Tag Archives: storage

892-899 D. Arslan
Effects of degradation preventive agents on storage stability of anthocyanins in sour cherry concentrate
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Effects of degradation preventive agents on storage stability of anthocyanins in sour cherry concentrate

D. Arslan

Division of Food Sciences, Department of Food Engineering, Faculty of Engineering and Architecture, Necmettin Erbakan University, Konya, Turkey e-mail: dears@konya.edu.tr

Abstract:

In this study the effects of sugar (sucrose, 25%), gallic acid (700 mg kg-1) and ascorbic acid (700 mg kg-1) were used in sour cherry concentrate in order to prevent the degradation of main anthocyanin compounds (cyanidin-3-glucosylrutinoside (Cy-3GR), cyanidin-3-rutinoside (Cy-3R) and cyanidin-3-glucoside (Cy-3G)) which are natural bioactive pigments responsible for red, blue and purple color of many fruits and vegetables. Thermal degradation of anthocyanins was evaluated by determination of anthocyanin content and calculation of the reaction rate constant, half-life of degradation, activation energy. Anthocyanin content decreased at all of the storage temperatures, as an example; there were 75, 51 and 55% reductions in Cy-3G contents of control samples (with no preventive agent) stored at 45, 24 and 4°C, respectively. The values of half-life time were above 200 days in most cases at all storage temperatures for sugar treated samples. Cy-3-GR (activation energy values 35.6-84.4 kJ mol-1) was found to be the most unstable among the other anthocyanins. The most contributing agent on anthocyanin stability was sugar, whereas ascorbic acid exhibited the lowest effect in terms of preventing anthocyanin degradation.

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1002-1009 T. Michlová,, H. Dragounová and A. Hejtmánková
Stability of vitamin A and E in powdered cow’s milk in relation to different storage methods
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Stability of vitamin A and E in powdered cow’s milk in relation to different storage methods

T. Michlová¹,*, H. Dragounová² and A. Hejtmánková¹

¹Czech University of Life Sciences Prague, Faculty of Agrobiology, Food and Natural Resources, Department of Chemistry, Kamýcká 129, 165 21, Prague, Czech Republic 2Dairy Research Institute Ltd, Ke dvoru 791/12A, 160 00, Prague, Czech Republic *Correspondence: michlova@af.czu.cz

Abstract:

In this article, the influence of different ways of storage on the content of vitamin A and E in powdered cow´s milk was studied. The cow´s whole milk powder was taken directly from the manufacturer and stored for one year in 4 different ways – in the light at room temperature, in the dark at room temperature, in a refrigerator at 8°C and in a freezer at -20°C. The content of vitamins was measured 4 times during the first month and then once a month. The samples were stored for one year. Vitamins A and E were determined by HPLC using DAD and FLD detectors. Vitamin A was identified in all samples but only α-tocopherol (out of various forms of vitamin E) was detected in all samples. In all cases steeper decline of both vitamins in first 14 days of storage was identified. The highest losses of vitamin A and E in powdered milk occurred during storage in the light at room temperature. The value decreased by 91 resp. 95% of the original value.

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197-204 L. Vent and A. Rybka
Storage technologies of picked hops during harvest
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Storage technologies of picked hops during harvest

L. Vent* and A. Rybka

Czech University of Life Sciences Prague, Faculty of Engineering, Kamýcká 129, Praha 6 – Suchdol, Postcode 16521, Czech Republic; *Correspondence: lvent@tf.czu.cz

Abstract:

