Food Biophysics最新文献

This study investigated the bitterness, structure, physicochemical properties and functional properties of peanut protein hydrolysate (PPH) debittered using β-CD and 2-butanol. The sensory properties of debittered PPH were characterized using sensory evaluation combined with electronic tongue and colorimetric analysis. High-performance size exclusion chromatography (HPSEC) and Fourier transform infrared (FTIR) spectroscopy characterized the structures of debittered PPH. Surface hydrophobicity, components of amino acids, and DPPH and ABTS radical scavenging capacities characterized the functional and physicochemical properties of debittered PPH. Bitterness of PPHF-4 with combined treatment of β-CD and 2-butanol was negligible with bitterness score (0.24) and almost unchanged color. Moreover, PPHF-4 retained a high level of umami with the electronic tongue umami response value (12.95). Surface hydrophobicity and amino acid analyses showed that PPHF-4 had the lowest surface hydrophobicity (8.36) and hydrophobic amino acids (202.62 mg/g) content among PPHs debittered. HPSEC analysis showed that compared to untreated PPH, protein hydrolysates less than 5.57 kDa in PPHF-4 were obviously reduced and less than 1.68 kDa were completely removed. The DPPH and ABTS radical scavenging IC50 of PPHF-4 was 0.67 and 0.40 mg/mL, which was decreased but still had a high level of antioxidant properties compared to PPH (0.44 and 0.34 mg/mL).

This study proposes efficient valorization of red pitahaya (Hylocereus sp.) peels by separating and purifying their structural and bioactive fractions to produce bioactive films through a multi-product cascade biorefinery approach. The process begins with the extraction of a betalain-rich extract (BET), followed by the separation of pectin (PEC), and finally, the production of cellulose nanofibers (CNF) from the remaining residue. The entire cascade process resulted in a successful utilization of 79.5% of the pitahaya peel. All fractions obtained were integrated into PEC-based films reinforced with CNF in the following proportions 5, 15, 30 and 45% CNF. The films were subsequently subjected to characterization in terms of their physical, chemical and mechanical properties. The optimal mechanical reinforcement effect was observed in films with 45% CNF, which exhibited an increased tensile strength of 20.47 MPa compared to 100% PEC, and higher thermal stability. Therefore, the ratio of 45% CNF was selected for the addition of the bioactive fraction, which comprised 5, 10, 15, 20, 30, 40 and 50% BET. In general, all bioactive films exhibited a compact and uniform structure. Films with higher percentages of BET showed a decrease in water vapor barrier properties (50-70% increase in water vapor permeability), probably due to the hydrophilic nature of BET. Additionally, the inclusion of BET resulted in enhanced wettability, as evidenced by a reduction in water contact angles (36.36º). The UV light blocking capacity increased (57% increase) while transparency decreased (43-50%) with the addition of BET.

Supercooling has numerous applications in the bio-preservation and food cold chain. This study investigated the effects of oscillating magnetic fields at different intensity levels on the preservation of cherries during supercooling. The magnetic field frequency was 50 Hz, and by applying the magnetic field of 0.1 mT level and mT level intensity, the experiment demonstrated that the magnetic field of mT level could better maintain the degree of supercooling of cherries, and realized 24 h supercooling storage at − 4 ℃. The supercooled samples exhibited food quality comparable to that of the fresh samples, with weight loss in the supercooled samples reduced by 73.2% in comparison to the control group. The mechanism of the effect of different level of magnetic energy density on cherry supercooling is explored from the macroscopic point of view of thermodynamic and the microscopic point of view of hydrogen bonding of water molecules. The oscillating magnetic field makes the Gibbs free energy of water molecules as a whole rise, which leads to a larger energy barrier required for crystallization. In addition, the magnetic field inhibits crystallization by weakening the hydrogen bonding within the water molecule clusters so that the water molecule cluster size does not reach the critical radius. To a certain extent the higher the magnetic energy density, about less prone to freezing under the same supercooling conditions, providing a reference for the future determination of the lowest magnetic energy density for different fruits, and helping to reduce the energy consumption of this technology.

