## 5 Animal Nutrition
### Novel Methods
The **\"instant controlled pressure-drop technology\"**, **known by its French acronym DIC** (Detente Instantanee Controlee), was created in 1988 as a solution to the drying shrinkage/collapse issues, in order to obtain a better quality of the dried foods or plants in terms of texture, colour, aroma, etc. DIC is a hydro-thermo-mechanical treatment that is mainly used with biological materials. The process is characterised by the fact that operating parameters such as temperature and pressure can be tightly controlled. DIC consists in placing the moistened product in a processing vessel and exposing it to a high saturated steam pressure (0.08-1 MPa) at high temperatures (up to 170 \({}^{\circ}\)C), over a relatively short duration (from a few seconds to one minute). The treatment duration is determined by a drop, generally instantaneous (<0.1 s), to a low absolute pressure of about 5 kPa. The vaporisation of water from the product produced by the drop in pressure generates micro-mechanical constraints that lead to a modification of the product's texture and result in a porous structure. The short duration of the treatment and the immediate drop in temperature following the fall in pressure prevent further thermal deterioration and ensure that the quality of the end product is maintained [154; 155]. Since then, DIC has led to remarkable developments in several aspects. DIC has shown its potential to remedy the mass transfer resistance linked to cell collapse in drying operations. Thanks to the newly generated porous structure, an increase in the starting and the effective diffusivity of food products was observed [156]. This intensification directly impacts the drying operation, reducing the total drying time (in some cases to 1 h instead of 6 h), and improves the integral quality of dried products [157; 158]. In extraction operations, DIC performs excellently as a pretreatment and as an extraction operation itself. First, in the case of DIC as a pretreatment, studies have concluded that, thanks to the new microstructure, the plant/food materials were better at releasing the desired (biologically active compounds, e.g., antioxidants, essential oils, vegetable oils) or undesirable (oligosaccharides) molecules [159]. DIC provides a new way to eliminate vegetative microorganisms and spores, thereby ensuring microbial decontamination for solid and powder foods [155]. In addition, DIC has been used to reduce non-nutritional compounds (e.g., from legumes, nuts), which could directly impact the consumption of plant proteins in human food and feed [160; 161; 162]. In this respect, new functional food products could now be developed from dried legumes or with proteins extracted by DIC. Finally, DIC can also improve other food unit operations, such as oil deodorisation, desolventation, dehydrofreezing, blanching, coffee drying, and roasting, among many others [163]. The operating parameters can be optimised to meet the exact needs of different industrial applications. Thus, it could be said that DIC is a disruptive technology with a high potential to redefine several food processing methods, even in the case of duckweed. According to the selected operative parameters, optimising DIC as a pretreatment for conventional (e.g., hydrodistillation) and emerging extraction technologies (e.g., ultrasound and microwaves) has been possible. Finally, no study on the application of the DIC process on duckweed has been carried out yet. Therefore, the impact of DIC on duckweed has yet to be explored.