Habib Kocabiyik

Infrared stabilization of rice bran and its effects on γ‐oryzanol content, tocopherols and fatty acid composition

BACKGROUND Rice bran is a nutritionally valuable by-product of paddy milling. In this study an experimental infrared (IR) stabilization system was developed to prevent rice bran rancidity. The free fatty acid content of raw and IR-stabilized rice bran samples was monitored every 15 days during 6 months of storage. In addition, energy consumption was determined. RESULTS The free fatty acid content of rice bran stabilized at 600 W IR power for 5 min remained below 5% for 165 days. No significant change in γ-oryzanol content or fatty acid composition but a significant decrease in tocopherol content was observed in stabilized rice bran compared with raw bran. IR stabilization was found to be comparable to extrusion with regard to energy consumption. CONCLUSION IR stabilization was effective in preventing hydrolytic rancidity of rice bran. By optimizing the operational parameters of IR stabilization, this by-product has the potential for use in the food industry in various ways as a value-added commodity.

Development of an electro-mechanic control system for seed-metering unit of single seed corn planters Part I: Design and laboratory simulation

Abstract The performance of precision planters is very important for attaining uniform seed spacing. While a planter is on work, undesired situations such as spinning and slipping on ground wheel, vibration, seizing and jamming on the chain-sprocket systems may occur during the transfer of the motion from the ground wheel to the seed-metering unit especially at high operating speeds. In order to overcome these problems, it was aimed to develop an electro-mechanic drive system (EMDS) for seed metering units of a classic single seed planter. The performances of the EMDS and the classic drive system (CDS) were tested at three different operating speeds (vf) (5, 7.5, 10 km/h) and ten different seed spacing (zt) from 6 to 29.3 cm at laboratory. Both systems were compared regarding to the seed spacing uniformity. When the EMDS was used, the quality of feed index (Iqf), multiple index (Imult), miss index (Imiss) and precision index (Ip) were ranged as such: 2.91–95.36%, 0–1.73%, 4.45–97.09% and 8.79–22.14%, respectively. At the test of the CDS, the performance indices varied as such: Iqf 2.09–98.55%, Imult 0–0.36% and Imiss 1.09–97.91%, Ip 5.79–20.92%. Seed spacing uniformities were found as “good” and “moderate” for both systems. Average seed spacing values obtained from the EMDS were found to be closer to the theoretical seed spacing values compared with that obtained from the CDS. EMDS enabled the suggested optimum seeding rate, a quick and simple setting possibility, synchronize and real-time control, the ability to work under higher speeds, individual movement and control for each metering unit. However, EMDS should be tested to determine the success of the system in practice. Therefore, the field performance of EMDS with respect to plant spacing uniformity and operational parameters (variation among rows, fuel consumption and negative slippage) were examined in the following part of this study (Part II: Field Performance).

Development of an electro-mechanic control system for seed-metering unit of single seed corn planters Part II: Field performance

Abstract Using single seed planters is important for a uniform distribution of plant growing area. Seed metering units of planters receive their motion from the drive wheel pass through various transmission members such as the chains, gears, shafts and belts. While the planter is being operated, the transmission system of the machine and drive system of the seed metering units naturally push the driving wheel. Because of this effect, the wheel experiences a loss of mobility or some sort of slipping. Consequently, all seed metering units are being affected due to the common mobility transmission system and changes in the desired plant spacing occur. In order to overcome these negativities, an electro-mechanic drive system (EMDS) alternative to classic driving system (CDS) was developed. Detailed information regarding the system design and laboratory simulation results of EMDS were provided in Part I of this study. In this part, it was aimed to investigate the effect of EMDS on the planting quality (plant spacing uniformity, variation among rows) and operational parameters (fuel consumption and negative slippage) in the field and compared with the CDS. While the quality of feed index (Iqf) 90.63%, multiple index (Imult) 0.94%, missing index (Imiss) 8.44% and precision index (Ip) 17.63% were obtained in trials performed by the EMDS, Iqf 88.13%, Imult 2.50%, Imiss 9.38% and Ip 17.81% were found in trials performed by the CDS. Plant spacing uniformity in the EMDS was found as “good” while it was “moderate” in the CDS, according to related criteria. Plant distribution uniformity in the EMDS were better than the CDS. Furthermore, the experimental plant spacing values obtained by the EMDS were closer to the theoretical (set) value than the values obtained by the CDS. The negative slipping in the planter’s drive wheel was found as 1.33% at trials with the EMDS while it was 6.79% with the CDS. When the EMDS used in the field operations, it provided approximately 22% fuel saving compared with the CDS. The results promise that the developed system can be used as an alternative to the CDS for single seed planters. However, in order to provide a complete mechanical rapport between the EMDS and the planter, future studies, various structural improvements in the seed metering unit designs and optimization of the seed plate thickness, number of holes and connection methods may be required.

Quality properties, mass transfer characteristics and energy consumption during shortwave infrared radiation drying of tomato

The influence of infrared radiation intensity (1,830, 2,640 and 3,165 W/m2) and air velocity (1.0, 1.5 and 2.0 m/s) on product quality, drying behaviour of tomato and energy consumption were investigated. Five analytical models were used to investigate mass transfer characteristics during infrared drying of tomato slices. The drying time and specific energy consumption varied between 141 and 246 min, and 10.04 and 15.13 MJ/kg water, respectively, and were significantly influenced by infrared radiation intensity and air velocity. Effective moisture diffusivity ranged from 3.89×10-7 to 6.67×10-7 m2/s and was significantly affected by the process variables. Vitamin C content decreased, while lycopene content increased during drying. Total colour change varied between 7.92 and 10.87 for all drying conditions. The logarithmic model gave the best predictions for the drying characteristics of tomato slices for all treatments. Some drying conditions had quite similar results with respect to the operational and qu...