Hazelnut Samples Research Articles

ДОСЛІДЖЕННЯ СКЛАДУ І ТЕПЛОТИ ЗГОРАННЯ ПІРОЛІЗНИХ ГАЗІВ ЯК ПАЛИВА ДЛЯ КОНВЕРТОВАНИХ НА ГАЗ ДИЗЕЛЬНИХ ДВИГУНІВ НАФТОГАЗОВОГО ТЕХНОЛОГІЧНОГО ТРАНСПОРТУ

Досліджені енергетичні цінності газоподібних продуктів піролізу типової лісової та водної рослинної біомаси України. Проведені теоретичні дослідження основних характеристики зразків типової рослинної біомаси України: акації, ліщини, мікроцистіса, елодеї. Сформульовані методика та планування експериментальних досліджень процесу піролізу рослинної біомаси. Виконані в лабораторних умовах експериментальні дослідження складу газоподібних продуктів піролізу різних видів рослинної біомаси для різних температур. Піроліз рослинної біомаси проводився з використанням спеціально спроектованої та виготовленої піролізної установки, головною частиною якої є піролізний реактор. Виготовлена установка призначена для повільного піролізу. У дослідженні для визначення факту присутності і процентного виходу продукту були використані якісний і кількісний аналізи газової хроматографії. Розраховані нижчі теплотворні здатності газоподібних продуктів піролізу зразків типової лісової та водної рослинної біомаси України. В результаті проведених розрахунків визначено, що при піролізі водних рослин та водорості суміш одержаних газів мала найвищі показники нижчої теплотворної здатності: 17,10-17,15 МДж/кг – для мікроцистіса і 16,45-16,50 МДж/кг – для елодеї. Газ одержаний при піролізі деревини акації мав найвищі показники нижчої теплотворної здатності в межах від 13,8 до 13,85 МДж/кг. Нижча теплотворна здатність пірогазу отриманого зі зразків ліщини перебувала в діапазоні 12,6–12,65 МДж/кг.Ключові слова: піроліз, нижча теплотворна здатність, газова хроматографія, альтернативні палива, дизельний двигун, конвертація двигуна на газ.

Untargeted metabolomics with multivariate analysis to discriminate hazelnut (Corylus avellana L.) cultivars and their geographical origin.

In the present study a metabolomics-based approach was used to discriminate among different hazelnut cultivars and to trace their geographical origins. Ultra-high-pressure liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry (UHPLC-ESI/QTOF-MS) was used to profile phenolic and sterolic compounds. Compounds were identified against an in-house database using accurate monoisotopic mass and isotopic patterns. The screening approach was designed to discern 15 hazelnut cultivars and to discriminate among the geographical origins of six cultivars from the four main growing regions (Chile, Georgia, Italy, and Turkey). This approach allowed more than 1000 polyphenols and sterols to be annotated. The metabolomics data were elaborated with both unsupervised (hierarchical clustering) and supervised (orthogonal projections to latent structures discriminant analysis, OPLS-DA) statistics. These multivariate statistical tools allowed hazelnut samples to be discriminated, considering both 'cultivar type' and 'geographical origin'. Flavonoids (anthocyanins, flavanols and flavonols-VIP scores 1.34-1.49), phenolic acids (mainly hydroxycinnamics-VIP scores 1.35-1.55) together with cholesterol, ergosterol, and stigmasterol derivatives (VIP scores 1.34-1.49) were the best markers to discriminate samples according to geographical origin. This work illustrates the potential of untargeted profiling of phenolics and sterols based on UHPLC-ESI/QTOF mass spectrometry to discriminate hazelnut and support authenticity and origin. © 2019 Society of Chemical Industry.

STORAGE STABILITY OF LOW AND HIGH HEAT TREATED HAZELNUT BEVERAGES

In this study, the changes in the quality parameters of hazelnut beverages treated with low (LHT; 72°C for 20 min) and high temperature (HHT; 105°C for 1 min) after high pressure homogenization process were determined during short (10 days) and long term (120 days) storage periods, respectively. Microbial viability was not detected in any thermally treated samples. Although pH and titration acidity values of LHT samples did not show important change during the storage, the pH values of HHT samples decreased significantly. While protein solubility of LHT samples increased during storage, it slightly decreased in HHT samples. Rheological properties and also serume stability of LHT and HHT hazelnut samples changed during storage. Hydroperoxide index value slightly increased in LHT samples while it increased more than three times in HHT samples during storage. As a result, the LHT and HHT hazelnut beverages had different structural and physicochemical properties during storage.

