Enhancing the Bio- and Techno-Functional Properties of Food Proteins
using Non-Thermal Plasma
Abstract
Food proteins, essential ingredients in food products, extend product
structuring and health-promoting benefits. The objective of the current
study is to improve the bio- and techno-functionalities of food proteins
simultaneously through non-thermal plasma exposure. Four different food
proteins (pea, rice, wheat gluten, and milk proteins) were exposed to
plasma at voltage 240V, frequency 1.5 kHz, and 30 min exposure time. The
structural, digestibility, bioactivity, and techno-functional properties
were analyzed. Plasma treatment alters the secondary structure of
proteins by increasing β-structures and random coils by 3-4 times while
decreasing α-helices by half, reducing surface hydrophobicity. The study
found that longer treatment times and higher voltage intensities enhance
protein digestibility and increase amino acid release, with gluten
showing the highest improvement in both digestibility and free amino
acid content among the proteins examined. The proteins also showed a
loss of radical scavenging capacity after treatment due to oxidation
reactions. Cold plasma treatment improved protein solubility but reduced
emulsifying and foaming properties. The enhancements in digestibility
and bioactivity can be attributed to structural unfolding and the
exposure of reactive sites on the proteins. In summary, the effects of
cold plasma treatment depend on the specific protein, treatment
parameters, and the degree of oxidation.