Hydrogen Peroxide Generation from Hydrated Protein Drink Mixes

Abstract

Generation of oxygen radicals upon hydration of powdered protein products was examined using luminol-enhanced chemiluminescence. Among individual proteins powders examined oxidative bursts occurred almost immediately, and then rapidly declined in the 1st 5 min. Commercially available powdered protein drink mixes behaved differently, with an initial lag phase followed by a sustained increase in luminol-enhanced luminescence, lasting for an hour or beyond. The drink mix that produced the highest level of luminol-enhanced luminescence also contained 379 nM ascorbate radical when hydrated (28 nmole/g of powdered drink mix). The entire ascorbic acid content of this drink mix was oxidized to nondetectable levels (using HPLC-diode array detection) within 60 min of being hydrated. Treatment of the hydrated drink mixes with the enzyme catalase almost completely inhibited the luminol-enhanced luminescence from the hydrated drink mix demonstrating that hydrogen peroxide generated via a chemical reaction among the drink mixes' ingredients was a primary reactive oxygen species (ROS). This is the strongest oxidative capacity demonstrated in a food product as consumed (without any manipulation to increase ROS) and the 1st time that the ascrobate radical in a food product as been quantified. Generation of hydrogen peroxide in the hydrated drink mixes from metal catalyzed reactions involving oxygen and reducing equivalents from ascorbic acid is proposed.

Interfacial peptide partitioning and undiminished antioxidative and emulsifying activity of oxidatively stressed soy protein hydrolysate in an O/W emulsion

“…2). On day 0 and day 1, slightly higher TBARS values were observed in emulsions prepared with protein or hydrolysate probably due to lipid carbonyls formed during soy protein isolate preparation and hydration (Boatright, 2013). However, after storage of 14 days, while the TBARS value in control emulsion (no protein) had a 10-fold increase when compared to the initial value at day 0, the value rose by only 114%, 183%, 88%, and 171% in emulsions containing SPH, oxi-SPH, SP, and oxi-SP, respectively.…”

Oxygen dependency of one-electron reactions generating ascorbate radicals and hydrogen peroxide from ascorbic acid

“…When commercially-available powdered protein drink mixes were hydrated, elevated levels of luminol-enhanced luminescence were produced (after an initial lag phase) that lasted for an hour and beyond (Boatright, 2013). The addition of catalase strongly inhibited the ROS-generated luminescence, implicating the role of hydrogen peroxide formed from the interaction of the drink mix ingredients after the powder was hydrated.…”