Nezihe Koksal

Convective, vacuum and microwave drying kinetics of mallow leaves and comparison of color and ascorbic acid values of three drying methods

Mallow leaves (Malva sylvestris L.) with initial moisture of 5.02±0.003 on dry basis (82.5% on wet basis) were dried using three different drying methods, microwave, convective and vacuum. The leaves that weigh 75 g each were dried until their moisture fell down to 0.10±0.005 on dry basis (approximately 9% on wet basis). The following drying levels were used in each of the drying processes: 6.67, 8.67, 10, 11.33 W g-1 microwave power density; 50, 75, 100 and 125 °C for convective drying; and 3, 7 kPa at 50 and 75 °C for vacuum drying. Drying periods ranged from 6-10, 26-150 and 38-130 min. for microwave, convective and vacuum drying, respectively. Effective moisture diffisuvities ranged from 2.04403 10-10-3.63996 10-12 m2 s-1, 1.70182 10-11-1.10084 10-10 m2 s-1 and 1.85599 10-11-5.94559 10-10 m2 s-1 for microwave, convective and vacuum drying, respectively. According to ascorbic acid content and color parameters, the best microwave power density was found 10 W g-1 with a drying period of 6.5 min.

Determination of physical, mechanical, and structural seed properties of pepper cultivars

Abstract The aim of the present study was to determine various physical, mechanical, and structural characteristics of seed of pepper cultivars Yağlık Kapya, Demre Sivri, Yalova Carliston, Kandil Dolma, and Cin Sus Yediveren, which are grown extensively in Turkey, with initial moisture content ranging between 7.03 and 7.21% (w.b.). Width, length, and thickness were found to be in the range of 3.00-3.72, 3.43-4.40, and 0.66-0.82 mm, respectively. It was revealed that sphericity of the seeds of Yağlık Kapya, Demre Sivri, Yalova Carliston, Kandil Dolma, and Cin Sus Yediveren were 51, 57, 56, 51 and 57%, respectively. In terms of the roundness which ranges between 76 and 85% depending on pepper cultivars. The aspect ratio of Yağlık Kapya, Demre Sivri, Yalova Carliston, Kandil Dolma, and Cin Sus Yediveren were determined to be 84.60, 88.04, 94.43, 85.55, and 87.67%, respectively. It was also noted that the porosity of the pepper seeds was in the range of 44.94-49.61%. Besides, we found that as the weight of pepper seeds increased, their terminal velocity increased accordingly, and thus terminal velocities were found to be 2.87-4.66 m s-1. In the current study, the static friction angle and coefficients of the cultivars were determined by means of six different plates including aluminium, stainless steel, galvanized iron, rubber, glass, and plywood. The plywood plate was found to be the least slippery; consequently, the static friction angle and coefficient were determined to be the highest for the plywood plate.

Supplemental LED lighting increases pansy growth

Pansy (Viola cornuta) is a facultative long-day plant that flowers from October until March in Turkey. During the winter months, low light levels can limit plant growth and development. Light emitting diodes (LEDs) can provide supplemental lighting in greenhouses which produce same light intensity with less energy than conventional incandescent lighting. Light emitting diode technologies have enabled affordable and efficient light systems to be installed in greenhouses and plastic tunnels in the field. In this experiment we evaluated the effects of supplemental red-orange LED lightening on the growth and development of pansy cv. Blue Blotch grown in plastic tunnels. The energy, which LEDs are to consume, was provided through a solar panel system with the aim of drawing attention to the cleanliness of solar energy source. Five hours of supplement LED lighting was applied after dusk starting from November to February. Pansy growth and development parameters were compared with non-light supplied control plants. Supplemental LED lighting significantly increased plant biomass weight, flower number and leaves number at the rate of 52%, 72%, and 47%, respectively. Moreover, LED lighting increased plant growth rate (0.109 and 0.306 g of fresh weight), compared with the no light control. LED lighting, however, had no effect on length of stems, number of branches and the diameter of flowers. Thus, this study indicated that pansies are light limited during the winter months and supplemental LED lighting can significantly increase pansy growth and development.

