Mechanical and thermal properties of microcrystalline cellulose-reinforced soy protein isolate–gelatin eco-friendly films

Abstract

Eco-friendly films containing soy protein isolate (SPI), gelatin, and microcrystalline cellulose (MCC) were made by casting. Effects of MCC content on mechanical and thermal properties of MCC-reinforced SPI-gelatin (MSG) films were studied. With the increasing of MCC content, thickness and tensile strength (TS) of MSG films increased, and the elongation at break (EB) decreased. MSG films containing 3.5% MCC (MSG3.5) had the limit values of the thickness, TS, and EB, which were 108%, 351%, and 27% of those of films without MCC, respectively. While all MSG films exhibited lower moisture content and total soluble matter compared to SPI-gelatin film. Film with 1.5% MCC (MSG1.5) had the minimum value of moisture content as 16.41%, and film with 2.5% MCC (MSG2.5) had the minimum value of total soluble matter as 24.87%. Scanning electron microscope photomicrographs showed that MCC dispersed well in the SPI-gelatin matrix, and the films had a relatively smooth surface. Blending of 2.5% MCC caused a rough and uneven surface, resulting in a more ductile failure of MSG2.5 films. Attenuated total reflectance-Fourier transform infrared spectroscopy revealed that there was no intermolecular association via chemical bonds between MCC and SPI-gelatin. Thermo-gravimetric analysis showed that the thermal degradation of MSG films initiated at higher and ended at lower temperature than the SPI-gelatin film. Date of differential scanning calorimetry scans indicated that MSG films had a smaller degree of crystallinity, which was also confirmed by test results of dynamic mechanical analyzer. Blending MCC with SPI-gelatin film has been successful in obtaining better mechanical and thermal properties as well as reduced moisture sensitivity. In addition, the films became more transparent, and transmittance was improved.

Gelatin-Based Antimicrobial Films Incorporating Pomegranate (Punica granatum L.) Seed Juice by-Product

“…These suggestions could be supported by previous studies in which the thermal stability of FG films was improved by the addition of ethanolic extracts from coconut husk [14], nano-SiO2 particles [12], cinnamon, clove and star anise [53]. Similar results were also reported for soy protein isolates and gelatin films reinforced with microcrystalline cellulose [56], where the thermal stability of films was improved by the addition of cellulose. Differential scanning calorimetry (DSC) thermal parameters obtained for FG/PSP films are shown in Table 4.…”

“…These suggestions could be supported by previous studies in which the thermal stability of FG films was improved by the addition of ethanolic extracts from coconut husk [14], nano-SiO 2 particles [12], cinnamon, clove and star anise [53]. Similar results were also reported for soy protein isolates and gelatin films reinforced with microcrystalline cellulose [56], where the thermal stability of films was improved by the addition of cellulose. of phenolic compounds with high antioxidant activity, in agreement with the TPC, DPPH, FRAP and ABTS results; b) the presence of xylan and cellulose as main polysaccharides in PSP resulting in a highly crystalline structure that could act as heat barrier by delaying the heat flow arising from an exterior source [55].…”

High-Performance Microcrystalline Cellulose/Soy Protein Isolate-Based Nanocomposite Film via Cu and Zn Nanoclusters Modification

“…With the addition of MCC, amide I and II of SPI-MCC film shifted to 1626 and 1537 cm -1 , respectively, indicating the films might expose more polar groups and increase the bindings between the peptide chains [27]. Meanwhile, it was observed that composite films modified with MCC exhibited a new peak at 1160 cm -1 , which was attributed to the bending mode of C-CH2-C, suggesting the unique bands of cellulose [28]. These results demonstrated that molecular hydrogen bonding might be formed between protein molecule chains and polar groups with the modification of MCC, which resulting in a cross-linked structure and improving mechanical properties of the composite films [29].…”

The Rape Pomace and Microcrystalline Cellulose Composites Made by Press Processing

“…The addition of MCC was from 2% to 8%. The variability of the additive resulted from the literature studies, where it was shown that a small amount of crystalline cellulose significantly increases the mechanical strength of the high protein films [20]. The samples prepared were mixed using the electric agitator CAT 30 at the speed of 300 rpm for 60 s. The moisture content of the material after mixing was 9% ± 0.2%.…”