bacterial contaminants to an acceptable limit. To design a thermal processing regime with an accurate time and temperature combination, the D-values of targeted microorganisms are either referred to or estimated. The D-value is the time required at a given temperature to reduce the bacterial population by 90%. The D-value can vary depending on various factors such as the food matrix, the bacterial strain, and the conditions it has previously been exposed to; the intrinsic properties of the food (moisture, water activity, fat content, and pH); the method used to expose the microorganism to the thermal treatment either at the laboratory or commercial scale; the approach used to estimate the number of survivors; and the statistical model used for the analysis of the data. This review focused on Bacillus cereus, Cronobacter sakazakii, Escherichia coli, Listeria monocytogenes, and Clostridium perfringens owing to their pathogenicity and the availability of publications on their thermal resistance. The literature indicates a significant variation in D-values reported for the same strain, and it is concluded that when designing thermal processing regimes, the impact of multiple factors on the D-values of a specific microorganism needs to be considered. Further, owing to the complexity of the interactions involved, the effectiveness of regimes derived laboratory data must be confirmed within industrial food processing settings.

Upcycled foods: A nudge toward nutrition

One of the aims of the United Nations Sustainable Development Goals (SDG) is to end hunger and ensure access by all people to safe, nutritious, and sufficient food all year round. An obvious synergy exists between the second SDG “Zero Hunger” and SDG target 12.3 which focuses on halving food waste and reducing food losses. In addition to helping improve global food security, reducing food waste provides financial and environmental benefits. Upcycling food is a technical solution for food waste reduction that retains the nutritional and financial value of food by-products. However, many of the upcycled foods produced are discretionary foods such as biscuits, crackers, and other snack food that are not part of a healthy dietary pattern, and should only be eaten sometimes in small amounts. Given the importance of ensuring a sustainable healthy diet, this paper discusses opportunities for upcycled food manufacturers to produce more nutritious products.

Effect of Pulsed Electric Fields (PEF) Pre-Treatment on the Quality of Sous Vide (SV) Processed Beef Short Ribs and Optimisation of PEF and SV Process Parameters Using Multiple Polynomial Regression Model

To maximise tenderness, minimise cooking loss, and decrease the adverse effects on the colour of beef short ribs, third-order multiple regression models were used to optimise the processing parameters during the pulsed electric fields (PEF) followed by sous vide (SV) processing. Electric field strength (EFS) and specific energy (SE) of PEF ranged from 0 to 0.85 kV/cm and 0 to 110.96 kJ/kg, respectively, and SV processing for 12, 24, or 36 h at 60 °C was applied. The optimum PEF-SV processing conditions for short ribs were found at EFS of 0.85 kV/cm and SE of 110.96 kJ/kg with SV processing at 60 °C for 23.96 h. In the absence of PEF pre-treatment, the optimum SV time at 60 °C was 36 h. PEF pre-treatments (SE, 99–110.96 kJ/kg) followed by SV (24 h) at 60 °C resulted in a significantly lower cooking loss (%) and texture profile analysis hardness compared to PEF at all treatment intensities, followed by SV at 60 °C for 36 h. Furthermore, significant differences were not observed in the redness, hue angle, and chroma at different PEF-SV processing parameters. Therefore, for industrial applications, PEF-SV processing with EFS (0.85 kV/cm), pulse width (20 µS), pulse frequency (50 Hz) and SE (110.96 kJ/kg), and SV temperature–time combination of 60 °C and 23.96 h is highly recommended.

Chinese Consumers' Acceptance of Novel Technologies Designed To Control Foodborne Bacteria

ABSTRACT

Chinese consumers (n = 604) were asked three times to rate their acceptance of traditional thermal processing and several newer technologies (high pressure processing, irradiation, bacteriophages, antimicrobial packaging, pulsed electric fields, and rinsing meat carcasses with antimicrobial solutions) designed to control foodborne bacteria in food (i) based on their existing knowledge, (ii) after the provision of information about L. monocytogenes, and (iii) after further reading a brief description of the technology. Thermal processing (6.00 of 7 on Likert scale) and high pressure processing (5.73 of 7) were rated the most acceptable technologies, and rinsing with antimicrobial solutions (4.43 of 7) was rated the least acceptable technology. Information outlining the benefits of a technology had a larger positive effect on acceptance of every novel technology discussed (increases of 0.14 to 0.49 units depending on the technology) than information about L. monocytogenes and a brief description of the technology. This research has shown that providing information about foodborne bacteria and a technology designed to control them will improve consumers' acceptance of the technology, with the provision of information being of most importance for technologies for which the consumers are less familiar. Chinese consumers accepted or rejected a food technology for a variety of reasons; however, consumers with a greater awareness of foodborne bacteria rated the acceptability of novel technologies designed to kill bacteria higher than those with a low awareness (0.56 to 1.71 units depending on the technology). The results of this research will be of benefit to food companies considering adopting novel technologies to control foodborne bacteria because they provide insights that will enable them to develop more effective communication and implementation strategies.

