Revealing oxidative degradation of lipids and screening potential markers of four vegetable oils during thermal processing by pseudotargeted oxidative lipidomics.

The oxidative degradation of lipids in vegetable oils during thermal processing may present a risk to human health. However, not much is known about the evolution of lipids and their non-volatile derivatives in vegetable oils under different thermal processing conditions. In the present study, a pseudotargeted oxidative lipidomics approach was developed and the evolution of lipids and their non-volatile derivatives in palm oil, rapeseed oil, soybean oil, and flaxseed oil under different thermal processing conditions was investigated. The results showed that thermal processing resulted in the oxidative degradation of TGs in vegetable oils, which generated oxTGs, DGs, and FFAs, as well as TGs with smaller molecular weights. The lower the fatty acid saturation, the more severe the oxidative degradation of vegetable oils and thermal processing at high temperatures should be avoided if possible. From the accumulation of oxTGs concentrations, the hazards during thermal processing at high temperatures were, in descending order, soybean oil, rapeseed oil, flaxseed oil, and palm oil. The non-volatile potential markers were screened in palm oil, rapeseed oil, soybean oil, and flaxseed oil for 1, 7, 5, and 2 markers related to thermal processing time, respectively. The study provided suggestions for the consumption of vegetable oils from multiple perspectives and identified markers for monitored oxidative degradation of vegetable oils.

Activation of SIRT1 by hyperbaric oxygenation promotes recovery of motor dysfunction in spinal cord injury rats.

BACKGROUND: Hyperbaric oxygenation (HBO) therapy can improve locomotor dysfunction following spinal cord injury (SCI). Emerging evidence has demonstrated that sirtuin1 (SIRT1) exerts protective effects on neurons. However, whether HBO alleviates locomotor dysfunction by regulating SIRT1 is unclear. METHODS: The traumatic SCI animal model was performed on the adult Sprague-Dawley rats. The Basso, Beattie Bresnahan (BBB) locomotor rating scale was used to evaluate the open-field locomotor function. Western blot, real-time quantitative reverse transcription polymerase chain reaction, SIRT1 activity assay, and enzyme-linked immunosorbent assays were performed to explore the molecular mechanisms. RESULTS: We found that series HBO therapy significantly improved locomotor dysfunction and ameliorated the decreased mRNA, protein, and activity of spinal cord SIRT1 induced by traumatic SCI injury in rats. In addition, intraperitoneal injection of SIRT1 inhibitor EX-527 abolished the beneficial effects of series HBO treatment on locomotor deficits. Importantly, series HBO treatment following the traumatic SCI injury inhibited the inflammatory cascade and apoptosis-related protein, which was retained by EX-527 and enhanced by SRT1720. Furthermore, EX-527 blocked the enhanced induction of autophagy series with the HBO application. CONCLUSION: These findings demonstrated a new mechanism for series HBO therapy involving activation of SIRT1 and subsequent modulation of the inflammatory cascade, apoptosis, and autophagy, which contributed to the recovery of motor dysfunction.

An integrated untargeted metabolomic approach reveals the quality characteristics of black soybeans from different geographical origins in China.

Black soybeans are extensively planted and consumed in China due to their high nutritional value and numerous health benefits. However, very few is known about the characteristic metabolites of black soybeans from different geographical origins in China. In the present study, 31 black soybean samples were collected from 11 main producing provinces in China. A combined metabolomics approach using ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) and gas chromatography coupled to an Orbitrap mass analyzer (GC-orbitrap-MS) was performed for the first time to comprehensively investigate the metabolite variability among the black soybeans from different geographical origins. A total of 48 differential non-volatile metabolites and 14 differential volatile metabolites were identified based on orthogonal partial least squares discriminant analysis (OPLS-DA) coupled with analysis of variance (ANOVA). Higher procyanidin B1, procyanidin B2, epicatechin, malonylated isoflavones, and ß-pinene were observed in Gansu black soybeans. Guangxi black soybeans had higher amounts of linoleic acid and its oxidation products of hexanal and pentane. The black soybeans from Xinjiang and Yunnan were found to have higher delphinidin-derived anthocyanins, gamma-glutamyl peptides, and aromatic hydrocarbons. The characteristic metabolites of black soybeans from other geographical origins were also clarified. This study indicated that the integrated untargeted metabolomic approach can be a powerful tool to provide knowledge for developing specialty black soybeans.

Metabolomic profiles of not from concentrate orange juice after different sterilization treatments based on HS-SPME-GC-MS and UPLC-QTOF-MS.

