The food industry is quite interested in the use of (techno)-functional bioactive compounds from by-products to develop ‘Clean label’ foods in a circular economy. Most studies are mainly focused on ultrasound extraction, which has been widely developed compared to microwave or enzymatic extractions, which should be deeply studied including combinations. After extraction, pomegranate peel by-products (in powders, liquid extract, and/or encapsulated, among others) have been incorporated into several food matrixes, as a good tool to preserve ‘Clean label’ foods without altering their composition and improving their functional properties. Future studies must clearly evaluate the energy efficiency/consumption, the cost, and the environmental impact leading to sustainable extraction of the key bio-compounds. Moreover, predictive models are needed to optimize the phytochemical extraction to help taking decisions along the supply chain
Technology | Carriers | Target Compound/Activity | Ref. | |||||||
---|---|---|---|---|---|---|---|---|---|---|
Spray-drying | Maltrodextrin | F-TPC, UPLC-TPC, Pn, EA, P, GA | [23][24] | |||||||
Maltrodextrin + others: Tween 80 (99:1); Skimmed milk powder (50:50); Whey protein isolate (50:50); Gum arabic (50:50) | NA (Yield/Stability) | [25][26] | ||||||||
Skimmed milk power | NA (Yield/Stability) | Powder home grinder (more information NA) Wonderful cv | [25][26] | |||||||
120 g/L EtOH solvent (50 and 80%) + 1% Citric acid | Postharvest. | Treatment of 1 × 1-mm injuries and inoculated ( | C. acutatum | ) by 10 µL of pomegranate peel extract (12, 1.2, or 0.12 g/L) | Reduction of fungal and bacterial population | [58] | Orange juice byproduct | F-TPC, DPPH | ||
Potato tubers | Air drier (28 °C, 10–15 days) Fine powder (more information NA) Baladi cv | [27][28] | ||||||||
1:10 solid–liquid (MetOH) 48 h 28 °C + evaporator + oven 50 °C 48 h | Postharvest. | Wound (3 × 3 mm φ and deep) + inoculation ( | F. sambucinum | ) (24 h) + dipping (1.25, 2.5, 5, 10, and 20 mg/mL water) + air dried (2 h at 28 °C). | Antifungal activity on the mycelial growth and spore germination | [59] | Maltodextrin/Pectin | TPC, Pn, EA | [29] | |
Strawberry | Drying and particle size information NA Dente di caballo cv |
Whey protein | Pn, EA, P, GA | [24] | ||||||
Arabic gum | Pn, EA | [30] | ||||||||
Chitosan | Pn, EA | [30][31] | ||||||||
Pectin | Pn, EA | [30] | ||||||||
Modified starch | Pn, TPC, HTC, DPPH | [32] | ||||||||
Alginate | NA (Yield/Stability) | [31] | ||||||||
Freeze-drying | Soy phosphatidylcholine liposomes | Pn, EA, rutin, epifallocatechin, TPC | [33] | |||||||
Maltodextrin (5 and 10%) and b-cyclodextrin (5 and 10%). | F-TPC, FRAP | [34] |
Matrix | Pomegranate Peel Byproduct |
Extraction | Incorporation Method | Benefit | Ref. | ||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Fresh whole F&V (pre- and postharvest) | Tomato | Drier (50–60 °C, 72 h) Fine powder (more information NA) cv information NA |
Ratio 3:10 EtOH 48 h + evaporator (65 °C) + re-dissolved in sterile distilled water (0.05%, 0.5%, 1% and 5% | w | / | v | ) | Preharvest. Tomato plants were sprayed in the leaves (bacteria inoculation) with the aqueous extract + 24 h drying |
Antibacterial activity at least 15 days Replacing, reducing, or even alternating treatments involving copper compounds |
[56] | |||
Sage herb | Air dried (more information NA) Grinder (more information NA) cv information NA |
1:10 solid–liquid ratio in water or EtOH 80% 24 h + evaporator + water dilution | Preharvest. Added in the soil (2, 4, and 6 g per plot) |