HIGHLIGHTS

Effect of Sous vide Processing on Quality Parameters of Beef Short Ribs and Optimisation of Sous vide Time and Temperature Using Third-Order Multiple Regression

The aim of this research was to study the effect of sous vide temperature (60, 65, and 70 °C) and time (12, 24, and 36 h) combination on the quality of beef short ribs, namely colour, cooking loss (%), shrinkage (%), soluble collagen (%), myofibrillar fragmentation index (MFI), Warner–Bratzler shear force (WBSF), and Texture Profile Analysis (TPA) parameters with different packaging materials. Aluminium and polyethylene, ethylene vinyl alcohol, and polyamide plastic laminate pouch were recommended for sous vide processing due to no detrimental effect on colour owing to its low oxygen permeability. The results showed a significant (p < 0.05) increase in shrinkage in volume (%), cooking loss (%), and the proportion of soluble collagen (%) and MFI when sous vide temperature and the processing time were increased to 70 °C and 36 h. WBSF and the TPA hardness value were significantly lower (p < 0.05) at 70 °C than at 60 °C both for 36 h due to higher level of solubilisation of collagen and myofibrillar fragmentation by prolonged heating in the moist in-pack environment and overpressure created by saturated steam. As the use of a laminate pouch reduced the oxidation of red myoglobin to brown metmyoglobin, the effect of sous vide temperature and time on International Commission on Illumination (CIE) hue angle and Chroma was not significant. Process optimisation using third-order multiple regression was conducted and the results revealed that optimum sous vide processing temperature and time combination for beef short ribs were 60 °C and 34.06 h.

A systematic review of food loss and waste in China: Quantity, impacts and mediators

Although food loss and waste (FL&W) is high on China's national policy agenda, there is still little scientific information published about how much FL&W exists in China, what its impacts are, and what needs to be done to reduce it. Furthermore, what is known about FL&W across the various hotspots of China's food supply chain is not accessible in one place due to the tendency of scholars to focus on one part of the food chain depending on their disciplinary backgrounds, thereby making it difficult to obtain a 'comprehensive whole supply chain perspective'. Thus, this review provides an interdisciplinary collation of what is already known about FL&W in China. A systematic review of both English and Chinese databases followed PRISMA guidelines further complemented with a qualitative content analysis process uncovered 57 articles. The view revealed confounding factors such as an inconsistency of the definitions and calculation methods used to measure FL&W, and research gaps such as a lack of focus on the behavioral factors pertaining to waste, and the limited range of social innovations studied to reduce it. Thus, this review will help in the development of research agendas designed to advance efforts in this field.

Supplier audits during COVID-19: a process perspective on their transformation and implications for the future

Purpose

Audits are an essential part of supply chain management, whether they be of a single supplier's facilities or the whole supply chain. Before the COVID-19 pandemic, auditors mainly conducted supplier audits in-person and on-site. Subsequent travel restrictions have meant that auditors have had to perform these audits remotely. The purpose of this paper is to conceptually describe the emerging phenomenon of remote audits and explore the implications of this change for the future.

Design/methodology/approach

This exploratory research used qualitative interviews with key stakeholders (firms, auditors and regulators) to provide an empirical basis for the study. A total of 60 interviews were conducted in two rounds with 40 respondents from 26 organizations. A process perspective lens was used to explore the fundamental changes in supplier audits.

Findings

The study provides an interpretative conceptual framework of remote supplier audits grounded in key factors (audit process, use of technologies, document and record sharing) and identifies a set of contingency factors (technological sophistication, reputation for integrity, maturity of internal audit processes, and level of complexities and risk involved) that affect the effectiveness of remote audits.

Originality/value

Remote supplier audits have radically changed how supply chains operate. This paper presents the first empirically-grounded study on remote auditing. It provides a springboard for future research in this domain and practical implications for managers to assist them with the development of remote auditing in their firms and supply chains.

