Ionic liquids in the selective recovery of fat from composite foodstuffs

Abstract

BACKGROUND: Ionic liquids (ILs) are able to dissolve a wide range of organic and inorganic molecules and have potential application in the separation and recovery of valuable components from wastes. The potential for ILs to separate sugar and fat from food waste is demonstrated using chocolate as a model system.

Separation and recovery of cellulose and lignin using ionic liquids: a process for recovery from paper‐based waste

“…There have been reports on the use of ILs as catalysts, 12 -14 as engineering fluids, 15,16 as performance additives, 15 -17 as replacements for traditional volatile organic solvents, 18 -20 as solvents in electrochemistry, 15,16,21 in commercial production processes, 15,16,22,23 in organic synthesis 24 -26 and in separation and extraction techniques. 8,9,15,16,23,27 Cellulose is the most abundant renewable organic polymer on earth, with lignin the second most abundant. Cellulose and lignin are both structural components of plants with cellulose being a component of the primary cell wall and lignin a component of the secondary cell wall.…”

Dual‐functionality ionic liquid mix for extraction and esterification of fatty acids as a step towards increasing the efficiency of conversion of waste cooking oils to biodiesel

“…The eight ionic liquids used in this work (Table ) were prepared by previously reported methods with modifications . The fatty acids used as model compounds in the extraction and esterification studies namely, palmitic acid (Sigma Aldrich, ≥99%), stearic acid (Fluka, ≥98.5%) oleic acid (Sigma Aldrich, ≥99%, GC grade), and linoleic acid (Sigma Aldrich, ≥99%, GC grade) were used as‐received, as were the vegetable oils used as model oils (food‐grade palm oil, sunflower oil and rapeseed oil).…”

“…The large size and low degree of symmetry of the cation reduces the lattice energy of the potential solid crystalline salt and as a result lowers the melting point . ILs can be synthesised by conventional chemical or microwave‐assisted methods, and the latter method results in major reduction in the reaction times required and the elimination of the need to use volatile organic solvents as reaction media. The majority of ILs are thermally stable up to 280 °C and thus have a wide thermal range for use in various applications.…”

“…They can be tailor‐made to selectively solubilise key substances from composite mixtures in a number of ways, including by varying the nature of the cations and anions, by altering the lengths of the alkyl chains in the cations, and by introducing functional groups to the cations. For this reason ILs can be designed to be either hydrophilic or hydrophobic, oleophilic or oleophobic or to achieve the selective solubility of specific compounds including the key components of wastes . Some properties of ionic liquids can also be temperature‐dependent for example hydrophilic at low temperature and hydrophobic at higher temperatures .…”

“…For this reason ILs can be designed to be either hydrophilic or hydrophobic, oleophilic or oleophobic or to achieve the selective solubility of specific compounds including the key components of wastes. 11,12 Some properties of ionic liquids can also be temperature-dependent for example hydrophilic at low temperature and hydrophobic at higher temperatures. 13 The use of ionic liquids in biodiesel production has been reviewed by Andreani and Rocha.…”