Table 2.

Applications of various processing techniques for the extraction of plant-based ingredients intended for dairy analogue production.

Technique	Source	Material	Process Application	Changes in Functional/ Textural Properties	Influence on Flavour/ Off-Flavour Formation	Impact on Nutrients/ Antinutrients
Mechanical Pre-Treatment and Extraction
Roasting	Ferawati et al. (2019) * [67]	Pulses (yellow pea, gray pea, faba bean, white bean)	Roasting before flour production	Increase in water-holding capacity (WHC)	-	Increase in total dietary fibre; Some pulses experienced increase in choline and folate
	Zaaboul et al. (2019) * [69]	Peanuts	Roasting before aqueous extraction	Higher protein solubility and extraction; Improved emulsion stability	-	-
	Ahmadian-Kouchaksaraei et al. (2014) * [70]	Sesame	Roasting before aqueous extraction	-	Reduced LOX activity; Reduced bitterness, ‘beany’ and ‘chalky’ flavours; Reduced oxidative off-flavour formation	-
Dehulling	Ma et al. (2021) [71]	Peas	Dehulling before aqueous extraction (yoghurt fermentation)	-	Reduced formation of the off-odorant 2-methoxy-3-isopropyl-(5/6)-methylpyrazine	Lowered amounts of extracted albumin (no effect on texture)
	Ghavidel andPrakash (2007) * [72]	Legumes (green gram, cowpea, lentil, chickpea)	Dehulling before flour production	-	-	Decreased soluble and insoluble dietary fibre; Decreased phytate; Increased iron and calcium bioavailability
Soaking and blanching	Ma et al. (2021) [71]	Peas	Blanching before aqueous extraction (yoghurt fermentation)	Increased firmness, viscosity and WHC of yoghurts	Reduced LOX activity and related lipid oxidation off-flavours	-
	Peng et al. (2015) [73]	Soy	Blanching before aqueous extraction (yoghurt fermentation)	Decreased soy protein solubility; Higher temperature blanching led to formation of softer, less firm yoghurts	Reduced ‘beany’ off-flavour and ‘chalky’ taste	-
	Ferawati et al. (2019) * [67]	Pulses (yellow pea, gray pea, faba bean, white bean)	Blanching/boiling before flour production	Improved WHC and gelation rates	-	Choline losses in some blanched pulse flours
Milling	Kaharso et al. (2021) * [74]	Soy	Anaerobic wet-milling for aqueous extraction	-	Reduced lipid oxidation products and off-odorants (e.g., alcohols and aldehydes)	-
	Kizzie-Hayford et al. (2015) * [64]	Tiger nut	Wet-milling with a pneumatic press	Increased milling intensity produced a smaller particle size distribution and higher total solids yield (improved PBAE colloidal stability)	-	-
Chemical and biological treatments
pH alterations	Ma et al. (2021) [71]	Peas	Alteration of soaking pH before aqueous extraction and yoghurt fermentation	Alkaline treatment reduced gel hardness (improved sensory scores for texture)	Alkaline and acid treatments reduced lipid oxidation products and improved sensory scores for smell and taste	-
	Pineli et al. (2015) * [75]	Quinoa	Alteration of cooking pH	Optimised pH and salinity resulted in three times greater soluble protein extraction versus pure water	-	-
	Ahmadian-Kouchaksaraei et al. (2014) * [70]	Sesame	Alkalinisation of soaking water before aqueous extraction	Increased protein solubility and fat extraction versus untreated soaking water	Lower LOX activity and theoretical reduction in off-flavour formation under alkaline conditions	-
Chemical deodorisation	Vatansever et al. (2021) * [76]	Pea	Treatment with supercritical CO2 and ethanol extraction	-	Reduction in total volatiles and odour-contributing compounds to below detection threshold levels	-
	Guldiken et al. (2021) * [77]	Lentil	Treatment with polymeric adsorbents	-	Reduced aldehydes (potential off-odorants)	-
	Wang et al. (2020) * [78]	Pea	Washing of flour with organic solvents	Reduction in emulsion stability and solubility of pea protein flour	Removed majority of volatile compounds, resulting in deodorised product	-
	Inouye et al. (2002) * [31]	Soy	Treatment with polystyrene and zeolite-based adsorbents	-	Reduced off-odorant (hexanal) in deodorised product	-
Enzymatic treatments	Jiang et al. (2020) [79]	Faba bean	Starch hydrolysis (Termamyl® Ultra 300 L) of slurry before yoghurt fermentation	Addition of enzymatic starch hydrolysate produced yoghurts with higher viscosities and gel strengths	-	-
	Zannini et al. (2018) [49]	Quinoa	Protease (Profix 100 L and Bioprotease PF50) treatment of slurry before yoghurt fermentation	Improved protein solubility in produced PBAE	-	-
	Park and Lee (2015) [80]	Soy	Flavourzyme® and Neutrase® treatment before yoghurt fermentation	Reduced yoghurt viscosity; Reduced WHC	Increased organic acid production during fermentation	-
	Luana et al. (2014) [53]	Oat	Enzymatic (Depol 740 L and Grindamyl 1000) treatment and yoghurt fermentation	Lower viscosity and WHC	Increased sweet and cereal taste	Significant increase in soluble fibre content
	Li et al. (2013) [81]	Soy	Enzymatic (papain) treatment of fermented or acidified coagulated PBAE for cheese production	Extensive hydrolysis of soy proteins, reducing graininess; Better stability, cheese homogeneity, and sensory acceptance	-	-
