جستجوی مقالات مرتبط با کلیدواژه "walnut" در نشریات گروه "زیست شناسی"

Walnut is an important economic and commercial product all over the world. The smell can be one of the key factors in determining the ripening time of the fruit and it depends on the content of the chemical compounds of the fruit and its skin. Crunchyness and easy peeling are the main features that affect the level of satisfaction of walnut consumers.The complexity of food odor makes it difficult to analyze them with conventional analytical techniques such as gas chromatography. However, sensory analysis by experts is a costly process and requires trained people who can only work for a relatively short period of time. Problems such as the human subjectivity of the response to smell and the variation between people should also be considered. Hence, there is a need for a tool such as an electronic nose with high sensitivity and correlation with human sensory panel data for specific applications in food control. Due to its easy construction, cheapness and the need for little time for analysis, the electronic nose is becoming an automatic non-destructive method to describe the smell of food.An olfactory machine can recognize the fragrance composition by estimating its concentration or determining some of its intrinsic properties, which the human nose is hardly able to do. In general, the human olfactory system is a five-step process including smelling, receiving the scent, evaluating, detecting and erasing the effect of the scent. The olfactory phenomenon begins with inhaling the intended smell and ends with breathing fresh air to remove the effect of the scent. The human olfactory system, with all its unique capabilities, also has disadvantages that limit its use in quality control processes, including subjectivity, low reproducibility (for example, results depending on time, people's health, analysis before the presence of odor and fatigue is variable), time-consuming, high labor cost, adaptation of people (less sensitivity when exposed to odor for a long time). In addition, it cannot be used to evaluate dangerous odors.The purpose of this research was to evaluate the ability of the electronic nose using chemometrics methods to detect the ripening time of walnuts with the help of its volatile compounds during the ripening period.

In each process of investigation (including 5 courses and intervals were determined as one week), premature walnut samples plus its ripe samples (in the last period) from one of the gardens around Ardebil (located in the village September) It was prepared and with an electronic data nose.In this study, the electronic nose was made in the Biosystem Engineering Department of Mohaghegh Ardebili University. The device uses 9 metal oxide semiconductor sensors (MOS) with low power consumption. The data is that the clean air was first passed through the sensor chamber for 150 seconds to clean the sensors from the smell and other gases. The sample smell was then sucked for 150 seconds by the pump from the sample chamber and directed to the sensors, and finally, clean air was injected into the sensor chamber for 150 seconds to prepare the device for recurring and subsequent tests. 20 repetitions are intended for each sample. During the above steps, the output voltage of the sensors was changed due to exposure to gases emitted from the sample (walnut aroma) and their smell response was collected and recorded by data collection cards.The Chemometrics method in this study will begin with the analysis of the main components (PCA) to discover the sensor output response and reduce the data dimension. The next step is to classify the time of walnut proceedings using artificial neural network analysis (ANN).

The scores chart (Figure 2) showed the total variance of the total data to PC-1 (98%) and PC-2 (1%), respectively, and the first two main components make up 99%of the total variance of normal data. When the total variance is above 90 %, it means that the first two PCSs are sufficient to explain the total variance. So it can be concluded that E-nose has a good response to peach smell and can be distinguished from peach figures, which indicates the high accuracy of the electronic nose in identifying the smell of different products. These results are highly compatible with the results obtained by XU et al., In a study conducted on class 6 rice digits, the PCA method was 99.5% accurate. The artificial neural network method was also used to identify and differentiate peaches based on the output of the sensors. The results of the diagnosis of walnut proceedings were obtained by 99% (Figure 3), which was the same as the PCA method.Aimin Li and colleagues, using an electronic nose with GC-MS tests, identified Chinese maca (MacA) at macroscopic and microscopic levels, concluding that there was a direct relationship between the Maca smell and chemical compounds (LI ET AL, 2019). Min Yee Lim and colleagues also achieved good results with the PCA method (Lim et al, 2020). They used the electronic nose to grade the quality of the Chinese commercial mum and were able to classify their quality with 94.3% accuracy, with the results of their PCA method in accordance with our research results. Arun Jana et al. (Jana et al, 2011) also used the olfactory machine with Ann, PCA and LDA to detect aromatic and non-aromatic rice, with the accuracy of the results used for the methods used, respectively: 93%, 96.5% and 80%. The results of our research were far more accurate than this study, which could be due to the presence of different volatile compounds in grape leaves.In this study, an olfactory machine with 9 metal oxide sensors was used to handle walnuts using their smell. Chemometrics, including PCA and ANN, were used for qualitative and quantitative data analysis of electronic sensor arrays. PCA was used to reduce data and, with two main components of PC1 and PC2, described 99% of the variance of the data set and provided an initial classification, as well as the artificial neural network capable of identifying and accurately classifying grape figures with grape cultivars the accuracy was 99%. The olfactory machine has the ability to use and operate as a rapid and non -destructive way to detect walnuts from their smell. Using this method will be very useful in identifying proper harvesting time for gardeners and manufacturers, especially processing units and food industries.