Not from concentrate (NFC) orange juice is minimally processed, natural-appearing food, and has become more popular. Sterilization is an important stage for NFC orange juice production. Here we present a comprehensive analysis of the effect of sterilization on the metabolites of NFC orange juices, including three thermal (pasteurization, high-temperature short time, and ultra-high temperature) and one nonthermal (high hydrostatic pressure) method. A total of 108 metabolites, including 59 volatiles and 49 nonvolatiles were identified in orange juice. Of which, only butyl butanoate and 3-carene were detected in fresh orange juice. Sterilization significantly changed the metabolites of orange juice, and different methods caused various changes. Esters were downregulated by both thermal and nonthermal sterilization, while most flavonoids and terpenes were upregulated. With comparative analyses of three thermal sterilization, we found that high temperature and relatively short-time treatment preserved esters and ascorbic acid more effectively than low temperature and prolonged treatment. Aldehydes, however, were the opposite. Nonthermal sterilization is effective in preserving the metabolites of orange juice, especially for esters, terpenes, and flavonoids. In addition, 19 distinct metabolites were characterized between thermal and nonthermal samples by chemometrics analysis. These findings provide a new sight of the optimization of sterilization methods and references for different types of NFC orange juice identification. PRACTICAL APPLICATION: This study provides a reference for the optimization of sterilization methods and identification of HHP and thermal NFC orange juice and also benefits the purchase of consumers.

Precise Authenticity of Quinoa, Coix Seed, Wild Rice and Chickpea Components Using Optimized TaqMan Real-Time PCR.

Functional food such as, quinoa, coix seed, wild rice and chickpea have experienced rapidly increasing demand globally and exhibit high economic values. Nevertheless, a method for rapid yet accurate detection of these source components is absent, making it difficult to identify commercially available food with labels indicating the presence of relevant components. In this study, we constructed a real-time quantitative polymerase chain reaction (qPCR) method for rapid detection of quinoa, coix seed, wild rice and chickpea in food to identify the authenticity of such food. Specific primers and probes were designed with 2S albumin genes of quinoa, SAD genes of coix seed, ITS genes of wild rice and CIA-2 genes of chickpea as the target genes. The qPCR method could specifically identify the four wild rice strains, yielding, LODs of 0.96, 1.14, 1.04 and 0.97 pg/µL quinoa, coix seed, wild rice and chickpea source components, respectively. Particularly, the method allowed the identification of the target component with content below 0.01%. A total of 24 commercially available food samples of different types were detected by using the method and the results indicate that the developed method is applicable to the detection of different food matrices, as well as authenticity verification in deeply processed food.

Quality changes of HHP orange juice during storage: Metabolomic data integration analyses.

High hydrostatic pressure (HHP) is a non-thermal method of sterilizing orange juice. However, knowledge of the quality variation during its storage is limited. This study aimed to comprehensively analyze metabolite variations during HHP orange juice storage using gas chromatography-mass spectrometer and liquid chromatography-mass spectrometry. Fifty-seven volatiles and 49 non-volatiles were identified. Partial least square analysis results showed that 21 days was a dividing point for metabolites highly varied. Results of relative odor activity value showed nonanal, methyl butanoate, and ethyl butanoate decreased after six days, which might reduce fruity flavor. After 21 days, over 60 % of metabolites such as linalool, α-pinene, and ascorbic acids decreased while α-terpineol and limonin increased, which would likely result in a change of coniferous, tarry, and bitter, as well as decreased organoleptic quality and antioxidative activities. This study provides a theoretical basis to optimize the shelf-life of HHP orange juice and advice for consumers' choices.

New insight into the evolution of volatile profiles in four vegetable oils with different saturations during thermal processing by integrated volatolomics and lipidomics analysis.

To compare the oxidation products of four types of vegetable oils (palm oil, soybean oil rapeseed oil, and flaxseed oil) during thermal processing, lipidomics, volatolomics and simulation analyses were integrated to investigate the evolution of volatile profiles. The evolution of volatile profiles in different vegetable oils were found to be different, which are attribute to their different lipid composition. There were potential markers of palmitic acid-based vegetable oils as undecanal, dodecanal and 2-hexanone. A potential marker of oleic acid-based vegetable oils was 2-undecenal. (E,E)-2,4-nonadienal, 3-octen-2-one, and 3-nonen-2-one were potential markers of linoleic acid-based vegetable oils. The potential markers of linolenic acid-type vegetable oils were 1-penten-3-ol, (E)-2-butenal, (E)-2-pentenal, (E,E)-2,4-heptadienal (1), (E,E)-2,4-heptadienal (2), 2-ethyl-furan (1), 2-pentanone, and 3-hexen-2-one. The present study provides a new and comprehensive strategy to elucidate the changes of volatile compounds in thermal processed vegetable oil.

