Table 5 Comparative overview of the performance of potato peel–derived cellulose nanofiber composites with those reported for starch films reinforced with cellulose from other sources.
From: Starch-based biocomposites reinforced with cellulose nanofibers from potato peel byproducts
Cellulose source | Extraction method | Cellulose properties | Effects on starch-based films | Reference | ||
|---|---|---|---|---|---|---|
Starch matrix | Cellulose content (% w/w) | Main findings | ||||
Potato peel | Alkaline treatment (KOH), delignification (NaClO₂, pH 5, 70 °C), acid hydrolysis (H₂SO₄, 1%), followed by mechanical refining | Cellulose nanofivers with average diameter of 64.73 ± 14.50 nm | Potato starch | 5, 10, 15 | ↑ Young’s modulus (1.31 → 14.45 MPa); ↑ tensile strength (21.1 → 55.2 MPa); ↓ WVP; opacity ↑ at 15% | This work |
Sugarcane bagasse | Unbleached pulp (UB): Alkaline treatment (NaOH)+ mechanical fibrillation Bleached pulp (B): bleaching (H₂O₂/NaOH) + mechanical fibrillation | UB-cellulose nanofibers: residual lignin 1.27%, cellulose 80.5%; B-cellulose nanofibers: cellulose 90.7%, lignin 0.83% | Cassava starch | 10, 20, 30, 50 | ↑ Tensile strength (control: 4.6 MPa → up to 15.7 MPa UB-CNF 20–50%); ↑ Young’s modulus (up to 100%); ↑ Elongation at break with B-CNF (~ 100%); WVP lowest at 50% CNF (2.05–2.18 g·mm/kPa·day·m²); contact angle > 90° (hydrophobic), except control and UB-CNF 30/50; strong starch–CNF adhesion (SEM) | |
Betel leaf petioles/CNC | Sulfuric acid hydrolysis (64% H₂SO₄, 45 °C, 9 h) + ultrasonication | Rod-like cellulose nanocrystals, length 54–347 nm, diameter 2.82–10.17 nm, Cristallinity Index = 67.6% | Potato starch–guar gum | 1 | ↑ Tensile strength (8.29 → 11.22 MPa, + 35%); ↑ elongation at break (8.6 → 24.9%, + 188%); ↓ water solubility (23.2 → 13%); ↓ WVP (1.89 → 1.36 × 10⁻⁷ g·mm/m²·Pa·s); opacity ↑ | |
Taro peel | Alkaline treatment (KOH), delignification (NaClO₂, pH 5, 70 °C), acid hydrolysis (H₂SO₄, 1%), followed by mechanical refining | Cellulose nanofibers 15–25 nm diameter, ~ 80 nm length; | Taro starch | 5, 10, 15 | ↑ tensile strength and modulus, ↓ WVP (5–10%); ↑ permeability at 15% | |
Sugarcane bagasse | Alkaline pretreatment (NaOH, 4–12% wt/vol) + bleaching + mechanical fibrillation | Type I cellulose structure; nanometric diameter; crystallinity index ↑ with higher NaOH concentration; smaller diameter at higher alkali concentration | Modified starch (MS) | 1 | Diameter and crystallinity index of cellulose nanofibers were governed by NaOH concentration. ↑ mechanical strength; ↑ resistance to moisture absorption; ↓ transparency | |
Wheat straw | Alkali (NaOH), NaClO + acetic acid | Larger particle size (2.5–6 μm); cellulose ~ 89.6% | Sweet potato starch | 1 | ↓ Tensile strength (–9.8%); ↓ WVP (7.1%); improved UV resistance; smoother film surface | |
Sugarcane bagasse | Narrower particle size (1.5–3.4 μm); cellulose ~ 92.9% | ↑ Tensile strength (67% → 3.75 MPa); ↑ contact angle (68.4°); ↓ WVP (9.4%) | ||||
Cornstalk | Larger particle size (3.7–6.7 μm); cellulose ~ 90.1% | Highest thermal stability (325 °C); ↓ tensile strength (–16%); ↓ WVP (11.3%) | ||||
Bamboo | Bimodal distribution (0.13–0.27 & 1.1–2.8 μm); cellulose ~ 90.7% | ↓ Tensile strength (–25.9%); ↓ WVP (12.7%); ↑ UV barrier; smoother surface | ||||
Rice bran | Larger particle size (4.1–8.2 μm); cellulose ~ 86.8% | ↓ Tensile strength (–36.6%); ↑ WVP; yellowish color (higher b* value) | ||||
Cotton | Sulfuric acid hydrolysis (64% H₂SO₄, 45 °C, 25 min) + ultrasonication | Rod-like cellulose nanocrystals, avg. length 68 nm, width 8 nm; tendency to aggregate into micron-sized clusters | Corn starch | 5, 10, 20, 50 | ↑ Tensile strength (e.g., 11.1 → 27.1 MPa with 30% sorbitol + CNC 50%); ↓ elongation at break; ↓ WVP up to 60% at 50% CNC; slight ↓ transparency (higher haze); reinforcement strongly dependent on plasticizer type and concentration | |