Higher dry mass and essential oils Inhibition of free radical scavenging |
[57] | ||||||||
US 40 °C 80% A 3 min (3 on, 8 off) | |||||||||||||
Ratio 1:10 (H | 2 | O 25%, propanol 25%, ethanol 25% and methanol 25%) + evaporator + Freeze-drier + re-dissolved in water | Postharvest. Immersion (30 s in a 2 L solution of pomegranate peel extract) + air-drying (1 h) |
Extension of shelf life Substitution of synthetic pesticides |
[60] | ||||||||
Prunus armeniaca | |||||||||||||
gum exudates | |||||||||||||
FRAP, DPPH | |||||||||||||
[ | |||||||||||||
35 | |||||||||||||
] | |||||||||||||
Chitosan | FRAP, DPPH | [35] | |||||||||||
Maltrodextrin | TPC, TFC, Pn, EA, FRAP, DPPH | [36] | |||||||||||
Maltodextrin and calcium alginate | ANCs, FRAP, DPPH | [37] | |||||||||||
Maltodextrin and soy lecitin | NA (Yield/Stability) | [38] | |||||||||||
Double emulsion | Water | 1 | in Oil in Water | 2 | : Water | 1 | (ethanolic solutions) in Oil (castor, soybean, sunflower, medium chain triglyceride and orange) in Water | 2 | (aqueous solution with Tween | 80 | ) | NA (Yield/Stability) | [39] |
Olive | Oven drier (40 °C) | ||||||||||||
Sweet cherry | Oven drier (40 °C) Particle size NA Mollar de Elche cv |
EtOH solvent (50 and 80%) + 1% Citric acid +evaporator + Water dilution | Postharvest. Dipping (2 min) in the pomegranate extract (12, 2.4 or 1.2 g/L) + air drying (2 h, 28 °C) + storage at 1 °C |
Inhibition of all fungal spore germination | [61] | ||||||||
Fresh whole F&V (pre- and postharvest) | Sweet cherry | Oven drier (40 °C) Fine powder < 470 µm cv information NA |
1:8 solid–liquid ratio (Water 28 °C 24 h) | Postharvest. Immersion in pomegranate peel extracts (3 min 20 °C) + room temperature drying |
Pomegranate peel extracts and calcium sulphate coatings, alone or in combination, decreased weight loss, decay, respiration rate, and increased acidity, firmness, ascorbic acid, DPPH, TPC, and TAC | [62] | |||||||
Apple | Oven drier (40 °C) Particle size NA Mollar de Elche cv |
EtOH solvent (50 and 80%) + 1% citric acid + evaporator + water dilution | Postharvest. Wounds treated with 10 μL of pomegranate peel extract (12, 1.2 or 0.12 g/L) + inoculation (10 μL | P. expansum | ) | Inhibition of fungal spore germination and decay of artificial inoculations | [61] | ||||||
Mango | Freeze drying (−45 °C, 94 h) Particle size and cv information NA |
MetOH 45 °C 30 min + Bath US + evaporator + water dilution | Postharvest. Chitosan (2%) in 0.5% citric acid solution + Pullulan (2%) in water (50:50 ratios). During stiring: 1% glycerol + 5% of pomegranate peel extract (0.02 g/mL). Dipping for 2 min |
Increase of firmness, TPC and AOX. Prolonged the shelf life | [63] | ||||||||
Apricot | Drier (60 °C, 48 h) Particle size < 0.251 mm cv information NA |
80% EtOH 25 °C + evaporator | Postharvest. Chitosan coating solution (1% chitosan in glacial acetic 1% + 0.8% glycerol + Tween 80 + 0.50, 0.75, and 1% pomegranate peel extract) |
Reduction of % decay and weight loss. Maintenance of DPPH radical scavenging activity, ascorbic acid content, titratable acidity and firmness. | [64] | ||||||||
Figs | Air dried few days (more information NA) Pulverized (more information NA) cv information NA |
Alcoholic buffer (EtOH 50%) | Postharvest. Alginic acid: agar (70:30) + 0.25 and 0.5% pomegranate peel extract Dipping in the coating solution + coating gelation |
Prolonged the shelf life | [65] | ||||||||
Dates | Drier (48 °C, 52 h) Ground peels (more information NA)cv information NA |
EtOH 70% + evaporator + Water dilution | Postharvest. 1% Chitosan, 1% nanochitosan or 1% pomegranate peel extract in 1% glacial acetic |
