Table 2.
Effect of HPP on the physical properties of the biopolymer-based films.
| Film Matrix | Processing Conditions | Food Simulant | Barrier Property (WVP/OP) | Mechanical Property | Thermal Properties | Additive Migration | R | |
|---|---|---|---|---|---|---|---|---|
| Tensile Strength (TS) | Elongation at Break (EAB) | |||||||
| PLA, PEG, and CIN | 200, 250, and 300 MPa at 23 °C for 10 min | Chicken | OTR of untreated PLA-PEG-CIN 4% film was 725.63 ± 20.00 (ml/m2 day) significantly increased to 771.58 ± 18.50 (ml/m2 day) when subjected to 300 MPa/23 °C /10 min | TS of untreated PLA-PEG-CIN 4% film was 10.08 ± 0.14 MPa and showed no significant variation when subjected to 300 MPa/23 °C /10 min and TS value was 9.82 ± 0.90 MPa | EAB of untreated PLA-PEG-CIN 4% film was 100.55 ± 4.51% and showed no significant variation when subjected to 300 MPa/23 °C /10 min and the EAB value was 104.64 ± 5.59% | Tg of untreated PLA-PEG-CIN 4% film was 1.44 ± 0.01 °C and showed no significant variation when subjected to 3300 MPa/23 °C /10 min; Tm significantly increased from 136.97 ± 0.14 to 137.59 ± 0.42 °C but Hm showed no significant variation; Tc and % χc significantly decreased from 62.20 ± 0.91 to 60.79 ± 0.78 °C and 11.03 ± 0.39 to 9.86 ± 0.25%, respectively when subjected to 300 MPa/23 °C /10 min | -- | [59] |
| PLASiOx/PLA | 500 MPa at 50 °C for 15 min | Olive oil, Distilled water |
WVP of the untreated film increased by 2170.0% when in contact with water and 71.0% when in contact with olive oil. OTR of the untreated film enhanced by 31.0% when in contact with olive oil and the increment was too large when in contact with distilled water making the film unsuitable for packaging | TS of untreated PLASiOx-PLA was 101.1 ± 4.6 MPa significantly decreased to 75.4 ± 2.5 MPa for HPP–oil simulant and 79.2 ± 4.4 MPa for HPP–aqueous simulant | EAB of untreated PLASiOx-PLA was 4.1 ± 0.2% significantly decreased to 2.8 ± 0.1% for HPP–oil simulant and 2.9 ± 0.2% for HPP–aqueous simulant | Tm of untreated PLASiOx-PLA was 148.3 °C significantly increased to 148.6 °C for HPP-oil simulant and but decreased to 146.0 °C for HPP in contact with aqueous simulant; ΔHm of the untreated film decreased from 11.9 to 6.5 J/g after HPP in contact with oil simulant, but increased to 17.7 J/g after HPP with aqueous simulant; similarly, ΔHc of the untreated film decreased from 9.7 to 4.9 J/g after HPP in contact with oil simulant, but increased to 15.9 J/g after HPP with aqueous simulant; % χc of the untreated film 2.4% decreased to 1.7 and 1.9% for HPP with oil simulant and HPP with aqueous simulant, respectively when subjected to 500 MPa/50 °C/15 min | -- | [12] |
| PLA | 200, 500 and 700 MPa for 5 min at 90 °C (sterilization) and 28.5 °C (pasteurization) | tap water, solid carrots, carrot puree and carrot juice | WVP of untreated PLA film at 25 and 30 °C was 1.47 × 10−8 and 1.40 × 10−8 g cm/(cm2 atm s) decreased to 1.22 × 10−8 and 1.14 × 10−8 g cm/(cm2 atm s), respectively when subjected to PLA pasteurized (carrot juice) at 700 MPa. But HP sterilization caused unacceptable embrittlement and opacification of the PLA film and thus WVP was not performed | -- | -- | Two Tg of untreated film 55.8 (associated with the amorphous external layers) and 62.45 °C (inner core of the film) showed no significant variation for pasteurization of tap water at 700 MPa and Tg was 55.6 and 62.25 °C, but Tg after sterilization of tap water at 700 MPa increased to 58.85 and 63.7 °C. Similarly, χc of the untreated film was 25.55% showed no significant variation for pasteurization of tap water at 700 MPa and 28.5 °C and it was 25.15% but increased to 29.4% after sterilization of tap water at 700 MPa and 90 °C | -- | [54] |
