Quality Preservation and Cost Effectiveness in the Extraction of Nutraceutically-Relevant Fractions from Microbial and Vegetal Matrices

Abstract

Terrestrial and microbial vegetal matrices are a major source of nutraceutically and pharmaceutically relevant chemical compounds of different nature. In several cases the consumption of the raw vegetal or microbial matrix has been part of established diet regimes and has provided the consumers with a host of once unknown dietary benefits. Nowadays, while the consumption of the raw matrix still provides the original functional value, the separation of bioactive-enriched fractions has enabled the production of nutraceuticals, while the addition of nutraceutical fractions to food previously lacking or partially possessing them has lead to the industrial production of functionalised or fortified food respectively. The separability of nutraceutically relevant fractions depends on the combination of several different features of the carrier matrix and of the fraction to be separated, namely: size, aggregation state and physical (hardness) and chemical (composition) features of the embodying matrix, chemical nature, bonding and degree of dispersion of the fraction of interest in the embodying matrix. Physical, chemical and electrostatic interactions between the embodying matrix, the fractions to be separated and exogenous agents (equipment and process auxiliary substances, and the environment) affect the desired separation; the chemical nature of the solvent (if any), the specific energy applied by the physical agent (if any), the frequency and intensity of the mechanical (e.g., ultrasound) and electromagnetic (e.g., microwave) field (if any), the processing time and temperature and the presence of specific case-by-case unwanted substances (e.g., water, oxygen, metal ions) play a role in the final outcome of the recovery process of the desired fraction

Optimization of heat- and ultrasound-assisted extraction of anthocyanins from Hibiscus sabdariffa calyces for natural food colorants

“…At industrial scale, higher solid/liquid ratios (S/L) are desirable to maximize the extraction yield with minimal solvent consumption, thus making the process more productive and sustainable. The extraction rate is also affected by the mass transfer resistance associated with the matrix structure (Marco, Agnese, & Giuseppe, 2012). The studies on S/L were performed at the global optimal conditions predicted by the polynomial models obtained for each extraction technique as previously described.…”

A simulation‐guided tri‐spiral condenser design for enhancing lemongrass essential oil recovery

“…Crucially, the design minimizes pressure drop, a decrease in pressure during vapor flow, by incorporating larger diameter tubes and a spiral structure (Turgut & Çoban, 2017). This ensures sustained efficiency and cost-effectiveness across various applications, ranging from MAE to distillation, reflux, and evaporation (Bravi et al, 2012).…”

Microwave-Assisted Solid Extraction from Natural Matrices

“…An evolution of the open vessel apparatus is the Focused Microwave-Assisted Soxhlet (FMASE) which combines the classical Soxhlet extraction (SE) technique with MW irradiation. In the closed vessel system the entire extraction vessel is located within the oven, thus allowing better control of the pressure and temperature during the extraction [16].…”

“…Nevertheless, the use of closed-vessel systems presents some drawbacks: the amount of samples that can be processed is limited; the addition of reagents or solvents during operation is forbidden and the vessel must be cooled down before it can be opened to avoid loss of volatile constituents [16]. For processing a large amount of material, an open-vessel system is more appropriate.…”

“…Moreover, the extraction of thermolabile metabolites is allowed since it usually reaches low temperatures relative to closed-vessel systems. On the other hand, the open-vessel systems ensure less reproducible results compared to the closed-vessel systems and the extraction in open-vessel could require a longer time to obtain results comparable to those achieved in closed-vessel [16].…”