Walnut is an important economic and commercial product all over the world. The reflected light spectrum can be one of the key factors in determining the ripening time of the fruit and it depends on the content of the chemical compounds of the fruit and its skin. Crunchyness and easy peeling are the main features that affect the level of satisfaction of walnut consumers. The complexity of the reflectance spectrum of food makes it difficult to analyze them with conventional analytical techniques such as gas chromatography. However, sensory analysis by experts is a costly process and requires trained people who can only work for a relatively short period of time. A near-infrared spectrometer can detect the spectrum of reflected light by estimating its concentration or determining some of its inherent properties.The quality assessment of agricultural products includes two main methods, quality grading systems based on the external characteristics of agricultural products and quality grading systems based on internal quality assessment, which has gained outstanding points in recent years. In the meantime, several methods have been invented so far for the qualitative grading of agricultural products based on the assessment of their internal properties in a non-destructive way, and only some of them have been able to meet the above conditions and have been justified in terms of technical and industrial aspects. To be meanwhile, spectrometry can be highly efficient in determining the quality of cultivars. Spectroscopy is a type of system that has a different structure and approach from other methods (image processing, neural network, etc.) and can perform classification and determination of digit quality.With increasing expectations for food products with high quality and safety standards, the need for accurate, fast and targeted determination of the characteristics of food products is now necessary. Because manual methods do not have automaticcontrol, they are very tiring, difficult and expensive, and they are easily affected by environmental factors. Today, spectroscopic systems are non-destructive and cost-effective and are ideally used for routine inspections and quality assurance in the food industry and related products. This technology allows inspection works to be carried out using wavelength data analysis techniques and is a non-destructive method for measuring quality parameters. In this research, the ripening time of walnuts was investigated using spectrometry and chemometrics methods.

In each treatment period (in total 5 periods were considered and the intervals of periods were determined as one week), unripe walnut samples in addition to ripe samples (in the last period) were taken from one of the orchards around Ardabil (located in Shahrivar village) was prepared, tested and data collected.A spectroradiometer model PS-100 (Apogee Instruments, INC., Logan, UT, USA) was used to acquire the spectrum of the samples. This spectroradiometer is very small, light, portable, has a single-wavelength sputtering type with a resolution of 1 nm and a linear silicon CCD array detector with 2048 pixels that covers the spectral range of 250-1150 nm (Vis/NIR) well. Also, there is the ability to connect the optical fibre to the PS-100 spectroradiometer and transfer the data to the computer with the purpose of displaying and storing the acquired spectra in the Spectra Wiz software through the USB port. With the aim of creating optimal light in contrast mode measurements, an OPTC (Halogen Light Source) model halogen-tungsten light source, which can be connected to an optical fibre, was used. This light source has three output powers of 10, 20, and 30 watts, which were used in this research. Also, a two-branch optical fibre probe model (Apogee Instruments, INC., Logan, Utah, USA), which includes 7 parallel optical fibres with a diameter of 400 micrometres, was used in counter-mode measurements. After providing the necessary equipment, the optimal spectroscopic arrangement was designed and implemented in order to facilitate the experiments and minimize the effect of environmental factors during the spectroscopic process, which is shown in Figure 1.