| PLA and Ag (1, 5, 10, 15, and 20 wt%) | 100, 200, 300, and 400 MPa for 10, 20, and 30 min | Isooctane | HPP (400 MPa for 20 min) increased the WVP of the nanocomposite film as the migration time increased and WVP was higher for the nanocomposite containing a higher content of Ag nanoparticles | HPP (400 MPa for 20 min) had no significant impact on TS of the composite film | HPP (400 MPa for 20 min) decreased the EAB with the increase in the migration time | HPP (400 MPa for 20 min) had no significant impact on Tm of the composite film; Tg of the composite films enhanced with the increase in the migration time but was independent of the nano-Ag content. Tc and χc increased as migration time and nano-Ag content increased | Migration Ag NPs enhanced with the increase in NPs concentration, pressure level, and migration time | [33] |
| PLA, polyethylene glycol (PEG), and GO nano-sheets (0, 1, and 2%) | 300, 450, and 600 MPa at 25–38 °C for 15 min | -- | WVP of untreated PLA-PEG-GO-2% was 1.05 ± 0.11 × 10−14 (kg m) (m² s Pa) increased to 1.30 ± 0.04 × 10−14, 1.57 ± 0.24 × 10−14, and 1.68 ± 0.21× 10−14 (kg m) (m² s Pa); similarly, OP of untreated PLA-PEG-GO-2% was 2.18 ± 0.12 × 10−18 (kg m) (m² s Pa) increased to 3.09 ± 0.20 × 10−18, 4.44 ± 0.10 × 10−18, and 6.54 ± 0.37 × 10−18 (kg m) (m² s Pa) when subjected to 300, 450, and 600 MPa, respectively | TS of untreated PLA-PEG-GO-2% was 50.80 ± 0.75 MPa decreased to 43.13 ± 6.64, 40.69 ± 0.77, and 40.14 ± 1.00 MPa when subjected to 300/450/600 MPa, respectively | EAB of untreated PLA-PEG-GO-2% was 25.31 ± 0.27% decreased to 20.32 ± 1.35, 17.98 ± 0.92, and 11.72 ± 1.35% when subjected to 300/450/600 MPa, respectively | Tg of the untreated PLA-PEG-GO-1% film 38.45 ± 0.89 °C, increased to 43.09 ± 0.39, 43.21 ± 0.97, and 49.35 ± 0.68 °C; Two Tm of untreated was film was 141.87 ± 0.89 and 149.68 ± 1.33 °C increased to 144.59 ± 1.22 and 150.40 ± 1.10, 141.66 ± 1.19 and 149.88 ± 0.87; 146.40 ± 1.24 and 150.29 ± 1.41 °C; Tc of the control film was 103.30 ± 0.58 °C increased to 108.45 ± 0.66, 110.10 ± 0.99, and 116.85 ± 0.98 °C; %χc of the untreated film was 26.42 ± 0.78% increased to 33.01 ± 1.13, 34.21 ± 1.20, and 35.76 ± 1.15% when subjected to 300/450/600 MPa, respectively | -- | [51] |
| Cellulose acetate (CA) | 200, 300 or 400 MPa for 5 or 10 min | -- | WVTR of untreated CA film was 232.56 ± 2.29 g.m−2. day−1 significantly decreased with the increase in pressure levels as follows: 205.57 ± 4.48 and 197.84 ± 1.86 g.m−2. day−1 when exposed to 200 MPa for 5 and 10 min, respectively; 192.35 ± 1.13, and 185.78 ± 1.77 g m−2 day−1 when exposed to 300 MPa for 5 and 10 min, respectively; 182.53 ± 0.68 and 177.36 ± 2.26 g.m−2. day−1 when exposed to 400 MPa for 5 and 10 min, respectively | TS of untreated CA film was 40.9 ± 1.2 MPa significantly decreased to 34.5 ± 1.5, and 34.9 ± 1.1 MPa when exposed to 200 MPa for 5 and 10 min, respectively; 28.9 ± 1.3 and 36.6 ± 1.3 MPa when exposed to 300 MPa for 5 and 10 min, respectively; 32.4 ± 0.7 and 32.6 ± 1.4 MPa when exposed to 400 MPa for 5 and 10 min, respectively | EAB of untreated CA film was 4.2 ± 0.1% significantly increased to 5.5 ± 0.3 