Hazelnut is an essential species for nut production worldwide; extensive orchard areas have recently been planted in Romania. To choose the best cultivars to be grown in the future, a study was done ...on the behavior of seven hazelnut cultivars in the eco-pedoclimatic conditions of the Bucharest area. 'Hall’s Giant', 'Tonda Gentile delle Langhe', 'Romavel', 'Red Lambert', 'Tonda di Giffoni', 'Tonda Gentile Romana', and 'Vâlcea 22' were planted in the Experimental Orchard of the Faculty of Horticulture within the University of Agronomic Sciences and Veterinary Medicine of Bucharest. The results presented the behavior of hazelnut cultivars detailing the number of branches per tree, according to their age, and annually for each branch, length, and total cross-section area were measured. The influence of cultivars on yield and fruit characteristics at the harvest moment was detailed. 'Romavel' and 'Vâlcea 22' had the fruits with the highest weight, more than 3.3 g/fruit, while 'Red Lambert' and 'Tonda di Giffoni' presented the lowest values. 'Hall’s Giant' was the most vigorous cultivar, and 'Vâlcea 22' the less vigorous. Interesting growth dynamics for each cultivar and all studied branches in the two experimental years were detailed. First and second-year branches had the highest TCSA growth rhythm, but that was not maintained for the third to fifth-year branches.
This study examined how advanced fingerprinting methods (i.e., non-targeted methods) provide reliable and specific information about groups of samples based on their component distribution on the GC
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GC chromatographic plane. The volatile fractions of roasted hazelnuts (
Corylus avellana L.) from nine different geographical origins, comparably roasted for desirable flavor and texture, were sampled by headspace-solid phase micro extraction (HS-SPME) and then analyzed by GC
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GC-qMS. The resulting patterns were processed by: (a) “chromatographic fingerprinting”, i.e., a pattern recognition procedure based on retention-time criteria, where peaks correspondences were established through a comprehensive peak pattern covering the chromatographic plane; and (b) “comprehensive template matching” with reliable peak matching, where peak correspondences were constrained by retention time and MS fragmentation pattern similarity criteria. Fingerprinting results showed how the discrimination potential of GC
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GC can be increased by including in sample comparisons and correlations all the detected components and, in addition, provide reliable results in a comparative analysis by locating compounds with a significant role. Results were completed by a chemical speciation of volatiles and sample profiling was extended to known markers whose distribution can be correlated to sensory properties, geographical origin, or the effect of thermal treatment on different classes of compounds. The comprehensive approach for data interpretation here proposed may be useful to assess product specificity and quality, through measurable parameters strictly and consistently correlated to sensory properties and origin.
The utilization of plant extracts in nanoparticle (NP) synthesis has been suggested as a nature-friendly method and an efficient alternative to the conventional approaches such as physical and ...chemical methods. Taxol is a valuable medicinal compound, and hazelnut has been suggested as one of the sustainable resources for producing this metabolite. In the present research, copper oxide (CuO) nanoparticles (NPs) were biologically synthesized by utilizing hazelnut leaf extracts. FTIR, XRD, EDAX, DLS, and SEM analyses were used for characterizing and confirming the synthesized NPs. The effect of biosynthesized CuO NPs (10 and 90 ppm), para-aminobenzoic acid (PABA) (20 ppm), and CuSO
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(10 ppm) on the cell viability, biochemical properties, expression of TAT and GGPPS genes, and accumulation of taxol and baccatin III in hazelnut cell cultures was investigated. The results indicated that biosynthesized CuO NPs significantly influenced the cell viability, amount of ROS, antioxidant capacity, lipid peroxidation, secondary metabolite production, and expression pattern of the genes engaged in the biosynthesis pathway of taxanes in the
C. avellana
L. cells. The cytotoxicity of CuO NPs to cells was dose dependent and increased with increasing its concentration, as evidenced by a decline in the survival rate and cell membrane integrity. Furthermore, the utilization of 10 ppm CuSO
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caused more toxicity in the cells than the same concentration of CuO NPs. This result could be attributed to the fact that plant extracts components act as a coating for the NPs and reduce their toxicity. Treatment of the cell cultures with CuO (10 ppm) + PABA (20 ppm) and CuO (10 ppm) induced the highest radical scavenging activity. The activity of antioxidant enzymes was increased with increasing the copper oxide NPs level from 10 to 90 ppm. Contrariwise, the cell’s survival rate, radical scavenging activity, and amount of secondary metabolites were significantly reduced in the higher levels of copper oxide NPs (90 ppm) compared to the 10 ppm. The combined utilization of 10 ppm copper oxide NPs and 20 ppm PABA considerably stimulated the TAT and GGPPS genes expression and produced the highest amount of taxol and baccatin III.
Key points
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CuO NPs were biologically synthesized using the hazel leaf extracts and confirmed by FTIR, XRD, EDAX, DLS, and SEM analyses.
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CuO NPs significantly affected the amount of ROS, antioxidant capacity, and lipid peroxidation in C. avellana L. cells.
