Effects of Storage Conditions on Consumer and Chemical Assessments of Raw ‘Nonpareil’ Almonds Over a Two‐Year Period.
Raw almonds are a major commodity, yet much is unknown about how storage conditions determine their shelf life. The storage stability, as measured by consumer assessments and chemical measures, of raw almonds was determined for samples stored in cardboard boxes and polypropylene packaging for 2 years at 4, 15, 25, and 35 °C, and at 50% and 65% relative humidity (RH). Samples stored in unlined cartons always failed (>25% rejection) before their counterparts stored in polypropylene bags under identical environmental conditions. Models determined that polypropylene packaging (as opposed to unlined cardboard cartons) extended the time until sample rejection by more than 7 months. Temperature and RH were both negatively associated with storage time until failure. Flavor was a greater contributor to consumer acceptability than texture or odor, while peroxide values and free fatty acids were of greater importance in predicting raw almond consumer quality than measures of conjugated dienes or 2-thiobarbituric acid-reactive substances.
Metabolic fingerprinting of must obtained from sun-dried grapes of two indigenous Cypriot cultivars destined for the production of ‘Commandaria’: A protected destignation of origin product.
Grapes's sun-dried process is one of the most critical steps in the production of 'Commandaria', a dessert wine product that is exclusively produced in Cyprus and derived from must obtained from two indigenous grape cultivars, namely 'Mavro' and 'Xynisteri'. Despite its significant economic importance, no data regarding the primary and secondary metabolites of the aforementioned cultivars exist. Thus, in the current study, the effect of sun drying process on the qualitative attributes and phenolic profile of 'Mavro' and 'Xynisteri' musts was dissected. Musts were analyzed at harvest and at the end of the sun-drying process that corresponds to ca. 30-40% water loss. Results highlighted significant differences in chemical composition of the must before and after the sun-drying process. Except for the increase of soluble solids content, a significant increment in glucose, fructose, total acidity, total phenols and total flavonoids contents was monitored. Subsequently, forty-two phenolic compounds were identified by LC-DAD-qTOF-MS revealing the polyphenolic fingerprint of the two cultivars. Results also indicated that changes in the phenolic composition of the obtained must are not only correlated with the dehydration effect, but both synthesis or degradation reactions occurred. In particular, the increases in the concentration of hydroxybenzoic acids were higher than the concentration effect for both cultivars. Regarding to hydroxycinnamates, dehydration caused a six-fold increase of hydroxycinnamic acid content in both cultivars. Intriguingly, the concentration of some hydroxycinnamic acids such as caffeic acid dihexoside and fertaric acid isomer went descending. Although the degradation of the internal side of the skin facilitate improved extractability from the skins to the grape pulp and therefore to the grape must, the sun-drying process may also induced stilbene and lignans synthesis production. A significant effect of dehydration on the postharvest biosynthesis of three groups of flavonoids (flavonols, flavan-3-ols, flavanonols), was also observed. This study sheds some light in the substantial changes that occur in specific metabolites during the sun drying process; such metabolites can be considered as potential factors that may determine organoleptic characteristics and biological properties of the end-product.
Is the Profile of Fatty Acids, Tocopherols, and Amino Acids Suitable to Differentiate Pinus armandii Suspicious to Be Responsible for the Pine Nut Syndrome from Other Pinus Species?
Pinus armandii is suspicious to be responsible for the Pine Nut Syndrome, a long lasting bitter and metallic taste after the consumption of pine nuts. To find chemical characteristic features for the differentiation of P. armandii from other Pinus species, 41 seed samples of the genus Pinus from 22 plant species were investigated regarding the content and the composition of fatty acids, tocopherols, and amino acids. The predominant fatty acids in the seed oils were linoleic acid (35.2 - 58.2 g/100 g), oleic acid (14.6 - 48.5 g/100 g), and pinolenic acid (0.2 - 22.4 g/100 g), while the vitamin-E-active compounds were dominated by γ-tocopherol. The amino acid composition was mainly characterized by arginine and glutamic acid with amounts between 0.9 and 8.9 g/100 g as well as 2.1 g/100 g and 8.3 g/100 mg. On the basis of this investigation, a Principle Component Analysis has been used to identify the most important components for the differentiation of P. armandii from other Pinus species. Using the data for glutamic acid, 20:2Δ5,11 , 18:3Δ5,9,12 , 18:1Δ9 , and oil content, a classification of the 41 samples into four different groups by cluster analysis was possible, but the characteristic features of P. armandii were too close to some other members of the genus Pinus, making a clear differentiation of this species difficult. Nevertheless, the investigation showed the similarities of different members of the genus Pinus with regard to fatty acids, vitamin-E-active compounds, and amino acids.
The classification of almonds (Prunus dulcis) by country and variety using UHPLC-HRMS-based untargeted metabolomics.
