Sustainable approaches to boost soluble dietary fibre in foods: A path to healthier foods

Soluble dietary fibre (SDF) provides a range of health benefits, from supporting digestive health and managing cholesterol to aiding in weight control and strengthening immunity. Its adaptability allows it to enhance food texture, stability, and satiety. However, unlike insoluble dietary fibre (IDF), SDF is scarce in natural sources and often found in low amounts, so modifying dietary fibre (DF) is a promising approach to increase SDF levels in foods. With a growing focus on sustainability, the food industry is increasingly turning to eco-friendly modification techniques to boost SDF content and improve its functional properties. This review explores recent advancements in sustainable methods for SDF production, including enzyme treatments, microbial fermentation, extrusion, microwave, ultrasound, high hydrostatic pressure, high-pressure homogenisation, steam explosion, and the use of green chemicals. Each technique's mechanisms, benefits, and challenges are discussed alongside the health benefits and potential industrial applications of SDF. Sustainable modification methods have shown significant potential to raise SDF yield and enhance its physical and chemical properties, with a lower environmental impact than conventional chemical treatments. Techniques such as enzyme treatment, extrusion, high hydrostatic pressure, steam explosion, and green chemical use appear especially promising for meeting industry demands for sustainable, high-SDF food products. While microbial fermentation, microwave, ultrasound, and high-pressure homogenisation also offer advantages, they remain costly and challenging to scale for large-scale production. • While SDF has exceptional health benefits, its intake from foods is insufficient. • Some green technologies can enhance the quantity and functional properties of SDF. • The mechanisms, advantages and limitations of these technologies were explained.