Food Biophysics最新文献

The encapsulation of essential oil (EO) from indigenous plants presents a promising strategy to improve its stability, controlled release, functional efficacy, and application in food systems. This study compared the effectiveness of four conventional wall materials (gum Arabic, GA; whey protein concentrate, WPC; sodium alginate, SA and chitosan) and two novel wall materials (Opuntia ficus-indica, L. cladodes mucilage and waste), in encapsulating EO from Helichrysum splendidum, a South African indigenous plant using the freeze-drying technique. The resulting powders were characterized based on their physical, technofunctional, chemical, and biological properties. The results revealed significant variations across the wall materials. Mucilage showed the highest encapsulation efficiency (62.54%) and favorable packing properties (highest bulk and tapped densities), WPC has the smallest particle size (0.22 µm) and PDI (0.23), superior DPPH radical scavenging activity (IC₅₀ = 3.6 mg/mL), good thermal stability (maximum degradation at 305 °C), and the highest cumulative in vitro EO release (65.60%), while chitosan exhibited the strongest antifungal activity (LD₁₀₀ = 1.25 mg/mL). Structural analysis using SEM, XRD, and FTIR confirmed successful encapsulation and revealed differences in morphology, crystallinity, and functional group interactions, while the in vitro release of EO from the wall materials was successfully modelled. The principal component analysis (PCA) revealed that no single wall material exhibited uniformly superior characteristics across all parameters suggesting that synergistic combinations of WPC and chitosan may enhance the microencapsulation of H. splendidum EO and its application in active food packaging.

In the present study, buckwheat (BS) and rice starches (RS) were crosslinked with 6% and 12% sodium trimetaphosphate (STMP), and their gels (at 5, 10, and 15% concentration) were analyzed for steady and dynamic rheology, creep recovery, and textural behavior. Rheological analysis revealed that crosslinked starches exhibited lower shear stress and viscosity than native starches due to reduced retrogradation, with BS showing higher viscosity than RS due to its higher amylose content. However, dynamic rheology demonstrated that crosslinking improved the viscoelastic properties, increasing elasticity and structural integrity. In addition, textural properties of starch gels generally improved after prolonging the retrogradation time (48 h). Based on the rheological and textural properties, starch aerogels were prepared using native and crosslinked RS and BS at 10 and 15% concentrations. Bulk density ranged from 0.121 g/cm³ (12% STMP BS at 10% concentration) to 0.332 g/cm³ (native BS at 15% concentration), while porosity varied between 76.84% and 88.62%. Native RS aerogels exhibited higher porosity and water absorption (upto 790%) due to lower retrogradation, whereas BS aerogels showed greater thermal stability and compressive strength (upto 17.46 N). BET surface area ranged from 5.17 to 11.46 m²/g and thermal conductivity was observed as low as 0.0615 W/m·K.

Non-thermal processing technologies exhibit superior potential compared with traditional thermal methods for retaining nutrients, preserving natural properties of food, and lowering energy use. In this study, processing characteristics of Ananas comosus (L.) Merr. (AC) treated with high-voltage pulsed electric field (PEF) and ultrasound-PEF combined pretreatment were investigated, including drying properties, active substances, physicochemical properties, structure, and calcium ion binding ability. After non-thermal treatment, drying time of AC was significantly shortened, and the IC₈₀ value for drying of AC prepared by ultrasound-PEF combined pretreatment at an electric field intensity of 1.5 kV/cm (ACUP1.5) was the shortest, which was 7.95 ± 0.27 h. The active substances of AC underwent notable changes, and the polyphenol content in AC treated with PEF at an electric field intensity of 1.0 kV/cm (ACP1) dried samples reached the highest magnitude, which was 3491.23 ± 50.31 µg/g. Meanwhile, ultrasound-PEF combined pretreatment altered AC structure, which effectively enhanced WI value, in vitro antioxidant capacity, physical properties, and rehydration characteristics of AC. In the study on calcium ion binding ability of AC, ACUP1.5 showed the strongest binding capacity (0.44 ± 0.06 mmol/g) in a 0.125 mol/L calcium ion solution; secondary drying time of the complex was significantly shortened, while secondary rehydration characteristics of the complex exhibited a decrease. These results provide a theoretical basis for facilitating the application of non-thermal processing technologies in the food industry and processing of AC specialty foods and functional foods.

