Food Biophysics最新文献

Silver gelled chitosan (CS-Ag) films with improved mechanical traits were prepared via a simple technique, which comprised freezing the CS solution, and then pouring the AgNO₃ solution onto it. This resulted in the creation of uniform and mechanically stable CS-Ag films due to the slow diffusion of AgNO₃ into the frozen solid CS. The films were characterized via scan electron microscopy (SEM) and energy-dispersive X-ray (EDX). Their antimicrobial and mechanical traits were inspected. The tensile strength (TS) of the 1.5% (w/w) AgNO₃ processed CS-Ag films reached 22.42 ± 0.89 MPa and its elongation at break was 33.01 ± 2.67%. The water vapor transmission rate (WVTR) of this film was also inspected and it was 167.77 g/m²day. This value was reduced to 146.95 and 120.68 g/m²day, after the inclusion of sunflower seed oil (SFO) within the CS-Ag films at 5% and 8% (w/w), respectively, and this reflected the increased water resistance of the SFO-CS-Ag films. The inclusion of SFO at concentration ≥ 5% (w/w) also increased the films antimicrobial traits when Aspergillus and Rhizopus species were inspected. On the other hand, the TS of the SFO-CS-Ag films was reduced to 15.13 ± 1.61 MPa and 10.17 ± 0.77 MPa for the 5% and 8% SFO, respectively. Nonetheless, these values were still within 8.3–31.4 MPa TS range of the frequently utilized packaging material; low-density polyethylene. Thus, the 5% and 8% (w/w) SFO-CS-Ag films were utilized to package white bread. The 8% (w/w) SFO-CS-Ag film efficiently preserved bread as no fungal growth observed for 10 storage days.

Real-time quality information on chicken freshness can be obtained using pH-sensing packaging. Real-time quality information on chicken freshness is crucial for ensuring food safety, as chicken is a highly perishable animal product prone to rapid spoilage. This study aimed to develop an pH-sensing film using red pitaya (red dragon) peel (RPP) to monitor chicken freshness. RPP containing 22% pectin, showed promise in forming a film and contains betacyanin, which is commonly used in pH-sensing films. The addition of konjac glucomannan (KGM) as a co-biopolymer to RPP films enhanced their physical and mechanical properties. We utilised Central Composite Design (CCD) within the Response Surface Methodology (RSM) framework, with varying concentrations of KGM from 0.80% to 2.20% and RPP from 0.40% to 1.10%. The optimal treatment involved using 1.74 g of KGM and 0.85 g of RPP powder. The variation in KGM and RPP powder concentrations resulted in the following outcomes: film thickness ranged from 0.11 to 0.15 mm, tensile strength from 2.4 to 7.03 MPa, elongation ranged from 22.50% to 49.17%, opacity from 3.68 to 6.50 mm⁻¹, water solubility from 82.70% to 97.82%, lightness from 61.20 to 74.70, redness from 12.90 to 30.80, and yellowness from 0.20 to 2.80. The incorporation of KGM as a co-biopolymer demonstrably enhanced the physical and mechanical properties of RPP powder-based pH-sensing films. The results highlight RPP/KGM-based films as a novel, sustainable option for intelligent packaging, while promoting red pitaya peel waste as a renewable source of pectin and natural colorants. The freshness of chicken breast is indicated by the color change in RPP/KGM coatings, caused by betacyanin degradation from purple-red to yellow (betalamic acid).

Graphical Abstract

Schematic illustration of the production of konjac and red pitaya peel pH-sensing films

In this study, the preparation of hydrogel beads through electrostatic interactions between Ι-carrageenan (IC) and ε-polylysine (ε-PL) using a dropwise method is reported. As the concentration of ε-PL increased, the degree of swelling of the hydrogel beads decreased. FTIR and XRD analyses revealed shifts in the absorption peaks, suggesting the formation of hydrogen bonding, electrostatic interactions in the hydrogel beads. TGA showed that the mass loss of the IC/ε-PL hydrogel beads was significantly lower compared to that of pure ε-PL. These results indicate that the IC component has a protective stabilizing effect on the hydrogel structure. ε-PL concentration of 2% yielded the highest encapsulation efficiency of curcumin (Cur) in the hydrogel beads. In vitro release studies showed that the hydrogel beads sustained the release of Cur and the release kinetics followed the first-order and Hixson-Crowell models. Collectively, these findings demonstrate that these hydrogel beads have the potential to be effective carriers of hydrophobic substances.

