Muscle health is vital for quality of life in older adults, but those with dysphagia often struggle to consume conventional protein or amino acid supplements. To offer an easier-to-consume alternative, we developed orally disintegrating films (ODFs) containing collagen hydrolysates (CH) from pollock skin and citrus peel extract. Two variants were prepared with leucine (0.5–1.0%) or β-hydroxy-β-methylbutyrate (HMB, 0.5–2.0%), designated as CH/Leu and CH/HMB. The films displayed uniform structural properties (thickness 0.21–0.27 mm; opacity 0.18–0.27) and rapidly disintegrated in the mouth (CH/Leu: 10–14 s; CH/HMB: 13–18 s). Surface pH values (5.67–6.93) were within physiologically acceptable limits.

Under simulated gastrointestinal conditions, both formulations showed efficient intestinal release, reaching cumulative release rates of 98% (CH/Leu) and 96% (CH/HMB). Release behavior fit well to the Kopcha (R² ≥ 0.996) and Peleg (R² ≥ 0.999) models, indicating a diffusion-dominant mechanism favorable for targeted nutrient delivery.

To further assess the muscle-supporting potential of the developed ingredients, we evaluated the bioactivity of green tangerine–extracted collagen (GEC) in C2C12 myoblasts. In a dexamethasone (DEX)-induced atrophy model, DEX reduced myotube diameter by 36.6%, while leucine or HMB partially restored it. Although GEC alone had minimal effect, co-treatment with GEC (100 μg/mL) and HMB (50 μM) produced a synergistic increase in myotube diameter that surpassed control levels. Immunofluorescence analysis showed that MyHC expression suppressed by DEX was fully restored by the combined treatment.

Western blot analysis supported these findings by showing that DEX downregulated MyHC, mTOR, and p70S6K while increasing MuRF1 and Atrogin-1. HMB partly reversed these changes, whereas GEC alone showed limited activity. In contrast, co-treatment restored anabolic signaling markers and reduced catabolic regulators to control or below-control levels. These results indicate that GEC enhances HMB-mediated protection against muscle atrophy by promoting anabolic pathways and suppressing muscle degradation.

Overall, CH-based ODFs enriched with leucine or HMB demonstrated favorable physicochemical properties, rapid oral disintegration, efficient intestinal release, and synergistic anti-atrophic effects when combined with GEC. These films offer a safe and practical nutritional strategy to support muscle health in older adults with dysphagia. Further studies should address long-term safety, regulatory considerations, and clinical validation, and explore optimized formulations or additional bioactives for personalized muscle health applications.

Elsevier Competition