Germination	Ogundipe et al. (2021) [82]	Tiger nut	Germination before aqueous extraction and yoghurt fermentation	Reduced fat content	Decreased aroma sensory score (negative impact)	Decreased anti nutrient content (oxalate, saponin, phytate, and trypsin inhibitor)
	Cáceres et al. (2019) [83]	Rice	Germination before preparation of flour-based yoghurts	Lowered yoghurt consistency after starch hydrolysis during germination	Improved sensory acceptance after fermentation versus non-germinated rice flour; Some increase in bitterness observed (likely lipid oxidation products generated during germination)	Increased antioxidant activity and γ-aminobutyric acid content
	Hwang et al. (2018) [84]	Soy	Germination before yoghurt production	-	-	Increased γ-aminobutyric acid, total phenolics, and isoflavone aglycone contents
	Yang et al. (2010) [85]	Soy	Germination (various hypocotyl lengths) for the preparation of yoghurts	Decreased yoghurt WHC with increased hypocotyl length; Decreased hardness, adhesiveness, and gumminess (more sensorially acceptable yoghurt texture)	Reduced the ‘beany’ off-flavour, likely due to reduced LOX activity; Longer hypocotyl length associated with an unpleasant soybean sprout and astringent flavour; Enhanced free amino acid content may lead to pleasant flavour development during fermentation	-
Germination	Le et al. (2021) * [86]	Soy	Germination before PBAE production	Protein denaturation led to larger droplet size and lower viscosity	Increase in overall sensory acceptability, likely due to the reduction in off-flavours	Increased γ-aminobutyric acid content
	Lopes et al. (2020) * [24]	Pulses (Sweet lupin, chickpea, green pea, yellow pea)	Germination before PBAE production	Reduced gelation in pulse beverages due to starch hydrolysis	-	-
Other novel treatments
High pressure homogenisation/Microfluidisation	Levy et al. (2022) [87]	Potato	HPH emulsions were fermented into yoghurts	Improved gelation and lowered creaming velocities for finer, more stable emulsions	-	-
	Demirkesen et al. (2018) [88]	Hazelnut	Microfluidisation of slurry before yoghurt fermentation	Improved WHC and higher slurry consistency (firmer yoghurts more similar to dairy yoghurt)	-	Successful production of high-fibre hazelnut yoghurt without residue removal during PBAE production
	Ferragut et al. (2009) [89]	Soy	UHPH PBAE was fermented into a yoghurt	Improved WHC, rigidity and firmness with increase in homogenisation pressure	-	-
	Xia et al. (2019) * [90]	Sweet lupin	Slurry was homogenised under high pressure to yield a PBAE	Decreased particle size, sedimentation and improved emulsion stability; Reduced viscosity	-	-
High pressure homogenisation/Microfluidisation	Jeske et al. (2019) * [91]	Lentil	Slurry was homogenised under high pressure to yield a PBAE	Reduced particle size, which increased solubility and reduced aggregation (improved stability); End product texturally comparable with other commercial PBAEs	-	-
Ultrasonication	Mu et al. (2022) * [92]	Soy	Ultrasonication of PBAE	Reduced particle size, improved thermal and emulsion stability	Decreased lipid oxidation off-odorants, including ‘grease-oxidative’ and ‘beany’ flavours	-
	Lu et al. (2019) * [93]	Coconut, maize	Ultrasonication of PBAE with maize additives	Reduced particle size, improved emulsion stability and homogenised mixture	-	-
	Abdullah et al. (2018) * [94]	Coconut	Ultrasonication of PBAE	Reduced particle size and creaming index, improving stability	-	-
High hydrostatic pressure (HHP)	Wang et al. (2021) [95]	Soy	Optimised HHP processing before yoghurt fermentation	Enhanced WHC and protein solubility Reduced yoghurt syneresis	Reduced LOX activity and related off-odour compounds	-
High hydrostatic pressure (HHP)	Sim et al. (2021) [96]	Legumes (mung bean, chickpea, pea, lentil, faba bean)	HHP processing to achieve yoghurt textures (no fermentation)	Formed pressure-induced, protein-based gels with viscoelastic properties similar to dairy yoghurt	-	-
	Dhakal et al. (2014) * [97]	Almond	HHP processing of PBAE	-	Allowed for protein modification without the formation of undesirable cooked flavours	Decreased amaldin content and hence allergenicity
Pulsed electric field (PEF)	Manzoor et al. (2020) * [98]	Almond	Comparison versus thermal treatment on PBAE	Increased colloidal stability and reduced sedimentation	Decreased LOX and peroxidase (POD) activity may result in reduced off-odour formation	Increased free amino acid content
	Li et al. (2013) * [99]	Soy	PEF treatment of PBAE	Reduction in viscosity	Decreased LOX activity may result in reduced off-odour formation	-

* Indicates that study investigated the unfermented plant ingredient (e.g., flours, PBAEs). HPH: high pressure homogenisation; UHPH: ultra-high pressure homogenisation; HHP: high hydrostatic pressure; PEF: pulsed electric field.