Postharvest Degradation of Microalgae: Effect of Temperature and Water Activity

• Main Author: Nelson, Jacob A.
• Format: Others
• Published: DigitalCommons@USU 2015
• Subjects: Postharvest Degradation; microalgae; temperature; water activity; Agronomy and Crop Sciences; Plant Sciences
• Online Access: https://digitalcommons.usu.edu/etd/4458; https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=5468&context=etd

Though usually a nuisance in swimming pools and ponds, algae has the potential to be a valuable commodity for use as food and fuel. But before algae butter and biofuel become commonplace, issues with harvesting and storing this new crop need to be overcome. Though there has been ample research into how to grow and use algae, scientists have spent little time figuring out what to do after you pull it out of the water and before you eat it (or turn it into biodiesel). Algae, like all food products, starts to spoil as soon as it is harvested. This study looked at three methods of preserving algae, freezing, drying, and pasteurization. Freezing is a good method for preserving fats and proteins, but it is expensive to freeze tons of algae. Freezing and thawing destroyed the algal cells, producing a soupy mixture that may cause complications for processing into foods or fuels. Drying was able to preserve the fats in algae, but only if it was dried just the right amount, about as dry as cheese or ham. Pasteurization was able to prevent the oils in the algae from going rancid by inactivating a protein in the algae that causes the oil to spoil rapidly. Overall, this research is an initial step in finding a process to produce a shelf stable algal commodity, opening the door to new and valuable products for human use.