Search

Understanding the metabolic modulation of major quality traits during ripening is critical for fruit quality improvement in kiwifruits. Here, integrated proteomic and metabolomic profiling was undertaken to comprehensively examine the dynamics of kiwifruit ripening. This data set presents a global view of the critical pathways involved in fruit ripening, and the contributions of key events to the regulation of kiwifruit ripening and softening, amino acid metabolism, balance in sugar accumulation and organic acid metabolism, glycolysis, and tricarboxylic acid (TCA) pathways were discussed. We suggested key enzymes for starch synthesis and degradation, including AGPase, SS, and SBE, especially for BMY, which was considered a key enzyme for starch degradation. In addition, our analysis implicated the key enzymes ACO4 and ACS9 in ethylene synthesis and the aspartate aminotransferase ASP3 in the conversion of amino acids. These results provide new insights into the modulation of fruit ripening, metabolism, and quality in post-harvest kiwifruits.

To tackle the urgency of smarter crop management, the complex nature of agricultural ecosystems needs to be better understood, employing and combining different techniques and technologies. In this study, untargeted metabolomics and agro-meteorological survey were coupled to study the variation of Sorghum bicolor (L.) Moench metabolome during crop development, in response to environmental and anthropic factors. Twelve crop fields in the Emilia-Romagna region, Italy, were monitored and sampled at different stages, seedling (Ss), advanced vegetative (Sv), and ripening (Sr), and subjected to 1H NMR-based metabolomics. The analytical method developed resulted to be successful to quickly analyze different sorghum organs. Dhurrin, a cyanogenic glucoside, resulted to be a biomarker of crop quality and development, and several insights into its turnover and functions were obtained. In particular, p-glucosyloxy-2-hydroxyphenylacetic acid was identified, for the first time, as the main metabolite accumulated in sorghum at Sr, after gradual dhurrin neutralization. During plant life, fertilization and biotic and abiotic stress reflected peculiar metabolomic profiles. Water supply and soil features (i.e., clay content) were correlated to metabolomic variations, affecting dhurrin (and related metabolites), amino acids, organic acids, and carbohydrate content. Increase in chlorogenic acid was registered in consequence of predator attacks. Moreover, grain from three fields presented traces of dhurrin and the lowest antioxidant potential, which resulted in poor grain quality. Metabolomics turned out to be a promising tool in view of smart agriculture for monitoring plant growth status and applying appropriate agricultural practices since the early stage of crop development.

Wine flavor and quality are determined by the assessment of multiple sensory stimuli, including aroma, taste, and mouthfeel. It is therefore important to consider the contribution of as many metabolites as possible when attempting to relate wine composition to quality. In this study, partial least squares regression of the volatile (untargeted headspace solid-phase microextraction coupled with gas chromatography time-of-flight mass spectrometry), non-volatile (untargeted reverse-phase ultra-high-performance liquid chromatography mass spectrometry), and combined metabolite profiles were used to predict Pinot Noir wine quality ratings as assessed by experts. Non-volatile metabolite profiles predicted wine quality ratings better than volatile metabolite profiles, suggesting that the non-volatile composition of Pinot Noir wines contributes to quality perception to a greater extent than the volatile composition. This was underscored by descriptive sensory analysis, which found that taste and mouthfeel attributes were better correlated with wine quality ratings than aroma attributes. Important predictors of Pinot Noir wine quality were also characterized. Some new relationships between wine metabolites and quality ratings were found: dipeptides and unsaturated fatty acids were positively related to Pinot Noir wine quality, while N-(3-methylbutyl)acetamide and xanthine were negatively associated.

The growth conditions and age of Panax ginseng are vital for determining the quality of the ginseng plant. However, the considerable difference in price according to the cultivation method and period of P. ginseng leads to its adulteration in the trade market. We herein focused on ginseng peptides and the possibility of these peptides to be used as biomarker(s) for discrimination of P. ginseng. We applied an ultraperformance liquid chromatography-high resolution mass spectrometry-based peptidomics approach to characterize ginseng peptides and discover novel peptide biomarkers for authentication of mountain-cultivated ginseng (MCG). We identified 52 high-confidence peptides and screened 20 characteristic peptides differentially expressed between MCG and cultivated ginseng (CG). Intriguingly, 6 differential peptides were expressed significantly in MCG and originated from dehydrins that accumulated during cold or drought conditions. In addition, 14 other differential peptides that were significantly expressed in CG derived from ginseng major protein, an essential protein for nitrogen storage. These biological associations confirmed the reliability and credibility of the differential peptides. Additionally, we determined several robust peptide biomarkers for discrimination of MCG through a precise selection process. These findings demonstrate the potential of peptide biomarkers for identification and quality control of P. ginseng in addition to ginsenoside analysis.