Growth inhibition of any fungal spore after 48 h of coating. | [66] | ||||||||
Citrus | Hot air drier (50 °C, 48 h) Particle size 0.250 mm cv information NA |
2.5:10 Solid–liquid ratio (Ac, EtOH, MetOH, H | 2 | O, DMSO) + shaking (6 h) + re-extracted with water evaporation | Postharvest. Immersion of wounded lemons (2 × 1 mm long and wide tip) in pomegranate peel extract (pre-infection and post-infection with | P. digitatum | ) + air drying | Prevention and control of | P. digitatum | [67] | |||
Fresh whole F&V (pre- and postharvest) | Grapefruit | Oven drier (40 °C) Particle size information NA Mollar de Elche cv |
EtOH solvent (50 and 80%) + 1% citric acid evaporator + water dilution |
Postharvest. Wounds treated with 10 μL of pomegranate peel extract (12, 1.2 or 0.12 g/L) + inoculation 10 μL | P. digitatum | and | P. italicum | Inhibition of all fungal spore germination and decay of artificial inoculations | [68] | ||||
Lemon | Oven drier (40 °C) Particle size information NA Mollar de Elche cv |
EtOH solvent (50 and 80%) + 1% citric acid + evaporator + water dilution | Postharvest. Wounds treated with 10 μL of pomegranate peel extract (12, 1.2 or 0.12 g/L) + inoculation 10 μL | P. digitatum | and | P. italicum | Inhibition of all fungal spore germination and decay of artificial inoculations | [61][68] | |||||
Mandarin | Drier (70 °C, 48 h) Ground peels (more information NA) Shirine Shahvar cv |
0.25:10 solid–liquid ratio (60% EtOH + 0.1% citric acid) | Postharvest. Wounded (1 × 2 mm φ and depth) + dipping 1 min in pomegranate peel extract concentrations (25, 50, 75, 100%) + inoculation ( | P. italicum | and | P. digitatum | ) + drying | Reduction of % infected wound and lesion φ (75% or/and 100% extract). Increase of TPC, TFC, and PAL activity (75% or/and 100% extract) | [69] | ||||
Orange | Drier (35 °C, 2 days) Particle size NA Gabsi cv |
1:10, 0.6:10, 0.3:10 solid–liquid ratio (MetOH or Water) + evaporated + drying (40 °C or freeze-drying) + re-dissolved in water | Postharvest. Chitosan coating solution (1% chitosan in glacial acetic 1% + 0.5% Locust bean gum + 20% glycerol + 7, 18, and 36% dry waster/MetOH pomegranate peel extract). Wounded oranges (4 times: 3 × 3 mm φ × deep) + Inoculation (20 μL of a | P. digitatum) | + drying + dipping in different coating solutions (2 min) | Controlled growth of | Penicillium digitatum | Reduction of postharvest decay |
[70] | ||||
Orange | Oven drier (40 °C) Particle size NA Mollar de Elche cv |
EtOH solvent (50 and 80%) + 1% citric acid + evaporator + water dilution | Postharvest. Wounded oranges (3 times 2 × 2 mm φ and deep) + 20 μL pomegranate peel extract (12 g/L) + Inoculation (20 μL of a | P. digitatum) | + 1% citric acid + drying | Enhanced defense pathways (antibiotic biosynthesis) | [71] | ||||||
Fresh whole F&V (pre- and postharvest) | Guava | Drier (60 °C, 72 h) Particle size 0.420 mm Bhagwa cv |
1:10 solid–liquid ratio (80% EtOH) + evaporation | Postharvest. Chitosan (1% chitosan in glacial acetic 1% + 0.75% glycerol) and alginate solution (2% alginate + 10% glycerol + 2% calcium chloride) with 1% pomegranate peel extract |
Preserved quality for 20 d under refrigeration | [72 | Ion gelation | Chitosan gel (1%):gelatin 2:1 | F-TPC, DPPH | [40] | |||
] | |||||||||||||
Capsicum | Drier (60 °C, 72 h) Particle size 0.420 mm Bhagwa cv |
1:10 solid–liquid ratio (80% EtOH) + evaporation | Postharvest. Chitosan (1% chitosan in glacial acetic 1% + 0.75% glycerol) and alginate solution (2% alginate + 10% glycerol + 2% calcium chloride) with 1% pomegranate peel extract |
