Study on the water-holding mechanism of chicken feet adding with lactic acid bacteria fermentation broth and L-arginine.

Conventional water retention heavily depends on phosphate additives, which are unfavorable for health and clean-label requirements. This study therefore employed the new green alternatives as lactic acid bacteria fermentation broth (LAB broth) and L-arginine (L-Arg). Sodium bicarbonate (SB) was served as a positive control. Cooking loss rates and textural properties were measured to reflect water retention and chicken feet structure. Further, infrared spectroscopy and laser confocal microscopy were observed to reveal protein secondary structures and collagen fibers. The results demonstrated that both treatments significantly enhanced protein hydration. The LAB broth group reduced cooking loss to 4.27%, lower than the control (9.74%), SB (5.06%) and L-Arg (5.25%) groups, with a weight gain rate of 15.47%, significantly higher than the control but lower than the L-Arg group (26.41%). L-Arg increased the product yield to 119.74%, markedly higher than the control (90.26%), SB (113.42%) and LAB broth (110.60%) groups, and decreased centrifugal loss to 4.54%, significantly lower than the control (8.31%) yet higher than LAB broth (3.95%). Further analysis revealed that LAB broth induced mild collagen unfolding and elevated α-helix proportion with slight collagen fiber swelling, enhancing bound water stability and thus achieving excellent WHC. In contrast, L-Arg caused intense swelling and absorbed large amounts of water, yet bound water was easily converted to free water with high water loss, while it increased β-turn content and formed a gel network to partially retain moisture.