Development of active hydrogel absorbent pads based on sodium alginate/potassium-doped carbon dots for chilled pork preservation

Abstract

In this study, potassium-doped carbon dots (K-CDs) were added to sodium alginate (NaAlg) hydrogel to yield high-strength, antibacterial, antioxidant NaAlg hydrogel absorbent pads (NaAlg/K-CDs) to absorb chilled pork exudate during storage. The results revealed that the swelling rates of the NaAlg/K-CDs peaked at 3286.83%, a figure exceeding that of the commercial absorbent pads. Based on the bacterial diversity and richness results, Pseudomonas aeruginosa (P. aeruginosa) was evidently the dominant spoilage organism during chilled pork storage. On storage day 6, the P. aeruginosa population in the NaAlg/K-CDs hydrogel absorbent pad group was 82% of that in the control group. The total volatile basic nitrogen (TVB-N) value of the NaAlg/K-CDs group remained lower than 0.15 mg/g on day 8. The pH, TVB-N, total viable count (TVC), cooking loss, and volatile odour values of the chilled pork in the NaAlg/K-CDs hydrogel absorbent pad group were significantly lower than those in other absorbent pad groups. Moreover, the colour change and shear force values of the chilled pork in the NaAlg/K-CDs hydrogel absorbent pad group were lower than those in the control and wood fiber paper absorbent pad groups. These results indicate that the shelf life of the NaAlg/K-CDs-packaged chilled pork was extended by 2 days compared with that of the control. Therefore, the NaAlg/K-CDs hydrogel absorbent pads potentially inhibited microbial growth and improved the storage quality of chilled pork. This study provides an alternative solution against traditional chilled pork absorbent pads, further promoting the advancement of fresh meat preservation techniques.