Inhibition of microbial growth. Preserved sensory quality. Extension of shelf life up to 25 d at 10 °C |
[73] | Spirulina | TPC, DPPH | ||||||
Pear | Drier (60 °C, 72 h) Particle size 0.420 mm Bhagwa cv | [17] | |||||||||||
Microalgae | EA | [41] | |||||||||||
Chitosan + others: Dialdehyde guar gum Gelatin-based materials |
F-TPC, DPPH | [42] |
1:10 solid–liquid ratio (80% EtOH) + evaporation | ||||||||||
Postharvest. | ||||||||||
Chitosan (1% chitosan in glacial acetic 1% + 0.75% glycerol) and alginate solution (2% alginate + 10% glycerol + 2% calcium chloride) with 2% pomegranate peel extract | ||||||||||
Lowered the cell wall degrading enzymes activity (firmness preservation) | ||||||||||
[ | ||||||||||
74 | ||||||||||
] | ||||||||||
Fresh-cut/Minimally processed F&V | ||||||||||
Fruit salad: nectarine and | ||||||||||
pineapple in cubes | ||||||||||
covered with | ||||||||||
fructose syrup | ||||||||||
Oven drier (38 °C, 48 h) | Particle size 500 mm Wonderful cv |
Powder | 2.5–5% ( | w | / | v | ) of pomegranate peel powder at the container bottom | Inhibition of mesophilic bacteria, total psychrotrophic microorganisms, yeasts, and lactic acid bacteria No negative effect on sensory characteristics |
[75] | |
Fresh-cut pear, apple and melon (plugs) |
Oven drier (40 °C) Particle size NA Mollar de Elche cv |
EtOH solvent (50 and 80%) + 1% citric acid + evaporator + water dilution | Inoculated plugs were dipped (10 min, 150 rpm) + dried (25 °C 30 min) | Reduction of | Listeria monocytogenes | [76] | ||||
Fresh-cut Golden apple wedges: thickness 30-mm and 30 g |
Drying and particle size information NA Dente di cavallo cv |
Pulsed UAE (10 min, <50 °C, 1:40, 26 kHz, 200 W, 40% A, 50% duty cycle) + encapsulation with pectin from citrus peel by spray drying | Enrichment with microencapsulates reconstituted in water 1:1 | Reduction of enzymatic browning. Color preservation | [77] | |||||
Beverages | Carrot juice | Oven drier (40 °C) Grounded in a colloid mill (more information NA) cv information NA |
High pressure-assisted extraction | 5 mg pomegranate peel extract per mL of carrot juice | Improvement of microbiological safety and AOX during storage. Color preservation | [78][79] | ||||
Beverages | Apple juice | Oven drier (55 °C, 12 h) Particle size and cv information NA |
Maceration extraction (1:50, 80% EtOH 1 h shaking) | Different% of pomegranate peel extract (0–2%) | Enhancing sensory quality and AOX. Low toxicity with 1% of pomegranate peel extract | [80] | ||||
Kiwi juice | Information NA | Commercial pomegranate extract (PureBulk, Roseburg) | Extract incorporation (180 μg/mL kiwi juice) + US bath (40 kHz, 180 W, 20 °C, 10–30 min) | US and pomegranate extract combined treatment: higher reductions on yeast and molds | [81] | |||||
Red wine | Green decoction: Boiled in water 60 min (1:40) Freeze-drying of the extract Wonderful cv |
Powder | Purification to obtain the tannins. 8 analyzed tannins (1 g L | −1 | wine solution) | Increase of protein stability Increase of color stability Reduction of sulfites |
[82] | |||
Symbiotic drink powder |
Hot oven (40 °C, 48 h) Particle size Kitchen-miller (more information NA) cv information NA |
Ethanolic extract (80%; 1:15) + evaporator + Freeze-drier | Formulation: beetroot peel extract powder (3%), pomegranate peel extract powder (1%), grape pomace extract powder (1.5%), quince seed gum (0.5%), stevia (4%), mint (0.1%) and water (89.9%). Pasteurization: 72 °C, 90 s | Maintenance of | L. casei | viability of the recommended level of 10 | −7 | CFU/g | [83] |