Abstract
Magnetic fluid treatment (MFT) and the addition of a magnesium hydrosilicate clay mineral, sepiolite, were evaluated as physical cost-effective methods to add value to Greek yogurt whey (GYW), a co-product of Greek yogurt manufacturing. Three separate batches of GYW were obtained from two US Greek yogurt manufacturers. A GYW sample was collected from each batch, adjusted to a pH of 7.2, and re-circulated for 5 min through a pumping system at a rate of 7.5 L/min with or without exposure to a 0.6 Tesla permanent magnetic field. The sample was split into thirds, heated to 80 °C, and then sepiolite was added at one of three levels: 0, 2, or 4 g of sepiolite per 100 g GYW. After centrifugation at 1000g for 5 min, samples formed a top aqueous and a bottom sediment layer. Top aqueous layers were analyzed for total solids, ash, lactose, protein, calcium, phosphates, and sodium contents along with color. MFT did not feasibly affect the analyzed GYW components from both manufacturers. Protein within the top aqueous layers compared to GYW significantly decreased about 60 % for manufacturer 1 and 45 % for manufacturer 2 with either amount of sepiolite treatment. The color values b* and a* in the GYW from both manufacturers significantly decreased with the addition of sepiolite by about 70 and 90 %, respectively. MFT in the present study was not a practical treatment method for de-mineralizing GYW. However, sepiolite was found to have possible applications in the removal of proteins, phosphates, and natural color pigments in GYW.
Original language | English (US) |
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Pages (from-to) | 553-563 |
Number of pages | 11 |
Journal | Food and Bioprocess Technology |
Volume | 9 |
Issue number | 4 |
DOIs | |
State | Published - Apr 1 2016 |
Externally published | Yes |
Bibliographical note
Funding Information:We would like to thank Dairy Management Inc. (Rosemont, IL) as administered by Dairy Research Institute for their financial support along with Wilsa Inc. Finally, we thank Dr. Daniel Boyle from the Division of Biology at Kansas State University for his help with microscopy analysis (contribution no. 15-421-J from the Kansas Agricultural Experiment Station).
Publisher Copyright:
© 2015, Springer Science+Business Media New York.
Keywords
- Greek yogurt whey
- Magnetic fluid treatment
- Sepiolite