α-Dicarbonyl compounds (α-DCs) are a major class of intermediates generated during Maillard reactions. They can serve as chemical markers of thermal processing and storage of sugar-rich foods. To distinguish between naturally matured acacia honey (NMAH) and artificially heated acacia honey (AHAH), we purified 12 major α-DCs quinoxaline derivatives to investigate the effects of temperature during heat treatment and storage on their accumulation in acacia honey. Nine of the 12 α-dicarbonyl compounds were found in acacia honey samples, and their contents varied depending on processing and storage conditions. Among them, the contents of 3-deoxyglucosulose (3-DG), 1,4-dideoxyglucosone (1,4-DDG), and 1-deoxyglucosone (1-DG) increased commensurately with heat. 3-DG content ranged from 103.7 to 146.6 mg/kg in NMAH and 572.4-1371.2 mg/kg in AHAH. Given the abundance and stability of 3-DG following heat treatment and storage, this compound can potentially serve as a reliable marker for distinguishing between NMAH and AHAH.

One of the greatest challenges facing the functional food and natural health product (NHP) industries is sourcing high-quality, functional, natural ingredients for their finished products. Unfortunately, the lack of ingredient standards, modernized analytical methodologies, and industry oversight creates the potential for low quality and, in some cases, deliberate adulteration of ingredients. By exploring a diverse library of NHPs provided by the independent certification organization ISURA, we demonstrated that nuclear magnetic resonance (NMR) spectroscopy provides an innovative solution to authenticate botanicals and warrant the quality and safety of processed foods and manufactured functional ingredients. Two-dimensional NMR experiments were shown to be a robust and reproducible approach to capture the content of complex chemical mixtures, while a binary normalization step allows for emphasizing the chemical diversity in each sample, and unsupervised statistical methodologies provide key advantages to classify, authenticate, and highlight the potential presence of additives and adulterants.

Volatile organic compounds strongly contribute to both the positive and negative sensory attributes of virgin olive oil, and more and more studies have been published in recent years focusing on several aspects regarding these molecules. This Review is aimed at giving an overview on the state of the art about the virgin olive oil volatile compounds. Particular emphasis was given to the composition of the volatile fraction, the analytical issues and approaches for analysis, the sensory characteristics and interaction with phenolic compounds, and the approaches for supporting the Panel Test in virgin olive oil classification and in authentication of the botanical and geographic origin based on volatile compounds. A pair of detailed tables with a total of approximately 700 volatiles identified or tentatively identified to date and tables dealing with analytical procedures, sensory characteristics of volatiles, and specific chemometric approaches for quality assessment are also provided.

A comprehensive fingerprinting strategy for golden rum classification considering different categories such as fermentation barrel, raw material, and aging is provided, using a metabolomic fingerprinting approach. A nontarget fingerprinting of 30 different rums using liquid chromatography coupled to high-resolution mass spectrometry (Exactive Orbitrap mass analyzer, LC-HRMS) was applied. Principal component analysis (PCA) was used to assess the overall structure of the data and to identify potential outliers. Different chemometric analyses such as partial least-squares discriminant analysis (PLS-DA) were used. A variable importance in projection (VIP) selection method was applied to identify the most significant markers that allow group separation. Compounds related to aging and fermentation processes such as furfural derivates (e.g., hydroxymethylfurfural) and sugars (e.g., glucose, mannitol) were found as the most discriminant compounds (VIP threshold value >1.5). Suitable separation according to selected categories was achieved, and a classification ability of the models of close to 100% was achieved.

Despite of favorable characteristics of high protein, low fat, and free-pollution, yak meat has intrinsically poor performance in tenderness and color, which is ever challenging yak sector. To this end, a three-way cross system was first developed for high quality beef of the Tibetan Plateau using Angus cattle ( Bos taurus) as terminal sire to mate with 1/2 yak (F1) generated from♂Qaidam cattle ( Bos taurus) × ♀yak ( Bos grunniens). The withers height, chest girth, and body weight of 1/4 yak (F2) were all great higher than that of yak and 1/2 yak ( P0.01), especially at later period, suggesting the faster growth rate of 1/4 yak. Also the dressing percentage was much better in 1/4 yak ( P0.01). Tenderness and meat color were both significantly improved in 1/4 yak with some unpleasant sacrifice of PUFAs, such as EPA and DHA, and meat protein, given the significantly lower shear force and higher L* ( P0.01). A total of 769 genes, including SREBF1, GHR, and FASN, the widely recognized causal genes of meat quality, were identified from 11947 differently expressed genes by the data integration of transcriptome, GWAS and QTL. These genes were significantly enriched for important pathway and GO terms, such as insulin signaling pathway, fatty acid biosynthesis, calcium signaling pathway, metabolic pathway, and cellular response to stress ( P0.01). And 12 promising candidates were exemplified with annotation of H3K4me3 data from divergent meat quality, such as OSTF1, NRAS1, and KCNJ11. Interestingly, 75 high-altitude adaptive candidate genes were also detected in the list. This study is a first step toward high quality beef of the Tibetan Plateau and provides useful information for their molecular understanding.