Forced-air, vacuum, and hydro precooling of cauliflower (Brassica oleracea L. var. botrytis cv. Freemont): Part II. Determination of quality parameters during storage

Cauliflower heads, which were precooled using four different methods including vacuum, forced-air, and high and low flow hydro precooling, were stored under controlled atmosphere and room conditions. Controlled atmosphere conditions (CA) were as follows: 1°C temperature, 90 ± 5% relative humidity, and 0:21 [(%CD 2 :%D 2 ) – (0:21) control] atmosphere composition. Room conditions (RC) were: 22±1°C temperature and 55-60% humidity. Various quality parameters of the cauliflower heads were assessed during storage (days 0, 7, 14, 21, 28, and 35) under controlled atmosphere and room conditions (days 0, 5, and 10). During storage, weight loss, deterioration rate, overall sensory quality score, hardness, and colour (L, a, b, C and α) were evaluated. In the present study, the strength and quality parameters of cauliflower under CA and RC conditions were obtained. Vacuum precooling was found to be most suitable method before cauliflower was submitted to cold storage and sent to market. Furthermore, the storage of cauliflower without precooling resulted in a significant decrease in quality parameters.

Forced-air, vacuum, and hydro precooling of cauliflower (Brassica oleracea L. var. botrytis cv. Freemont): part I. Determination of precooling parameters

The aim of the present study was to precool cauliflower using forced-air, vacuum and high and low flow hydro cooling methods. The weight of the precooled cauliflower heads (5000±5 g) was measured before they were placed in standard plastic crates. Cauliflower heads, whose initial temperature was 23.5 ± 0.5 oC, were cooled until the temperature reached at 1 oC. During the precooling process, time-dependent temperature and energy consumption were measured, and during vacuum precooling, the decreasing pressure values were recorded, and a curve of time-dependent pressure decrease (vacuum) was built. The most suitable cooling method to precool cauliflower in terms of cooling time and energy consumption was vacuum, followed by the high and low flow hydro and forced-air precooling methods, respectively. The highest weight loss was observed in the vacuum precooling method, followed by the forced-air method. However, there was an increase in the weight of the cauliflower heads in the high and low flow hydro precooling method. The best colour and hardness values were found in the vacuum precooling method. Among all methods tested, the most suitable method to precool cauliflower in terms of cooling and quality parameters was the vacuum precooling method.

The Importance of Pre-cooling Methods and Usage Possibilities in Ornamental Plants

Geliş 29 Ocak 2018 Kabul 10 Mart 2018 Kesme çiçek sektöründe, çiçeğin kalite parametrelerinin ve vazo ömrünün uzun süre korunması hem ürünün ekonomik değerini hem de satıla bilirliğini artırmak açısından önem taşımaktadır. Benzer şekilde, hasattan sonra soğanlı süs bitkilerinin toprak altı organlarının soğuklama gereksiniminin giderilmesi amacıyla depolanması aşamasında, ürünün hasat sıcaklığından depolama sıcaklığına hızlı bir şekilde getirilmesi önem arz etmektedir. Ürünün kalitesini artırırken kayıpları en aza indirmek için geçmişten günümüze pek çok yöntem geliştirilmiştir. Bu yöntemlerden biri de ön soğutma yöntemidir. Ön soğutma, ürünün hasat sıcaklığından depolama sıcaklığına hızlı ve etkin bir şekilde düşürülmesi olarak tanımlanmaktadır. Ön soğutma, hem ürünün hasat sonrası soğuk depoya konulması hem de depolama yapılmaksızın doğrudan satışa çıkarılması durumlarında, ürünün dayanım süresini ve kalite parametrelerini artırmak için kullanılabilmektedir. Uygulandığı tarımsal ürünlerin yapısal ve fizyolojik özelliklerine bağlı olarak ön soğutma, havayla, suyla ve vakumla olmak üzere temelde üç ayrı yöntemle yapılabilmektedir. Bu çalışmada, ön soğutma yöntemleri süs bitkilerine uygunlukları bakımından detaylı bir şekilde tartışılmıştır. Anahtar Kelimeler: Havayla ön soğutma Kesme çiçek Suyla ön soğutma Vakumla ön soğutma Çiçek soğanı