Genetic profiling: Differentiation and identification of hazelnut cultivars (Corylus avellana L.) using RAPD-PCR

The present work demonstrates a fast and cost efficient method to verify the authenticity of hazelnut cultivars. RAPD-PCR analysis was used to experimentally check 13 different hazelnut cultivars by using 16 RAPD-primers. It was possible to distinguish between all hazelnut cultivars by agarose gel electrophoresis band pattern. For an easier evaluation, which primer should be used to confirm one of the cultivars, the band pattern was transferred into bar diagrams. Furthermore, a cultivar tree was created to quickly classify hazelnut samples, in the case where the confirmation of the cultivar has failed. For a complete characterization, all results were transcribed in a 0/1 matrix to be applied to the Jaccard similarity index for creating a dendrogram, which can also be used as another evaluation tool for the identification of unknown hazelnut cultivars.

Effect of Cu, Fe, Mn, Ni, and Zn and Bioaccessibilities in the Hazelnuts Growing in Sakarya, Turkey using In-Vitro Gastrointestinal Extraction Method

Total concentrations of heavy metals such as Cu, Fe, Mn, Ni, and Zn in different hazelnut samples obtained by different regions of Sakarya city, Turkey were identified for the determination of heavy metal in the first section of this study. In the second section of our study, metal concentrations that can pass to the body by stomach and intestine in case of consuming hazelnuts as in vitro with gastrointestinal methods. It is performed by using enzymes and hydrochloric acid with model intestine and stomach system. In vitro gastrointestinal extraction method aims to identify how much the chemicals obtained by the sample matrices as vegetables, fruits, and soil, which are obtained within daily diet and examines the bioefficacy and bioaccessibility ingesting, used for evaluation of the chemical risk for humans were released. Total metal concentrations in the hazelnuts and metal concentrations passing to the stomach and intestines via in vitro gastrointestinal extraction method were identified with ICP-OES. As the result, heavy metal amounts of hazelnut samples are below the limits identified by Turkish Food Codex (TFC) and World Health Organization (WHO) and in harmony with the literature results so there is no objection in terms of health.

Assessment of Mixtures by Spectral Superposition. An Approach in the Field of Metabolomics.

A recent field of metabolomic applications is the analysis of mixtures, for example, in food science or the early recognition of diseases. Particularly in large-scale studies, the number of intermediate states or mixtures tends to expand significantly and in practice, a manual analysis is extremely difficult if not nearly impossible. In this study, we present a model in which the NMR spectra of mixtures are calculated based on the spectral superposition of corresponding pure samples. Instead of using real spectra, where chemical shifts may be influenced by matrix effects, the linear combination of reduced data (buckets) was applied for the calculation. Starting from a set of 262 hazelnut samples of five Eurasian countries we obtained more than 160 000 NMR spectra with mixed geographic origin. Using these as a basis we calculated assessment curves to estimate to which extent admixtures are recognized within a multivariate classification model. Subsequently the calculated data were compared with the measured spectra of tangible mixtures to validate and assess the suitability of this method. The calculated spectra are very similar to the acquired data, and the resulting deviations are on a similar scale to the errors of current metabolomic measurements. Thus, with a suitable sample basis, various different mixtures can be simulated and limitations of the model can be described. This approach reduces time and resource consumption and allows valid predictions based on calculated NMR spectra. In addition to the first example dealing with the admixtures classification of single commodity foods, this approach may also be applied to simulate metabolic progression in other areas.

