From Open Sun to Advanced Hybrid Systems: A 50-Year Journey of Solar Drying Evolution Through Bibliometric Insights

Solar drying is a foundational dehydration technique that has evolved significantly from its empirical origins to become a sophisticated engineering discipline. This study presents a comprehensive bibliometric mapping of 50 years of solar drying research (1976–2025) using 4384 documents retrieved from the Web of Science Core Collection. The analysis reveals a steady annual growth rate of 5.42% and a profound shift in research priorities toward the Energy–Food–Health Nexus. While India leads in publication volume (1113 documents), Turkey exhibits the highest research efficiency (60.53 citations per paper). Current trends indicate a move away from open-sun drying toward advanced hybrid systems incorporating Phase Change Materials (PCM), Computational Fluid Dynamics (CFD), and a focus on preserving bioactive compounds, as evidenced by the dominance of SDG 3 (Good Health and Well-being). This review serves as a strategic guideline for future institutional investment and international collaboration to bridge current research gaps in high-solar-potential regions.