Tuba Dilmaçünal

Effect of harvesting hour on some physical and mechanical properties of Rosa damascena Mill.

BACKGROUND Mechanization of Rosa damascena flower harvest is limited because of the asynchronous flowering period, the necessity for the harvest operation to take place in the early hour of the morning, and a lack of knowledge regarding the physical-mechanical properties of R. damascena. This study investigated the effect of harvesting hour on some physical-mechanical properties of R. damascena. RESULTS The terminal velocity of the rose flower ranged from 4.00 to 2.38 m s(-1) . The highest picking force was found to be 6.29 N for the harvesting hour of 06:00 am. Tear forces of petal changed from 1.54 to 0.97 N for the harvesting hour of 06:00 am and 12:00 pm, respectively. The tension force of pedicel varied between 8.25 and 7.76 N. The weight of the rose flower was measured as an average of 1.61 and 1.50 g at 06:00 am and 12:00 pm, respectively. Horizontal and vertical projection areas of rose flowers were positively correlated with harvesting hour, with an R(2) of 0.97 and 0.75, respectively. Results showed that there was a minor loss in colour for both inner and outer surfaces of petals. CONCLUSION The results of physical-mechanical properties of R. damascena obtained from this study should be considered for the operation of flower harvest mechanization.

Novel Strategies for the Reduction of Microbial Degradation of Foods

Abstract Microbial quality of fresh and dried foods and spices plays a key role in determining the shelf life of the product. Major cause of spoilage in food products are molds and yeasts. Molds may also produce compounds such as aflatoxins which can cause serious health problems. In addition to spoilage, contaminated vegetables and fresh-cut fruits can serve as a carrier to many infectious microorganisms such as cholera, hepatitis, and giardiasis. Spices and vegetable seasonings are also a potential source of bacterial contamination causing food spoilage. In addition to causing food-borne diseases, degradation of products causes economic losses in considerable amounts. Microbial contamination can be reduced through good agricultural practices, application of advanced processes, and packaging. The main source of microbial contamination of food products are soil, air, water, and human. Among these, air and soil are the major source of mold spores which are responsible from majority of food degradation. The number of spoilage microorganisms increase during inappropriate transportation and storage conditions. Postharvest process is also important to prevent further spoilage. Microbial contamination can be prevented by employing trained staff, application of proper storage conditions, and using advanced processes and packaging materials. Rapid detection of microbial contaminants with new technologies may also extend the shelf life and quality of fresh and processed foods, fruits, and vegetables and also reduce postharvest losses.