Molecular characterization and sequence detection of Apple mosaic virus hazelnut isolates

One of the most important factors, limiting the production of hazelnut in Turkey is Apple mosaic ilarvirus (ApMV). Due to the easy distribution of the pathogen by vegetation and pollen, there is no chemical control available, it causes widespread dissemination in both pome fruit and hazelnut plantations in Turkey. The pathogen was detected on several plant species in Turkey: stone and pome fruits, roses and finally hazelnut. Virus isolates were collected from mainly hazelnut production areas in Black sea region of Turkey and analyzed by DAS-ELISA and RT-PCR assays. During the surveys, 95 hazelnut samples were collected from the research area and using DAS-ELISA it was determined that 57 of them were infected by ApMV. Different RNA isolation methods were tested because of the high tannin content of the leaves, the best results were obtained using the procedure of Rott and Jelkmann (2001) and 262 bp long amplification products were obtained in RT-PCR tests. 9 hazelnut isolates collected from different locations were sequenced and phylogenetic analysis were performed by Mega programme. According to the results of phylogenetic analysis. Hazelnut sequences were gathered in different clusters and compared to the other hosts of the virus.

Effects of the Varietal Diversity and the Thermal Treatment on the Protein Profile of Peanuts and Hazelnuts

Several buffer compositions were compared for their efficiency in protein extraction from both raw and roasted peanut and hazelnut samples, the final goal being to understand the modification of protein solubility upon roasting and maximize the extraction yield. Denaturant conditions provided by urea-TBS buffer resulted in satisfactory extraction yields for both peanut and hazelnut samples, before and after the thermal treatment. In addition, different varieties of peanuts and hazelnuts were characterized to highlight the extent of variability in the protein profile accounted by the varietal factor and eventual differential resistance among cultivars to protein modification induced by the thermal processing. The protein profile was characterized by gel electrophoresis, and specific bands were analyzed by micro-HPLC-MS/MS coupled to software-based protein identification. No significant difference was observed for the investigated hazelnut cultivars, namely, Campana, Romana, and Georgia, whereas interesting features were presented for the peanut varieties Virginia, Zambia, and China. In particular, Zambia variety lacked two bands of approximately 36 and 24 kDa that were visible in Virginia and China varieties, which could suggest a lower allergenic potential of this particular variety which deserves to be further investigated before drawing final conclusions.

Phenolic profiles and antioxidant activity of Turkish Tombul hazelnut samples (natural, roasted, and roasted hazelnut skin)

The phenolic profiles and antioxidant status of hazelnut samples [natural (raw) hazelnut, roasted hazelnut, and roasted hazelnut skin] were compared. Free and bound (ester-linked and glycoside-linked) phenolic acids were examined using liquid chromatography–tandem mass spectrometry (LC–MS/MS). Comprehensive identification of phenolics was carried out using Q-exactive hybrid quadrupole-orbitrap mass spectrometer (Q-OT-MS). Samples were also assessed for their total phenolics and antioxidant activities using three different assays. Ten free and bound phenolic acids were quantified in hazelnut samples. Roasted hazelnut skin contained the highest content of total phenolic acids, followed by natural and roasted hazelnuts. The majority of phenolic acids were present in the bound form. Using a Q-OT-MS, 22 compounds were tentatively identified, 16 of which were identified for the first time in hazelnut samples. The newly identified compounds consisted of flavonoids, phenolic acids and related compounds, hydrolysable tannins and related compounds, and other phenolics. Three antioxidant assays demonstrated similar trends that roasted hazelnut skin rendered the highest activity. The present work suggests that roasted hazelnut skin is a rich source of phenolics and can be considered as a value-added co-product for use as functional food ingredient and antioxidant.

