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Pulsed electric field (PEF) treatment may pose a potential to be an alternative to chemical use for seed surface disinfection and seed vigour improvement. In order to test effectiveness of PEF treatment, a new pilot-scale PEF treatment unit was designed and used to treat wheat grains with the energy range of 1.07-17.28 J. Compared to the control samples, all PEF treatments significantly increased germination and seedling rates by 10 and 28%, respectively. Electrical conductivity was significantly affected by the delayed measurement time rather than PEF treatment. PEF-treated seed samples had significantly higher tolerance to cold and salt stresses. Endogenous microflora of total aerobic mesophilic bacteria and total mold and yeast were significantly reduced by the applied energy. Salt stress on day 8 (100 mM NaCI) exhibited the highest predictive power of 98.43% in modelling studies. The multi-objective optimization of the 19 responses pointed to 161.8 Hz, 6.1 J, and 19.5 s as the optimal settings (D = 0.52). It was concluded that PEF processing of the wheat seeds improved vigor, promote cold and salt stress tolerance, and inactivated surface microflora.

Tohumlar yüzeylerinde birçok mikroorganizma bulundurmakta ve bu mikroorganizmalar tohum kalitesini ve doğrudan ürün verimini de önemli ölçüde etkilemektedir. Bu nedenle, ürün verimliliğinde artış sağlayan ve tohumun fizyolojik yapısını olumsuz yönde etkilemeyecek çeşitli dezenfeksiyon yöntemleri uygulanmaktadır. Uygulanan yöntemlerden bazıları tohuma zarar vermeden ve çimlenmede artış sağlamakta iken bazı uygulamalar ise tohuma zarar vererek çimlenmeyi azaltmaktadır. Bu nedenle, tohuma uygulanan dezenfeksiyon yönteminin seçilmesi tohum canlılığını ve tohum refahını korumak için önemli bir işlemdir., Seeds have many microorganisms on their surfaces and these microorganisms also significantly affect seed quality and yield. For this reason, various disinfection methods are applied to the seeds to increase the productivity without adversely affecting the physicological structure of the seeds. Some of the applied methods increase germination without damaging the seed, while the others reduce germination by damaging the seed. Therefore, choosing the appropriate disinfection method to the seed is an important process to protect both the seed viability and seed vigour.

Seed processing technologies are essential for seed safety and functionality through protection of physicochemical quality, pathogen inactivation, aflatoxin detoxification and alleviation of mutagenicity. Design of a pilot-scale unit of pulsed electric fields (PEF) to treat sesame seeds with respect to quality parameters,Aspergillus parasiticusinactivation and aflatoxin reduction as well as alleviation of aflatoxin mutagenicity were prompted in this study. PEF energy ranged from 0.97 to 17.28 J achieved maximum reductions of peroxide value and acidity number of 67.4 and 85.7%, respectively, and did not change colorL*,a*,b* and hue values. A 60% reduction ofA. parasiticuscounts occurred at the maximum PEF energy. Aflatoxins G1, G2, B1, and B2 contents decreased by 94.7, 92.7, 86.9, and 98.7%, respectively. Except for the samples treated by 2.16 J with 100 mu g/plate and by 6.80 J with 10 mu g/plate, PEF treatment provided elimination of aflatoxin mutagenity. It is concluded that PEF treatment can be used to treat sesame seeds with preservation of physicochemical properties, inactivation ofA. parasiticusand decomposition of aflatoxins with reduced mutagenicity.

Chemicals used for seed treatments help to increase the agricultural production by preventing pests and pathogens but also cause environmental and health problems. Thus, environmentally-friendly technologies need to be developed for a seed treatment that inactivates surface microflora and improves seed vigor. One such pulsed electric field (PEF) treatment applied to cucumber seeds in the range of 1.07-17.28 Joule (J) significantly enhanced a mean germination rate (MGR) by up to 9%, a normal seedling rate by 25.73%, and a resistance to 100 and 200 mM salt stresses by 96% and 91.67%, respectively, with a stronger and faster growth of roots and seedlings. PEF treatment provided 3.34 and 3.22 log-reductions in the surface microflora of total mold and yeast and total aerobic mesophilic bacteria, respectively. The electrical conductivity (EC) values of the control samples increased over time, from 4 to 24 h. Those of the PEF-treated samples after 4, 12, and 24th hours were also more affected by the measurement time not by the PEF treatment. The joint optimization of 18 responses based on the best-fit Gaussian process model pointed to 19.78 s and 17.28 J as the optimal settings. The PEF treatment appeared to improve seed germination ability and stress resistance with the adequate inactivation of surface microflora.