A review of drying technologies for the production of powdered sea buckthorn (Hippophae rhamnoides l.) juice

Abstract

Sea buckthorn (Hippophae rhamnoides L.) is a nutrient-dense berry rich in vitamin C, flavonoids, and polyphenolic compounds; however, its pulp, containing approximately 80–90% moisture, is highly perishable and prone to rapid deterioration without appropriate preservation. The conversion of sea buckthorn juice into a dry powder represents an effective strategy to extend shelf life, reduce transportation and storage costs, and produce a stable ingredient suitable for applications in the food, nutraceutical, and cosmetic industries.This review provides a comprehensive overview of drying technologies applied to sea buckthorn juice, encompassing both conventional methods (natural sun and shade drying, hot-air drying) and advanced techniques, including heat-pump drying, infrared drying, spray drying, pulsed-vacuum drying, freeze-drying, and hybrid drying approaches. The operating principles, drying kinetics, and effects of each method on critical quality attributes—such as color stability, vitamin C retention, total phenolic content, and sensory properties—are systematically compared. Freeze-drying consistently demonstrates superior preservation of bioactive compounds, often yielding phenolic contents 1.5–3 times higher than those obtained by alternative drying methods; however, its industrial application is constrained by high energy consumption and prolonged processing times. Spray drying offers advantages in terms of rapid processing and scalability, although the elevated inlet temperatures (150–220 °C) may lead to significant degradation of thermolabile constituents. Pulsed-vacuum drying has emerged as a promising alternative, achieving nutrient retention comparable to freeze-drying while substantially reducing processing costs. Furthermore, hybrid drying strategies, such as infrared-assisted hot-air drying, have been shown to significantly shorten drying time and enhance the retention of bioactive compounds. Based on the reviewed literature, this paper highlights the importance of optimizing carrier agents, pretreatment strategies, and combined drying techniques to improve process efficiency and ensure high-quality sea buckthorn juice powders suitable for industrial applications.