Recent Advances in Food Process Engineering

Engineering Synergies in Hybrid Non-Thermal Food Processing: A Critical Appraisal of Combined High-Pressure, Pulsed Electric Field, Cold Plasma, Ultrasound and Ultraviolet Treatments

2026-09-21T06:17:06+00:00

Non-thermal preservation technologies have matured individually, yet each retains a characteristic ceiling: high-pressure processing struggles with bacterial endospores, pulsed electric fields depend on matrix conductivity and cell size, cold plasma acts mainly at surfaces, ultrasound is energy-intensive at lethal intensities, and ultraviolet light is defeated by turbidity. Combining these processes is widely presented as the route past those ceilings, and the combination literature has expanded rapidly. This critical narrative review evaluates whether the evidence supports that expectation, and on what terms. Peer-reviewed literature published between January 2003 and 8 July 2026 was identified through structured searching of open scholarly indexes and citation registries, supplemented by backward and forward citation tracking, and was appraised for mechanistic coherence, methodological adequacy and engineering realism rather than assembled descriptively. The evidence indicates that reproducible enhancement is concentrated in pairings whose primary lethal targets differ and whose delivery constraints are complementary, particularly ultrasound with plasma-activated liquids, ultrasound with ultraviolet light, and ultraviolet or ultrasound pretreatment before high-pressure processing. Enhancement is far less consistent where two processes converge on the same target, and combinations that improve microbial lethality do not reliably improve nutritional or sensory outcomes; several rigorous comparisons report that a single optimised process outperforms its combination on quality endpoints. Three weaknesses recur across the field. Synergy is asserted without a declared additivity baseline; single-technology comparators are rarely matched for delivered energy or equivalent lethality; and sublethal injury is seldom quantified, so apparent enhancement may reflect enumeration artefacts rather than lethality. Engineering integration remains the binding constraint, because batch pressure vessels, continuous electrical treatment chambers and surface-limited plasma or photon sources impose incompatible residence times and throughput. Priorities are proposed for baseline-anchored synergy reporting, equivalent-lethality comparators, injury-aware enumeration, and pilot-scale demonstration of sequencing feasibility.

Advances in Pulsed Electric Field, Ohmic Heating, Radiofrequency and Microwave Technologies for Low-Carbon Food Processing: A Critical Narrative Review of Energy, Emissions and Implementation Evidence

2026-09-21T06:24:04+00:00

Food manufacturing depends heavily on thermal unit operations supplied by fossil-fuelled steam and hot water, and the temperature profile of that demand is unusually favourable to electrification. Pulsed electric field treatment, ohmic heating, radiofrequency heating and microwave heating are frequently presented as a coherent family of electrically driven alternatives capable of reducing both energy use and greenhouse gas emissions, yet the evidence supporting that claim is more heterogeneous and more contested than promotional accounts suggest. This review critically evaluates the published evidence on the energy and carbon performance of these four technologies in food processing, examines why quantitative findings diverge so sharply, and assesses what can defensibly be concluded about their contribution to low-carbon manufacturing. Literature was identified through open scholarly indexes and citation tracking, appraised for methodological adequacy, and synthesised thematically around mechanisms, measured energy outcomes, sources of disagreement, and conditions for implementation. The strongest and most internally consistent evidence concerns process intensification in drying and dehydration, where electromagnetic and electroporation-based methods reduce specific energy consumption substantially relative to purely convective operations. Evidence for pasteurisation and sterilisation is markedly weaker and openly contradictory: independent assessments of comparable products report pulsed electric field processing as both more and less carbon-intensive than conventional thermal treatment, and at least one industrial-scale comparison found microwave flow pasteurisation to consume considerably more electricity than a conventional process. These disagreements are traceable to identifiable methodological choices rather than to genuine physical inconsistency, principally the treatment of conversion losses, the presence or absence of heat recovery in the comparator, the assumed carbon intensity of electricity, the functional unit adopted, and the scale at which measurements were taken. Confidence in aggregate decarbonisation claims is therefore limited. Priorities include standardised energy reporting, transparent system boundaries, pilot-to-industrial validation, and analysis that couples processing choices to grid decarbonisation trajectories and demand-side flexibility.