The Implications of COVID-19 on Chinese Consumer Preferences for Lamb Meat

This study assessed if Chinese consumer attitudes towards a range of lamb attributes (such as origin, food safety, appearance, taste, price), and their opinions of New Zealand lamb (9- and 7-point Likert scales, respectively), had changed since the outbreak COVID-19. The same survey was carried out in Shanghai and Beijing pre (December 2018) and post COVID-19 (November 2020), ~9 months after China's initial outbreak, with 500 and 523 consumers, respectively. From December 2018 to November 2020, there was an increase in the proportion of Chinese consumers purchasing red meat online or from a butcher, and cooking their lamb well-done. In contrast, there were minimal differences in Chinese consumer ratings between December 2018 and November 2020 for different lamb attributes and opinions of New Zealand lamb. Cluster analysis revealed that many consumers (140 in December 2018/376 in November 2020) used only a small portion of the high end of the scale when rating lamb attributes, resulting in little differences between the attributes. This study suggests COVID-19 has enhanced some food safety related behaviors but had little effect on Chinese opinions and preferences for New Zealand lamb attributes. It also highlights that survey design should be carefully considered when collecting responses from Chinese consumers.

Characterization of blue cheese volatiles using fingerprinting, self-organizing maps, and entropy-based feature selection

Understanding which volatile compounds discriminate between products can be useful for quality, innovation or product authenticity purposes. As dataset size and dimensionality increase, linear chemometric techniques like partial least squares discriminant analysis and variable identification (PLS-DA-VID) may not identify the most discriminant compounds. This research compared the performance of self-organizing maps and entropy-based feature selection (SOM-EFS) and PLS-DA-VID to identify discriminant compounds in 17 blue cheese varieties. A total of 172 volatiles were detected using headspace solid phase microextraction, gas chromatography and mass spectrometry, including 1-nonene and 2,6-dimethylpyridine, which were newly identified in blue cheese. Despite SOM-EFS selecting only 14 volatiles compared to 78 for PLS-DA-VID, SOM-EFS proved more effectively discriminant and improved the median five-fold cross-validated prediction accuracy of the model to 0.94 compared to 0.82 for PLS-DA-VID. These findings introduce SOM-EFS as a powerful non-linear exploratory data analysis approach in the field of volatile analytical chemistry.

Understanding the Frying Process of Plant-Based Foods Pretreated with Pulsed Electric Fields Using Frying Models

Deep-fried foods (e.g., French fries, potato/veggie crisps) are popular among consumers. Recently, there has been an increased interest in the application of Pulsed Electric Fields (PEF) technology as a pretreatment of plant-based foods prior to deep-frying to improve quality (e.g., lower browning tendency and oil uptake) and reduce production costs (e.g., better water and energy efficiencies). However, the influence of a PEF pretreatment on the frying process and related chemical reactions for food materials is still not fully understood. PEF treatment of plant tissue causes structural modifications, which are likely to influence heat, mass and momentum transfers, as well as altering the rate of chemical reactions, during the frying process. Detailed insights into the frying process in terms of heat, mass (water and oil) and momentum transfers are outlined, in conjunction with the development of Maillard reaction and starch gelatinisation during frying. These changes occur during frying and consequently will impact on oil uptake, moisture content, colour, texture and the amount of contaminants in the fried foods, as well as the fried oil, and hence, the effects of PEF pretreatment on these quality properties of a variety of fried plant-based foods are summarised. Different mathematical models to potentially describe the influence of PEF on the frying process of plant-based foods and to predict the quality parameters of fried foods produced from PEF-treated plant materials are addressed.

Modifying the Functional Properties of Egg Proteins Using Novel Processing Techniques: A Review

Egg proteins can be used in a wide range of food products, owing to their excellent foaming, emulsifying, and gelling properties. Another important functional property is the susceptibility of egg proteins to enzymatic hydrolysis, as protein digestion is closely related to its nutritional value. These functional properties of egg proteins are likely to be changed during food processing. Conventional thermal processing can easily induce protein denaturation and aggregation and consequently reduce the functionality of egg proteins due to the presence of heat-labile proteins. Accordingly, there is interest from the food industry in seeking novel nonthermal or low-thermal techniques that sustain protein functionality. To understand how novel processing techniques, including high hydrostatic pressure, pulsed electric fields, ionizing radiation, ultraviolet light, pulsed light, ultrasound, ozone, and high pressure homogenization, affect protein functionality, this review introduces the mechanisms involved in protein structure modification and describes the structure-functionality relationships. Novel techniques differ in their mechanisms of protein structure modification and some have been shown to improve protein functionality for particular treatment conditions and product forms. Although there is considerable industrial potential for the use of novel techniques, further studies are required to make them a practical reality, as the processing of egg proteins often involves other influencing factors, such as different pH and the presence of other food additives (for example, salts, sugar, and polysaccharides).