Real-time qPCR for the detection of puffer fish components from Lagocephalus in food: L. inermis, L. lagocephalus, L. gloveri, L. lunaris, and L. spadiceus.

Puffer fish is a type of precious high-end aquatic product, is widely popular in Asia, especially in China and Japan, even though it naturally harbors a neurotoxin known as tetrodotoxin (TTX) that is poisonous to humans and causes food poisoning. With the increasing trade demand, which frequently exceeds existing supply capacities, fostering fraudulent practices, such as adulteration of processed products with non-certified farmed wild puffer fish species. To determine the authenticity of puffer fish processed food, we developed a real-time qPCR method to detect five common puffer fish species in aquatic products: Lagocephalus inermis, Lagocephalus lagocephalus, Lagocephalus gloveri, Lagocephalus lunaris, and Lagocephalus spadiceus. The specificity, cross-reactivity, detection limit, efficiency, and robustness of the primers and probes created for five species of puffer fish using TaqMan technology have been determined. No cross-reactivity was detected in the DNA of non-target sample materials, and no false-positive signal was detected; the aquatic products containing 0.1% of a small amount of wild puffer fish materials without certification can be reliably tracked; the statistical p-value for each method's Ct value was greater than 0.05. The developed qPCR method was sensitive, highly specific, robust, and reproducibility, which could be used to validate the authenticity of wild puffer fish in aquatic products sold for commercial purposes.

Assessment of deep learning assistance for the pathological diagnosis of gastric cancer.

Previous studies on deep learning (DL) applications in pathology have focused on pathologist-versus-algorithm comparisons. However, DL will not replace the breadth and contextual knowledge of pathologists; rather, only through their combination may the benefits of DL be achieved. A fully crossed multireader multicase study was conducted to evaluate DL assistance with pathologists' diagnosis of gastric cancer. A total of 110 whole-slide images (WSI) (50 malignant and 60 benign) were interpreted by 16 board-certified pathologists with or without DL assistance, with a washout period between sessions. DL-assisted pathologists achieved a higher area under receiver operating characteristic curve (ROC-AUC) (0.911 vs. 0.863, P = 0.003) than unassisted in interpreting the 110 WSIs. Pathologists with DL assistance demonstrated higher sensitivity in detection of gastric cancer than without (90.63% vs. 82.75%, P = 0.010). No significant difference was observed in specificity with or without deep learning assistance (78.23% vs. 79.90%, P = 0.468). The average review time per WSI was shortened with DL assistance than without (22.68 vs. 26.37 second, P = 0.033). Our results demonstrated that DL assistance indeed improved pathologists' accuracy and efficiency in gastric cancer diagnosis and further boosted the acceptance of this new technique.

An Accurate and Rapid Way for Identifying Food Geographical Origin and Authenticity: Editable DNA-Traceable Barcode.

DNA offers significant advantages in information density, durability, and replication efficiency compared with information labeling solutions using electronic, magnetic, or optical devices. Synthetic DNA containing specific information via gene editing techniques is a promising identifying approach. We developed a new traceability approach to convert traditional digitized information into DNA sequence information. We used encapsulation to make it stable for storage and to enable reading and detection by DNA sequencing and PCR-capillary electrophoresis (PCR-CE). The synthesized fragment consisted of a short fragment of the mitochondrial cytochrome oxidase subunit I (COI) gene from the Holothuria fuscogilva (ID: LC593268.1), inserted geographical origin information (18 bp), and authenticity information from Citrus sinensis (20 bp). The obtained DNA-traceable barcodes were cloned into vector PMD19-T. Sanger sequencing of the DNA-traceable barcode vector was 100% accurate and provided a complete readout of the traceability information. Using selected recognition primers CAI-B, DNA-traceable barcodes were identified rapidly by PCR amplification. We encapsulated the DNA-traceable barcodes into amorphous silica spheres and improved the encapsulation procedure to ensure the durability of the DNA-traceable barcodes. To demonstrate the applicability of DNA-traceable barcodes as product labels, we selected Citrus sinensis as an example. We found that the recovered and purified DNA-traceable barcode can be analyzed by standard techniques (PCR-CE for DNA-traceable barcode identification and DNA sequencing for readout). This study provides an accurate and rapid approach to identifying and certifying products' authenticity and traceability.

