Volatile Metabolite Profiling of Durum Wheat Kernels Contaminated by Fusarium poae

E-Nose Technology for Mycotoxin Detection in Feed: Ready for a Real Context in Field Application or Still an Emerging Technology?

Mycotoxin risk in the feed supply chain poses a concern to animal and human health, economy, and international trade of agri-food commodities. Mycotoxin contamination in feed and food is unavoidable and unpredictable. Therefore, monitoring and control are the critical points. Effective and rapid methods for mycotoxin detection, at the levels set by the regulations, are needed for an efficient mycotoxin management. This review provides an overview of the use of the electronic nose (e-nose) as an effective tool for rapid mycotoxin detection and management of the mycotoxin risk at feed business level. E-nose has a high discrimination accuracy between non-contaminated and single-mycotoxin-contaminated grain. However, the predictive accuracy of e-nose is still limited and unsuitable for in-field application, where mycotoxin co-contamination occurs. Further research needs to be focused on the sensor materials, data analysis, pattern recognition systems, and a better understanding of the needs of the feed industry for a safety and quality management of the feed supply chain. A universal e-nose for mycotoxin detection is not realistic; a unique e-nose must be designed for each specific application. Robust and suitable e-nose method and advancements in signal processing algorithms must be validated for specific needs.

Volatile Metabolite Profiling of Wheat Kernels Contaminated by Fusarium graminearum

Traditional methods used to detect fungi or mycotoxins are time-consuming and prevent real-time monitoring. In this study, solid-phase microextraction combined with full two-dimensional gas chromatography time-of-flight mass spectrometry was utilized to detect volatile organic compounds (VOCs) produced by fungi during grain infestation predictive F. graminearum PH-1 infestation in wheat. The results show that the VOCs emitted by F. graminearum can distinguish strains at different growth stages. The growth matrices (potato dextrose agar medium and wheat kernels) play a large role in VOC production. The infection of wheat sample F. graminearum showed that a specific relationship between VOCs and the composition of fungal flora, for example, 5-pentyl-cyclohexa-1,3-diene, 3-hexanone, and 1,3-octadiene, was positively correlated with the infection rate of PH-1. In the correlation study of fungal mycotoxins and VOCs, zearalenone produced by F. graminearum was predicted based on the VOCs released. Further analysis determined the correlation of three VOCs, 6-butyl-1,4-cycloheptadiene, hexahydro-3-methylenebenzofuran-2(3H)-one, and (E,E)-3,5-octadien-2-one, with zearalenone production, confirming the ability of VOCs as characteristic markers of mycotoxins.

Volatile Organic Compounds and Physiological Parameters as Markers of Potato (Solanum tuberosum L.) Infection with Phytopathogens

The feasibility of early disease detection in potato seeds storage monitoring of volatile organic compounds (VOCs) and plant physiological markers was evaluated using 10 fungal and bacterial pathogens of potato in laboratory-scale experiments. Data analysis of HS-SPME-GC-MS revealed 130 compounds released from infected potatoes, including sesquiterpenes, dimethyl disulfide, 1,2,4-trimethylbenzene, 2,6,11-trimethyldodecane, benzothiazole, 3-octanol, and 2-butanol, which may have been associated with the activity of Fusarium sambucinum, Alternaria tenuissima and Pectobacterium carotovorum. In turn, acetic acid was detected in all infected samples. The criteria of selection for volatiles for possible use as incipient disease indicators were discussed in terms of potato physiology. The established physiological markers proved to demonstrate a negative effect of phytopathogens infecting seed potatoes not only on the kinetics of stem and root growth and the development of the entire root system, but also on gas exchange, chlorophyll content in leaves, and yield. The negative effect of phytopathogens on plant growth was dependent on the time of planting after infection. The research also showed different usefulness of VOCs and physiological markers as the indicators of the toxic effect of inoculated phytopathogens at different stages of plant development and their individual organs.