The aim of this study was to use an untargeted UHPLC-HRMS-based metabolomics approach allowing discrimination between almonds based on their origin and variety. Samples were homogenized, extracted with ACN:H2O (80:20) containing 0.1% HCOOH and injected in a UHPLC-QTOF instrument in both positive and negative ionization modes. Principal component analysis (PCA) was performed to ensure the absence of outliers. Partial least squares - discriminant analysis (PLS-DA) was employed to create and validate the models for country (with 5 different compounds) and variety (with 20 features), showing more than 95% accuracy. Additional samples were injected and the model was evaluated with blind samples, with more than 95% of samples being correctly classified using both models. MS/MS experiments were carried out to tentatively elucidate the highlighted marker compounds (pyranosides, peptides or amino acids amongst others). This study has shown the potential of HRMS to perform and validate classification models, also providing information concerning the identification of the unexpected biomarkers which showed the highest discriminant power.
Flavor and Acceptance of Roasted California Almonds During Accelerated Storage.
Monitoring oxidative flavor changes in almonds is only possible if the chemical and sensory profile during roasting and storage is first established. Herein almonds roasted at two different temperatures (115 and 152 °C) were stored at 39 °C for 0 to 12 months and were analyzed by Headspace Solid-phase Microextraction Gas Chromatography-Mass Spectrometry (HS-SPME-GC/MS), descriptive analysis and consumer hedonic analysis. Volatile profiles, descriptive sensory profiles and consumer hedonic scores were analyzed for predictive relationships. Descriptive attributes involving Roasted and Nutty, as well as consumer liking were highest in fresh almonds, while flavors typically associated with oxidative rancidity such as Cardboard, Painty/Solvent, Soapy, and Total Oxidized increased during storage. Compounds most important for predicting rancidity-related attributes were lipid oxidation products, including pentanal, hexanal, heptanal, and octanal. Consumer liking was best predicted by similar compounds to those predicting Clean Nutty flavor, including Maillard reaction products, such as 2- and 3-methylbutanal, 2-methylpyrazine and 2,5-dimethylpyrazine.
Should Younger Siblings of Peanut Allergic Children Be Screened for Peanut Allergy?
The role of screening younger siblings of peanut allergic children with allergy testing before peanut introduction is controversial. Although certain guidelines note some value in screening this population, it is not a direct indication in the recent National Institute of Allergy and Infectious Diseases guideline. Some studies suggest that siblings of peanut allergic children are at increased risk of peanut allergy, whereas others note that delayed ingestion or mislabeling of allergy in these children may be the main factors accounting for this increased risk. The low risk of severe reaction with first ingestion and risks of pre-emptive testing must be balanced against data suggesting that families are reluctant to introduce peanut in siblings without testing. The goal of this article is to critically appraise the debated issues in this topic, providing a practical approach to this common clinical dilemma.
Pine nut allergy in Korean children: Clinical characteristics and diagnostic values of specific IgE against pine nuts.
BACKGROUND: Hypersensitivity reactions to pine nuts in children have been occasionally encountered recently, although reports on pine nut allergy cases are rare worldwide. The study aimed to feature clinical and laboratory findings pertaining to pine nut allergy in Korean children. METHODS: Forty-two subjects were enrolled through a retrospective review of medical records, from September 2010 to December 2015, at the Department of Pediatrics in Ajou University Hospital. The demographic profiles, clinical characteristics, and laboratory findings were evaluated. RESULTS: Twenty-four patients showed immediate-type reactions after exposure to pine nuts (the allergic group), while the remaining 18 were atopic controls, who exhibited no allergic symptoms (the tolerant group). The median age of the subjects in the allergic group was three years. More than half of the subjects in this group experienced allergic symptoms within 5min, and seven of them experienced anaphylaxis. The median level of pine nut-specific immunoglobulin E (sIgE) in the allergic group (1.62kUA/L) was significantly higher (p=0.014) than that in the tolerant group (0.11kUA/L), with an optimal cut-off level of 0.40kUA/L (sensitivity, 66.7% and specificity, 77.8%). The positive decision point of pine nut-sIgE (specificity, 100%) to distinguish the allergic and tolerant groups was 2.84kUA/L. However, there was no difference in pine nut-sIgE levels between the anaphylaxis and non-anaphylaxis cases. CONCLUSION: About 30% of children with pine nut allergy experienced anaphylaxis. The optimal cut-off level of pine nut-sIgE to distinguish the allergic and tolerant groups was 0.40kUA/L and the positive decision point was 2.84kUA/L.
Diagnostic accuracy, risk assessment, and cost‐effectiveness of component‐resolved diagnostics for food allergy: a systematic review.