EVALUATION OF AFLATOXIN CONTAMINATION AND QUALITY OF NUTS IN EGYPTIAN MARKETS AND AFTER COLD STORAGE

Aflatoxins (AFs) are secondary metabolites produced by toxigenic fungi in the field or during storage. A total of 72 in-shell and shell-less samples of almonds, hazelnuts and walnuts were collected from small retails and hyper-Egyptian markets from middle June to middle July of 2015. This is the period of the holy month of Ramadan in Islamic calendar; the main season for consuming nuts in Egypt. Fruit quality and aflatoxins contamination including AFB1, AFB2, AFG1, AFG2 and total AFs were measured after collecting samples from market, and after six months of cold storage, at 7°C and 70 % relative humidity, using high performance liquid chromatography (HPLC). All nut samples collected from small retails and hyper-markets were free from AFs. After six months of cold storage, only one sample of shell-less almonds recorded 1.6 µg AFG2/kg kernels. Nut quality had deteriorated after storage, especially for shell-less walnuts and shell-less hazelnuts, compared to other nuts. We concluded that storage of in-shell nuts is preferred than the shell-less ones to keep good taste, avoid insect and fungal infection, and to protect nuts from AFs contamination. Strict quarantine of nuts and other imported food products is important to ensure food safety and AFs free.

The Cyclic Diarylheptanoid Asadanin as the Main Contributor to the Bitter Off-Taste in Hazelnuts (Corylus avellana L.).

Activity-guided fractionation and taste dilution analysis (TDA), followed by LC-MS/MS, LC-TOF-MS, and 1D/2D-NMR spectroscopy, led to the identification of the cyclic diarylheptanoid asadanin exhibiting a human bitter recognition threshold of 13 μmol/kg, as the major inducer of the sporadic bitter off-taste of hazelnut kernels (Corylus avellana L.). Sensory analysis of hazelnut samples from two origins (Ordu/2013 and Akçakoca/2014) and from Cimiciato-infected hazelnut kernels, followed by LC-MS/MS quantitation of 1 and calculation of dose-over-threshold (DoT) factors, showed established evidence for the Cimiciato infection as the major inductor of asadanin biosynthesis in hazelnut kernels and, as a consequence, as the reason for bitter off-taste development.

Food Fingerprinting: Metabolomic Approaches for Geographical Origin Discrimination of Hazelnuts (Corylus avellana) by UPLC-QTOF-MS.

Ultraperformance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) was used for geographical origin discrimination of hazelnuts (Corylus avellana L.). Four different LC-MS methods for polar and nonpolar metabolites were evaluated with regard to best discrimination abilities. The most suitable method was used for analysis of 196 authentic samples from harvest years 2014 and 2015 (Germany, France, Italy, Turkey, Georgia), selecting and identifying 20 key metabolites with significant differences in abundancy (5 phosphatidylcholines, 3 phosphatidylethanolamines, 4 diacylglycerols, 7 triacylglycerols, and γ-tocopherol). Classification models using soft independent modeling of class analogy (SIMCA), linear discriminant analysis based on principal component analysis (PCA-LDA), support vector machine classification (SVM), and a customized statistical model based on confidence intervals of selected metabolite levels were created, yielding 99.5% training accuracy at its best by combining SVM and SIMCA. Forty nonauthentic hazelnut samples were subsequently used to estimate as realistically as possible the prediction capacity of the models.

Modeling engineering characteristics of hazelnut kernel during infrared fluidized bed drying

In this study, a laboratory scale infrared fluidized bed dryer was used to dry the hazelnut kernels. The drying experiments were performed under the following drying conditions: air temperatures of 45, 65 and 85 °C, air velocities of 1.30, 3.09 and 4.87 m/s and infrared powers of 500, 1000 and 1500 W. Maximum and minimum values of effective moisture diffusivity for hazelnut kernels were obtained 1.87 × 10−9 and 1.75 × 10−10 m2/s, respectively. Activation energy was obtained between 33.02 and 50.22 kJ/mol. Specific energy consumption of hazelnut kernels was obtained between 1.72 × 103 and 2.23 × 104 MJ/kg. Six mathematical models were used to predict the drying behavior of hazelnut samples. Among these models, the Midilli model sufficiently fitted the experimental drying data. The shrinkage values were obtained within the range of 0.10 and 0.24. The results obtained showed that the \({{L}^{*}},\)\({{a}^{*}},\)\({{b}^{*}}\) and \(\Delta E\) color values of the kernels were significantly affected (P < 0.05) by air temperature. The highest color changes were related to the air temperature of 85 °C at all air velocities and infrared powers. Maximum values of energy (103.57 N mm) and force (129.84 N) at initial rupture point was related to air temperatures of 85 °C and infrared powers of 1500 W. Minimum values of energy (16.47 N mm) and force (31.74 N) at initial rupture point was related to air temperatures of 45 °C and infrared powers of 500 W.

