Osmoconditioned seeds as a foodstuff
The technique of seed osmoconditioning, which consists of a controlled hydration and dehydration, was evaluated for use in foodstuff production;In the first experiment, soybean, wheat, mungbean, and sesame seeds were hydrated in polyethylene glycol (PEG), chitosan plus water (CH), citric acid (CA), and water (W). Hydrated seeds were either dehydrated to their original moisture content or left fully-hydrated and stored at 5°C or 15°C for 2 or 4 weeks. Fully-hydrated and dehydrated seeds sprouted faster than untreated seeds, but the performance of fully-hydrated seeds declined during storage. Phytate content in soybean and mungbean seeds increased with the initial hydration. Phytate decreased when seeds were dehydrated, but phytate content in fully-hydrated seeds remained high. To assess microbiological safety, aerobic plate counts, total coliform counts, and yeast and mold counts were performed. Dehydrated seeds had lower microbial counts than fully-hydrated seeds. Polyethylene glycol and citric acid had an antimicrobial effect;In the second experiment, soybean and wheat seeds were surface-sterilized with NaOCl, EtOH, or a control. Seeds were hydrated in PEG, CA, or W. Following hydration, seeds were treated with calcium propionate or a control, and then dehydrated. The crops were analyzed as dry, unsprouted seeds and as 48-hour sprouts. Citric acid and NaOCl had antimicrobial impacts on unsprouted seeds, but sprouted seeds had microbial counts up to 10[superscript]5 higher than unsprouted seeds regardless of treatment. The calcium propionate treatment reduced total coliform counts in wheat by a factor of 10. Some counts declined after 16 weeks of 4°C storage. Sprouting resulted in increased phytate in soybeans (40%) and wheat (10%). Sprouts from osmoconditioned and untreated seeds were rated similarly in sensory analyses;In the final experiment, phytate content and phytase activity of soybean and wheat seeds were determined during the osmoconditioning process and during a subsequent 144-192 hour sprouting period. While phytate content in wheat seeds and sprouts did not change during osmoconditioning or sprouting, phytase activity increased throughout the sprouting period. Phytate in soybean seeds increased at 8 hours of sprouting, and decreased at 192 hours. The reduced content at 192 hours coincided with an increase in phytase activity. Osmoconditioned and untreated sprouts did not differ with regard to phytate content or phytase activity.