INFORM June 2026

LIPID OXIDATION AND QUALITY INFORM 15

LOOKING TOWARD THE FUTURE Research on reducing off flavors in pea protein isolates is nascent compared to soy, but it is growing. “When we initially dove into the literature, there was some research going on, but now it has just exploded,” says Trindler. “It is a hot topic.” Abdollahi says that most peas grown and harvested in Sweden are destined to become animal feed and he wants to change that. “The entire value chain needs to be re-engineered and optimized,” he says. “There is a lot of potential to have better products on the market.” For hyperlinks to references visit inform.aocs.org Katie Cottingham is a freelance science writer and editor whose work has appeared in publications, such as Science, Scientific American , and Smithsonian Magazine . She can be contacted at katie.cottingham@ yahoo.com.

The volatiles correlated with the PUFA content and LOX activity of the extracts. Immediately after harvesting, pretreating pea seeds could be another option to minimize lipid oxidation and off-flavor formation in subsequent steps. In a recent paper, Abdollahi’s team pretreated pea seeds with radiofrequency (RF) heating. They tested various RF pretreatment conditions with the goal of inactivating most of the LOX without discoloring the seeds or degrading pea antioxidants. At the optimal settings, RF pretreatment could halt oxidation at the propagation stage with an accumulation of hydroperoxides that had not yet broken down into volatile compounds. “We mentioned that 13-HODE could be a good marker, and that is exactly what Dias’s team also found,” says Abdollahi. “Our industry partner is adopting 13-HODE as a marker, and they will measure it from now on in their production.” “I started to think that maybe in peas things are more complicated and it is not only LOX that drives the lipid oxidation,” says Abdollahi. “We have shown that we inactivate LOX using RF, but we are using heat, which is also promoting autoxidation pathways. That is why we are going back again to the antioxidant as a promising option.”

Preserving intrinsic antioxidant activity in peas and perhaps adding antioxidants during processing could help slow or inhibit lipid oxidation. A new paper from Abdollahi’s team has shown that adding potent antioxidants called catechins during protein isolation significantly reduced lipid oxidation and its associated volatile compounds. A sensory panel indicated that this treatment reduced the beany flavor of a pea protein isolate, though it added bitterness and astringency. Supercritical carbon dioxide, a green solvent, holds promise for reducing off-flavor compound concentration in both pea flour and protein extracts. Recently, a group tested a scaled-up method using a high-pressure supercritical fluid extruder. Volatile concentrations dropped, and a sensory panel perceived the treated samples as being less beany than untreated ones. Fermentation with microbes could alter the flavor of proteins either before or after processing, says Trindler. “Fungi or lactic acid bacteria can modify the flavor and produce new food without extracting proteins,” he says. “And when fermenting the pure protein, you can produce new aroma compounds.” Microbes also could be modified to steer the protein isolates toward a particular desired flavor that could mask the funk of the lipid oxidation products.