Tag Archives: onion

xxx O. Zavadska, І. Bobos, I. Fedosiy, H. Podpriatov, O. Komar, B. Mazur and J. Olt
Suitability of various onion (allium cepa) varieties for drying and long-term storage
Abstract |
Full text PDF (717 KB)

Suitability of various onion (allium cepa) varieties for drying and long-term storage

O. Zavadska¹, І. Bobos¹, I. Fedosiy¹, H. Podpriatov¹, O. Komar¹, B. Mazur¹ and J. Olt²*

¹National University of Life and Environmental Sciences of Ukraine, 15 Heroyiv Oborony Str., UA 03041 Kyiv, Ukraine
²Estonian University of Life Sciences, Institute of Technology, 56 Kreutzwaldi Str., EE 51006 Tartu, Estonia
*Correspondence: jyri.olt@emu.ee

Abstract:

In the paper, the results are presented obtained in the research into the fresh bulbs and the dried products of 9 onion varieties cultivated in the conditions of the Ukrainian Forest Steppe area with regard to their economical biology, biochemical, marketability and organoleptic indices. The varieties that are most suitable for convection drying and long-term storage have been identified. It has been established that the marketability of both the fresh bulbs and dried products depends on the masses of the bulbs. The Bronze d’Amposta and Harmony varieties deliver the greatest amount of marketable output (94.0 and 93.2%) featuring marketable bulbs with masses of 67.4 g and 70.4 g, respectively (r = 0.82). As the bulb mass increases, the amount of non-standard (r = 0.81) and small (r = 0.76) particles in the dried product decreases substantially. It has been found that the content of solid matter and sugars in fresh bulbs has effect on the yield and quality of the dried and reconstituted products. The Harmony and Skvirskaya varieties, the bulbs of which during the vegetation season build up 12.9% and 13.8% of solid matter, respectively, are distinguished by the highest dry product yield – 17.1 and 16.8%, respectively. Correlation has been established between the contents of solid matter and sugars in fresh bulbs (r = + 0.58). During the tasting of reconstituted onion products, the highest scores were awarded to the samples produced from the Skvirskaya and Harmony varieties – 7.0 points each on the 9-point scale, as their bulbs had accumulated over 7.0% of sugars (total). Judging by the aggregate of the researched indices, the Harmony and Skvirskaya varieties of onions are the most suitable for convection drying. It has been established that the preservation of onions in the conditions of stationary buried storage without artificial cooling depends on the duration of storage and the specific varietal features. Within the five months of the test storage, the preservation of bulbs of all the varieties was high and varied within the range of 80–93%. Longer storage is expedient only in case of the Harmony, Skvirskaya and Gospodinya, for which the bulb preservation rates for a seven month storage period has been shown to be equal to 90.2, 88.4 and 87.2%, respectively. It has been proved that the quantity of healthy bulbs depends to a significant extent on the solid matter content in the bulbs (r = 0.93).

Key words:

, , , , , , ,




294-302 V. Dubrovskis and I. Plume
Anaerobic digestion of vegetables processing wastes with catalyst metaferm
Abstract |
Full text PDF (230 KB)

Anaerobic digestion of vegetables processing wastes with catalyst metaferm

V. Dubrovskis* and I. Plume

Latvia University of Agriculture, Faculty of Engineering, Institute of Agriculture Energetics, 5, Cakstesblvd, LV3001 Jelgava, Latvia *Correspondence: vilisd@inbox.lv

Abstract:

There are 54 active biogas plants in Latvia today. It is necessary to investigate the suitability of various biomasses for energy production. Maize is the dominating crop for biogas production in Latvia. The cultivation of more varied crops with good economical characteristics and a low environmental impact is thus desirable. One of the ways for improving biogas yield in Latvian conditions is using biological catalysts. This paper explores the results of the anaerobic digestion of vegetables’ processing wastes using the new biological catalyst Metaferm. The digestion process was investigated in view of biogas production in sixteen 0.7 l digesters operated in batch mode at the temperature of 38 ± 1.0 °C. The average methane yield per unit of dry organic matter added (DOM) from the digestion of onions was 0.433 l g–1DOM; with 1 ml ofMetaferm: 0.396 l g–1–1DOM, and with 2 ml of Metaferm: 0.394 l gDOM . The average methane yieldfrom the digestion of carrots was 0.325 l g–1–1DOM; with 1 ml of Metaferm: 0.498 l gDOM , and with2 ml of Metaferm: 0.426 l g–1DOM. The average additional methane yield per unit of dry organicmatter from the digestion of 50%:50% mixed onions and carrots was 0.382 l g–1DOMwith 2 mlof Metaferm. The average additional methane yield per unit of dry organic matter from the digestion of cabbage leftovers was 0.325 l g–1–1DOM; with 1 ml of Metaferm: 0.375 l gDOM , andwith 2 ml of Metaferm: 0.415 l g–1DOM. The average additional methane yield per unit of dryorganic matter from the digestion of potato cuttings was 0.570 l g–1DOM; with 1 ml ofMetaferm: 0.551 l g–1–1DOM, and with 2 ml of Metaferm:0.667 l gDOM . The average additionalmethane yield per unit of dry organic matter from the digestion of 50%:50% mixed cabbages and potatoes was 0.613 l g–1DOMwith 2 ml of Metaferm. All investigated vegetable wastes canbe successfully cultivated for energy production under agro-ecological conditions in Latvia. Adding the catalyst Metaferm increased methane yield, except for onions.

Key words:

, , , , , , ,




147-150 V. Bulovienė and E. Survilienė
Effect of environmental conditions and inocolum concentration on sporulation of Peronospora destructor
Abstract |
Full text PDF (147 KB)

Effect of environmental conditions and inocolum concentration on sporulation of Peronospora destructor

V. Bulovienė and E. Survilienė

Lithuanian Institute of Horticulture, Kauno str. 30, LT - 54333 Babtai, Kaunas distr.,Lithuania; e-mail: v.bandzeviciute@lsdi.lt

Abstract:

The effect of inoculum concentration, incubation time, relative humidity (RH) and temperature on sporulation of Peronospora destructor on onion leaves was analyzed under controlled environmental conditions in a greenhouse. The shortest period for spore germination and sporulation was on onion leaves inoculated with 106 spores/ml distilled water suspension. The intensity of infection and the sporulation of infected plants were affected greatly by the time and temperature of incubation. Exposure of inoculated plants at 15°C for 8 days and then at 22°C for 5 days resulted in the percentage of infection and the most abundant sporulation. Results of this experiment indicated that the period of P. destructor sporulation on one plant lasted 4–8 days.

Key words:

, , , , ,