We tested whether introducing an arbuscular mycorrhizal fungi (AMF)-host plant with a reduced P application rate could maintain soybean seeds' nutrient quality. The dynamic variation of 14 nutrients was analyzed in source and sink organs during the seed-filling stage. The AMF-host and non-AMF-host plants, sunflower and mustard, were grown as preceding crops (PCs). Soybeans, the succeeding crops, were planted with three different phosphorus levels, namely, 0, 50, and 150 kg P2O5 ha-1. The results showed that the AMF-host PC with a reduced P application rate maintained the seed's yield and nutrients quality. During the seed-filling stage, the AMF-host PC with a reduced P application rate increased the uptake of most nutrients compared to the non-AMF-host PC, and improved the remobilization efficiency of all nutrients except Mn, Fe, and Se, compared to the optimal P application rate. These results could help improve the utilization efficiency of P fertilizers and protect soybeans' nutritional value.

Aroma is a primary hedonic aspect of a good coffee. Coffee aroma quality is generally defined by cup tasting, which however is time-consuming in terms of panel training and alignment and too subjective. It is challenging to define a relationship between chemical profile and aroma sensory impact, but it might provide an objective evaluation of industrial products. This study aimed to define the chemical signature of coffee sensory notes, to develop prediction models based on analytical measurements for use at the control level. In particular, the sensory profile was linked with the chemical composition defined by HS-SPME-GC-MS, using a chemometric-driven approach. The strategy was found to be discriminative and informative, identifying aroma compounds characteristic of the selected sensory notes. The predictive ability in defining the sensory scores of each aroma note was used as a validation tool for the chemical signatures characterized. The most reliable models were those obtained for woody, bitter, and acidic properties, whose selected volatiles reliably represented the sensory note fingerprints. Prediction models could be exploited in quality control, but compromises must be determined if they are to become complementary to panel tasting.

Untargeted screening using high resolution mass spectrometry (HRMS) is a promising approach for screening the food supply for contaminants, but the sheer amount of information inherent to the HRMS data set presents analytical challenges. Red apples, collected during the U.S. FDA's Total Diet Study, were studied to determine whether bioinformatic software can be used to distinguish spiked model compounds from those native to apples. A workflow was created, in which initial data sets of over 44,000 features in each of the two spiked samples were reduced by several orders of magnitude to a scale suitable for visual inspection. After visual inspection to address degeneracy and data quality, the final data sets contained 30 and 2 suspect compounds, respectively. To the best of our knowledge, this is the largest scale case-control study on food matrices to date and the first use of market basket samples as references in an untargeted screening study.

Flavonoids are products from specialized metabolism that contribute to fruit sensorial (color) and nutritional (antioxidant properties) quality. Here, using a pseudo full-sibling F

Long-term low-temperature conditioning (LT-LTC) decreases apple fruit quality, but the underlying physiological and molecular basis is relatively uncharacterized. We identified 12 clusters of differentially expressed genes (DEGs) involved in multiple biological processes (i.e., sugar, malic acid, fatty acid, lipid, complex phytohormone, and stress-response pathways). The expression levels of genes in sugar pathways were correlated with decreasing starch levels during LT-LTC. Specifically, starch-synthesis-related genes (e.g., BE, SBE, and GBSS genes) exhibited downregulated expression, whereas sucrose-metabolism-related gene expression levels were up- or downregulated. The expression levels of genes in the malic acid pathway (ALMT9, AATP1, and AHA2) were upregulated, as well as the content of malic acid in apple fruit during LT-LTC. A total of 151 metabolites, mainly related to amino acids and their isoforms, amines, organic acids, fatty acids, sugars, and polyols, were identified during LT-LTC. Additionally, 35 organic-acid-related metabolites grouped into three clusters, I (3), II (22), and III (10), increased in abundance during LT-LTC. Multiple phytohormones regulated the apple fruit chilling injury response. The ethylene (ET) and abscisic acid (ABA) levels increased at CS2 and CS3, and jasmonate (JA) levels also increased during LT-LTC. Furthermore, the expression levels of genes involved in ET, ABA, and JA synthesis and response pathways were upregulated. Finally, some key transcription factor genes (MYB, bHLH, ERF, NAC, and bZIP genes) related to the apple fruit cold acclimation response were differentially expressed. Our results suggest that the multilayered mechanism underlying apple fruit deterioration during LT-LTC is a complex, transcriptionally regulated process involving cell structures, sugars, lipids, hormones, and transcription factors.

Antarctic krill oil (AKO) is susceptible to oxidation due to the high unsaturation degree of bioactive substances. Herein, a lipidomics method for in situ monitoring of the dynamic oxidation characteristics in AKO was explored based on electric soldering iron ion source (ESII) coupling with rapid evaporative ionization mass spectrometry (REIMS). The lipidomics profiles of AKO at different storage periods were successfully acquired. On the basis of principal component analysis and orthogonal partial least-squares analysis, the obtained REIMS data were employed to build a multivariate recognition model. The ions of

Parts of Salvia species such as its flowers and leaves are currently used as a culinary herb and for some medicinal applications. To distinguish the different sage extracts it is necessary to analyze their individual chemical compositions. Their characteristic compounds might be established as markers to differentiate between sage flowers and leaf extracts or to determine the manufacturing technology and storage conditions. Tri-p-coumaroylspermidine can be detected only in flowers and has been described here for Salvia and Lavandula species for the first time. Markers for oxidation processes are the novel compounds salviquinone A and B, which were generated from carnosol by exposure to oxygen. Caffeic acid ethyl ester was established as an indirect marker for the usage of ethanol as extraction solvent. The compounds were identified by LC-QTOF-HRESIMS, LC-MS, NMR, IR, and single-crystal X-ray diffraction after isolation by semipreparative HPLC. Furthermore, sage flower resin showed interesting antibacterial in vitro activities against Gram-positive and Gram-negative bacteria.