The average absorption spectra of Vis/NIR absorption spectra for different treatments in the range of 680-970 nm are presented in Figure 1.Environmental factors (light and heat) as well as the spectrometer's expression quality cause disturbances in the initial and final wavelengths of the spectra, so some of these wavelengths are removed from the data set. And as it is clear in Figure 1, the samples had an almost similar trend; this may be affected by the colour of the samples. According to Figure 1, there are two distinct peaks for the spectra and it is that the peaks appeared around the wavelength of 680 and 970 nm. It can also be seen in Figure 1 that the amount of absorption of ripe walnuts is higher compared to other periods, which can be due to the difference in the content and texture of the product.Based on the PCA analysis results presented in Figure 2, the first principal component (PC-1) describes 94% and the second principal component (PC-2) describes 5% of the variance of the tested samples. As a result, the first two principal components together express 99% of the data. Considering that it is possible that the degree of correlation between the properties of different samples during the tests, due to various reasons such as technical problems of the equipment, data collection, incorrect sampling, etc., in some samples, inappropriate or so-called outliers.The values of R2 and RMSE for calibration and validation sets of different regression models (PLS) with raw and processed data are presented in Figure 3, which is equal to 0.98. The results show that the spectra are able to detect the ripening time of walnuts with high accuracy. Khodabakhshian et al investigated the potential of visible and infrared spectroscopy to classify the ripening stage and predict the quality traits of pomegranate varieties including SSC and TA. Among the methods of centring, Savitzky-Golay smoothing, median filter, standard normal variable, incremental spread correction (MSC) and differentiation with first derivative and second derivative, the use of incremental spread correction (MSC) has the highest accuracy in identifying pomegranate quality parameters. followed Zhang and colleagues (Zhang et al, 2018) in estimating the SSC of red Fuji apple using near-infrared spectroscopy to reduce noises using the functions of additive scatter correction (MSC) and standard normal distribution (SNV) and reported that the additive scatter correction method (MSC) compared to the standard normal distribution (SNV) will result in a more accurate estimate of the SSC value. Kim et al. estimated the SSC of oriental melon using near-infrared spectroscopy among different pre-processing methods including Savitzky-Golay smoothing, normalization with maximum and minimum, stable normalization, standardization, stable normal variable, distribution Standard normal (SNV) and incremental spread correction (MSC) reported that the best result was obtained with a standard normal distribution (SNV). Although considering the different nature of the samples, measurement methods and equipment, and other conditions affecting the spectral properties of the product, it is better not to compare the data obtained from different researches with each other.

The presence of abundant calcium carbonate and alkaline soil reaction in most of the country's soils has reduced the bioavailability of some elements for plants. The application of some soil amendments such as sulfur and organic matter can improve the nutrient status of the soil. For this purpose, a factorial experiment was conducted in a randomized complete block design with 18 treatments and 3 replications on the underground soil of walnut trees. The experimental factors included Thiobacillus at two levels (without inoculation and with inoculation), sulfur (S) at three levels (0, 1000 and 2000 kg. ha-1 ) and organic matter (OM) at three levels (0, 5 and 10 T. ha-1 ). The results showed that S treatment significantly affects soil pH (p <0.01), P (p <0.05) and iron (Fe) concentration on soils beneath the tree covers (p <0.05). The highest P concentration (9.06 mg / kg) and available Fe (6.34 mg / kg) was observed in the treatment of 2000 kg. ha-1 of sulfur. Organic matter treatment significantly has changed the soil pH (p <0.01), available Zn (p <0.01) and plant available P and Fe concentration in soils beneath the tree covers. As the level of applied OM increased, the soil pH decreased. The highest concentration of available P, Fe and Zn was observed in the treatment of 10 tons per hectare of OM. Inoculation with Thiobacillus bacteria decreased the soil pH and increased soil available P concentration. According to the results, the simultaneous application of S, Thiobacillus and OM can increase the phytoavailability of P, Fe and Zn in soils beneath the walnut trees.

The aim of this study was to determine the chemical composition and evaluation of extraction methods of tannin from leaves of Iranian walnut (Juglans regia L.) and estimation of fermentative parameters by gas production technique. Mentioned methods include maceration method, boiling method, percolation method, and Soxhlet method. The results showed that the number of tannins in all the processing methods was reduced significantly compared to the control treatment (p<0.05). Crude protein, crude energy, natural detergent fiber and acid detergent fiber were also increased to compare to other treatments, significantly (p<0.05). Soaking Process compared to other treatments increased significantly cumulative gas production, the fermentable fraction (b) of gas production and also increased insignificantly the parameters of rate (c) of gas production, metabolizable energy, and digestibility of organic matter. Therefore, by comparing the chemical composition and fermentative characteristics of the processed products, it can be concluded maceration method and use distilled water compared to ethanol, is a suitable method for the extraction of tannin and its use in ruminants' feedstuff.

