Journal of Food Science最新文献

ABSTRACT

Cronobacter sakazakii, an opportunistic foodborne pathogen, primarily with the infections that can cause bacteremia, necrotizing enterocolitis, and neonatal meningitis. These pathogens are Gram-negative rods, motile with peritrichous flagella without spore-forming capability, can grow under aerobic and anaerobic conditions, and tolerance to acidic conditions and desiccations stress. Phenyllactic acid (PLA), a phenolic acid with broad-spectrum antibacterial activity, is a promising natural preservative. However, its effects on C. sakazakii biofilms remain unclear. This study evaluated the antibiofilm potential of PLA, a natural antimicrobial metabolite, against C. sakazakii and investigated its effects on cell membrane integrity. First, the minimum inhibitory concentration (MIC) of PLA was assessed at 4 mg/mL. The MIC (4 mg/mL) of PLA was observed to reduce C. sakazakii for planktonic cells and biofilm formation on food-contact surfaces (stainless steel, silicon rubber, and polyvinyl chloride) by about 3 log CFU/cm², respectively. PLA at 4 mg/mL significantly altered ALP activity, intracellular and extracellular ATP, suggested membrane disruption, cell integrity, and leakage of intracellular components. Fourier-transform infrared spectroscopy (FTIR) analysis provided extracellular polymeric substances composition. As confirmed by confocal laser scanning microscopy and scanning electron microscopy revealed disrupted biofilm architecture and altered cell morphology. Mechanistic analyses demonstrated that PLA exposure increased membrane permeability, indicated by elevated extracellular ATP and protein leakage, while intracellular ATP levels decreased. All things considered, these results clarify PLA's effectiveness against biofilm of C. sakazakii. These results demonstrate that PLA inhibits C. sakazakii biofilm formation primarily by disrupting membrane integrity, suggesting its potential as a natural antimicrobial strategy for controlling biofilms and supports the potential application of PLA as an effective antimicrobial agent in food industry to enhancing food safety.

High-moisture meat analogs (HMMAs) acquire their fibrous texture primarily during cooling in an extrusion die, yet practical guidance for selecting die cooling media temperatures is scarce. Understanding melt fracture behavior from nonfood polymer processing can be applied to a viscous food protein suspension to identify physical material transitions that recent work has shown govern HMMA structure formation and heat transfer. A pressurized (6 bar) parallel-plate rheometer operated at constant shear rate (2.5 Hz) and ramped cooling (−2.5°C min⁻¹) was used to measure the torque response of soy protein hydrated at two levels (50% and 60% w.b.). The shear stress response of the material decreased upon cooling and exhibited plateaus interpreted as slip regimes. We define T_critical (slip onset, upper bound) and T_freeze (maximum slip, lower bound) to demarcate a “texturization zone” where partial slip allows sustained deformation and fibrous alignment of the soy protein. Guided by these thresholds, we performed HMMA extrusion trials with a segmented cooling die, with the first section (of three) carrying heat transfer media at discrete levels between 100°C and 145°C, whereas the remaining sections were held at 36°C. Products extruded at 115–130°C (first-section media) showed visibly larger, more continuous fiber bundles and significantly higher anisotropy indices at higher moisture. In contrast, hardness was unaffected by the first-section temperature (p > 0.05) and was primarily influenced by moisture content. These findings demonstrate a rheology-to-process linkage, where maintaining product residence within the slip-bounded texturization zone by elevating the initial die-section temperature improves HMMA structural anisotropy.

Field heat and lignin accumulation significantly impact bamboo shoot quality. In this study, crushed-ice precooling was utilized for field heat removal, with different endpoint temperatures (0°C, 5°C, 10°C) evaluated against untreated controls during storage at 4°C. Results demonstrated that the treatment with a 5°C endpoint temperature (T2) optimally preserved quality with minimal lignification, outperforming the 0°C (T1), 10°C (T3), and the control (CK) treatments. The T2 treatment reduced respiratory rate by suppressing the accumulation of malondialdehyde (MDA), H₂O₂, and O₂⁻, and by inhibiting the activities of phenylalanine ammonia-lyase (PAL), peroxidase (POD), and polyphenol oxidase (PPO), while enhancing the activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), and catalase (CAT). This collectively slowed the lignification process. Additionally, the T2 treatment better maintained moisture content, soluble proteins, soluble sugars, flavonoids, and phenolics, thereby effectively delaying quality deterioration.