Proteins and amino acids are known to influence the foam characteristics of sparkling wines. However, it is unclear to what extent they promote foam formation and/or stability. This study aimed to investigate the effect of protein content and amino acid composition, measured via the bicinchoninic acid assay and high-performance liquid chromatography, respectively, on the foaming properties of 28 sparkling white wines, made by different production methods. Foam volume and stability were determined using a robotic pourer and computer vision algorithms. Modifications were applied to the protein determination method involving the use of yeast invertase as a standard in order to improve quantification accuracy. The protein content was found to be significantly correlated to parameters representative of foam stability, as were the amino acids arginine, asparagine, histidine, and tyrosine. Additionally, the production method was found to influence the foam collar height, which favored foaming in Méthode Traditionnelle wines over other those made by production methods. Understanding the contributions of key wine constituents to the visual and mouthfeel parameters of sparkling wine will enable more efficient production of high-quality wines.

Recombinant wheat endoplasmic reticulum oxidoreductin 1 (wEro1) with considerable ability was expressed in Escherichia coli. The functional roles of wEro1 in flour processing quality were investigated by farinographic, rheological, texture profile analysis, electrophoresis, size exclusion chromatography, scanning electron microscopy, and Fourier transform infrared spectroscopy. wEro1 exhibited an obvious oxidation activity of sulfhydryl groups in small molecule and protein. Addition of wEro1 could strengthen the processing quality of dough, indicated by the improved mixing characteristics, viscoelastic properties, and bread qualities. These improvement effects of wEro1 could be attributed to the formation of macromolecular gluten polymers and massive gluten networks by disulfide cross-linking. Additionally, the increased β-turn structure further demonstrated the enhancement of dough strength. Moreover, the amount of peroxide in dough was improved significantly from 2.36 to 2.82 μmol/g of flour with 0.15% wEro1 treatment. Therefore, the results suggested that wEro1 is a promising novel flour improver.

Honey is a natural sweet substance produced by bees (Apis mellifera). In this work, the main parameters used in routine quality control of honey and the most commonly used analytical methods for their determination are reviewed. Honey can be adulterated with cheaper sweeteners or, indirectly, by feeding the bees with sugars. Therefore, methods for detecting and quantifying adulteration are necessary. Chromatographic techniques are widely used in honey analysis. More recently, techniques such as Raman, near-infrared, mid-infrared, and nuclear magnetic resonance spectroscopy in combination with chemometric data processing have been proposed. However, spectroscopy does not allow the determination of enzyme activities, one criteria of great importance for the honey trade. Methylglyoxal is an interesting compound for its antibacterial properties. Methods for its determination are also reviewed.

Durum wheat ( Triticum turgidum L. subsp. durum (Desf.) Husn) is a major food source in Mediterranean countries since it is utilized for the production of pasta, leavened and unleavened breads, couscous, and other traditional foods. The technological and nutritional properties of durum wheat semolina depend mainly on the type of gluten proteins and on their amount, which is a genotype- and environment-dependent trait. Gluten proteins are also responsible for celiac disease (CD), an autoimmune enteropathy with a prevalence of about 0.7-2% in the human population. At this purpose, two Italian durum wheat cultivars, Saragolla and Cappelli, currently used for monovarietal pasta, were chosen to compare (i) the reserve and embryo proteome, (ii) the free and bound phenolics, antioxidant activity, and amino acid composition, and (iii) the content of immunogenic peptides produced after a simulated gastrointestinal digestion. The results obtained from 2 years of field cultivation on average showed a higher amount of gluten proteins, amino acids, and immunogenic peptides in Cappelli. Saragolla showed a higher abundance in bound phenolics, antioxidant enzymes, and stress response proteins in line with its higher antioxidant activity. However, the impact of the year of cultivation, largely depending on varying rainfall regimes through the wheat growth cycle, was significant for most of the parameters investigated. Differences in technological and nutritional characteristics observed between the two cultivars are discussed in relation to the influence of genetic and environmental factors.

Most of the health hazards in fried foods are related to unqualified frying oil and excessive oil content. In this study, the feasibility of using low-field nuclear magnetic resonance techniques (LF-NMR) for analysis of the water and oil contents in French fries, as well as simultaneous evaluation of frying oil quality during deep frying, was investigated. Three proton populations were identified and successfully assigned to water and oil relaxation signals. Significant correlation between the T2 relaxation parameters ( Awater and RCoil) and the water and oil content was acquired. MRI could visualize the changes of signal intensity and spatial distribution, as well as the internal structural changes during frying. Using the correlation model built by multiple regression analysis, the total polar compounds content of the frying oil could be successfully predicted by LF-NMR relaxation characteristics, which indicates that LF-NMR was an effective method to monitor the quality of frying oil.