Integration of lipidomics and metabolomics for the authentication of camellia oil by ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry coupled with chemometrics.

The integration of lipidomics and metabolomics approaches, based on UPLC-QTOF-MS technology coupled with chemometrics, was established to authenticate camellia oil adulterated with rapeseed oil, peanut oil, and soybean oil. Lipidomics revealed that the glyceride profile provides a prospective authentication of camellia oil, but no characteristic markers were available. Sixteen characteristic markers were identified by metabolomics. For camellia oil, all six markers were sapogenins of oleanane-type triterpene saponins. Lariciresinol, sinapic acid, doxercalciferol, and an unknown compound were identified as markers for rapeseed oil. Characteristic markers in peanut oil were formononetin, sativanone, and medicarpin. In the case of soybean oil, the characteristic markers were dimethoxyflavone, daidzein, and genistein. The established OPLS-DA and OPLS prediction models were highly accurate in the qualitative and quantitative analyses of camellia oil adulterated with 5% other oils. These results indicate that the integration of lipidomics and metabolomics approaches has great potential for the authentication of edible oils.

An effective analytical droplet digital PCR approach for identification and quantification of fur-bearing animal meat in raw and processed food.

Available nuclear gene sequences for meat detection are still rare and little applicability in the investigation of new types of meat adulteration such as fox, mink and raccoon dog was performed. In the present work, we developed a reliable qualitative and quantitative detection method for fur-bearing animal meat based on droplet digital PCR (ddPCR). Three sets of primers and probes targeted nuclear genes for fox, mink and raccoon dog were designed for ddPCR system; In addition, turkey was selected as internal reference to transform the copy numbers to the fraction of target species. Results indicated that the dynamic ranges of three fur-bearing animals were all from 1% to 90%; the limit of detection (LOD) and limit of quantification (LOQ) for three fur-bearing animals were same, with LOD 0.1% (w/w) and LOQ 1% (w/w). Moreover, we confirmed that different additives had no effect on quantification accuracy in the ddPCR assay.

Application of DNA barcoding and metabarcoding for species identification in salmon products.

Mislabelling is a significant manifestation of food fraud. Traditional Sanger sequencing technology is the gold standard for seafood species identification. However, this method is not suitable for analysing processed samples that may contain more than one species. This study tested the feasibility of next-generation sequencing in identifying mixed salmon products. Salmon samples containing up to eight species were amplified using 16S rRNA mini-barcode primers, and sequenced on an Illumina HiSeq2500 platform. All species were accurately identified, and mixtures as low as 1% (w/w) could be detected. Furthermore, this study conducted a market survey of 32 products labelled as salmon. For pure and mixed fish products, Sanger and next-generation sequencing techniques were respectively used for species identification, and for NGS results, we also used real-time PCR method to cross-validate the mixed products to further verify the accuracy of the DNA metabarcoding technology established in this study. DNA barcoding and metabarcoding of commercial salmon food products revealed the presence of mislabelling in 16 of 32 (50%) samples. The developed DNA barcoding and metabarcoding methods are useful for the identification of salmon species in food and can be used for quality control of various types of salmon products.

Rapid Classification and Quantification of Camellia (Camellia oleifera Abel.) Oil Blended with Rapeseed Oil Using FTIR-ATR Spectroscopy.

Currently, the authentication of camellia oil (CAO) has become very important due to the possible adulteration of CAO with cheaper vegetable oils such as rapeseed oil (RSO). Therefore, we report a Fourier transform infrared (FTIR) spectroscopic method for detecting the authenticity of CAO and quantifying the blended levels of RSO. In this study, two characteristic spectral bands (1119 cm-1 and 1096 cm-1) were selected and used for monitoring the purity of CAO. In combination with principal component analysis (PCA), linear discriminant analysis (LDA), and partial least squares regression (PLSR) analysis, qualitative and quantitative methods for the detection of camellia oil adulteration were proposed. The results showed that the calculated I1119/I1096 intensity ratio facilitated an initial check for pure CAO and six other edible oils. PCA was used on the optimized spectral region of 1800-650 cm-1. We observed the classification of CAO and RSO as well as discrimination of CAO with RSO adulterants. LDA was utilized to classify CAO from RSO. We could differentiate and classify RSO adulterants up to 1% v/v. In the quantitative PLSR models, the plots of actual values versus predicted values exhibited high linearity. Root mean square error of calibration (RMSEC) and root mean square error of cross validation (RMSECV) values of the PLSR models were 1.4518%-3.3164% v/v and 1.7196%-3.8136% v/v, respectively. This method was successfully applied in the classification and quantification of CAO adulteration with RSO.

