Date of Award

Spring 5-2020

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Food Science

First Advisor

Lilian Were, Ph.D.

Second Advisor

Rosalee Hellberg, Ph.D.

Third Advisor

Cedric Owens, Ph.D.

Fourth Advisor

Aftab Ahmed, Ph.D.

Abstract

Thiol oxidation can form disulfide bonds that modify protein conformations, resulting in lower free thiol content. The effect of dried (lyophilized and oven-dried) mushroom powder (Agaricus bisporus or Pleurotus ostreatus) added to bovine lyophilized and native myofibrillar proteins (MP) on thiol oxidation was investigated. Mixtures of 10mg/mL MP with 0.1% and 0.2% mushroom powder in 0.3M NaCl were stored at 2ºC and 80 ºC for 10 days. Oven-dried A. bisporus had higher Folin-Ciocalteu reducing capacity at 8.05±0.71 gallic acid equivalent (GAE) mg/g compared to 4.97±0.20 GAE mg/g oven-dried P. ostreatus. Lyophilized P. ostreatus contained 164% more ergothioneine than lyophilized A. bisporus and oven-dried P. ostreatus contained 70% more ergothioneine than oven-dried A. bisporus. Free thiols were higher in native myofibrillar protein with 0.1% added P. ostreatus when stored at 80ºC after 2 days. Circular dichroism confirmed changes in secondary protein structures of lyophilized and native myofibrillar protein as time and temperature changed. Lyophilization physically changes MP and it is recommended to not lyophilize myofibrillar protein for future thiol oxidation studies. The addition of 0.1% P. ostreatus powder may prevent thiol loss in MP.

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

Available for download on Wednesday, May 12, 2021

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