A competitive indirect enzyme-linked immunosorbent assay (ciELISA) using a polyclonal antibody was developed to detect tyramine in meat and seafood. This ciELISA had a 50% inhibition concentration (IC50) of 0.20 mg/L and a limit of detection (LOD) of 0.02 mg/L and showed no cross-reactivity with tyrosine or other biogenic amines. The average recoveries of tyramine from spiked samples for this ciELISA ranged from 85.6 to 102.6%, and the results exhibited good correlation with high-performance liquid chromatography (HPLC) results. The LOD of this assay for tyramine in meat and seafood samples was 1.20 mg/kg. The ciELISA was successfully applied to detect tyramine in positive fish samples, and the results were validated by HPLC to be reliable. The developed ciELISA allows for the rapid, specific, and accurate detection of tyramine in meat and seafood samples, and it could be a potentially useful tool for the evaluation of the freshness of protein-rich foods.

This paper reports on the optimization, characterization, and applicability of gas chromatography coupled to triple-quadrupole tandem mass spectrometry (GC-QqQ(MS/MS)) for the determination of 14 polybrominated diphenylethers (PBDEs) and 2 emerging brominated flame retardants, 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) and decabromodiphenylethane (DBDPE), in functional food samples. The method showed satisfactory precision and linearity with instrumental limits of detection (iLODs) ranging from 0.12 to 7.1 pg, for tri- to octa-BDEs and BTBPE, and equal to 51 and 20 pg for BDE-209 and DBDPE, respectively. The highest ΣBFR concentrations were found in fish oil supplements (924 pg/g fresh weight, fw), followed by biscuits (90 pg/g fw), vegetable oil supplements (46 pg/g fw), chicken eggs (45 pg/g fw), cow's milk (7.7 pg/g fw), and soy products (1.6 pg/g fw). BDE-47, BDE-99, and DBDPE were the most abundant compounds. Foodstuffs enriched with omega-3 presented concentrations similar to or even lower than those of conventional foods commercialized in Spain since 2000., Financial support was obtained from MICINN (Projects AGL2009-09733 and AGL2012-37201), the Community of Madrid (Spain), and European funding from FEDER program (Projects S2009/AGR-1464, ANALISYC-II, and S2013/ABI- 3028-AVANSECAL). A.G.B. thanks the Spanish Ministry of Education and Science for his Ph.D. grant

Colorimetric films incorporated with anthocyanins as an indicator for freshness monitoring have aroused growing interest recently. However, the application of the films is limited by the easily oxidizable nature of anthocyanins. In this work, we developed a novel colorimetric film with a barrier by coating mulberry anthocyanin (MBA) on the internal side of an ethylene-vinyl alcohol copolymer–montmorillonite (EVOH–MMT) multilayer film. A facile layer-by-layer (LBL) assembly was employed under a parallel electric field to build the EVOH–MMT multilayer structure, in which the exfoliated MMT nanosheets were well-oriented and assembled on the EVOH matrix to form a tightly stacked layer between two EVOH layers. The interlayer of MMT significantly enhanced the barrier and mechanical properties of the films (below 40 layers). The interactions between EVOH and MMT and between EVOH and MBA were confirmed to be intermolecular hydrogen bonds. The colorimetric response of (EVOH–MMT)40–MBA3 to volatile ammonia and pH w...

Catechins are important chemical components determining the quality of tea. The catechin index (CI, ratio of dihydroxylated catechin (DIC)/trihydroxylated catechin (TRIC)) in the green leaf has a major influence on the amounts of theaflavins in black tea. In this work, the major catechin profiles of wild tea plants originating from Guizhou Province with high CI trait were investigated. We identified a novel flavonoid 3',5' hydroxylase gene ( F3' 5' H) allele with a 14 bp deletion in the upstream regulation region and developed an insertion/deletion (InDel) marker accordingly. The 14 bp deletion in the novel F3' 5' H allele was associated with low F3' 5' H mRNA expression, thereby resulting in low TRIC content and high CI value. The allelic variant in the novel F3' 5' H allele associated with high CI values and DIC contents was confirmed by the introgression lines derived from a distant cross population. The novel F3' 5' H allele in wild tea plants is a valuable gene resource, which could be applied to breeding improvement on tea quality.

Natural polysaccharides are attracting increasing attention from food and pharmaceutical industries for their wide range of valuable biological activities. However, the poor repeatability of the methods used in sample preparation and chemical characterization is hampering both research and product development. The unstandardized quality, in turn, undermines efforts to understand the mechanism by which they work via oral dose, which is essential to realize the full beneficial potential of polysaccharides. Some scientists believe polysaccharides work by direct gut absorption; however, increasing evidence points to the gut microbiome and intestinal Peyer’s patches as holding the keys to how they work.