Bran-Enriched Milled Durum Wheat Fractions Obtained Using Innovative Micronization and Air-Classification Pilot Plants

Dietary guidelines recommend the consumption of unprocessed, or minimally processed, wheat foods because they are richer in health-promoting components (i.e., minerals, vitamins, lignans, phytoestrogens, and phenolic compounds) compared to traditionally refined products. The design and implementation of technological solutions applied to the milling process are becoming a key requirement to obtain less refined mill products characterized by healthier nutritional profiles. This study presents the development of an upgraded micronization plant and of a modified air-classification plant to produce several novel types of durum wheat milling fractions, each enriched in bran particles of different sizes (from 425 µm > Ø to Ø < 180 µm) and percentage ratios. A preliminary quality assessment of the milling fractions was carried out by measuring yield percentages and ash content, the latter being related to detect the presence of bran particles. A wide array of milling fractions with different original particle size compositions was provided through the study of the process. Results indicate the ability of the novel pilot plants to produce several types of less refined milling fractions of potential interest for manufacturing durum wheat end-products beneficial for human health.

Metabolomics Provides Valuable Insight for the Study of Durum Wheat: A Review

Metabolomics is increasingly being applied in various fields offering a highly informative tool for high-throughput diagnostics. However, in plant sciences, metabolomics is underused, even though plant studies are relatively easy and cheap when compared to those on humans and animals. Despite their importance for human nutrition, cereals, and especially wheat, remain understudied from a metabolomics point of view. The metabolomics of durum wheat has been essentially neglected, although its genetic structure allows the inference of common mechanisms that can be extended to other wheat and cereal species. This review covers the present achievements in durum wheat metabolomics highlighting the connections with the metabolomics of other cereal species (especially bread wheat). We discuss the metabolomics data from various studies and their relationships to other "-omics" sciences, in terms of wheat genetics, abiotic and biotic stresses, beneficial microbes, and the characterization and use of durum wheat as feed, food, and food ingredient.

Interacting Environmental Stress Factors Affects Targeted Metabolomic Profiles in Stored Natural Wheat and That Inoculated with F. graminearum

Changes in environmental stress impact on secondary metabolite (SM) production profiles. Few studies have examined targeted SM production patterns in relation to interacting environmental conditions in stored cereals. The objectives were to examine the effect of water activity (a_w; 0.95–0.90) x temperature (10–25 °C) on SM production on naturally contaminated stored wheat and that inoculated with Fusarium graminearum. Samples were analysed using Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) on (a) total number of known SMs, (b) their concentrations and (c) changes under environmental stress. 24 Fusarium metabolites were quantified. Interestingly, statistical differences (ChisSq., p < 0.001) were observed in the number of SMs produced under different sets of interacting environmental conditions. The dominant metabolites in natural stored grain were deoxynivalenol (DON) and nivalenol (NIV) followed by a range of enniatins (A, A1, B, B1), apicidin and DON-3-glucoside at 10 °C. Increasing temperature promoted the biosynthesis of other SMs such as aurofusarin, moniliformin, zearalenone (ZEN) and their derivatives. Natural wheat + F. graminearum inoculation resulted in a significant increase in the number of metabolites produced (ChisSq., p < 0.001). For ZEN and its derivatives, more was produced under cooler storage conditions. Fusarin C was enhanced in contrast to that for the enniatin group. The relative ratios of certain groups of targeted SM changed with environmental stress. Both temperature and a_w affected the amounts of metabolites present, especially of DON and ZEN. This study suggests that the dominant SMs produced in stored temperate cereals are the mycotoxins for which legislation exists. However, there are changes in the ratios of key metabolites which could influence the relative contamination with individual compounds. Thus, in the future, under more extreme environmental stresses, different dominant SMs may be formed which could make present legislation out of step with the future contamination which might occur.

Characterization of Volatile Compounds of Bulgur (Antep Type) Produced from Durum Wheat

Bulgur is enjoyed and rediscovered by many people as a stable food because of its color, flavor, aroma, texture, and nutritional and economical values. There is more than one type of bulgur overall the world according to production techniques and raw materials. The volatile compounds of bulgur have not been explored yet. In this study, Headspace Solid Phase Microextraction (HS-SPME) and Gas Chromatography–Mass Spectroscopy (GS-MS) methods were used to determine the volatile flavor compounds of bulgur (Antep type, produced from Durum wheat). Approaching studies were used and the results were optimized to determine the ideal conditions for the extraction and distinguish the compounds responsible for the flavor of bulgur. Approximately, 47 and 37 important volatile compounds were determined for Durum wheat and bulgur, respectively. The study showed that there was a great diversity of volatiles in bulgur produced using Durum wheat and Antep type production method. These can lead to a better understanding of the combination of compounds that give a unique flavor with more researches.