In this study, carbon dots (CDs) were synthesized from Pleurotus ostreatus liquid culture and incorporated into polyvinyl alcohol (PVA) and chitosan (Chi) nanofibers, fabricated via the electroblowing technique to create an active packaging material. TEM analysis confirmed that the synthesized CDs possessed uniform size and morphology, while UV-Vis spectroscopy validated their optical properties. SEM imaging revealed that the electroblown nanofibers had a smooth surface morphology and uniform distribution of CDs within the PVA-Chi matrix. The nanofibers also exhibited enhanced thermal stability, as determined by thermogravimetric analysis (TGA). The developed CD-PVA-Chi nanofiber packaging was applied to oyster mushrooms, where it significantly reduced weight loss by over 50%, inhibited microbial growth by approximately 60%, and preserved 80% of the mushrooms’ firmness over a 6-day storage period compared to control packaging. The cytotoxicity tests confirmed that the packaging material was non-toxic, making it safe for food contact applications. This study demonstrates that the CD-PVA-Chi nanofiber packaging is a promising, eco-friendly alternative to conventional packaging materials, with potential for extending the shelf life of perishable foods through its bioactive properties and scalability for industrial production.

Cassava ranks as the 2nd most important staple food in Uganda. Several climate-smart cassava varieties have been developed but remain nutrient deficient. This study evaluated the impact of adding house cricket powder on cassava’s sensory, functional, and nutritional quality behaviour. Using design expert software (version 13) and sensory analysis techniques, the study screened and selected four cassava–cricket composites based on two cassava varieties (Narocass 1 and Magana) containing between 8.36% and 10.52% house cricket powder. These composites exhibited significantly lower scores (P < 0.05) for colour, aroma, aftertaste, and overall acceptability, although they remained within sensory acceptable limits, i.e., 5–7 on a 9-point hedonic scale. Cricket powder incorporation significantly increased the protein content from 1.05-1.11% to 6.46–6.81% (P < 0.001), fat content from 0.71-0.74% to 2.30–2.77% (P < 0.001), and protein digestibility from 83-84% to 88–94% (P < 0.001). The functional properties were statistically significantly (P < 0.05) influenced, however, there were not any significant changes in the sensory properties (taste, texture, flavour, mouth-feel, etc.) such as taste and mouthfeel that the significant changes in functional properties would influence. The pasting properties were not generally affected. Hence,  nutritionally richer cassava–cricket powder composites can substitute the food functions of plain cassava flour. The sensory quality of house cricket powder should be improved through refining techniques known to positively influence the sensory properties of cereal and tuber flours to which it is normally added as an ingredient.

This research work characterized and screened local rice varieties in order to select the most suitable variety for production of ready-to-eat breakfast meals through extrusion cooking. Eight improved FARO 61-67 paddy rice varieties were milled, characterised and screened for extrusion properties. The milling characteristics, axial dimensional, physical, physicochemical, functional and cooking properties of the varieties were studied. The yield for brown rice ranged from 78.16-79.91% while head brown rice yield ranged from 23.82-75.61%. The bran yield after milling for 60 s ranged from 1.98-7.22%, while degree of milling ranged from 2.52-9.04. Length, width, and thickness for all varieties ranged from 6.21- 6.91 mm, 2.02-2.46 mm, and 1.55-1.82 mm, respectively. Length-breadth ratio, aspect ratio and kernel volume of milled rice ranged between 2.59-3.33, 0.30-0.39 and 10.72-15.97 mm³, respectively. The thousand kernel weight has range of 16.55-20.66 g, while bulk density ranged from 0.567-0.652 kgm³. Gelatinization temperature has three categories of high alkaline digestion value 6-7 (55-69 ℃), intermediate 4-5 (70-74 ℃) and low 2-3 (75-79 ℃). Cooking time was from 12.67-30.67 min while the gel consistency ranged from 33.22-37.99 mm. Total starch and amylose concentration ranged from 66.83-82.43%, and 22.21-25.96, respectively. Water absorption capacity ranged from 5.61-6.71, and length-wise expansion ratio, breadth-wise expansion ratio, and cooked length-breadth ratio ranged from 1.23-1.47, 1.38-1.50 and 2.43-2.66. Results of physical, physicochemical l, functional, cooking, and expansion characteristics of milled rice show FARO 64 variety has optimum extrusion properties. It is therefore considered the most suitable for use in rice extrusion process.

