Determination of the Best Drying Temperature of Hazelnut (Corylus avellana) after Six Months of Storage (original) (raw)
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2019
The aim of the work was to assess the effect of different drying conditions and storage time on raw unshelled Tonda Gentile Romana hazelnuts (harvest 2017). Drying was conducted with a laboratory desiccator at 20, 30, and 40 °C, applying two air circulation velocity until the moisture content of samples was lower than 6%. The oxidation state of the lipid fraction and volatile profile of hazelnuts were studied during 15 months of storage. In addition, sensory analysis was performed among samples.
Turkish Journal of Food and Agriculture Sciences
The main aim of this study was to evaluate the effect of nut sizes and drying methods on the sensory attributes of hazelnut cultivars (Corylus avellana L. cvs. Çakıldak, Palaz and Tombul) during the storage. Shelled hazelnut were dried under sun, shadow at room conditions and cold dried at 2 °C and 7 °C and stored at 20±5 °C and 80±5 % relative humidity. Evaluation of sensory attributes was carried out quarterly (harvest, 3, 6, and 9 months). In the Çakıldak cultivar (in 16 mm size), the odor of cold-dried hazelnuts at 2°C was higher than other drying methods in the last two measurements. It was observed that shadow-dried hazelnuts and at 7°C cold, dried hazelnuts had lower rancidity. No significant effect of drying methods was observed on the cultivars' flavor, firmness and color. As a result, it is revealed that drying methods have an effect on the rancidity in hazelnut kernels during storage.
Drying Kinetics and Moisture Transfer Parameters of Hazelnut
Journal of Food Processing and Preservation, 2011
In this experimental study, drying kinetics, sorption isotherms and mass transfer parameters (mainly the diffusion coefficient and hm) of hazelnut are investigated under various drying air conditions. Experiments were conducted in a lab-scale convective drier under the following drying conditions: temperatures at 25C, 35C, 45C and 55C; velocities at 0.3, 0.6 and 0.9 m/s; relative humidity values at 20%, 40%, 60% and 80%. Initially, sorption isotherms of the dried hazelnut are determined for different temperatures and equilibrium relative humidity values. Then, the drying characteristics of hazelnut are determined for various values of drying air parameters tested. In addition, the mass transfer parameters (i.e., Bi, moisture diffusion coefficient and hm) of hazelnut were evaluated using a correlation. The Bi numbers were in the range 0.4216-1.4806 and moisture diffusion coefficient and hms in the range from 0.7056 ¥ 10-9 to 3.2933 ¥ 10-9 and from 1.2401 ¥ 10-7 to 1.7361 ¥ 10-7 m/s, respectively. PRACTICAL APPLICATIONS Turkey is the largest hazelnut-producing country, providing most of world hazelnut production. Supplying the market with the best product available is always critical. Therefore, ensuring better harvesting and processing conditions of hazelnut attracts a great deal of research interest. To prevent field losses by unfavorable weather conditions, there is a tendency to harvest hazelnuts at moisture contents above safe storage levels. In this regard, drying seems to be necessary.
LWT, 2018
Hazelnut kernels obtained from the commercial processes were analyzed for proximate composition, bioactive compounds, lipid oxidation, and enzyme (lipase, peroxidase, and polyphenol oxidase) activities and compared among three cultivars (Barcelona, Yamhill, and Jefferson) and two agricultural practices (with and without fertigation for Jefferson). The influence of drying temperature (38, 43, and 49°C) and relative humidity (RH, 40 and 60%) on drying characteristics (drying rates of inshells and corresponding moisture content (MC) and water activity (a w) of kernels when inshells reached ∼10 g/100 g MC or equilibrium MC (MC eq)), bioactive compounds, lipid oxidation, and enzyme activity of the kernels were investigated. Oleic acid and α-tocopherol were the predominant fatty acids and vitamin in hazelnuts. Yamhill contained the highest phenolic (0.12 mg GAE/g), vitamin E (14.26 mg/100 g, α-tocopherol), and lowest unsaturated/saturated fatty acids ratio (8.7) among cultivars. Drying characteristics and chemical and enzymatic reactions of hazelnuts varied depending on drying condition and cultivar of nuts, in which drying at 43-49°C and 40% RH improved drying efficiency and retained quality of dried hazelnuts. This study suggested the ideal drying conditions that could produce dried hazelnuts with optimal range of MC and a w for retaining bioactive compounds and minimizing lipid oxidation and enzyme activity.
Postharvest Biology and Technology, 2013
(AAM) is copyrighted and published by Elsevier. It is posted here by agreement between Elsevier and the University of Turin. Changes resulting from the publishing process-such as editing, corrections, structural formatting, and other quality control mechanisms-may not be reflected in this version of the text. The definitive version of the text was subsequently published in Effect of storage conditions on chemical and physical characteristics of hazelnut (Corylus avellana L.
