Effect of pulsed electric field on the quality of PSE-like chicken breast meat: Insights into water distribution and structural rearrangement

In the world of food science, the journey from farm to fork involves a delicate biological race against time. When a chicken is slaughtered, its muscles begin to change immediately. If these changes happen too quickly, the meat can develop a specific set of flaws known as PSE-like quality. This condition, which stands for pale, soft, and exudative, results in meat that looks washed out, feels mushy to the touch, and leaks too much liquid when cooked. For consumers, this means a dry, unappealing meal; for producers, it represents a significant economic loss and wasted protein. The root of the problem lies in the muscle fibers themselves. Under normal circumstances, these fibers act like tiny sponges, holding water within a complex network of proteins. However, when the pH level of the meat drops too fast after death, the proteins shrink and squeeze out their water, leaving the meat pale and dry.

Scientists have long sought ways to fix this defect without using heat, which can cook the meat prematurely or destroy its nutrients. One promising avenue involves electricity, specifically a technique called pulsed electric field treatment. This method uses short, sharp bursts of high voltage to gently poke holes in the membranes of cells, a process that can rearrange the internal structure of the muscle without significantly raising its temperature. The goal is to coax the proteins back into a shape that can hold water more effectively, turning a subpar cut of meat into something usable and delicious. The question remains, however, whether this electrical nudge can actually repair the damage in PSE-like meat, or if it might simply make the structural collapse worse.

A team of researchers at Nanjing Agricultural University and collaborating institutions set out to answer this question by treating PSE-like chicken breast with varying strengths of electric fields. They took boneless chicken breasts that had already been identified as having the pale, soft, and watery defects and subjected them to a series of electrical pulses. The team tested a range of intensities, from no treatment at all up to a maximum strength of 4 kilovolts per centimeter. Their aim was to find the "sweet spot"—a specific level of electrical force that could improve the meat's ability to hold water and improve its texture without causing new problems like oxidation or structural collapse.

The results revealed a clear pattern where the strength of the electric field dictated the outcome. When the researchers applied a moderate level of electricity, specifically 2 kilovolts per centimeter, the meat showed remarkable improvement. The most noticeable change was in how much water the meat could keep. In the untreated samples, nearly 20 percent of the weight was lost during cooking, and over 21 percent was lost when spun in a centrifuge to simulate squeezing. At the moderate 2 kilovolt level, these losses dropped significantly to about 16 percent and 14 percent, respectively. This meant the meat retained more of its natural juices, a crucial factor for both flavor and yield.

Beyond just holding water, the texture of the meat also transformed. The researchers measured how hard it was to chew and cut the meat, finding that the moderate electrical treatment made the chicken significantly softer and easier to shear. This suggests that the electric pulses helped loosen the tight, shrunken protein structures typical of PSE meat, allowing them to relax into a more open and tender arrangement. When the team looked at the meat under a powerful microscope, they saw that the fibers in the moderately treated samples had separated just enough to create small, uniform pores. These tiny spaces acted as reservoirs, trapping water within the muscle network rather than letting it leak out.

However, the study also highlighted that more electricity is not always better. When the researchers increased the field strength to 4 kilovolts per centimeter, the benefits began to fade. While the meat was still better than the untreated control, it did not hold water as well as the samples treated at the moderate level. The microscopic images showed that the higher voltage caused the muscle fibers to break apart too much, creating large, irregular gaps that could no longer hold water effectively. It was as if the electrical force had been too aggressive, tearing the fabric of the meat rather than mending it. This excessive damage also led to a slight increase in chemical changes associated with spoilage, such as lipid oxidation, indicating that the meat's stability was compromised at these higher intensities.

The researchers used a specialized imaging technique that measures how water moves inside the meat to understand these changes on a molecular level. They found that in the best-treated samples, the water was locked into a tighter, more stable state within the muscle, whereas in the over-treated samples, the water became too free and mobile, ready to escape. This confirmed that the improvement in quality was not just about adding water, but about changing how the water was held. The study also checked for signs of spoilage and found that at the moderate treatment level, the meat remained stable, with no significant increase in the chemical markers that indicate protein breakdown or rancidity.

Ultimately, the work demonstrates that electricity can be a precise tool for rescuing low-quality meat, but only if applied with care. The study suggests that a moderate pulse of 2 kilovolts per centimeter is the ideal setting for transforming PSE-like chicken breast. At this level, the treatment successfully rearranges the muscle structure to trap water and soften the texture, effectively reversing the worst aspects of the defect. Going beyond this point risks damaging the very structure the researchers are trying to repair. This finding offers a practical path forward for the poultry industry, providing a way to utilize meat that would otherwise be discarded, turning a quality defect into a manageable variable through controlled, non-thermal processing.