Orange trees affected by huanglongbing (HLB) exhibit excessive fruit drop, and fruit loosely attached to the tree may have inferior flavor. Fruit were collected from healthy and HLB-infected ( Candidatus liberibacter asiaticus) 'Hamlin' and 'Valencia' trees. Prior to harvest, the trees were shaken, fruit that dropped collected, tree-retained fruit harvested, and all fruit juiced. For chemical analyses, sugars and acids were generally lowest in HLB dropped (HLB-D) fruit juice compared to nonshaken healthy (H), healthy retained (H-R), and healthy dropped fruit (H-D) in early season (December) but not for the late season (January) 'Hamlin' or 'Valencia' except for sugar/acid ratio. The bitter limonoids, many flavonoids, and terpenoid volatiles were generally higher in HLB juice, especially HLB-D juice, compared to the other samples. The lower sugars, higher bitter limonoids, flavonoids, and terpenoid volatiles in HLB-D fruit, loosely attached to the tree, contributed to off-flavor, as was confirmed by sensory analyses.

Fruit quality is an important trait in strawberry and is determined by many factors. The soluble solid content in strawberry fruits is positively related to the phosphorus content. MicroRNA399 (miR399) is involved in the regulation of phosphate (Pi) homeostasis. However, the effect of miR399 on strawberry quality remains unknown. In this study, miR399a-overexpressing transgenic woodland strawberries (Fragaria vesca) were obtained via an Agrobacterium-mediated transformation. The phosphorus (P) content was 1.1-fold to 2.1-fold higher in the leaves and fruits of the miR399a-overexpressing plants than in the wild type (WT). However, the P content in the miR399a-overexpressing plants was decreased by 25% to 45% in the roots. The primary root length of the transgenic lines in both the high-Pi and low-Pi media was shorter than that of the WT. Interestingly, the transgenic lines in pots under Pi-sufficient conditions grew better than the WT, and the fruit quality, including the contents of fructose and glucose and soluble solid, was significantly higher in the transgenic lines than in the WT. The overexpression of miR399a in strawberry can be used to improve the parameters involved in fruit quality and provides information regarding breeding nutrient-improved strawberry.

Fish substitution and fish fraud are widely observed in the global food market. To detect and prevent substitution, DNA-based methods do not always meet the demand of being time- and cost-efficient; therefore, methodology improvements are needed. The use of species-specific protein patterns, as determined by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry, has recently improved species identification of prokaryotes both time- and cost-wise. We used the method to establish a database containing protein patterns of common food fish prone to substitution. The database currently comprises 54 fish species. Aspects such as the sensitivity of identification on the species level and the impact of bacterial contamination of fish filets are assessed. Most database entries are characterized by low intraspecies but high interspecies variability. Hitherto, 118 validation samples were successfully determined. The results presented herein underline the potential and reliability of eukaryotic species identification via MALDI-TOF mass spectrometry.

The electrochemical genosensor is one of the most promising methods for the rapid and reliable detection of pathogenic bacteria. In a previous work, we performed an efficient electrochemical genosensor detection of Staphylococcus aureus by using lead sulfide nanoparticles (PbSNPs). As a continuation of this study, in the present work, the electrochemical genosensor was used to detect Escherichia coli O157:H7. The primer and probes were designed using NCBI database and Sigma-Aldrich primer and probe software. The capture and signalizing probes were modified by thiol (SH) and amine (NH2), respectively. Then, the signalizing probe was connected using cadmium sulfide nanoparticles (CdSNPs), which showed well-defined peaks after electrochemical detection. The genosensor was prepared by immobilization of complementary DNA on the gold electrode surface, which hybridizes with a specific fragment gene from pathogenic to make a sandwich structure. The conductivity and sensitivity of the sensor were increased by using multiwalled carbon nanotubes (MWCNT) that had been modified using chitosan deposited as a thin layer on the glass carbon electrode (GCE) surface, followed by a deposit of bismuth. The peak currents of E. coli O157:H7 correlated in a linear fashion with the concentration of tDNA. The detection limit was 1.97 × 10(-14) M, and the correlation coefficient was 0.989. A poorly defined current response was observed as the negative control and baseline. Our results showed high sensitivity and selectivity of the electrochemical DNA biosensor to the pathogenic bacteria E. coli O157:H7. The biosensor was also used to evaluate the detection of pathogen in real beef samples contaminated artificially. Compared with other electrochemical DNA biosensors, we conclude that this genosensor provides for very efficient detection of pathogenic bacteria. Therefore, this method may have potential application in food safety and related fields.

An experimental study was conducted to assess the stability of a single-variety (Arbequina) extra virgin olive oil (EVOO) as a function of container type and storage conditions over a period of 11 months. EVOO quality was assessed by using ion mobility spectrometry (IMS), which provides increased simplicity, expeditiousness, and relative economy. The results were compared with the ones obtained by using the official method based on classical physico-chemical analysis. Bag-in-box, metal, dark glass, clear glass, and polyethylene terephthalate containers holding EVOO were opened on a periodic basis for sampling to simulate domestic use; in parallel, other containers were kept closed until analysis to simulate the storage conditions on market shelves. The results of the physico-chemical and instrumental analyses led to similar conclusions. Thus, samples packaged in bag-in-box containers preserved oil quality for 11 months, better than other container types. The HS-GC-IMS results confirm that 2-heptenal and 1-penten-3-one are two accurate markers of EVOO quality.