Comparison of Four Extraction Techniques for the Evaluation of Volatile Compounds in Spray-Dried New Zealand Sheep Milk

Recent growth and diversification of sheep milk products means more sophisticated methods are required to ensure their flavour quality. The objective of this study was to compare four extraction techniques for the analysis of volatile compounds in sheep milk by gas chromatography-mass spectrometry (GC-MS). Solvent Assisted Flavour Evaporation (SAFE), Solid Phase Microextraction (SPME), Headspace Sorptive Extraction (HSSE) and Stir Bar Sorptive Extraction (SBSE) were evaluated for their sensitivity, selectivity, reproducibility, and overall efficiency. A total of 48 volatile compounds from nine compound classes were identified in the spray-dried sheep milk. Alcohols, aldehydes, alkanes, carboxylic acids, ketones, lactones, sulphur compounds, nitrogen compounds, and terpenes were all present, but the differences between the methods were most apparent for lactones. SBSE extracted eight lactones, SAFE extracted four lactones and HSSE and SPME only detected trace levels of two lactones. Six of the lactones—δ-hexa-lactone, δ-octalactone, γ-decalactone, γ-dodecalactone, δ-tetradecalactone, and δ-hexadeca-lactone—were identified for the first time in spray-dried sheep milk. The present work demonstrated that SBSE is an effective tool for the extraction and analysis of volatiles, especially lactones, in sheep milk and dairy products in general. A discussion of the benefits and limitations of each method is included.

Effect of medium compositions on microbially mediated volatile organic compounds release profile

AIMS

To monitor temporal changes in the volatile organic compounds' (VOCs) profile generated by the metabolic activities of Pseudomonads in real time.

METHODS AND RESULTS

Three Pseudomonas strains were cultivated in Vogel's broth, supplemented with glucose (0·5 or 1%) and/or protein (egg white powder at 0 or 2%) at 25°C. Glucose or egg white protein contents influenced the VOCs' release profile for alcohols, carbonyls and sulphur derivatives. Increasing glucose content resulted in higher alcohol and ketone contents. Glucose showed a lower effect on the VOCs' release profile, mainly impacting on individual compounds, such as m/z 89 (3-methyl-1-butanol). In contrast, egg white protein enhanced production of VOCs such as m/z 75 (2-methyl-1-propanol) and m/z 63 (dimethyl sulphide) regardless of glucose level present in the medium. At the end of bacteria growth phase (54, 60 and 72 h), the fingerprint of VOCs was different from the early growth phase. Cells near to the end of their growth phase (54, 60 and 72 h) produced a distinctly different array of compounds compared to those produced in early growth phase, for example, cyclic compounds were detected in early growth phase, whereas sulphur derivatives were more common in late growth phase.

CONCLUSIONS

Pseudomonads-mediated VOCs' fingerprint as a response to varying growth conditions can be identified as latent biomarkers.

SIGNIFICANCE AND IMPACT OF THE STUDY

Understanding how microbially mediated VOCs' release profile responds to varying growth conditions can potentially be used as a rapid method for detecting microbial activities in controlled conditions such as food quality systems.

Comparing conventional Descriptive Analysis and Napping®-UFP against physiochemical measurements: a case study using apples

BACKGROUND

The extensive time and cost associated with conventional sensory profiling methods has spurred sensory researchers to develop rapid method alternatives, such as Napping® with Ultra-Flash Profiling (UFP). Napping®-UFP generates sensory maps by requiring untrained panellists to separate samples based on perceived sensory similarities. Evaluations of this method have been restrained to manufactured/formulated food models, and predominantly structured on comparisons against the conventional descriptive method. The present study aims to extend the validation of Napping®-UFP (N = 72) to natural biological products; and to evaluate this method against Descriptive Analysis (DA; N = 8) with physiochemical measurements as an additional evaluative criterion.

RESULTS

The results revealed that sample configurations generated by DA and Napping®-UFP were not significantly correlated (RV = 0.425, P = 0.077); however, they were both correlated with the product map generated based on the instrumental measures (P < 0.05). The finding also noted that sample characterisations from DA and Napping®-UFP were driven by different sensory attributes, indicating potential structural differences between these two methods in configuring samples.