DNA barcoding and mini-barcoding in authenticating processed animal-derived food: A case study involving the Chinese market.

This study used DNA barcoding and DNA mini-barcoding to test a variety of animal-derived food products sold in the Chinese market for potential mislabeling. Samples (52) including meat, poultry, and fish purchased from retail and online sources were examined. Regions of cytochrome C oxidase I (COI) gene (~650 bp) and 16S rRNA (~220 bp) were used as full- and mini-barcode markers, respectively. Approximately 94% (49 of 52) of the samples generated barcode sequences. The failure rate for full COI full-barcodes was 44%, but we obtained the 16S rRNA mini-barcode from 87% of the COI-failed cases. Overall, the survey revealed that 23% (12 of 52) of animal-derived products were mislabeled and, in most cases, contain undeclared species. Thus, regulatory measures and continuous monitoring for mislabeling of animal-derived products should be conducted.

Authentication of Edible Bird's Nest (EBN) and its adulterants by integration of shotgun proteomics and scheduled multiple reaction monitoring (MRM) based on tandem mass spectrometry.

Edible bird's nest (EBN) has been traditionally regarded as a kind of medicinal and healthy food in Asia. However, economically motivated adulteration (EMA) has been an issue in the EBN supply chain. To develop an accurate high-throughput approach for detecting EBN and its adulterants (exemplified by porcine skin, swim bladder, white fungus, and egg white), shotgun proteomics was applied for discovery of specific peptides that were subsequently converted into scheduled multiple reaction monitoring (MRM) transitions. Totally, 28 specific peptides were verified as unique to EBN and its adulterants by tandem mass spectrometry. Subsequently, 9 quantitative MRM-transitions of peptides from adulterants and 2 internal standard references from EBN were screened for the quantitative analysis of the adulterants, which allowed detection of adulterants in EBN matrix in the range of 1-80%. These results suggested that integration of shotgun proteomics and scheduled MRM had potential for the authentication of EBN and its adulterants.

Impact of different types of stoppers on sensorial and phenolic characteristics evolution during a bottle storage time of a white wine from Chardonnay grape variety.

The objective of this work was to study the correlation between the variation of phenolic compounds and sensory characteristics in white wine during bottle storage and to explore the compounds that affected sensory evolution. Chardonnay (Vitis vinifera L. cv.) dry white wines were bottled under six types of stoppers and stored for 18 months. The composition of phenolic compounds was analyzed, and the sensory attributes of these wines were evaluated by professional panel. Multivariate statistical analysis demonstrated that bottle aging period exhibited a more important effect on phenolic compound evolution than stopper type. Most of the phenolic compounds disappeared after 18 months of bottle storage, whereas the wine sensory attributes were significantly improved after 15-month of bottle aging. No strong correlation existed between the phenolic variation and the dissolved oxygen content. Wine color characteristics developed towards better quality accompanying with the reduction of detectable hydroxycinnamic acid derivatives and flavan-3-ols, while the wine mouth-feel was related mainly to gallic acid and ferulic acid ester. This work provided some references for wine producers to select appropriate storage duration for bottled white wine.

A systematic analysis strategy for accurate detection of anthocyanin pigments in red wines.

RATIONALE: To develop a reliable and accurate method for the identification of anthocyanins and their subsequent derivatives formed during red grape fermentation and wine maturation. METHODS: By using a Poroshell 120 EC-C18 column in a high-performance liquid chromatography/triple-quadrupole tandem mass spectrometry (HPLC/QqQ-MS/MS) system, combined with multiple reaction monitoring (MRM), it was possible to establish and validate a method for the determination of anthocyanin and a range of complex reaction products. A selected range of six 3-O-glucosidic anthocyanins were used as standards. A database was established from these results. Then various red wines were examined and quantified by this method. RESULTS: With the range of accuracy and precision being 86.97-111.39% and 0.09-4.32%, respectively, the HPLC/QqQ-MS/MS method was found to be a reliable method for anthocyanin detection. By using this HPLC/QqQ-MS/MS method combined with the inclusive database, accurate identification of 95 anthocyanin compounds of different families from various wine samples was systematically achieved in 29 min. CONCLUSIONS: By combining this analytical system with an inclusive database, it was possible to determine a wide range of anthocyanins and related complex derivatives for the first time. We consider that it should be possible to extend this method further to include more complex anthocyanins, and to other complex compounds. Copyright © 2016 John Wiley & Sons, Ltd.