Food Biophysics最新文献

Button mushroom (Agaricus bisporus) is a widely consumed edible mushroom, but its quality deteriorates rapidly after harvest. Therefore, the use of edible coatings with natural preservative compounds is essential for delaying microbial growth and maintaining mushroom quality. This study examined the effects of a nano-chitosan (NC) and aloe vera (AV) edible coating combined with tomato seed protein hydrolyzate (TPH) as a natural preservative on the chemical, microbial, and organoleptic properties of button mushrooms. TPH was prepared using the enzyme Alcalase. Five edible films containing NC, NC-AV, and varying concentrations of TPH (0%, 0.5%, 1%, 1.5%) were produced. The relationship between the concentration of TPH and the resulting physicochemical properties was investigated. The shelf lives of coated mushrooms were evaluated during 16 days of refrigerated storage (4 ± 1 °C). Results showed that TPH had high levels of protein (90.16%), hydrophobic amino acids (31.78%), and aromatic amino acids (11.74%). The produced films exhibited significant antioxidant and antimicrobial activities, with improvements observed at higher concentrations of TPH (P < 0.05). The interaction between the protein hydrolyzate film and the mushroom’s natural proteins may enhance nutrient retention and stability. Compared to uncoated mushrooms, the nanocomposite coatings significantly reduced physicochemical changes, quality degradation, and microbial spoilage. Increased concentrations of TPH further enhanced browning inhibition, free radical scavenging, and reduction of microbial spoilage (P < 0.05). Sensory evaluation indicated that the sample containing 1.5% TPH had the highest overall acceptance. The NC-AV composite coating containing TPH effectively extended the shelf life of button mushrooms by approximately 8 days.

In the present study, water-in-oil-in-water (W₁/O/W₂) emulsions were prepared from modified guinea starch nanoparticles, and the impact of Pickering stabilization was assessed. Three types of emulsion formulations were developed: conventional surfactant-stabilized, partially Pickering-stabilized, and solely Pickering particles-stabilized emulsions. These emulsions were characterized for their storage stability, droplet size distribution, zeta potential, microstructure, rheological properties, and thermal stability under low- and high-temperature loop cycles. The results showed that the surfactant-stabilized and partially Pickering-stabilized emulsions had excellent physical stability during storage of four weeks with full emulsified phase coverage. In contrast, solely Pickering particles-stabilized emulsions were stable for up to two weeks. The droplet size of all samples ranges from 152.30 nm to 627.30 nm, and no significant change were observed in zeta potential over 28 days. Optical microscopy revealed that the double emulsions formed three types of internal droplets, A type (single large internal droplet), B and C type (few and several small internal droplets) respectively. Confocal microscopy confirmed the formation of W₁/O/W₂ emulsions, with all the droplets appearing spherical. The inner water droplets in the surfactant-only stabilized emulsions were smaller and more evenly distributed compared to other emulsion systems. Power law indicated that solely particle-stabilized (S5) had highest flow behavior index (n) and lowest consistency index (k) values indicates that deformation of the droplets is more prominent. The storage modulus (G′) and loss modulus (G″) of all samples demonstrated frequency-dependent behavior, with G′ consistently higher than G″, indicating elastic-dominant behavior. The thermal stability test shows the structural changes was minimum in surfactant and partially Pickering stabilized emulsions in low and high temperature loop cycles. These findings suggest that Pickering stabilization of a double emulsion has the potential to be an effective carrier of nutrients or bioactive compounds in the food and pharmaceutical industries.

Structured emulsions are bi-phasic systems where the dispersed and continuous phases are organized into a specific structure using emulsifiers and structuring agents. This structure can enhance the stability and functionality of emulsions, making them suitable for various food applications. In this study, low-saturated (6-10.8% saturated fatty acids, SFA) structured emulsions (water-in-oil type, at water-to-oil ratios of 50:50, 60:40, 70:30) were prepared from corn oil at different levels of glycerol monopalmitate (GMP, 3, 4, 5%) as a commercial monoacylglycerol (MAG) and gelatin (1, 3, 5%). When GMP was used alone, a higher GMP level or lower water-to-oil ratio improved the textural parameters, as confirmed by texture profile analysis. The use of gelatin with GMP further enhanced the textural properties (p < 0.05). In terms of rheological properties, as the levels of GMP or gelatin increased, or the water-to-oil ratio decreased, the elastic (G’) and loss (G’’) moduli rose. All samples exhibited solid-like behavior (G’> G’’) at least up to 40 °C. The peak melting point of samples were recorded at 46.9–76.5 °C for samples prepared using GMP alone. When gelatin was used with GMP, peak melting point of samples rose significantly (from 51.2 to 55.6–78.4 °C) depending on gelatin concentration (p < 0.05). Emulsification using GMP alone reduced oxidative stability. However, when gelatin was used with GMP, the oxidative stability of the structured emulsions was comparable to the initial oil (p < 0.05). Therefore, the combination of gelatin and GMP allows the formulation of structured emulsions with enhanced textural and oxidative properties at lower oil and SFA content.

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.