CONCLUSIONS

Overall, these findings lent support for the extended use of Napping®-UFP for evaluations of natural biological products. Although DA was shown to be a better method for establishing sensory-instrumental relationships, Napping®-UFP exhibited strengths in generating informative sample configurations based on holistic perception of products. © 2017 Society of Chemical Industry.

The Role of Personality in Daily Food Allergy Experiences

Food allergies present numerous challenges to coping in everyday life. Even simple things like planning a lunch with a friend can be stressful for people with food allergies. But are some people more adversely impacted by having a food allergy than other people? This paper addressed this question by investigating whether individual differences in the Big Five personality traits (neuroticism, extraversion, openness, agreeableness, and conscientiousness) are related to food allergy-related problems in everyday life among adults with food allergies. Participants were 108 adults (85% female; mean age = 40.2; age range 18–87) with a physician-diagnosed food allergy [most commonly to gluten (54.6%), peanuts (21.3%), cow's milk (16.7%), and shellfish/seafood (16.7%)]. Participants completed an initial online survey that measured demographics, food allergy information, and personality traits using the Big Five Inventory (John et al., 1991). For 2 weeks, participants completed a daily online survey that queried the occurrence of 25 food allergy issues that day and participants' overall stress and mood that day. Neuroticism did not predict more frequent allergy issues or greater stress/poorer mood on days with more allergy issues. Instead, higher openness to experience predicted a range of issues including going hungry because there is no safe food available, problems finding suitable foods when grocery shopping, feeling anxious at social occasions involving food, being excluded, and feeling embarrassed and poorly understood about their food allergy. Conscientious people were less embarrassed or self-conscious about their food allergy, but they had more problems eating out, and their positive mood was more impaired by allergy issues than their less conscientious peers. Extraversion and agreeableness played minor roles. Personality testing can identify people that may have difficulty living with food allergies–such as those higher in openness to experience.

PTR-MS volatile profiling of Pinot Noir wines for the investigation of differences based on vineyard site

This study investigated the effect of vineyard site on the volatile profiles of Pinot Noir wines using proton-transfer reaction mass spectrometry with prior headspace dilution. The ANOVA and PCA enabled discrimination of wine based on vineyard site. Sample separation was due to differences in the ratios of a mixture of compounds, including higher alcohols, ethyl, and acetate esters. Proton-transfer reaction mass spectrometry appears to be a useful technique for rapidly discriminating wines based on vineyard site. The similarities and differences expressed in the wines' volatile profiles may help winemakers to reveal the potential of individual vineyard sites to produce wines of certain character. Copyright © 2017 John Wiley & Sons, Ltd.

Bioactive peptides derived from egg proteins: A review

Egg proteins have various functional and biological activities which make them potential precursor proteins for bioactive peptide production. Simulated in vitro gastrointestinal digestion and enzymatic hydrolysis using non-gastrointestinal proteases have been used as tools to produce these peptides. Bioactive peptides derived from egg proteins are reported to display various biological activities, including angiotensin I-converting enzyme (ACE) inhibitory (antihypertensive), antioxidant, antimicrobial, anti-inflammatory, antidiabetic and iron-/calcium-binding activities. More importantly, simulated in vitro gastrointestinal digestion has indicated that consumption of egg proteins has physiological benefits due to the release of such multifunctional peptides. This review encompasses studies reported to date on the bioactive peptide production from egg proteins.

The adsorption behaviour of lysozyme as a potential antibiofouling agent

Introduction: Biofilms can be problematic or beneficial. Reports on the underlying adsorption in such context-dependent fouling phenomena have been extensive. However, the mechanisms involved is scarce and appears adsorbate or foulant-specific. Methods: In this study, attenuated total reflection infrared spectroscopy was used to probe the solid-liquid interfacial phenomena involving lysozyme for assessing its surface antibacterial actions. Results: Lysozyme preferentially adsorbed more on to the hydrophilic coated ZnSe IR prism than to an uncoated ZnSe IR prism. Data on discrete adsorption rates suggested that lysozyme was adsorbing as multi-layer aggregates on to the ZnSe prism, and showed faster adsorptiondesorption patterns on an uncoated compared to a TiO2-coated ZnSe IR prism. A novel phosphate-modified TiO2 coating material for ZnSe IR prism was prepared as adsorbate which increased the negative charge on the TiO2 surface via P-O-Ti coordinated linkages, increasing the initial rate of lysozyme adsorption. Enhanced adsorption of lysozyme was achieved by increasing both the solution pH and NaCl concentration. Maximum adsorption occurred at pH 11 which corresponded to the protein’s isoelectric pH. Conclusions: ATR-IR spectroscopy has proved to be a useful method to study surface adsorption of antibacterial agents such as lysozyme for further explorations into approaches to control biofouled surfaces.