Persian walnut (Juglans regia L.) belongs to the family Juglandaceae is one of the most important nut crops in Iran. In this research, morphometric and genetic variations among some genotypes of Persian walnut collected from different parts of west Iran were evaluated based on nut characteristics and RAPD markers. In the first experiment, 29 traits related to nut and kernel were used to evaluate genetic potential of 119 walnut genotypes. The primary results of fruit morphometric characteristics showed that there is high variability in the some evaluated traits such as fruit shape, nut diameter and Kernel removal from nut in studied genotypes. Also, in the second experiment, the genetic diversity among 50 genotypes of walnut was evaluated using 13 RAPD markers. A total of 87 alleles were produced in the 13 RAPD markers with their sizes ranging from 140 to 2500 bp. The number of observed alleles for each locus ranged from 4 (OPA-18 and OPA-13) to 11 (OPA-09), with an average of 6.46 alleles per locus. Shannon's information index (I) value was observed to be highest (3.20) in the OPA-09 locus, while the OPA-13 locus had the lowest value (0.70) with an average of 1.66 among RAPD locus. The Jaccards’ genetic similarity coefficient ranged from 0.08 to 0.79 among genotypes. Finally, our results demonstrate some of these genotypes have been desirable traits and must be conserved as valuable genetic resources, from the perspective of breeding.

Bacterial canker in walnut is caused by Brenneria nigrifluens. The prevalence of this disease has been increasing in recent years and it is a serious threat to walnut tree in the appropriate conditions. The aim of this study was to isolate and identify the prevalence bacterial walnut canker in Lorestan and to determine their pathogenesis in the raw walnut.

This cross-sectional study was carried out on 105 branches and trunk bark walnut trees suffering of the symptoms of shallow bark canker. After purification and isolation of the disease agents, the bacteria were identified based on phenotypic characteristics. Next, the results were analyze by Ntsys-pc version 2.02 software. The PCR reactions were performed for more accurate identification of the isolates. Overall, five bacterial isolates were selected to study their pathogenesis on the walnut fruits and trunks.

According to the results of phenotypic characteristics of isolates, these strains were classified as B. nigrifluens. Furthermore, based on numerical analysis of the strains with 94% similarity, these isolates were classified into four groups. All isolates produced an expected 255 bp band in the PCR reaction. These strains caused necrotic area on fruit with reddish brown ooze.

The differential phenotypic tests, the pathogenicity test on the raw fruits and specific primers are reliable methods for diagnosis of the etiology of this disease. In our knowledge, the present study is the first report regarding the occurrence of this disease in Lorestan province and also first report of the pathogenicity of B. nigrifluens on fruit in Iran.

The effects of different concentrations of walnut leaf extract on physiological and biochemical characteristics of parsley plants inoculated with mycorrhizal fungus Glomus versiforme and non-mycorrhizal plants were studied under greenhouse conditions. In the present study, three different concentrations of walnut extract (full extract, half and quarter concentration levels) were used. The results of the 45 day-old plants showed that the increasing of the concentration of walnut extract decreased amounts of chlorophyll a and b but increased the carotenoids content. This increase was more pronounced in mycorrhizal plants than non-mycorrhizal ones. When ¼ concentration of extract was applied the total protein content in mycorrhizal and non-mycorrhizal plant shoots was increased and then decreased at higher concentrations with increasing in concentrations of aqueous extract of walnut leaves. The free amino acids and proline content in plants were increased but such effects in non-mycorrhizal plants were greater than in mycorrhizal ones. Ascorbate peroxidase (APX) and Guaiacol peroxidase (GPX) activities in mycorrhizal and non-mycorrhizal plants also increased due to walnut extract, but the increased activity of these enzymes was higher in the inoculated plants. Results of this study indicated that by inoculating mycorrhizal fungi with root of parsley adverse potential effects of allelopathic extract on the physiological and biochemical characteristics of these plants.

Walnut is one of the most important trees that are cultivated in the large area in Iran. Various microorganisms comprising useful and harmful agents are associated with walnut root and rhizosphere. Almost all of the studies carried out for identification of microorganisms related to walnut until now، have been achieved on plant pathogen agents. Therefore in this research isolation and identification of Trichoderma spp. associated to walnut root and rhizosphere was studied. Sampling has performed of 68 places from Hamedan province and 235 isolates of Trichoderma were obtained. Macroscopic and microscopic features such as shape and size of conidium، conidiophore، phialide، chlamydospore، presence of aerial and submerged mycelia on culture media and growth rate as well as temperature examination data were used for identification of Trichoderma species. Consequently six species comprising T. atroviride، T. brevicompactum، T. citrinoviride، T. harzianum، T. ghanense and T. longibrachiatum were identified. Regarding to positive role of Trichoderma related to root and rhizosphere that cause increasing health and improving growth of plants، this study recommend a kind of horticultural management that could be able to protect and support these fungi in walnut root and rhizosphere.