and 5.5 ± 0.3% when exposed to 200 MPa for 5 and 10 min, respectively; 6.3 ± 0.4 and 5.3 ± 0.3% when exposed to 300 MPa for 5 and 10 min, respectively; 6.2 ± 0.3 and 5.8 ± 0.3% when exposed to 400 MPa for 5 and 10 min, respectively | Tg of untreated CA film was 203 °C, decreased to 197.25, and 195.33 °C when exposed to 200 MPa for 5 and 10 min, respectively; decreased to 196.88, and 196.08 °C when exposed to 300 MPa for 5 and 10 min, respectively; decreased to 196.95, and 196.95 °C when exposed to 400 MPa for 5 and 10 min, respectively. Similarly, Tm of untreated CA was 227.40 °C and showed minimal change in a narrow range between 227.66 to 226.59 °C when exposed to 400 to 200 MPa for 10 min | -- | [56] |
| Co-extruded PLA | 300, 450, and 600 MPa for 15 min at 25–38 °C | -- | WVP of the untreated film (25-μm) was 2.05 ± 0.43) × 10−14 kg·m/ (m²·s·Pa) showed no significant variation in the WVP and the values were (2.02 ± 0.23) × 10−14, (1.95 ± 0.11) × 10−14, and (2.13 ± 0.10) × 10−14 kg·m/ (m²·s·Pa) when subjected to 300, 450, and 600 MPa; but WVP of the 75-μm showed no significant variation when subjected to HPP. OP of the untreated film (25-μm) was (6.55 ± 0.41) × 10−18 [kg·m/ (m²·s·Pa)] and significantly increased to (9.67 ± 0.84) × 10−18 [kg·m/ (m²·s·Pa)] when subjected to 600 MPa and 75-μm showed no significant variation of the OP when subjected to HPP |
-- | -- | Tm of both the untreated film was 166.87 °C and HPP (600 MPa) showed no significant variation. Similarly, fusion enthalpies (ΔE) of untreated 25 and the 75-μm film was 35.10 and 34.41 J/g values changed insignificantly (34.37–38.13 J/g) after the HPP except for 25-μm film with 600 MPa (31.43 J/g) | -- | [57] |
| PLA and TiO2 nanoparticles | 300 MPa for 10 min | water | WVP of the untreated PLA loaded with 0, 10, and 20% TiO2 nanoparticles film was 5.28 ± 0.08, 4.78 ± 0.26, and 5.33 ± 0.17 (g·m)/(m2·s·Pa) significantly decreased to 4.81 + 0.17, 4.12 + 0.15, and 4.97 + 0.18 (g·m)/(m2·s·Pa), respectively 300 MPa for 10 min | TS of untreated film containing 0, 10, and 20% TiO2 nanoparticles film was 30.71 ± 1.18, 34.89 ± 1.19, and 32.45 ± 1.42 MPa showed no significant variation and values were 31.32 ± 0.94, 36.08 ± 1.25, and 33.72 ± 1.78 MPa, respectively when subjected to 300 MPa for 10 min | EAB of untreated film containing 0, 10, and 20% TiO2 nanoparticles film was 83.7 ± 5.21, 72.1 ± 6.81, and 75.2 ± 5.12% decreased to 79.1 ± 5.86, 64.2 ± 4.62, and 72.1 ± 5.67%, respectively when subjected to 300 MPa for 10 min | Tg, Tc, Tm, and χc of untreated PLA film were 45.2 °C, 112.2 °C, 168.2 °C, and 14.5% changes insignificantly to 45.8 °C, 108.3 °C, 172.1 °C, and 18.3% when subjected to 300 MPa for 10 min; Similarly, Tg, Tc, Tm, and χc of untreated PLA/ TiO2-10% film was 49.7 °C, 105.2 °C, 168.4 °C, 18.7% changes to 48.8 °C, 102.5 °C, 168.5 °C, 22.4%, respectively when subjected to 300 MPa for 10 min | -- | [55] |
| PLA and TiO2 nanoparticles | 300 MPa for 10 min | Ethanol Solution | WVP of HPP of PLA 4.81 ± 0.17 (g·m)/(m2·s·Pa) (on 0 day) showed no significant variation over the period of 30 day, 5.55 ± 0.15 (g·m)/(m2·s·Pa) (on 30th day); similarly for PLA- TiO2-20%, WVP 4.97 ± 0.18 (g·m)/(m2·s·Pa) (on 0 day) showed no significant variation over the period of 30 days, 5.61 ± 0.13(g·m)/ (m2·s·Pa).Similarly, OP of PLA film 4.02 ± 0.18 [(cm3/(24 h m2)].(cm/bar) (on 0 day) showed no significant variation over the period of 30 day, 4.77 ± 0.15 (cm3/(24 h.m2)].