To prevent interrupting the process of drying or picking due to lack or surplus of hops coming out of picking line, in most cases there is placed a storage container as a capacity equipment. In a container, however, hops are layered, thus temperature and relative humidity increase owing to an increased intensity of hop cones breathing and an insufficient airing, i.e. they mowburn. In the process of breathing a cone loses important substances which results in its worse quality and correspondingly in worse quality of the final product. This work builds on research from 2011. There were monitored changes of physical characteristic of picked hops during storage in container and compared with control variant. This aim of this work is to compare different storage technologies of picked hop in the container. There was a three variants. The control variant was a common stack with a perforated bottom. The second variant was a stack with active ventilation by electric fan. The third variant was a covered stack with passive air circulation. Al stacks had one cubic volume. Data of temperature and relative humidity were continually recorded by MINIKIN TH measuring equipment by EMS Brno company. Another analogue sensors to measure relative humidity and temperature were independently installed for check. The monitoring was each time carried out for 24 hours. Next there were collected a samples for laboratory analysis for product quality. During storage both the temperature and relative humidity of the control variant increased substantially, with temperature values reaching up to 41°C and relative humidity values 100%. The progress of temperatures was almost identical with all the measurements, that is why we present only the average values. The relative humidity of active ventilated variant increased up to 100% but temperature only up to 15°C. The values of humidity of passive ventilated variant were the same (100%) but values of temperature were lower instead of control variant. The highest measured temperature was about 22°C. The conclusion we may draw here says that the best way is passive air circulation. The lowest temperature was measured at variant with fan and it is most important for storage quality of hops but this variant is more expensive due to electric power.

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125-130 L. Vent and A. Rybka
Physical characteristics of picked hops during storage
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Physical characteristics of picked hops during storage

L. Vent* and A. Rybka

Czech University of Life Sciences Prague, Faculty of Engineering,Kamýcká 129, Praha 6 – Suchdol, Postcode 16521, Czech Republic;
*Correspondence: lvent@tf.czu.cz

Abstract:

To prevent interrupting the process of drying or picking due to lack or surplus ofhops coming out of the picking line, hops, in most cases are placed in a storage container.. In acontainer, however, hops are layered, thus temperature and humidity increase owing to anincreased intensity of hop cones breathing and an insufficient airing, i.e. they mowburn. In theprocess of breathing a cone loses important substances which results in its deteriorated qualityand correspondingly in the poor quality of the final product. Our task was to observe the courseof hop temperature and humidity in a storage container and to compare it with the checkvariant, which was loosely spread hops outside the container. Data of temperature and humiditywere continually recorded by COMET D 3631 measuring equipment with N1ATG8/Cmeasuring probe by the Comet System company. Other analogue sensors to measure humidityand temperature were independently installed for checking. The monitoring was each timecarried out for 24 hours. During storage both the temperature and humidity of the hops in thecontainer increased substantially, with temperature values reaching up to 49 °C and humidityvalues 100%. The progress of temperatures was almost identical with all the measurements, thatis why we present only the average values. The highest temperature inside the container was inthe range of 39 °C to 49 °C with individual measurements. The temperatures of the checksamples were identical with the air temperature in the daytime with all the repeats. Themaximum temperature of the check samples ranged from 21 °C to 27 °C with eachmeasurement. In the same way as with the temperature, during the individual measurements thehumidity showed similar progress and the measurements did not differ from each other in anysubstantial way. The humidity level in the container rose up to the maximum value of 100%already two hours after the measurement had started and stayed like this until the end. Thehumidity of the hop check samples was 2.24% higher than the air humidity, which might beexplained by water vapour emission due to an increased intensity of hop cones breathing. Theconclusion we may draw here says that with an increasing volume and, probably above all,height of the stored hops layer, the influence of the surroundings on the conditions inside thecontainer will decline.

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117-124 L. Vent and A. Rybka
Influence of humidity on the quality of baled hops at grower
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Influence of humidity on the quality of baled hops at grower

L. Vent* and A. Rybka

Czech University of Life Sciences Prague, Faculty of Engineering,Kamýcká 129, Praha 6 – Suchdol, Postcode 16521, Czech Republic;
*Correspondence: lvent@tf.czu.cz

Abstract:

Nowadays, in most of cases cured hops are pressed into square bales instead of roundbales. The specific weight of packaged hop is about 22% higher in the square bale and intensityof moistening of packaged hop is very important in this case. There is an increased risk ofdampening of hops in the square bale when the moistening intensity is too high. In the oppositecase is increased risk of destruction of hop cones due to low moistening intensity. The aim ofthis work was find out the influence of the intensity of moistening of hops before pressing intothe square bales on the development of humidity and quality of hops after pressing duringstorage at the grower. There were pressed square bales with humidity of hops from 9.2% to16.2%. The square bales with hop’s humidity 9–10% represented a dry variant, square baleswith hop’s humidity 11–12% represented an normal variant and square bales with hop’shumidity 13% and higher represented a wet variant. The square bales were stored on the firstfloor of the drying machine house at the grower. The range of storage temperature was from 7to 40 °C. All square bales were of the same condition. Humidity of the hops was monitoredduring 10 days. At the end of the measurement, there was carried out a laboratory analysis ofhops of all square bales. Samples were analysed for content of α – bitter acid and destruction ofhop cones. During storage, the humidity of wet variant dropped from 14.2 to 12.7% and thehumidity of dry variant increased from 9.37 to 11.1%. The destruction of hop cones was highestat dry variant (28%). On the contrary the lowest value was at normal variant (12.3%) and it isabout 43% less. However, the dependence of destruction of hop cones by humidity at asignificant level α = 0.05 has not been proven. There was no proven differences of content ofα – bitter acid between all three variants. The highest value 4.9% was at wet variant. We foundout a direct dependence of content of α – bitter acid on the humidity of hops in this case. Theresults of content of α – bitter and destruction of hop cones show that the best one was normalvariant with starting humidity from 11.2 to 11.6%.

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427-431 A. Valiuškaitė, N. Kviklienė, D. Kviklys and J. Lanauskas
Post-harvest fruit rot incidence depending on apple maturity
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Post-harvest fruit rot incidence depending on apple maturity

A. Valiuškaitė, N. Kviklienė, D. Kviklys and J. Lanauskas

Lithuanian Institute of Horticulture, Babtai, Kaunas distr., LT-54333,Lithuania; e-mail: a.valiuskaite@lsdi.lt

Abstract:

The effect of fruit maturity on apple storage ability and rot development wasinvestigated in 2003–2004 at the Lithuanian Institute of Horticulture. Two apple cultivars ‘Ligol’ and ‘Lodel’ on M.26 rootstock were tested. Fruits were harvested 5 times at weekly intervals and were stored for six months in cold storage. Maturity index was calculated at each harvesting.Fruit quality parameters and rot incidence were evaluated after 90, 150 and 180 days ofstorage. While in storage ‘Lodel’ apple rot was caused by Monilinia sp., Gloeosporium spp., Penicillium spp., Alternaria spp. and Botrytis sp. Cv. ‘Ligol’ apples were infected by Monilinia sp., Gloeosporium spp. and Penicillium spp. Both tested cultivars were mostly infected by fungus of Gloeosporium genus. Cv. ‘Lodel’ was more sensitive to fungal rots.The time and intensity of rot incidence depended on cultivar, harvest date and climaticcondition during the vegetation. More rot injuries were detected on apples picked later. A significantly smaller number of rotten apples was recorded in apples picked at optimum maturity. Cold and wet weather during the ripening period determined an earlier and significantly higher occurrence of fungus during storage.

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543-548 U. Moor, M. Toome and A. Luik
Effect of different calcium compounds on postharvest quality of apples
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Effect of different calcium compounds on postharvest quality of apples

U. Moor, M. Toome and A. Luik

Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences,Kreutzwaldi St. 64, EE51014 Tartu, Estonia, e-mail: ulvimoor@emu.ee

Abstract:

The research was conducted with apple (Malus domestica Borkh.) cultivars ‘Antei’ and ‘Talvenauding’ in the Rõhu Research Centre and the Estonian University of Life Sciences in 2005–2006. The aim of the study was to determine the influence of different Ca compounds (CaCl2, Ca(NO3)2 and Boramin Ca) used as preharvest sprays on the mineral content of appleleaves and fruits and apple postharvest quality. Apples were stored in normal atmosphere at 2–5ºC and 80–85% RH. The storage time for ‘Talvenauding’ was 5 months and for ‘Antei’ 6 months. The percentage of spoiled apples was calculated monthly. The content of Ca, N, P, K and Mg from apple leaves was determined at the end of August and from fruits after the harvest. The average effect of calcium treatment was significant only in the variant where Ca (NO3)2 +CaCl2 were used: the percentage of spoiled fruits was 25% compared to 39% in the controlvariant. Correlation analysis showed that the amount of spoiled fruits in January and at the end of storage had negative correlations with content of Ca in leaves and content of Mg in fruits. At the same time positive correlations were found between N-, P-, K- and Ca content of fruits and spoilage. Only the increasing fruit Mg had a positive effect on apple fruit quality in the present experiment. The content of mineral elements in leaves had no positive correlation with the content of mineral elements in fruits.