In the present study an HPLC-DAD method was developed for the determination of the main carotenoid, zeaxanthin dipalmitate, in the fruits of Lycium barbarum. The aim was to develop and optimize an extraction protocol to allow fast, exhaustive, and repeatable extraction, suitable for labile carotenoid content. Use of liquid N2 allowed the grinding of the fruit. A step of ultrasonication with water removed efficiently the polysaccharides and enabled the exhaustive extraction of carotenoids by hexane/acetone 50:50. The assay was fast and simple and permitted the quality control of a large number of commercial samples including fruits, juices, and a jam. The HPLC method was validated according to ICH guidelines and satisfied the requirements. Finally, the overall method was validated for precision (% RSD ranging between 3.81 and 4.13) and accuracy at three concentration levels. The recovery was between 94 and 107% with RSD values2%, within the acceptable limits, especially if the difficulty of the matrix is taken into consideration.

An electronic nose (E-nose) and an electronic tongue (E-tongue) have been used to characterize five types of strawberry juices based on processing approaches (i.e., microwave pasteurization, steam blanching, high temperature short time pasteurization, frozen-thawed, and freshly squeezed). Juice quality parameters (vitamin C, pH, total soluble solid, total acid, and sugar/acid ratio) were detected by traditional measuring methods. Multivariate statistical methods (linear discriminant analysis (LDA) and partial least squares regression (PLSR)) and neural networks (Random Forest (RF) and Support Vector Machines) were employed to qualitative classification and quantitative regression. E-tongue system reached higher accuracy rates than E-nose did, and the simultaneous utilization did have an advantage in LDA classification and PLSR regression. According to cross-validation, RF has shown outstanding and indisputable performances in the qualitative and quantitative analysis. This work indicates that the simultaneous utilization of E-nose and E-tongue can discriminate processed fruit juices and predict quality parameters successfully for the beverage industry.

Blending of protein sources can increase protein quality by compensating for limiting amino acids present in individual sources, whereas processing grain flours by extrusion or baking can also alter protein quality. To determine the effect of baking and extrusion on the protein quality of blended flours from buckwheat and pinto beans, a rodent bioassay was performed and compared to an in vitro method of protein quality determination. Overall, extruded products had higher protein efficiency ratio values, increased digestibility, and greater protein digestibility corrected amino acid score (PDCAAS) values than baked products, with the extruded buckwheat/pinto blend having the greatest PDCAAS value of the experimental diets investigated. A correlation was found between both digestibility and PDCAAS values generated from in vitro and in vivo methods. The use of in vitro digestibility analysis should be investigated as a potential replacement for the current rodent assay for nutrient content claim purposes.

New Zealand manuka honey is well-known for its unique antibacterial activity. Due to its high price and limited availability, this honey is often subject to honey fraud. Two pteridine derivatives, 3,6,7-trimethyl-2,4(1H,3H)-pteridinedione and 6,7-dimethyl-2,4(1H,3H)-pteridinedione, have now been identified in New Zealand manuka honey. Their structures were elucidated by LC-QTOF-HRMS, NMR, and single-crystal X-ray diffraction after isolation via semipreparative HPLC. Their marker potential for authentic manuka honey was proved as both substances were detectable in neither the pollen-identical kanuka honey nor the nine other kinds of monofloral New Zealand honey analyzed (clover, forest, kamahi, pohutukawa, rata, rewarewa, tawari, thyme, and vipers bugloss). The fluorescence property of the pteridine derivatives can be used as an easy and fast TLC screening method for the authentication of genuine manuka honey. 6,7-Dimethyl-2,4(1H,3H)-pteridinedione has been described for the first time.

The authenticity of some mixed drinks such as vodka or rum was correlated to the conductivity of the dilution water. Authentic drinks demonstrated low conductivity, suggesting the use of treated water, whereas fraud drinks were mixed with regular tap water. The objective of the present study was to test if this criterion is valid for distilled anis, also known as ouzo. Several Greek distilled anis samples, mostly ouzo samples, were tested for different parameters including conductivity, pH, and percentage of different alcohol constituents. Because ouzo in Greece is commonly produced by small enterprises, no correlation between conductivity and the size of the producer was possible. Neither was it possible to correlate the price or high consumption with conductivity and, thus, prior water treatment. Alcohol quality in terms of undesirable constituents, such as methanol content, was good and comparable among samples. In ouzo, water is related to the producer quality goal for the final product and, thus, it is treated and used accordingly.

