Food Biophysics最新文献

Traditional squid products often exhibit a firm texture, which adversely affecting their palatability. This study investigated the potential of ultrasound pretreatment and sous-vide cooking as alternatives to the conventional sodium tripolyphosphate pretreatment and high-temperature cooking methods, aiming to better preserve the color, tenderness, flavor, and overall sensory attributes of squid products. Results showed that treating squid with ultrasound at 200 W and 25 kHz for 15 min yielded tenderness comparable to that obtained from soaking in a 1% sodium tripolyphosphate solution for 2 h. After ultrasound treatment, the hardness of the squid initially decreased and then increased as sous-vide cooking time extended. The squid exhibited the lowest hardness and optimal color when cooked at 70 °C for 20 min. Compared to traditional high-temperature cooking, sous-vide cooking retained higher free amino acids content, which allowed more formation of umami and sweet-tasting amino acids. The radar plots from electronic nose detection also indicated that sous-vide process presented a more pronounced flavor profile. Therefore, the combination of ultrasound pretreatment and sous-vide cooking significantly enhanced the edible quality and flavor characteristics of squid, demonstrating substantial potential to replace traditional squid processing methods.

Chitosan nanoparticles loaded with tea tree essential oil (TTO-CHNPs) were fabricated and the effects of chitosan molecular weight (MW) (50, 200, and 500 kDa) on the physicochemical properties and biological activities of TTO-CHNPs were investigated. TTO was successfully encapsulated into chitosan nanoparticles with encapsulation efficiency (EE) ranging from 74.15 to 80.94%. TTO encapsulation significantly improved the antioxidant and antimicrobial activities of TTO-CHNPs. The chitosan MW significantly affected the antioxidant and antimicrobial activities of TTO-CHNPs and the preservation effect for mini-cucumbers coated with TTO-CHNPs. Among TTO-CHNPs with different MW of chitosan, those prepared using low MW of chitosan (TTO-LCHNPs) exhibited the highest EE of TTO, the greatest antibacterial activity against Staphylococcus aureus and antifungal activity against Botrytis cinerea in vitro, and the highest reduction in disease incidence and severity of B. cinerea inoculated mini-cucumbers. TTO-LCHNPs coating presented the best preservation effect on mini-cucumbers, extending their shelf life by 9 days.

This study presents a novel multifunctional hydrogel synthesized by crosslinking Chlorella protein using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/n-hydroxysuccinimide, aimed at extending the shelf life of perishable fruits like cherries. Structural, rheological, and scanning electron microscopy analyses revealed that Chlorella protein hydrogels (CPH) possess excellent solid-like properties and a stable porous structure. The water-holding capacity improved significantly from 67.11 ± 0.72% to 96.53 ± 0.61% with increasing CP concentration (10–22.5%, w/v). Additionally, CPH decomposition temperatures were ~ 150 °C (5% weight loss), demonstrating good thermal stability. Due to the ionization of -COOH and -NH₂ groups, the CPH showed excellent pH sensitivity, with low dissolution rates in acidic environments (64.97%) and significantly higher rates in alkaline environments (448.50%). Furthermore, the CPH inhibited the penetration of Staphylococcus aureus and Escherichia coli, and exhibited good free radical scavenging abilities against DPPH (74.50%) and ABTS^•+ (97.92%). In cherries preservation tests, CPH extended preservation time to 15 days compared to 5 days in the control group, effectively inhibiting decay, suggesting CPH is a promising choice for multifunctional fruit preservation.

Graphical abstract

Protein-polyphenol conjugates, formed through chemical modifications, can alter the structure of proteins, thereby enhancing their functional properties and enabling the development of novel ingredients for diverse applications. Despite this potential, the covalent conjugation of ovalbumin (OVA) with ferulic acid (FA) and the determination of their optimal binding ratios have not been previously studied. To address this gap, we investigated the formation of OVA-FA conjugates using an alkaline method and identified an optimal ratio of 0.9 g of FA per g of OVA. The resulting conjugates displayed substantial alterations in the secondary and tertiary structures of OVA, increased hydrophobicity, and a higher molar mass. These structural modifications significantly improved the solubility, emulsification capacity, and foam-forming ability of OVA, while also enhancing its antioxidant activity compared to the unmodified protein. These findings demonstrate the potential of OVA-FA conjugates as multifunctional emulsifiers with antioxidant properties, broadening their applications in the food and nutraceutical industries.

Mercury (Hg) and arsenic (As) are highly toxic metal(loid)s, and the consumption of food (particularly rice and seafood) represents a significant pathway for human exposure to these elements. Dietary habits, such as the intake of herbal tea and soup, may profoundly influence this exposure, which can be assessed through bioaccessibility. This study investigated the effects of various herbal tea ingredients on the bioaccessibility of Hg and As. Our findings revealed that certain ingredients significantly reduced Hg bioaccessibility from food, with reductions ranging from 30.1 to 90.2%; chrysanthemum exhibited the highest efficacy, followed closely by honeysuckle. Notably, inorganic mercury (iHg) bioaccessibility was more susceptible to reduction than methylmercury (MeHg) when co-digested with herbal tea ingredients. Only glabrous greenbrier and abrus herb effectively reduced bioaccessible As from food, with bioaccessibility decreasing in the following order: inorganic As (iAs) > dimethylarsinic acid (DMA) > arsenobetaine (AsB). These findings suggest that specific ingredients can mitigate human exposure to Hg and As, highlighting the necessity for further research into their chemical properties and functional implications.

Betacyanin and betaxanthin are well-known secondary metabolites of betalains in red beet (Beta vulgaris), which contribute to the natural red–purple and yellow–orange color. Various analytical techniques, such as chromatography and nuclear magnetic resonance spectroscopy, are currently available and have been performed to quantify the betalain content. However, evidence shows that these methods remain arguable because of their disadvantages, such as being time-consuming, labor-intensive, destructive, and producing chemical wastes. This study aimed to encompass the spectroscopic techniques through near-infrared (NIR) and mid-infrared (MIR) spectroscopy coupled with partial least squares regression PLSR analysis for rapid and nondestructive measurements of red beet powder betalain content. This study evaluated full and effective wavebands to determine the optimum model for predicting betacyanin and betaxanthin in red beet powder. The finding of effective wavebands was done by employing a variable important in projection (VIP) technique. This study demonstrated that betacyanin and betaxanthin were optimally predicted using NIR, with an R² of 0.92 and a RMSEP of 0.07 mg/g for betacyanin and R² of 0.83 with RMSEP of 0.04 mg/g for betaxanthin. This optimum model was achieved through the effective wavebands via VIP method. Thus, the proposed model is applicable for predicting betalain content in red beet powder nondestructively.

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.