FT-Raman and NIR spectroscopy data fusion strategy for multivariate qualitative analysis of food fraud

Two data fusion strategies (high- and mid-level) combined with a multivariate classification approach (Soft Independent Modelling of Class Analogy, SIMCA) have been applied to take advantage of the synergistic effect of the information obtained from two spectroscopic techniques: FT-Raman and NIR. Mid-level data fusion consists of merging some of the previous selected variables from the spectra obtained from each spectroscopic technique and then applying the classification technique. High-level data fusion combines the SIMCA classification results obtained individually from each spectroscopic technique. Of the possible ways to make the necessary combinations, we decided to use fuzzy aggregation connective operators. As a case study, we considered the possible adulteration of hazelnut paste with almond. Using the two-class SIMCA approach, class 1 consisted of unadulterated hazelnut samples and class 2 of samples adulterated with almond. Models performance was also studied with samples adulterated with chickpea. The results show that data fusion is an effective strategy since the performance parameters are better than the individual ones: sensitivity and specificity values between 75% and 100% for the individual techniques and between 96–100% and 88–100% for the mid- and high-level data fusion strategies, respectively.

Characterization of Apple mosaic virus isolates detected in hazelnut in Poland

Apple mosaic virus (ApMV) infects over 65 plants species of Rosaceae family including hazelnut. The virus causes chlorotic or yellow patterns, rings and mosaic symptoms on the leaves and losses in yield of nuts. The occurrence and genetic diversity of ApMV were evaluated in 14 plantations of hazelnut in Poland. A total of 13 of 125 hazelnut samples tested positive for ApMV using ELISA and reverse transcriptase-polymerase chain reaction. Several primer pairs were used for RT-PCR to amplify the coat protein (CP) and movement protein (MP) genes as well as complete RNA-3 of the ApMV. Genetic diversity was observed in full-length sequences of RNA-3 of the ApMV isolates from hazelnut. The similarity of nucleotide sequence of the CP and MP genes of the isolates was 90.3–99.9, and 87–99.7 %, respectively. Phylogenetic analysis showed that ApMV isolates from hazelnut grouped separately from the virus strains found in other plant species.

Aflatoxins in hazelnuts and dried figs: Occurrence and exposure assessment

A total of 300 samples of hazelnuts and dried fig were analysed for the incidence of any aflatoxins (AFs). High-performance liquid chromatography coupled with fluorescence detection (HPLC-FLD) method was used to quantify the amounts of AFs. The limit of quantification varied from 0.21 to 0.30μgkg−1. No AFs were detected in shells of the hazelnuts, while six raw hazelnut kernel samples (12%) and five roasted hazelnut kernel samples (8.3%) contained AFs ranging from 0.09 to 11.3μgkg−1 and from 0.17 to 11.2μgkg−1, respectively. Sixteen dried fig samples (12.3%) contained AFs ranging from 0.1 to 28.2μgkg−1 and a mean value of 3.8μgkg−1. Three hazelnuts and six dried fig samples exceeded the European maximum limits (MLs) of 5 and 2μgkg−1 for aflatoxin B1 (AFB1), respectively. The contribution of hazelnuts to AFs exposure is higher than that of dried figs.

Determination of aflatoxins in walnut sujuk and Turkish delight by HPLC-FLD method

This study aims to assess the risk of aflatoxins (AFs) in traditional confectionery products (walnut sujuk and Turkish delight) of Turkey. A high performance liquid chromatography coupled with fluorescence detection (HPLC-FLD) method was used for the determination of AFs. Evaluation of the method showed good selectivity, linearity, recovery and precision. The limit of quantification (LOQ) ranged from 0.106 to 0.374 μg kg−1. The expanded measurement uncertainty was less than 40% for all target analytes. The validated method was successfully applied to the determination of AFs in 112 traditional confectionery products containing nuts (hazelnuts and walnuts). AFs were detected in 43.8% of walnuts and 60.9% of hazelnuts used as ingredients in walnut sujuk and Turkish delight and at levels ranging from 0.58 to 15.2 μg kg−1 and 0.43–63.4 μg kg−1, respectively. This means that AFs levels in walnut sujuk and Turkish delight were up to levels of 6.1 and 9.5 μg kg−1, respectively. Six walnut samples and twenty-one hazelnut samples were above the EU maximum limits (MLs) of 2 and 5 μg kg−1 for aflatoxin B1 (AFB1), respectively.