This study aimed to investigate and compare the viscoelastic synergism of xanthan gum (XG) and guar gum (GG) mixtures at different XG/GG mixing ratios (25/75, 50/50, and 75/25) in both aqueous and gum arabic-based emulsion systems. A total concentration of XG and GG was fixed at 1.0 wt.%. All mixtures exhibited pseudoplastic flow behavior. In the aqueous system, XG-GG mixtures exhibited higher consistency index (K) and apparent viscosity at 50 s⁻¹ (η_a,50) values compared to individual gums. Their relative K and η_a,50 values were higher than 1, indicating a synergistic interaction between the polymers. Conversely, in the emulsion system, the relative K and η_a,50 values were lower than 1. The XG50/GG50 mixture exhibited the lowest value, indicating no synergism. Both individual gums in the systems displayed nearly time-independent flow behavior, whereas all mixtures exhibited thixotropic behavior. Notably, a larger thixotropic area was observed in the XG50/GG50 and XG75/GG25 mixtures in the aqueous system compared to their counterparts in the emulsion system. In the aqueous system, the elastic modulus (G') of mixtures was higher than that of individual gums. The XG25/GG75 mixture exhibited higher relative G' and lower tan δ values than other mixtures. A similar trend was observed in the emulsion system, but the tan δ value of the mixtures in the aqueous system was lower than that in the emulsion system. These findings demonstrate that XG and GG exhibit different rheological synergies in aqueous and emulsion systems.

Sorghum (Sorghum bicolour L. Moench), as the world’s fifth-largest cereal, possesses characteristics such as reducing cholesterol, anti-inflammatory, and antioxidant properties. However, sorghum-based food products suffer from drawbacks such as hardness, cooking challenges, and suboptimal texture. Lactobacillus plantarum, a beneficial bacterium, has the capacity to ferment sorghum, enhancing its palatability and flavor. This study aimed to evaluate alterations in dietary fiber, protein, and starch resulting from L. plantarum fermentation of sorghum, alongside analyzing the flavor profile of the fermented sorghum grains using HS-GC-MS technology. The findings indicated that upon reaching saturation water absorption capacity, sorghum fermented by L. plantarum (3 × 10⁶ CFU/mL, 36 h and 30 °C) enhanced the structural integrity of dietary fiber, protein, and starch, while the elevation of compounds such as ketones, alcohols, and free amino acids contributed to the improved aroma profile of sorghum grains. This research provides a theoretical foundation for enhancing the physicochemical structure and flavor of sorghum.

Attaining an appropriate color is a pivotal factor in achieving a desirable appearance for pea-based products. Although the color of lutein is vibrant, its stability during thermal processing remains a significant challenge that has yet to be overcome. A comprehensive understanding of the interactions between pea protein isolate (PPI) and lutein, as well as their influence on lutein retention and the solution behavior of PPI itself, is crucial for the development of pea protein-based products with optimized color. Currently, PPI provided a pronounced protective effect against the thermal degradation of lutein, primarily by influencing the retention rate, overall color variation, and total antioxidant capacity of lutein. Fluorescence spectroscopy revealed static quenching with strong affinity between PPI and lutein. The surface hydrophobicity of PPI after binding lutein decreased significantly (p < 0.05), while the secondary structure of PPI remained stable without notable relaxation or unfolding. Notably, lutein exists in both dispersed and aggregated forms, while the resulting lutein–PPI complex manifested as stable spherical nanoparticles. Polydispersity index and Z-average diameter measurements reveal that the lutein–PPI complex is more homogeneous and stable than PPI alone. In summary, compared to previous references, the present study fundamentally enhanced understanding of the underlying mechanisms involved in the interaction of PPI with lutein, thereby providing valuable insights for the development of novel plant-derived protein products with improved color stability.

This study investigated the effectiveness of ozonised mist and protective film (low-density polyethylene - LDPE) in preserving red peppers during storage. Ozonised mist was applied at 20.10 mg L-¹ and 2.0 L min-¹ for 5, 10 and 15 min, with and without protective film, and compared with untreated controls and chlorine treatment. Stored for 21 days at 25 °C and 60% relative humidity, peppers treated with ozonised mist showed significant reductions in total molds and yeasts counts, with the 15-minute treatment achieving reductions of 4.00 logs for molds and 4.34 logs for yeast, surpassing the chlorine treatment. The protective film effectively minimised weight loss and maintained the commercial appearance of the bell peppers. Importantly, the combination of ozonised mist and protective film did not significantly affect the physico-chemical quality of the bell peppers. These results suggest that ozonised mist and protective film are effective in reducing post-harvest losses of bell peppers, with practical benefits for the storage sector.