Process Intensification in Food Manufacturing: a Critical Appraisal of Engineering Pathways towards Faster, Cleaner and More Resource-Efficient Production

2026-09-21T06:27:40+00:00

Food manufacturing converts biological raw materials into safe, stable and palatable products through unit operations that were largely configured for throughput and shelf-life rather than for energy or material frugality. Process intensification offers a structured engineering response, promising smaller, faster, cleaner and better-integrated plants, yet its translation from chemical engineering into food production has been uneven and its evidential foundations have received limited critical scrutiny. This review examines how intensification principles have been interpreted, tested and contested in food manufacturing, and asks what the accessible evidence can legitimately support. Literature was identified through open scholarly indexes and citation searching, appraised for methodological adequacy and scale of demonstration, and synthesised thematically around the structural, energetic, synergistic and temporal dimensions of intensification. The strongest evidence concerns field-assisted pretreatments and electrically driven heating, where independent studies at pilot and factory scale report reproducible reductions in processing time, energy input and material loss. Evidence for separation and extraction intensification is abundant but dominated by small-scale, single-laboratory optimisation exercises whose energy and environmental claims frequently rest on incomplete system boundaries. Recurrent weaknesses limit inference across the field: matrix-dependent responses reported as general effects, comparators chosen without equivalent optimisation, treatment-chamber energy reported in place of specific energy consumption for the whole line, and microbiological validation conducted under conditions far removed from commercial operation. Adoption surveys indicate that capital intensity, validation burden and regulatory uncertainty constrain implementation more tightly than technical performance. Intensification in food manufacturing is best understood not as a catalogue of replacement technologies but as a redesign problem in which the unit operation, the product specification and the process chain are reconsidered together. Confidence in reported gains will remain conditional until scale-resolved energy accounting and independent replication become routine.

Next-generation Food Drying: A Critical Synthesis of Hybrid Technologies, Heat Recovery, Renewable Energy Integration and Intelligent Process Control

2026-09-21T06:31:23+00:00

Drying remains one of the most energy-intensive unit operations in food manufacturing, and the pressure to decarbonise process heat has pushed the field beyond incremental improvement of convective dryers towards four partly overlapping strategies: hybridisation of heat-transfer mechanisms, recovery of thermal energy that conventional dryers discard, substitution of fossil-derived heat with renewable supply, and replacement of experience-based operation with sensor-driven, model-based control. This critical narrative review examines how far the evidence for each strategy has matured, where the four strands reinforce one another, and where the literature has advanced claims that the underlying studies do not sustain. Peer-reviewed research published between 2018 and mid-2026 was located through open scholarly indexes and citation searching, appraised for methodological adequacy, and synthesised thematically rather than catalogued. The evidence is strongest and most internally consistent for hybrid electromagnetic-convective configurations, which shorten drying time substantially and often improve energy efficiency, and for heat-pump and exhaust-stream recovery, where thermodynamic accounting is comparatively transparent. It is weaker for renewable-integrated dryers, where performance is reported under climate-specific conditions that limit transferability, and weakest for intelligent control, where most contributions demonstrate predictive accuracy on retrospective data rather than closed-loop benefit on operating plant. Three problems recur across the field: incompatible energy indicators that prevent quantitative comparison, evaluation at laboratory scale under conditions that favour the novel configuration, and quality assessment restricted to a narrow set of physical and antioxidant indicators. The synthesis argues that the principal barrier to next-generation drying is no longer the availability of individual technologies but the absence of shared measurement conventions, validated real-time sensing, and independent evaluation at production scale. Priorities are proposed for reporting standards, sensor development, controller validation and context-sensitive techno-economic assessment.

Engineering Alternative Proteins for Future Foods: A Critical Appraisal of Protein Fractionation, High-Moisture Extrusion, Precision Fermentation and Cultivated Meat

2026-09-21T06:40:02+00:00

Alternative protein manufacture has moved from conceptual advocacy to an engineering discipline in which ingredient fractionation, thermomechanical structuring, recombinant protein expression and mammalian cell culture are being developed as parallel routes to foods that displace conventional animal products. This critical narrative review examines the engineering evidence base across four platforms that are usually treated separately: plant protein extraction and fractionation, high-moisture extrusion and related shear-structuring technologies, precision fermentation of recombinant food proteins, and cultivated meat. Literature was identified through structured searching of open scholarly indexes and registries, supplemented by backward and forward citation tracking and by examination of authoritative institutional documents, with critical appraisal directed at methodological transparency, replication, scale relevance and the alignment between reported measurements and the claims they are used to support. Four cross-cutting problems emerge. First, ingredient purity is treated as a proxy for functionality even though comparative fractionation studies show that less-refined concentrates can outperform isolates in structuring, so purification frequently imposes environmental and economic costs without commensurate technical return. Second, mechanistic accounts of fibre formation during high-moisture extrusion remain contested, and the diversity of non-standardised texture measurements prevents quantitative comparison between laboratories. Third, recombinant food proteins are widely described as identical to their animal-derived counterparts, whereas the available structural and functional characterisations record systematic deviations in post-translational modification, aggregation state and interfacial behaviour. Fourth, techno-economic and life-cycle assessments of cultivated meat diverge by orders of magnitude because they encode incompatible assumptions about cell density, medium cost, facility design and energy supply, and the recent appearance of empirical pilot-scale data has narrowed rather than resolved that disagreement. Confidence is strongest for descriptive process–structure relationships and weakest for projected cost, environmental performance and long-term nutritional adequacy. Progress will depend less on new platforms than on standardised measurement, transparent assumption reporting and independent replication at pilot scale.