Bioaccessibility of Copper in Turkish Hazelnuts (Corylus avellana L.) by Chemical Fractionation and In Vitro Methods.

Copper is known as either an essential or toxic trace element in foods to living organisms at sufficient or excess intake levels, respectively. In this study, in vitro simulated gastric and intestinal digestion methods combined with n-octanol extraction and activated carbon adsorption were applied to Turkish hazelnuts (Corylus avellana L.) to evaluate the bioaccessibility of copper. Additionally, analytical fractionation procedures based on water, diethyl ether, n-hexane, and methanol extractions were applied to identify copper-related matrix structures. The macrochemical compositions of the samples were determined to be associated with the fractionation results. The total contents of copper in the samples, digests, and fractions were determined by inductively coupled plasma mass spectrometry after microwave-assisted digestion, and additional validation was performed using atomic absorption spectroscopy. The limits of detection and quantification were 0.016 and 0.053mgkg(-1), respectively. The bioaccessibility of copper was found to be in the range from 16 to 31% for hazelnut samples. The recommended dietary allowance of copper for adults is 0.9mg daily, and considering this value, 100g of hazelnuts supplies 33-44% of daily copper intake.

Fractionation analysis of manganese in Turkish hazelnuts (Corylus avellana L.) by inductively coupled plasma-mass spectrometry.

In this study, an analytical fractionation scheme based on water, diethyl ether, n-hexane, and methanol extractions has been developed to identify manganese-bound fractions. Additionally, in vitro simulated gastric and intestinal digestion, n-octanol extraction, and activated carbon adsorption were used to interpret the manganese-bound structures in hazelnuts in terms of bioaccessibility. The total content of manganese in the samples was determined by inductively coupled plasma-mass spectrometry after microwave-assisted digestion, and additional validation was performed using atomic absorption spectroscopy. Water fractions were further evaluated by high-performance liquid chromatography hyphenated to inductively coupled plasma-mass spectrometry for the identification of water-soluble manganese fractions in hazelnut samples. The limits of detection and quantification were 3.6 and 12.0 μg L(-1), respectively, based on peak height.

Effects of Water, Sodium Hypochlorite, Peroxyacetic Acid, and Acidified Sodium Chlorite on In‐Shell Hazelnuts Inoculated with Salmonella Enterica Serovar Panama

Recent foodborne disease outbreaks involving minimally processed tree nuts have generated a need for improved sanitation procedures. Chemical sprays and dips have shown promise for reducing pathogens on fresh produce, but little research has been conducted for in-shell hazelnuts. This study analyzed the effectiveness of 3 chemical sanitizers for reducing Salmonella on in-shell hazelnuts. Treatments of water, sodium hypochlorite (NaOCl; 25 and 50 ppm), peroxyacetic acid (PAA; 80 and 120 ppm), and acidified sodium chlorite (ASC; 450, 830, and 1013 ppm) were sprayed onto hazelnut samples inoculated with Salmonella enterica serovar Panama. Hazelnut samples were immersed in liquid cultures of S. Panama for 24 h, air-dried, and then sprayed with water and chemical treatments. Inoculation achieved S. Panama populations of approximately 8.04 log CFU/hazelnut. Surviving S. panama populations were evaluated using a nonselective medium (tryptic soy agar), incubated 3 h, and then overlaid with selective media (xylose lysine deoxycholate agar). All of the chemical treatments significantly reduced S. Panama populations (P ≤ 0.0001). The most effective concentrations of ASC, PAA, and NaOCl treatments reduced populations by 2.65, 1.46, and 0.66 log units, respectively. ASC showed the greatest potential for use as a postharvest sanitation treatment.