More than 10 million tons of textile waste are disposed through landfill every year in North America. The disposal of textile waste via landfill or incineration causes environmental problems and represents a waste of useful resources. In this work, we explored the possibility to directly extract cellulose nanocrystals (CNCs) from untreated textile waste through two methods, namely sulfuric acid hydrolysis and three-step oxidization. CNCs with cellulose I_β crystalline structure and rod-like shape were successfully obtained. The aspect ratios of CNCs prepared from acid hydrolysis and oxidization were 10.00 ± 3.39 and 17.10 ± 12.85, respectively. Their application as reinforcing agent of soybean protein isolate (SPI) film was evaluated. With the addition of 20% CNCs, the composite film maintained the high transparency, while their water vapor barrier property, tensile strength, and Young’s modulus were significantly improved. This research demonstrates a promising approach to recycle textile waste, and more value-added applications based on the derived CNCs could be expected.

Gelation, as an important functional property of soy protein isolate (SPI), can be improved by some green technologies in food manufacturing, including ultrasound, ultrahigh pressure and microwave treatments. This work investigated the effect of an alkaline solubilisation step in SPI extraction combined with sonication on protein properties. The TGase-induced gel of the modified SPI was prepared to explore the effect of ultrasound on gel properties, including structures, strength, water-holding capacity and rheological properties. Additionally, the differences between traditional ultrasound modification of SPI and current modification methods were analyzed. The results showed that the ultrasonication-assisted extraction method could result in a significant increase in extraction rate from 24.68% to 42.25%. Moreover, ultrasound-assisted modification of SPI gels induced with transglutaminase (TGase) exhibited significant improvement in mechanical properties, such as texture, water-holding capacity and rheological properties, In particular, SPI extracted at 400 W ultrasound intensity for 180 s showed the best overall performance in terms of gel properties. Our method efficiently uniformizes gel structure, enhancing mechanical properties compared to conventional ultrasound methods, which reduced energy consumption and costs. These findings provide insights into the production of high-gelation SPI in food manufacturing.

Composite films based on chitosan (CS) incorporating Galla chinensis extract (GCNE) at different CS/GCNE weight ratios, which are both biodegradable and multifunctional, were fabricated using the solution-casting method. The FTIR analyses indicated that a good interaction was presented among the GCNE and CS through an intermolecular hydrogen bond. The incorporation of the GCNE improved the films’ elongation at break, UV-light blocking, and decreased the moisture regain (from 16.68% to 10.69%) and water absorption (from 80.65% to 54.74%). Moreover, the CS/GCNE films exhibited a strong antioxidant activity (from 57.11% to 70.37% of DPPH and from 35.53% to 46.73% of ABTS scavenging activities) mainly due to the high content of phenolic compounds in the incorporated GCNE. The CS/GCNE film-forming solution coatings demonstrated their effectiveness in preserving the quality of postharvest mangoes, specifically by minimizing the change in the firmness, weight loss, titratable acidity, and total phenolic and ascorbic acids. These findings suggest that the multifunctional composite films possess a high application potential to preserve postharvest fruits.

In this study, soy protein isolate (SPI) films incorporating quercetin-grafted dialdehyde starch (DAS-QR) and DAS/QR, respectively, were developed. The structural, physical, and functional properties of the composite films were determined. The results suggested that DAS-QR and DAS/QR formed hydrogen bonding with the SPI matrix, which improved the structural properties of the films. The light-blocking capacity, thermal stability, hydrophobicity, tensile strength, elongation at break, and antioxidant and antibacterial abilities of SPI films were improved by DAS-QR and DAS/QR. Notably, SPI films incorporated with DAS-QR exhibited better performance than those with DAS/QR in terms of antioxidant (SPI/DAS-QR: 79.8% of DPPH and 62.1% of ABTS scavenging activity; SPI/DAS/QR: 71.4% of DPPH and 56.0% of ABTS scavenging activity) and antibacterial abilities against S. aureus (inhibition rate: 92.7% for SPI/DAS-QR, 83.4% for SPI/DAS/QR). The composite coating film SPI/DAS-QR effectively maintained appearance quality, delayed the loss of weight and total soluble solids, postponed malondialdehyde accumulation, and decreased peroxidase activity and microbial contamination in fresh-cut potatoes. These good performances highlight SPI/DAS-QR as a promising active packaging material for fresh-cut product preservation.