ABSTRACT

This is the first comprehensive study that investigates quince juice clarification using novel protein–polysaccharide fining agents (casein [CA], chitosan [CH], xanthan gum [XG]) and their combinations with optimized dose, temperature, and time conditions, compared against the conventional gelatin (GE) + kieselsol (KS) + bentonite (BE) combination, while also quantifying the discrete contribution of ultrasound to process performance and storage stability. Single-agent applications reduced turbidity but did not reach commercial clarity. By contrast, the full-dose current combination (0.50 g/L CA + 0.10 g/L XG + 0.75 g/L CH, 40°C) achieved 2.68 Nephelometric Turbidity Unit (NTU) at 210 min, whereas the conventional combination (0.05 g/L GE + 0.75 g/L KS + 0.75 g/L BE, 40°C) reached 2.38 NTU at 120 min. Ultrasound-assisted clarification (45 kHz, 5 min) initially increased turbidity due to cavitation but ultimately decreased to 6.79 NTU at 210 min, which was the lowest value. To further evaluate product quality and stability, clarified quince juices were characterized for compositional attributes (pH, titratable acidity, total soluble solids, and color), antioxidant properties (total phenolic compound, 2,2-diphenyl-1-picrylhydrazyl [DPPH], 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid diammonium salt [ABTS⁺], Ferric Reducing Antioxidant Power [FRAP]), and storage stability over 6 months at 4°C, including turbidity, browning index (BI), whiteness index, heat–cold stability, and pH value. Clarified samples consistently demonstrated superior performance relative to cloudy control, with lower turbidity and BI, higher whiteness stability, and more stable pH profiles throughout storage. Overall, the findings confirm that optimized combinations of current fining agents provide an effective alternative to conventional clarification, offering both scientific and industrial insights into clarifier selection, product quality, and long-term shelf life of clarified fruit juices.

This study aims to comparatively investigate the production of jam from Rheum ribes L., a plant known for its functional properties, using both conventional and ohmic heating methods, and to evaluate the effects of these methods on quality parameters. Ohmic heating was applied at three different voltage gradients (25, 30, and 35 V/cm) and compared with conventional heating. In both methods, jam samples were produced until they reached a total soluble solids (TSS) content of 66%, after which total phenolic content (TPC), antioxidant activity, ascorbic acid (vitamin C), hydroxymethylfurfural (HMF), and individual phenolic compounds were analyzed. According to the results, the highest TPC (488.37 mg gallic acid equivalent [GAE]/kg), antioxidant activity (595.6 mg ascorbic acid equivalent [AAE]/kg), and vitamin C content (23.6 ppm) were obtained at 35 V/cm. In contrast, the conventional method yielded significantly lower values for these parameters and a higher HMF content (29.9 ppm). Ohmic heating enabled a much shorter processing time, reducing energy consumption by approximately sixfold and contributing to better retention of nutritional components. Additionally, higher voltage gradients resulted in improved preservation of individual phenolic compounds (such as gallic acid, catechin, and rutin). The findings indicate that, compared to the conventional method, ohmic heating offers higher efficiency, better retention of bioactive compounds, and a more sustainable production approach due to its lower energy requirement.

The immune system plays a crucial role in protecting the body against infections, and its suppression can lead to severe complications during chemotherapy. Bee products are rich in bioactive phenolic compounds with antioxidant and immunomodulatory properties. This study aimed to characterize the phenolic composition of Moroccan honey, bee pollen, and propolis and to evaluate their potential, individually and in combination, to counteract CTX-induced immunosuppression in mice. Phenolic compounds were analyzed by HPLC-DAD, total phenolics, and flavonoids were quantified using colorimetric assays, and antioxidant activity was determined by DPPH, RP, and TAC methods. In vivo, CTX-induced immunocompromised mice were distributed into six groups and treated orally for 21 days with honey (1 g/kg), bee pollen (100 mg/kg), propolis (100 mg/kg), or their mixture at a volume ratio of 1:1:1 (v/v/v). Results showed that propolis had the highest total phenolic and flavonoid content and exhibited the strongest antioxidant activity. All bee products significantly improved leukocyte counts, thymus and spleen indices, IgG/IgM levels, and delayed hypersensitivity response compared with the CTX non-treated group, with propolis, bee pollen, and the mixture showing the most pronounced effects. Molecular docking revealed strong interactions of major phenolics (apigenin, kaempferol, isorhamnetin, pinocembrin) with immune-related proteins (STAT3, JNK, and SYK), suggesting a multi-target mechanism of immunoprotection. These findings highlight Moroccan bee products as promising natural adjuvants for supporting immune function during chemotherapy.