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Treatment of the hazel cells with CuO NPs increased the production of secondary metabolites including taxol and baccatin III and expression of the genes involved in taxol and baccatin III biosynthesis (TAT and GGPPS).
► The effect of three storage conditions on quality parameters of hazelnuts was studied in commercial scale conditions. ► Time and storage conditions affected significantly acidity and peroxide ...value. ► Low temperature and modified atmosphere (1% oxygen, and 99% nitrogen) decreased additively the lipid oxidation. ► Low temperature maintained high level of phenolic content and antioxidant capacity.
This study evaluated the effect of different storage conditions currently used by the industry, on the chemical, physical and sensory characteristics of ‘Tonda Gentile delle Langhe’ hazelnuts, during one year of storage. The traditional method of in-shell preservation in a storage room at ambient temperature was compared with refrigerated storage of shelled nuts at 4°C and 55% relative humidity, with or without modified atmosphere (1% oxygen, 99% nitrogen). The following parameters were measured: moisture content, lipid content, total phenolic content, and antioxidant capacity of the kernel; acidity and peroxide value of the oil. The kernel resistance to breakage was evaluated by texture analysis using a compression test. The hazelnuts were also evaluated by sensory analysis. The results showed that the acidity and the peroxide value were the most discriminating parameters. After one year of storage, the acidity of hazelnuts stored at ambient temperature (0.47% oleic acid) was higher than the value considered the acceptable limit after storage (0.40% oleic acid), while refrigerated storage maintained a low level of acidity and lipid oxidation, with the best performance in modified atmosphere (0.13% oleic acid; 0.057 O2 mmolkg−1). Sensory analysis after 12 months also showed differences among the three storage treatments. In-shell storage of hazelnuts at ambient temperature was able to preserve the kernels below threshold limits of acidity and oxidative degradation for up to 8 months, but refrigeration was necessary to maintain high quality for up to one year. The use of modified atmosphere is recommended for long periods of storage.
Microbial contamination, seed browning, bad taste and lipid oxidation are primary causes of quality deterioration in stored hazelnuts, affecting their marketability. The feasibility of NIR ...spectroscopy to detect flawed kernels and estimate lipid oxidation in in-shell and shelled hazelnuts was investigated. ‘Mortarella’ hazelnuts were measured twice by NIR spectroscopy, first in-shell, and then as kernels. Afterwards, the kernels were evaluated visually, externally and internally, and by sensory evaluation with a subsequent measurement of fat oxidation. A satisfactory PLS model was created for the detection of flawed kernels. For lipid oxidation estimation the best performance of PLS models was obtained by first removing the flawed kernels from the calibration set. The PLS model for the K232 extinction coefficient, that is indicative of lipid primary oxidation, was able to predict K232 for both in-shell (R2 = 0.79) and shelled (R2 = 0.85) hazelnuts. Our results suggest, for shelled hazelnuts, a two-step NIR procedure: a first PLS model to detect and separate flawed kernels and then a second PLS model to grade healthy kernels by lipid oxidation levels.
•We use Maxent algorithm to hindcast the distributions of two plant species and validate the projections with fossil data.•We study the effects of model complexity on the Maxent's predictive power ...across time.•Maxent default settings can lead to the generation of overly complex models.•Models of intermediate complexity lead to better predictions of past distributions.•Controlling for complexity leads to improved cross-temporal model transferability.
Maximum entropy modeling (Maxent) is a widely used algorithm for predicting species distributions across space and time. Properly assessing the uncertainty in such predictions is non-trivial and requires validation with independent datasets. Notably, model complexity (number of model parameters) remains a major concern in relation to overfitting and, hence, transferability of Maxent models. An emerging approach is to validate the cross-temporal transferability of model predictions using paleoecological data. In this study, we assess the effect of model complexity on the performance of Maxent projections across time using two European plant species (Alnus glutinosa (L.) Gaertn. and Corylus avellana L.) with an extensive late Quaternary fossil record in Spain as a study case. We fit 110 models with different levels of complexity under present time and tested model performance using AUC (area under the receiver operating characteristic curve) and AICc (corrected Akaike Information Criterion) through the standard procedure of randomly partitioning current occurrence data. We then compared these results to an independent validation by projecting the models to mid-Holocene (6000 years before present) climatic conditions in Spain to assess their ability to predict fossil pollen presence–absence and abundance. We find that calibrating Maxent models with default settings result in the generation of overly complex models. While model performance increased with model complexity when predicting current distributions, it was higher with intermediate complexity when predicting mid-Holocene distributions. Hence, models of intermediate complexity resulted in the best trade-off to predict species distributions across time. Reliable temporal model transferability is especially relevant for forecasting species distributions under future climate change. Consequently, species-specific model tuning should be used to find the best modeling settings to control for complexity, notably with paleoecological data to independently validate model projections. For cross-temporal projections of species distributions for which paleoecological data is not available, models of intermediate complexity should be selected.
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