Graphical Abstract

This study establishes a method for tracing the origin of Pacific oysters based on transmission mid-infrared spectroscopy (TMIRS) combined with multivariate statistical techniques. The acquired mid-infrared (MIR) spectral data were preprocessed by absorbance transformation (AbT), automatic baseline correction (AutoBC), etc. Then, principal component analysis (PCA) was performed in the wavenumber ranges of 3800 –2300 cm⁻¹ and 1900 − 800 cm⁻¹. Taking the principal component scores and their combinations as input variables, four modeling methods including Fisher Discriminant Analysis (FDA), Partial Least Squares Discriminant Analysis (PLS-DA) Orthogonal Partial Least Squares-Discriminant Analysis (OPLS-DA) and BP Neural Network (BPNN) were used to conduct the origin tracing research. The results indicate that AbT is the optimal preprocessing method. The accuracy rates of the training sets for all four models are exceeding 98%, and the accuracy rates of the test sets are higher than 97%, all four models are applicable to the origin traceability of pacific oysters. The combination of TMIRS and multivariate statistical methods provides a convenient and efficient tracing technique, offering technical support for safeguarding consumers’ rights and interests and promoting the sustainable development of the oyster industry.

Overcoming the strong sensitivity of starch film to water is essential for its wide application. This study investigated the incorporation of octenyl succinate starch (OS) as a homologous hydrophobic modifier into hydroxypropyl distarch phosphate/poly(butylene adipate-co-terephthalate) (PBAT) blown films. OS established hydrogen bonding interactions between with hydroxypropyl distarch phosphate, competitive binding with glycerol, PBAT terminal groups, and water molecules. OS addition (≤ 5% w/w) improved matrix compatibility and interfacial uniformity, whereas excessive OS induced phase separation and microstructural defects, causing brittleness and reduced moisture barrier. Increasing OS content enhanced the films’ surface hydrophobicity from 55.8° to 97.2°, and reduced non-bound water due to shielding of hydroxyl groups. Although the films with OS exhibited improved water resistance and surface hydrophobicity, but excessive OS negatively impacted structural and barrier performance, highlighting the need for formulation balance in high-throughput processing. Overall, this study provides a reasonable design idea and reference for the improvement of hydrophobicity of such starch/PBAT films.

In the present study, pearl millet varieties (ProAgro 9444 and HHB 67) with different amylose contents were used to synthesize starch nanocrystals (SNCs) through acid hydrolysis. The obtained SNCs were incorporated as nanofillers into starch-based nanocomposite films at varying concentrations (0–20%). The films were characterized for their mechanical, barrier, morphological, structural, thermal, and biodegradable properties. Control starch films, prepared without SNCs, exhibited tensile strengths of 4.31 MPa (ProAgro 9444) and 2.96 MPa (HHB 67). Maximum tensile strength (TS) and minimum water vapor permeability (WVP) were achieved at 7.5% SNC loading for ProAgro 9444 (12.56 MPa, 2.45 × 10⁻¹⁰ gPa⁻¹s⁻¹m⁻¹) and at 10% for HHB 67 (12.12 MPa, 2.31 × 10⁻¹⁰ gPa⁻¹s⁻¹m⁻¹) (p < 0.05). Elongation at break decreased in nanocomposite films compared to controls, dropping from 53.12% to 17.88% for ProAgro 9444 films and from 62.77% to 20.34% for HHB 67 films. Morphological analysis revealed no phase separation in nanocomposites up to 7.5% and 10% SNC incorporation, respectively. The nanocomposites exhibited A- and Vh-type crystallographic patterns with higher crystallinity than control films. Thermogravimetric analysis indicated enhanced thermal stability in SNC-containing nanocomposites. All films biodegraded in a three-stage process, with ProAgro 9444 nanocomposites showing the highest weight loss (97.39%), followed by HHB 67 nanocomposites (94.34%). Overall, SNCs and amylose content demonstrated a synergistic effect in enhancing the functional properties of starch-based nanocomposite films.