GC-MS Metabolite Profiling of Extreme Southern Pinot noir Wines: Effects of Vintage, Barrel Maturation, and Fermentation Dominate over Vineyard Site and Clone Selection

Wine is an extremely complex beverage that contains a multitude of volatile and nonvolatile compounds. This study investiged the effect of vineyard site and grapevine clone on the volatile profiles of commercially produced Pinot noir wines from central Otago, New Zealand. Volatile metabolites in Pinot noir wines produced from five grapevine clones grown on six vineyard sites in close proximity, over two consecutive vintages, were surveyed using gas chromatography-mass spectrometry (GC-MS). The raw GC-MS data were processed using parallel factor analysis (PARAFAC2), and final metabolite data were analyzed by principal component analysis (PCA). Winemaking conditions, vintage, and barrel maturation were found to be the most dominant factors. The effects of vineyard site and clone were mostly vintage dependent. Although four compounds including β-citronellol, homovanillyl alcohol, N-(3-methylbutyl)acetamide, and N-(2-phenylethyl)acetamide discriminated the vineyard sites independent of vintage, Pinot noir wines from different clones were only partially discriminated by PCA, and marker compound selection remained challenging.

Computing Morse-Smale Complexes with Accurate Geometry

Topological techniques have proven highly successful in analyzing and visualizing scientific data. As a result, significant efforts have been made to compute structures like the Morse-Smale complex as robustly and efficiently as possible. However, the resulting algorithms, while topologically consistent, often produce incorrect connectivity as well as poor geometry. These problems may compromise or even invalidate any subsequent analysis. Moreover, such techniques may fail to improve even when the resolution of the domain mesh is increased, thus producing potentially incorrect results even for highly resolved functions. To address these problems we introduce two new algorithms: (i) a randomized algorithm to compute the discrete gradient of a scalar field that converges under refinement; and (ii) a deterministic variant which directly computes accurate geometry and thus correct connectivity of the MS complex. The first algorithm converges in the sense that on average it produces the correct result and its standard deviation approaches zero with increasing mesh resolution. The second algorithm uses two ordered traversals of the function to integrate the probabilities of the first to extract correct (near optimal) geometry and connectivity. We present an extensive empirical study using both synthetic and real-world data and demonstrates the advantages of our algorithms in comparison with several popular approaches.

Diverse spore rains and limited local exchange shape fern genetic diversity in a recently created habitat colonized by long-distance dispersal

BACKGROUND AND AIMS

Populations established by long-distance colonization are expected to show low levels of genetic variation per population, but strong genetic differentiation among populations. Whether isolated populations indeed show this genetic signature of isolation depends on the amount and diversity of diaspores arriving by long-distance dispersal, and time since colonization. For ferns, however, reliable estimates of long-distance dispersal rates remain largely unknown, and previous studies on fern population genetics often sampled older or non-isolated populations. Young populations in recent, disjunct habitats form a useful study system to improve our understanding of the genetic impact of long-distance dispersal.

METHODS

Microsatellite markers were used to analyse the amount and distribution of genetic diversity in young populations of four widespread calcicole ferns (Asplenium scolopendrium, diploid; Asplenium trichomanes subsp. quadrivalens, tetraploid; Polystichum setiferum, diploid; and Polystichum aculeatum, tetraploid), which are rare in The Netherlands but established multiple populations in a forest (the Kuinderbos) on recently reclaimed Dutch polder land following long-distance dispersal. Reference samples from populations throughout Europe were used to assess how much of the existing variation was already present in the Kuinderbos.

KEY RESULTS

A large part of the Dutch and European genetic diversity in all four species was already found in the Kuinderbos. This diversity was strongly partitioned among populations. Most populations showed low genetic variation and high inbreeding coefficients, and were assigned to single, unique gene pools in cluster analyses. Evidence for interpopulational gene flow was low, except for the most abundant species.

CONCLUSIONS

The results show that all four species, diploids as well as polyploids, were capable of frequent long-distance colonization via single-spore establishment. This indicates that even isolated habitats receive dense and diverse spore rains, including genotypes capable of self-fertilization. Limited gene flow may conserve the genetic signature of multiple long-distance colonization events for several decades.