Precision Fermentation for Next-Generation Food Ingredients: A Critical Review of Bioreactor Engineering, Downstream Processing, Scale-Up and Sustainability

2026-09-21T06:49:31+00:00

Precision fermentation uses engineered microorganisms to manufacture defined food ingredients, but successful expression does not establish industrial feasibility or environmental advantage. This critical narrative review examines the coupled biological, engineering and assessment decisions that determine whether fermentation-derived ingredients become functional, affordable and resource-efficient products. The scope centres on recombinant dairy and egg proteins, with oligosaccharides, sweet proteins, haem proteins and tailored lipids used to expose differences between product classes. Accessible scholarly literature was selected through topic-specific searches, citation tracing and bibliographic verification, and appraised according to experimental scale, product characterisation, process completeness and the transparency of economic and environmental assumptions. The evidence supports microbial production of several functional food proteins, while showing that secretion, post-translational modification and recovery can remain limiting even when total expression improves. Large-scale performance depends on oxygen delivery, heat removal, broth rheology, feeding gradients and population stability; laboratory titre alone therefore provides an incomplete basis for investment. Downstream processing must reconcile impurity control with retained functionality, because maximising purity can increase losses, water consumption and cost without improving the intended application. Environmental assessments identify electricity, carbon substrates, utilities and allocation choices as major determinants, with some fermentation scenarios outperforming agricultural comparators and others offering similar or higher burdens. These findings do not support a universal sustainability ranking. The review develops an integrated decision framework based on saleable functional output, demonstrated process robustness and comparison with an explicitly defined incumbent ingredient. Immediate priorities include paired fermentation–recovery experiments, representative scale-down testing, transparent process inventories and food-matrix validation. Precision fermentation is best understood as a set of product-specific manufacturing routes whose contribution to sustainable food production must be demonstrated across the complete process chain.

From Food Waste to High-Value Ingredients: A Critical Appraisal of Process Engineering Strategies for Circular Food Biorefineries

2026-09-21T06:55:46+00:00

Food waste represents the largest single stream of avoidable organic loss in the global food system, and its conversion into high-value ingredients has become a central ambition of circular bioeconomy policy. Progress in the underlying process engineering has nonetheless been uneven. The purpose of this critical narrative review is to evaluate, rather than catalogue, the engineering strategies through which heterogeneous food-waste streams are converted into ingredients of nutritional, functional or material value, and to establish where the evidence supports confident conclusions and where it does not. Literature was identified through structured searching of open scholarly indexes and registries, supplemented by citation tracking and by institutional sources, with appraisal focused on demonstrated scale, transparency of mass and energy accounting, and the coherence between experimental performance and system-level assessment. Four themes organise the synthesis: feedstock composition and variability as a design constraint rather than an operating nuisance; separation-led recovery of structurally intact molecules, including solvent design, energy-assisted intensification and pressurised fluids; bioconversion-led routes through carboxylate, polymer, protein and peptide platforms; and the integration of these unit operations into cascades whose economics and environmental performance can be defended. The evidence is strongest for laboratory and bench demonstration of individual recovery steps and for the direction of economic sensitivity in modelled biorefineries, which consistently identifies feedstock scale, high-value co-product price and downstream purification as dominant. It is weakest precisely where circularity claims are made: sustained operation on real, variable waste, solvent and enzyme recycling over many cycles, and life-cycle accounting whose boundaries and allocation rules permit comparison between studies. Reported gains from intensified extraction and from cascade sequencing are rarely accompanied by the energy and solvent inventories needed to verify them. Confidence in current conclusions is therefore asymmetric, and the field’s principal deficit is not the discovery of new recovery chemistries but the demonstration of integrated, instrumented and reproducible processing at pilot scale under realistic feedstock variation.