Graphical Abstract

Transportation logistics are crucial for moving harvested produce from the field to the table. However, mechanical damage incurred during transport considerably contributes to mushroom spoilage during storage. This study revealed the results of spraying CaCl₂ on the appearance, reactive oxygen species (ROS), nutritional content, cell wall composition, and degradative enzymes of mushrooms in storage after a simulated vibration. The results indicated that exogenous CaCl₂ treatment effectively delayed mushroom browning and softening during storage following vibration stress and inhibited ROS accumulation by modulating antioxidant enzyme activities, and mitigated membrane lipid peroxidation. Furthermore, CaCl₂ inhibited cell wall-degrading enzyme activities to delay cell wall degradation. Moreover, CaCl₂ treatment enhanced the cinnamate 4-hydroxylase (C4H) and 4-coumarate: CoA ligase (4CL) activities and promoted total phenols and flavonoid synthesis, contributing to the recovery of mechanical damage caused by vibration. Additionally, TEM revealed that the cells in the control samples at the vibration sampling point were loosely organized, exhibiting marginally thicker cell walls in contrast to the CaCl₂-treated cells. This study highlights the potential of spraying CaCl₂ to alleviate mechanical damage to mushrooms during transportation stress and offered a viable method for enhancing mushroom transportation and storage.

To explore a non-destructive identification method for distinguishing Chinese chive (Allium tuberosum Rottl. ex Spreng) seeds from their adulterant, scallion (Allium fistulosum L.) seeds, machine vision and electronic nose technologies were employed. Principal component analysis (PCA), linear discriminant analysis (LDA), artificial neural networks (ANNs), and random forest (RF) algorithms were utilized to perform discriminant analyses based on the acquired data. The comprehensive results indicated that the image-based discrimination method, which integrates PCA with LDA and RF, demonstrated excellent accuracy using the obtained image information. Notably, the RF model established using odor information from the electronic nose achieved the lowest error rates of 0.98% for the training set and 0.70% for the test set. Overall, it was found effective and feasible to apply pattern recognition technology, combining both image and odor information, for the discrimination between Chinese chive seeds and their adulterated scallion seeds.

This study aimed to fabricate and characterize fibers based on germinated and non-germinated wheat starches incorporated with titanium dioxide (TiO₂). Fibers made from germinated wheat starch (20% and 30%, w/v) and non-germinated wheat starch (20% and 30%, w/v), encapsulated with TiO₂ at concentrations of 0%, 3%, and 5% (w/v), were fabricated by electrospinning. The polymeric solutions were evaluated for electrical conductivity and rheology. Fibers were characterized by morphology, size distribution, thermogravimetric analysis, and infrared spectra. The electrical conductivity of the polymeric solutions increased with TiO₂ concentration. Rheological parameters showed non-Newtonian pseudoplastic behavior. The fibers exhibited homogeneous and cylindrical morphology. TiO₂ addition reduced the diameter of the fibers compared to the fibers without this compound and altered their thermal stability. Infrared spectra indicated interactions between both starches and TiO₂. The results demonstrate the feasibility of fabrication fibers from germinated and non-germinated wheat starches with similar amylose content (30.2% and 29.5%, respectively) incorporating TiO₂, as they exhibited comparable behavior. This application could enhance the value of germinated wheat starch, which typically has low economic value. Further research is needed to explore these starch fibers for active food packaging applications as ethylene absorbers.

This study aims to optimize and assess the efficacy of chitosan (Ch)/starch/aloe vera oil (AV) films as active packaging for beef fillet preservation using Response Surface Methodology (RSM). The optimum formulation was reached at 1.4% w/v Ch, 1.8% w/v starch, and 0.5% v/v AV, employing nine responses: moisture (17.17%), water vapor permeability (0.92 g/m²·h), tensile strength (1596.33 N/m²), elongation (12.84%), antioxidant activity (56.68%), and antibacterial activity against Escherichia coli (9.55 mm inhibition zone), Salmonella typhi (8.39 mm), Staphylococcus aureus (11.09 mm), and Staphylococcus epidermidis (11.46 mm). The optimized Ch/starch/AV films exhibited enhanced functional properties, including improved water barrier, physical and mechanical strength, and heightened antimicrobial and antioxidant activities. To elucidate the antibacterial mechanism, active compounds from AV were molecularly docked into the active site of the FtsA enzyme. The beef fillets were stored at 4 °C for 12 days, and the Ch/starch/AV films significantly improved the shelf-life of beef fillets compared to Ch/starch films during the storage period. Additionally, sensory tests indicated favorable consumer acceptance and environmental assessments demonstrated reduced emission residue, waste disposal impact, toxicity potential, affordability, and social acceptability. Overall, this study provides valuable insights into creating sustainable and efficient packaging materials for high-value meat products, encouraging reduced food waste and environmental impact.