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55–62 R. Sestras, E. Tamas and A. Sestras
Morphological and genetic peculiarities of fruits in several winter apple varieties which confer resistance to damage
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Morphological and genetic peculiarities of fruits in several winter apple varieties which confer resistance to damage

R. Sestras¹, E. Tamas¹ and A. Sestras²

¹University of Agricultural Sciences and Veterinary Medicine, Faculty of Horticulture, No. 3-5 Manastur St., 3400 Cluj-Napoca, Romania; e-mail: rsestras@email.ro
²Horticultural Research Station, 3-5 Horticultorilor St., Cluj-Napoca, Romania

Abstract:

Among 15 winter apple varieties studied for their resistance to the damage of fruits, Golden Delicious was susceptible to fruit injury, while the Florina, Idared and Granny Smith can be considered resistant to pricking, cutting and hitting of the fruits. The variability of the morphological characteristics of the fruits was relatively low, the fruit volume being averagely variable and the fruit resistance to injury being the character with the highest variability (s% = 26.4). The resistance of the fruits to injury was not correlated with their height, diameter, weight, shape and volume. The characteristics of the fruits have a strong genetic determinism, but the additive effects of the genes do not play the most important role in all cases. For the fruit resistance to injury the big differences between heritability coefficients values in a broad and narrow sense signify the fact that the resistance to injury of apples is influenced not only by additive effects but also by the dominance and epistasis effects of the genes.

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115–122 V. Eremeev, J. Jõudu, A. Lõhmus, P. Lääniste and A. Makke
The effect of pre-planting treatment of seed tubers on potato yield formation
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The effect of pre-planting treatment of seed tubers on potato yield formation

V. Eremeev, J. Jõudu, A. Lõhmus, P. Lääniste and A. Makke

Department of Field Crop Husbandry, Estonian Agricultural University, Kreutzwaldi 64, 51014 Tartu, Estonia; e-mail: slava@eau.ee

Abstract:

In the trials conducted in 2000–2002, we examined possibilities for growing potato using different methods of pre-planting treatment of seed tubers.
The varieties exploited were ‘Varajane kollane’ (early), ‘Piret’ (medium early) and ‘Ants’ (medium late). There were used the following ways of treatment for all varieties: PS – pre-sprouting, TT – thermal treatment and 0 – tubers not treated.
The dynamics of tuber yield formation during the vegetation period was significantly influenced by the weather. In terms of potato growth, weather conditions were the most favourable in 2001. The weather in 2000 and 2002 was not the most suitable for potato growth and development, and the yield in these years proved lower than the three-year average.
The average results from the three years show that potatoes could not realise their full potential to reach maximum yield. Pre-planting germination and thermal treatment had positive effects during the entire vegetation period, the effect being stronger at the beginning and then gradually decreasing.
Pre-planting treatment of seed tubers had a different effect on varieties with different growing times.
A comparison between the varieties showed that ‘Piret’ and ‘Varajane kollane’ started to form tubers early and thus exceeded the development of the variety ‘Ants’ until the 60th day of growth. ‘Ants’ reached its maximum yield, 47.0 t ha-1, already by the 114th day, followed by the fast-ripening ‘Varajane kollane’ and the medium-ripening ‘Piret’. Thermal treatment did not give any advantage in terms of total yield formation compared to untreated seeds, except for the pre-planting germination variant of the variety ‘Varajane kollane’, the total yield of which exceeded that of its untreated variant by 7.08 t ha-1.

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