Maintaining the quality of unripe, fresh hazelnuts through storage under modified atmospheres (original) (raw)
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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.
Effect of Modified Atmosphere Storage on Hazelnut Quality
Journal of Food Processing and Preservation, 2001
Hazelnut quality was studied after storage in selected modijied atmosphere conditions. Hazelnuts of the Negret cultivar collected in Tarragona, Spain, were used in the experiments. The shelled and unshelled hazelnuts were stored with different oxysen concentrations (I %, S%, 10% and 20% 03 at two different temperatures (7Cand 25C). The qualiry of the hazelnuts during storage was monitored by determining the peroxide value, acid value, KB2 and K,, indices, percentage of unsaturated fatty acids and sensory analysis of the hazelnuts. It was observed that after one year storage period, none of the storage modes had given rise to signijicant rancidity. It was also conjinned that the shell protected the hazelnut from oxidative deterioration. Nevertheless, storage in atmospheres with oxygen levels lower than lo%, autoxidation was signijicantly reduced and the low temperature delayed lipid rancidity.
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.
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.
2018
Drying is one of the most important stages of hazelnut processing and its optimization improves the quality of the final product. The quality of hazelnut is dependent on chemical and organoleptic characteristics of fruit that is affected in the drying process. In present research, samples of Gerd cultivar of hazelnut (Corylus avellana) were dried in shelled and in-shell forms using a laboratory dryer in single-layered form, in three temperatures of 40, 50 and 60°C and 1 m/s air velocity, and stored for six months. The time and energy required for drying and qualitative changes of hazelnut (oil content, protein content, acidity content and peroxide value of oil) were evaluated. The results showed that the hazelnuts dried under 60°C required the lowest time and energy for drying and the in-shell hazelnuts dried under this temperature (60°C) had the lowest acidity compared to other treatments. In addition, temperature had a significant effect on the qualitative traits of hazelnut. The...
Storage Hazelnuts: Effect on Aromatic Profile and Sensory Attributes
Acta Horticulturae, 2009
The hazelnuts quality was studied during and after the storage in selected maintenance conditions. Hazelnuts of 'Tonda Gentile Romana' cultivar and Turkish provenance were stored with and without oxygen presence (air, vacuum with or without nitrogen saturation packaging) at two different temperatures (4-20°C). During storage, the quality was monitored by assessment of the peroxides value, acidity level, sensory analysis, total phenolic compounds content and hexanal content. It was observed that after nine months storage period, the trials without oxygen were in better condition to preserve the hazelnuts from oxidative decline. The best analytical parameter to identify the oxidative state of hazelnuts was the hexanal content conducted through the SPME/GC method, and the decrease in amount of polyphenolic compounds. INTRODUCTION A study was carried out on fresh and stored, raw and roasted hazelnuts ('Tonda Gentile Romana' and 'Turkish') during storage under different conditions (room temperature, 4°C and vacuum, with and without nitrogen saturation) mainly on the volatile compounds, chemical parameters and sensory characteristics for monitoring shelf-life and the oxidation state of hazelnuts. The hazelnuts, as with most other foods with high fat content, are susceptible to lipid enzymatic or non-enzymatic oxidation. The primary oxidation products from unsaturated fatty acids, are the hydroperoxides, highly reactive compounds, that decompose rapidly, yielding a complex mixture of non-volatile and volatile compounds such as hydrocarbons (ethane, pentane), aldehydes (pentanal, hexanal, hexenal, 2-octenal, 2-nonenal) and ketones, which affect the overall quality of the product. Aldehydes are particularly important in relation to flavour alteration and from a toxicological perspective (Frankel, 1980,1982,1993). Extended storage of raw and roasted hazelnuts increases the production of fat oxidation off-flavours. The major product of fat oxidation that increases in content during storage is hexanal, more researchers have proposed it as an indicator of fat oxidation rather than the traditional oxidation indicators which are acidity or peroxide values (P.V.). The main aim of our work was to identify for hazelnuts good shelf-life indicators of the oxidative condition of the products during storage. MATERIALS AND METHODS Samples of hazelnuts of two different provenences, Italy, Latium Viterbo area, var. 'Tonda Gentile Romana' (TGR) and Turkish, both raw (Natural N) and roasted (R) were used. The hazelnuts were stored at 4°C (r) or room temperature 20-22°C (a), in open air (a) or into multilayer bags under vacuum. More specifically, the specimens were packed into 10 kg-multilayer bags that were under-vacuum sealed (V) or alternatively into 1 mg-multilayer bags, that were previously flushed with nitrogen to remove all the air and finally under-vacuum sealed (NV). All specimens were scheduled to be stored for 9 months, from February-November 2007 and to be sampled after 2, 4, 7 and 9 months (Fig. 1). All samples were provided by Stelliferi & Itavex (Caprarola-VT).
Food Chemistry, 2017
Roasted hazelnuts can be consumed as whole nuts, or as an ingredient in the confectionary and bakery industries and are highly appreciated for their typical taste, aroma and crunchy texture. In this work, two hazelnut types (TGT, Ordu) from two harvests were roasted using two different systems (hot air, infrared) at different time/temperature combinations, and the evolution of oxidative stability, the total phenolic content (TPC), the antioxidant capacity, the mechanical and acoustic properties and the sensory perception were determined during storage. The results showed that the oxidative stability was increased by roasting hazelnuts at 120°C for 40 min with hot air system. Similar overall trends were not found for the TPC, the antioxidant capacity and the mechanical-acoustic properties. However, for the maintenance of high antioxidant activity, a storage time of 6 months at 4°C is recommended. The two roasting systems gave hazelnuts with significant sensory differences only at high roasting temperature.