Liquiritin was reacted with a keyhole limpet hemocyanin (KLH) to synthesize a liquiritin-KLH conjugate as an immunogen for mice. A hybridoma cell line named 2F8 secreted a monoclonal antibody (mAb) against liquiritin, which was applied to an enzyme-linked immunosorbent assay (ELISA) for liquiritin. ELISA showed a good linear range from 0.39 to 25 μg/mL of liquiritin. The maximum relative standard deviation (RSD) values for the intra-assay and interassay were approximately 5%. The recovery rates of liquiritin were in the range of 100.9-103.7%, and the concentrations of liquiritin in various licorice roots, as determined by ELISA, showed a good correlation with those analyzed by high-performance liquid chromatography (HPLC; R² = 0.948). These results suggested that ELISA with anti-liquiritin mAb could be a simple, rapid, convenient, and accurate method for the high-throughput analysis of liquiritin in various licorice products including liqueurs, sweets, and food supplements.

A high-performance liquid chromatography with photodiode array detection method (HPLC-DAD) was validated for the analysis of floral bioresidues obtained in saffron spice production by using three different solvent mixtures [water/hydrochloric acid (HCl) (100:1, v/v), water/acetonitrile/trifluoroacetic acid (47:50:3, v/v/v), and water/acetonitrile/HCl (50:50:1, v/v/v)]. Fifteen phenolic compounds were tentatively identified, kaempferol 3-O-sophoroside and delphinidin 3,5-di-O-glucoside being the main ones. The extracts showed very different phenolic profiles obtained by HPLC-DAD coupled with electrospray ionization mass spectrometry (ESI-MSn), and several experiments were carried out to explain this. The use of acetonitrile as solvent causes the chromatographic splitting of the peak of the delphinidin 3,5-di-O-glucoside into two peaks. Results obtained in this paper show that the extract prepared with water/HCl (100:1, v/v) would be the best suited for determining phenolic compounds in the quality control of the floral bioresidues from Crocus sativus L. © 2014 American Chemical Society., This study was supported by the Consejería de Educación y Ciencia of the JCCM, FSE, and FEDER (project ref POIC10-0195-9848) and the Ministerio de Educación (PNMRH del PN de I−D+i 2008−2011, ref EX2009-0395).

Volatile compounds in packed and unpacked commercial tofu were extracted by solid phase microextraction fibers and analyzed by gas chromatography-mass spectrometry. The tofu samples were stored at 4 °C for 15 days to measure freshness and quality changes during storage. Totals of 41 and 35 volatile compounds were identified from packed tofu and unpacked tofu, respectively. Peak area ratio (PAR) of hexanal in packed tofu increased from 11.44 (day 0) to 496.30 (day 9) and finally decreased to 11.06 on day 15 of storage. PAR of ethanol and 1-hexanol increased from 5.41 and 0.76 (day 1) to 66.93 (day 9) and 47.46 (day 15), respectively. Changes in these volatiles in unpacked tofu were similar to those in packed tofu. The results show that hexanal, ethanol, and 1-hexanol are characteristic volatile compounds for providing quantitative and qualitative information regarding deterioration of tofu.

A rapid, sensitive, and direct method (without derivatization) was developed for the detection of reduced glutathione (GSH) in cultured hepatocytes (HepG2 cells) using high-performance liquid chromatography with electrochemical detection (HPLC-ECD). The method was validated according to the guidelines of the U.S. Food and Drug Administration in terms of linearity, lower limit of quantitation (LOQ), lower limit of detection (LOD), precision, accuracy, recovery, and stabilities of GSH standards and quality control samples. The total analysis time was 5 min, and the retention time of GSH was 1.78 min. Separation was carried out isocratically using 50 mM sodium phosphate (pH 3.0) as a mobile phase with a fused-core column. The detector response was linear between 0.01 and 80 mu mol/L, and the regression coefficient (R-2) was >0.99. The LOD for GSH was 15 fmol, and the intra- and interday recoveries ranged between 100.7 and 104.6%. This method also enabled the rapid detection (in 4 min) of other compounds involved in GSH metabolism such as uric acid, ascorbic acid, and glutathione disulfite. The optimized and validated HPLC-ECD method was successfully applied for the determination of GSH levels in HepG2 cells treated with buthionine sulfoximine (BSO), an inhibitor, and alpha-lipoic acid (alpha-LA), an inducer of GSH synthesis. As expected, the amount of GSH concentration-dependently decreased with BSO and increased with alpha-LA treatments in HepG2 cells. This method could also be useful for the quantitation of GSH, uric acid, ascorbic acid, and glutathione disulfide in other biological matrices such as tissue homogenates and blood.

Twenty-eight coffee samples from around the world were tested for caffeine levels to develop near-infrared reflectance spectroscopy (NIRS) calibrations for whole and ground coffee. Twenty-five individual beans from five of those coffees were used to develop a NIRS calibration for caffeine concentration in single beans. An international standard high-performance liquid chromatography method was used to analyze for caffeine content. Coffee is a legal stimulant and possesses a number of heath properties. However, there is variation in the level of caffeine in brewed coffee and other caffeinated beverages. Being able to sort beans on the basis of caffeine concentration will improve quality control in the level of caffeine in those beverages. The range in caffeine concentration was from 0.01 mg/g (decaffeinated coffee) to 19.9 mg/g (Italian coffee). The majority of coffees were around 10.0-12.0 mg/g. The NIRS results showed r(2) values for bulk unground and ground coffees were >0.90 with standard errors