Drying and moisture sorption in bananas present ongoing challenges, especially in terms of providing accurate storage recommendations and minimizing drying time. This study aimed to investigate the moisture sorption isotherms and drying kinetics of bananas. Moisture sorption was analyzed using the static gravimetric method with saturated solutions, covering a water activity range of 0.14–0.88, and at incubation temperatures of 30, 40, and 50 °C. The models used in this study included Peleg, Oswin, Halsey, Brunauer–Emmett–Teller (BET), Guggenheim–Anderson–de Boer (GAB), and Courie. Statistical analysis showed that the Peleg model performed best. A comparison between the Peleg model and an Artificial Neural Network (ANN) revealed that the conventional Peleg model provided more accurate predictions. The Peleg model produced a sigmoid-shaped sorption curve. As temperature increased, the number of sorbed water monolayers, the sorption surface area, the percentage of bound water, and the monolayer moisture content all decreased. The thickness of the bound water monolayer and the pore radius ranged from 0.32 to 0.95 nm and 176.23–4981.34 nm, respectively. Field emission scanning electron microscopy (FESEM) revealed that the surfaces of dried bananas developed cracks, which facilitated a faster adsorption process. Energy dispersive spectroscopy (EDS) analysis showed that the surface of dried bananas was primarily composed of carbon (63%) and oxygen (35%). Higher temperatures accelerated the reduction in moisture content, with the average drying rate ranging from 0.12 to 0.15%d.b./min. The total color difference, volume of the visible object, and shrinkage were observed in the ranges of 45.92–48.49%, 40.26–47.54%, and 52.46–59.74%, respectively. The FTIR curve revealed distinct wavelengths for each type of bond. Based on the relationship between equilibrium moisture content (EMC) and water activity, dried bananas are recommended to have a safe moisture content of 14.94–16.85% (d.b.) during storage. Furthermore, the suggested drying time at temperatures between 40 and 60 °C ranges from 1800 to 3540 min.

Cocoa contains polyphenols that offer potential health benefits. However, the processing of cocoa beans often leads to a reduction in their polyphenol content. This study aimed to evaluate the antioxidant and methylxanthines profiles of chocolates made from cocoa beans fermented with specific yeast starter cultures: Pichia kudriavzevii (PK) (MH979681), Hanseniaspora thailandica (HT) (MH979675), and a combination of both (mix). Fermentation with HT or PK significantly influenced the process, producing less acidic beans, which impact the levels of catechin and epicatechin in the resulting chocolate. Additionally, chocolate made from beans fermented with HT or PK displayed higher concentrations of caffeine and theobromine, respectively. The highest caffeine level was found in HT-fermented chocolates, whereas PK-fermented chocolates showed the highest theobromine content compared to the control and Ghana chocolates. HT and PK are suggested as promising yeast starters for producing chocolates with enhanced methylxanthines profiles, offering potential for the development of functional and health-oriented chocolate products.

In order to analyze the formation mechanism and explore the potential applications of Canna starch and its derivatives (Canna Starch OSA Ester (CSOE)) and Canna Starch Phosphate Ester (CSPE)), the samples were subjected to an environment of iodine. The resulting complex was analyzed using small angle X-ray scattering and fluorescence (SAXS and XRF). The findings revealed that CSPE exhibited the highest binding capacity (5.19% at aw 0.15; 25.03% at aw 0.99). Interestingly, iodine tended to accumulate within the hilum rather than the periphery of the starch particles, resulting in smoother surfaces. Furthermore, it was observed that the process of octenylsuccinylation and phosphorylation caused a shift in the scattering peak towards higher values in the SAXS graphs, indicating a shorter lamellar repeat distance (CSPE, 9.52 nm; CSOE, 8.16 nm). These results have the potential to advance characterization techniques and contribute to the development of applications involving amylose-restrained materials.