Effect of Different Storage Conditions on Hazelnut Quality
The aim of this study was to evaluate the effect of different storage conditions on the quality of the hazelnut cultivar 'Tonda Gentile delle Langhe'. The traditional method of in-shell nut storage, in storage room at ambient temperature, was compared with preservation of shelled nuts in refrigerated room at 4°C and 55% RH with or without modified atmosphere (1% oxygen, 99% nitrogen). In order to evaluate nut quality, the following parameters were considered: humidity, lipid content, total phenolic content and antioxidant capacity of the seed; acidity and peroxide value of the oil. 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 the storage at low temperature permitted to maintain a low level of acidity and lipid oxidation, with the best performance in modified atmosphere (0.13% of oleic acid and 0.11 mEq O 2 /kg). In conclusion, the in-shell storage of hazelnuts at ambient temperature was able to preserve the kernel below threshold limits of acidity and oxidative degradation up to a period of 8 months; the application of refrigeration was necessary to maintain a high quality up to one year. The use of modified atmosphere is recommended for a longer period of storage.
Changes in the Properties of Hazelnut Shells Due to Conduction Drying
Agriculture
In this study, the physical properties of two hazelnut species were investigated before and after drying at different temperatures and durations. The results showed that the physical properties of the hazelnut samples, including size, volume, density, weight, kernel mass, and shell mass, were significantly affected by temperature, duration, and their interactions. In addition, the moisture content of the samples decreased with increasing temperature and drying duration. The lowest value for the Istarski duguljasti variety was 5.36% (160 °C and 45 min), while the lowest value for Rimski okrugli was measured at 160 °C and 60 min (5.02%). Ash content was affected by both temperature and time, with the Istarski duguljasti variety having a minimum value of 0.84% at 120 °C and 60 min and Rimski okrugli a maximum value of 1.24% at 100 °C and 30 min. The variables of the ultimate analysis, such as nitrogen, carbon, sulfur, and hydrogen, increased with increasing temperature and time. The ox...
Influence of Storage on Pomological and Sensory Characteristics of Hazelnut Fruit
The Journal "Agriculture and Forestry", 2021
The research aims to study the changes in pomological and sensory characteristics of hazelnuts fruits before and after NA cold storage for five months. The paper analyzes fruits of hazelnut cultivars grown in agroecological conditions of northwestern Bosnia and Herzegovina, in the area of municipality Kostajnica. The fruits were collected in the period of full maturity, in the 2020 year, and the following cultivars were analyzed: Istrian Long, Istrian Round, Romische Zellernuss and Cosford. The first analysis of fruits was performed after harvest, and the second analysis was executed after the storage of fruits in the shell. Fruit characteristics, studied on both period, were fruit weight, kernel weight, fruit length, fruit width, fruit thickness, kernel length, kernel width, kernel thickness, shell thickness, fruit shape, texture, color, taste, kernel bitterness, kernel sweetness, hardness, crunchiness, presence of double fruits, blank nuts, fruit roundness index and kernel percentage. The results of the research show that there are significant differences in the values of the examined parameters before and after storage of fruit hazelnut. The biggest changes are recorded precisely on the shrinkage in the storage process and changes in the taste of stored hazelnuts. These results show the need to more investigate storage systems and optimal storage conditions for each variety.
Investigation of the effect of roasting temperature on the nutritive value of hazelnuts
Plant Foods for Human Nutrition, 2003
In this study, Corylus maxima Miller (foşa) hazelnut from the Trabzon area (Black Sea Coast-Turkey) was used. The moisture, oil, protein, total carbohydrate, and ash contents of the hazelnuts were determined using respective AOAC methods. The fatty acid constituents of hazelnut oil were analyzed using Gas Chromatography. Physicochemical properties of the oil were also determined. The amino acids of the samples were analyzed using a liquid-chromatographic “Amino Acid Analyzer.” Sugars were separated and detected using Thin Layer Chromatography. The hazelnut samples were roasted at 135 °C for 10, 15, 20, 25 and 30 minutes in order to determine the effect of roasting temperature. Moisture, oil, protein, total carbohydrate, total sugar and starch were also determined as a function of roasting time. Although there were not significant changes in the amount of oil, protein and starch contents (p > 0.05), the moisture and total sugar contents decreased significantly (p < 0.05) during the roasting process. The fatty acids composition, the physicochemical properties of the hazelnut oil, and the total amino acids were determined also during to the roasting process. It was found that the linoleic acid, as well as the essential amino acids and total sugar contents decreased significantly (p < 0.05) after 20 minutes of being roasted at 135 °C. It was concluded that roasting for 15 minutes at 135 °C was ideal for maintaining the desired nutritional value of hazelnuts.