BACKGROUND: Component-resolved diagnostics (CRD) are promising tools for diagnosing food allergy, offering the potential to determine specific phenotypes and to develop patient-tailored risk profiles. Nevertheless, the diagnostic accuracy of these tests varies across studies; thus, their clinical utility remains unclear. Therefore, we synthesized the evidence from studies investigating the diagnostic accuracy, risk assessment ability, and cost-effectiveness of CRD for food allergy. METHODS: We systematically searched 10 electronic databases and four clinical trial registries for studies published January 2000-February 2017. The quality of included studies was assessed using QUADAS-2. Due to heterogeneity, we narratively synthesized the evidence. RESULTS: Eleven studies met inclusion criteria, altogether recruiting 1,098 participants. The food allergies investigated were cow's milk, hen's egg, peanut, hazelnut, and shrimp. The components with the highest diagnostic accuracy for each allergen, along with their sensitivity-specificity pairs, were: Bos d 4 for cow's milk (62.0% and 87.5%), Gal d 1 for hen's egg (84.2% and 89.8% for heated egg, and 60.6% and 97.1% for raw egg), Ara h 2 for peanut (80.3% and 95.1%), Cor a 14 for hazelnut (100% and 93.8%), and Lit v 1 for shrimp (82.8% and 56.3%) allergy. CONCLUSION: Selected components of cow's milk, hen's egg, peanut, hazelnut, and shrimp allergen showed high specificity, but lower sensitivity. However, few studies exist for each component, and studies vary widely regarding the cut-off values used, making it challenging to synthesize findings across studies. Further research is needed to determine clinically appropriate cut-off values, risk assessment abilities, and cost-effectiveness of CRD approaches.
Risk Factors and Clinical Features in Cashew Nut Oral Food Challenges.
BACKGROUND: Cashew nuts (CN) are capable of causing severe allergic reactions. However, little has been reported about the details of CN oral food challenges (OFC). METHODS: CN-specific IgE (sIgE) levels were measured for 1 year in 66 patients who underwent an OFC with >3 g CN for diagnosis or confirmation of tolerance acquisition between June 2006 and August 2014. We retrospectively analyzed the OFC and patient background. RESULTS: The median (IQR) age of the 66 patients (48 boys/men and 18 girls/women) was 7.0 years (5.7-8.8). Twelve patients (18.2%) had a positive OFC result; 6 of 8 (75%) patients with a history of an immediate reaction to CN failed the OFC. Anaphylaxis was experienced by 5 of these 12 (42%) patients. A history of an immediate reaction to CN and the CN sIgE levels were significantly different for patients with a positive or negative OFC result (p < 0.01). Among patients without a previous immediate reaction to CN, the 95% positive predictive value (PPV) for the CN sIgE level for a positive OFC result was 66.1 kUA/L. CONCLUSIONS: A history of an immediate reaction to CN and high CN sIgE were risk factors for a positive OFC result. The number of positive OFC results was relatively low, but there was a high probability of anaphylaxis. We should consider the indication of OFC carefully for patients with a history of immediate reactions to CN and avoid OFC for patients without such a history whose CN sIgE values are >66.1 kUA/L (95% PPV).
Prediction of the severity of allergic reactions to foods.
BACKGROUND: There is currently considerable uncertainty regarding what the predictors of the severity of diagnostic or accidental food allergic reactions are, and to what extent the severity of such reactions can be predicted. OBJECTIVE: To identify predictors for the severity of diagnostic and accidental food allergic reactions and to quantify their impact. METHODS: The study population consisted of children with a double-blind, placebo-controlled food challenge (DBPCFC) confirmed food allergy to milk, egg, peanut, cashew nut and/or hazelnut. The data was analyzed using multiple linear regression analysis. Missing values were imputed using multiple imputation techniques. Two scoring systems were used to determine the severity of the reactions. RESULTS: 734 children were included. Independent predictors for the severity of the DBPCFC reaction were: age (B=0.04, p=0.001), skin prick test ratio (B=0.30, p<0.001), eliciting dose (B=-0.09, p<0.001), level of specific immunoglobulin E (B=0.15, p<0.001), reaction time during the DBPCFC (B=-0.01, p=0.004), and severity of accidental reaction (B=0.08, p=0.015). The total explained variance of this model was 23.5%, and the eliciting dose only contributed 4.4% to the model. Independent predictors for more severe accidental reactions with an explained variance of 7.3% were: age (B=0.03, p=0.014), milk as causative food (B=0.77, p<0.001), cashew as causative food (B=0.54, p<0.001), history of atopic dermatitis (B=-0.47, p=0.006), and severity of DBPCFC reaction (B=0.12, p=0.003). CONCLUSIONS: The severity of DBPCFCs and accidental reactions to food remain largely unpredictable. Clinicians should not use the eliciting dose obtained from a graded food challenge for the purposes of making risk-related management decisions.