Hydrocolloids are commonly used as additives to suppress retrogradation of starch-based foods. However, the impact of hydrocolloids on starch retrogradation differs for starches with different components. In this study, the pasting and retrogradation behaviours of tapioca (amylose/amylopectin ratio is 0.226) and potato starches (amylose/amylopectin ratio is 0.483) with different hydrocolloids (Arabic gum, carrageenan, guar gum, and xanthan gum) were thoroughly investigated using ultraviolet-visible spectroscopy, rapid viscometer analysis, differential scanning calorimetry, Fourier-transform infrared spectroscopy, and scanning electron microscopy. The addition of hydrocolloids reduced the setback and R_1047/1022 values of tapioca starch, suggesting that both short- and long-term retrogradation of tapioca starch were inhibited. In addition, swelling capacity, freeze-thaw stability, and scanning electron microscopy analyses indicated that tapioca starch interacted with hydrocolloid molecules, forming a denser network structure, which enhanced the water retention and improved the freeze-thaw stability of tapioca starch gel. Compared with tapioca starch, potato starch with hydrocolloids exhibited a more relaxed network structure with large voids, and the hydrocolloids exhibited a weaker inhibitory effect on the retrogradation of potato starch owing to its high amylose/amylopectin ratio. These results provide a theoretical basis for the application of hydrocolloid additives to enhance the anti-retrogradation properties of starch-based foods with different amylose/amylopectin ratios.

In this study, the effect of ultrasonic treatment on sweet potato protein (SPP) was discussed. The structural and functional characteristics of SPP treated with different ultrasonic amplitudes (20–50%) were analyzed. The findings of the study suggested that the protein size and zeta potential decreased from 1711.00 nm and − 17.87 mV to 447.03 nm and − 42.52 mV (30% amplitude). Appropriate ultrasonic amplitude (30%) can significantly increase protein solubility (72.54%→79.89%) and free sulfhydryl group content (34.65→41.09 µmol/g). Surface hydrophobicity increased significantly by 34.71% at 40% amplitude. The structure of SPP was unfolded and intermolecular interactions were reduced by ultrasonic treatment, affecting the secondary structure and tertiary conformation of SPP, according to Fourier transform infrared spectroscopy, fluorescence spectroscopy and ultraviolet spectroscopy. The proportion of α-helix and random coil increased, while the proportion of β-sheet decreased. When the ultrasonic amplitude reached 30%, the emulsifying activity and stability of SPP were increased by 85.76% and 180.82%, respectively. Moreover, the microstructure and rheological characteristics of the SPP emulsion were investigated in order to assess the impact of ultrasonic treatment on the stability of the emulsion. The results demonstrated that the emulsion produced by the SPP that had undergone ultrasonically treatment had significantly improved emulsion stability due to the increased surface charge, improved network structure, and smaller and more uniform protein size. The study provides a theoretical foundation for promoting the use of SPP in food processing.

Preservation of vegetables by drying, freezing, and pickling often leads to alterations in their nutritional characteristics. To promote preservation, this research explores the design and examines the effects of Radio Frequency (RF) and starch-based nanocomposite (SISN) packaging on the quality of habanero peppers during refrigerated storage. RF device was designed and applied to treat peppers at frequencies of 15.5 MHz, 20.22 MHz, and 27.12 MHz for 2, 4, and 6 min. The frequency was varied using a microcontroller MOSFET equipped with a voltage-controlled oscillator (VCO), phase-locked loop (PLL), and a frequency synthesizer. The treated samples were packaged with SISN films made of Irish potato starch and African star apple nanoparticles in three thicknesses (15.6 μm, 21.22 μm, 30.4 μm) and stored for 30 days at 6 °C. Microbial and nutritional properties, including lycopene, carotene, total phenolic compounds, and antioxidant activity, were examined. The optimal process parameters were identified using the Box-Behnken Design methodology. Results showed thicker films had better barrier properties due to lower permeance values, while thinner films exhibited higher thermal stability due to their tightly packed structure. Samples treated at 27.12 MHz for 6 min showed superior nutritional properties and the lowest microbial counts (fungi: 2.9 × 10² CFU/g, bacteria: 3.5 × 10³ CFU/g) at p < 0.05. At optimal conditions (23.73 Hz, 2 min, 28.14 μm film), microbial counts were reduced (fungi: 3.67 × 10² CFU/g, bacteria: 4.76 × 10³ CFU/g) compared to the control. Under these conditions, lycopene (6.31 mg/kg), β-carotene (3.68 mg/kg), and vitamin C (87.61 mg/100 g) levels increased, while antioxidant activity slightly decreased to 147.47 µmol TE/100 g. Thus, applying RF treatment before SISN packaging effectively preserved the quality of habanero peppers and is recommended for vegetables preservation.