(cm/bar); similarly for PLA- TiO2-20%, OP 3.98 ± 0.21 (cm3/(24 h m2)].(cm/bar) (on 0 days) showed no significant variation over the period of 30 days, 4.81 ± 0.20 (cm3/(24 h m2)].(cm/bar) | -- | -- | Tg, and Tc, of PLA film after HPP at 300 MPa/10 min on 0 day was 46.0 °C, and 119.2 °C, increased to 59.9 °C, and 121.5 °C, respectively on the 30th day; Tm on 0 day was 171.3 °C insignificantly deceased to 169.4 °C on 30th day; χc on 0 day was 20.5% decreased to 15.2% on 30th day; similarly, thermal properties after HP treatment on 0 to 30th day for PLA- TiO2-20% was as follows: Tg increased from 48.8 to 62.5 °C; Tm value increased from 108.6 to 119.0 °C, Tc value 170.0 °C insignificantly changed to 170.5 °C; χc value decreased from 25.4% to 19.4% | Under HPP, migration of TiO2 NPs increased with the increase in the concentration of NPs, and migration time | [60] |
| PLA/Uvitex OB® | 800 MPa at 20, and 90 °C for 5 min | Distilled water 3% acetic acid, 15% ethanol, Olive oil |
-- | -- | -- | -- | The migration of Uvitex OB® due to HPP was too low to be detected | [61] |
| Co-extruded PLA | 450, and 600 at 26–39 °C for 15 min | water | WVP of the untreated film (1.55 ± 0.12) × 10−14 (kg·m/[m2·s·Pa]) significantly increased to (1.59 ± 0.10) × 10−14 and (1.62 ± 0.13) × 10−14 (kg·m/[m2·s·Pa]) when subjected to 450 and 600 MP, respectively; OP of the untreated film (6.58 ± 0.33) × 10−18 (kg·m/[m2·s·Pa]) significantly increased to (8.67 ± 0.26) × 10−18 and (9.16 ± 0.44) × 10−18 (kg·m/[m2·s·Pa]) when subjected to 450 and 600 MP, respectively | TS of the untreated film 36.40 ± 1.11 MPa significantly decreased to 33.04 ± 0.45 and 31.02 ±1.97 MPa when subjected to 450 and 600 MPa, respectively | EAB of the untreated film 31.92 ± 2.81% significantly decreased to 21.58 ± 2.76 and 17.54 ± 1.39% when subjected to 450 and 600 MPa, respectively | Tg and Tm of the untreated film do not show significant variation with the increase in the pressure level, however, Tc of the untreated film 118.08 ± 0.56 °C significantly increased to 120.34 ± 0.59 °C when subjected to 450 MPa but decreased to 117.33 ± 0.62 MPa when treated with 600 MPa; χc of the untreated film 26.35 ± 0.21% decreased to 25.80 ± 0.22 and 19.98 ± 0.19% when subjected to 450 and 600 MP, respectively | -- | [58] |
| PLA (Biophan 121 of 40 μm) | 800 MPa, 40, and 115 °C for 5 min | Distilled water, 3% acetic acid, 15% ethanol, and Olive oil |
-- | -- | -- | -- | HP pasteurization at 800 MPa, 40 °C for 5 min, significantly decreased the absorption of aroma compounds, and the losses of ethyl hexanoate were up to 17%; But HP sterilization at 800 MPa, 115 °C for 5 min, significantly increased the absorption of aroma compounds and the losses of ethyl hexanoate were up to 60% | [62] |
| Wheat gluten, montmorillonite (MMT), Uvitex OB® | 800 MPa at 20, 90 °C for 5 min | Distilled water, 3% acetic acid, 15% ethanol, and Olive oil |
-- | -- | -- | -- | HP pasteurization (800 MPa at 20 °C for 5 min) had no impact on migration behavior, but HP sterilization (800 MPa at 20 °C for 5 min) melted the film | [63] |
OTR: Oxygen transport rate, OP: Oxygen permeability; WVTR: Water vapor transport rate; WVP: Water vapor permeability; TS: Tensile strength; EAB: Elongation at break; Tg: Glass transition temperature; Tm: Melting temperature; Tc: Crystallization temperature; χc: % Crystallization, PEG: Polyethylene Glycol, CIN: Cinnamon oil, GO: Graphene Oxide.