Starch Nanoparticles by Sonochemical Protocols: Food Industry, Nutraceutical, and Drug Delivery Applications

This review summarizes scientific advances about the sonochemical synthesis of starch nanoparticles (St-NPs) for the food industry, as well as nutraceutical and drug delivery applications. High-intensity ultrasonication (HIU) has been explored as a versatile and environmentally friendly alternative to conventional methods for synthesizing St-NPs with high yields (>90%), controlled size (~100 nm), and minimal effluent generation. Thus, HIU has been explored (pre- or post-treatment) to mitigate the inherent disadvantages (high-cost, low yields, and environmental impact) of hydrothermal gelatinization, acid/alkaline hydrolysis, enzymatic hydrolysis, enzyme branching, water-in-oil and oil-in-water emulsions, non-solvent nanoprecipitation, extrusion, high-pressure homogenization, high-energy milling, and cold plasma. Conventional sources of starch (corn [normal, waxy, high-amylose] and potato) and other unconventional sources (tubers [cassava, yam, malanga], seeds and grains [sorghum, barley, quinoa, lotus], breadfruit, pinhao seed, Araucaria angustifolia) have been subjected to single or assisted sonochemical protocols to obtain St-NPS with unique structural, physicochemical, and technological properties. The physical–mechanical effects of ultrasonication (cavitation, heat, and pressure) directly promote surface functionalization (i.e., esterification, pore formation) and impact the St-NPS’s particle size, double-helix structure, enzymatic-resistance properties, crystallinity, and intra- and intermolecular arrangements. Pickering additives in food systems, colloids in beverages, nanocomposites in biofilms for food packaging, and nanocarriers for drug and nutraceutical delivery (oral and transdermal) have been the most reported applications.