Milk is one of the most widely consumed foods; however, people with lactase nonpersistence or milk protein allergies have difficulty consuming milk, as well as digesting most dairy products. Therefore, plant-based butters made from alternative plant-derived milks have attracted attention. “Fujiharu Butter” is a butter made from plant-based milk. Although it is produced without cow milk, the sensory characteristics of Fujiharu Butter are said to be similar to those of animal-based butter. Nonetheless, these sensory characteristics have only been qualitatively assessed and not thoroughly elucidated. This study aimed to quantitatively evaluate Fujiharu Butter in comparison with animal-based butter and other butter substitutes, such as fat spreads and commercially available soy milk-derived butter substitutes. The microstructure of Fujiharu Butter was determined using confocal Raman microscopy. Fujiharu Butter was found to be similar to the commercially available animal-based butter in terms of moisture content, crystal structure, and heat flow, differing from fat spreads and commercially available soy milk-derived butter substitute. These results suggest that Fujiharu Butter has structural and thermal properties comparable to those of commercially available animal-based butter. This indicates its potential as an alternative that circumvents dairy-related dietary restrictions.

Practical Applications

The Fujiharu Butter evaluated in this study possessed a structure and thermal properties similar to those of animal-based butter. These findings demonstrate its potential as a novel food ingredient alternative to milk fat and hold promise for application in the development of foods suitable for individuals with milk protein allergies.

This study systematically characterizes and compares the structural and functional properties of peanut protein isolates from native kernels (LPPI) and hot-pressed meal (HPPI) to identify differences in emulsification stability mechanisms. Comparative analysis between peanut protein isolate extracted from peanut kernels (LPPI) and protein from hot-pressed peanut meal (HPPI) revealed significant structural disparities. LPPI exhibited higher molecular weight subunits (65 kDa), elevated β-sheet content (39%), and enhanced surface hydrophobicity. In contrast, HPPI showed subunit degradation (absence of 65 kDa conarachin II), increased α-helix content (13%), and reduced solvent-exposed aromatic residues. These structural modifications directly influence interfacial behavior. LPPI demonstrated improved adsorption kinetics and formed viscoelastic interfacial films with a higher complex modulus. Emulsions stabilized by LPPI exhibited smaller droplet sizes and a lower Turbiscan Stability Index, attributed to its capacity to overcome interfacial energy barriers through rapid adsorption and steric stabilization. The deterioration of HPPI's emulsification performance was mechanistically linked to thermal-induced subunit dissociation, which impaired hydrophobic interactions and interfacial film cohesion. These findings establish critical structure-function relationships that help explain performance differences between native and hot-pressed peanut proteins, providing a theoretical foundation for developing targeted modification strategies to enhance the functional value of peanut meal by-products in emulsified food systems.

Ultrasound-assisted papain extraction of taurine from Mytilus coruscus and Crassostrea gigas was investigated in this study. Single-factor experiments and response surface optimization (RSM) were used to study the effects of three factors: enzyme addition amount, ultrasound time, and enzymatic hydrolysis time. Taurine content was detected using high-performance liquid chromatography (HPLC) to develop a species-specific taurine extraction process. According to response surface analysis, the optimal parameters for taurine extraction in M. coruscus were 2263.02 U/g of enzyme addition, 44.80 min of ultrasound time, and 4.55 h of enzymatic hydrolysis time, yielding a taurine extraction content of 4.10 ± 0.08 mg/g. The optimal parameters for taurine extraction from C. gigas were enzyme addition of 2738.05 U/g, ultrasound time of 35.84 min, and enzymatic hydrolysis time of 4.57 h. The taurine content was 3.27 ± 0.07 mg/g. Compared with boiling, enzymatic hydrolysis, ultrasonication, and 50°C water bath constant temperature methods, ultrasonic-assisted enzymatic hydrolysis represents increases of 77.45%, 25.08%, 56.49%, and 91.59% in taurine extraction content of M. coruscus and 185.42%, 41.35%, 116.56%, and 202.78% in taurine extraction content of C. gigas, respectively, indicating that the method has obvious advantages in the extraction of taurine.

Practical Applications

This study precisely optimized the taurine extraction process for Mytilus coruscus and Crassostrea gigas through ultrasonic-assisted enzymatic hydrolysis, providing species-specific solutions for the high-value processing of marine shellfish. By determining the optimal parameters for enzyme dosage, ultrasonication duration, and enzymatic digestion time for both species, this method significantly enhanced taurine extraction efficiency. This enables shellfish processing enterprises to customize production based on raw material characteristics, maximize resource utilization, and provide technical support for the sustainable development of shellfish aquaculture in coastal areas.