Food Physics最新文献

Nanoemulsions - colloidal dispersions of nanoscale droplets in a continuous phase, have garnered significant attention in recent years due to their versatile properties and wide-ranging applications. This review paper presents a comprehensive overview of nanoemulsions production methods focusing on their formulation strategies, functional properties and different applications in food processing. Various low and high energy methods such as phase inversion, high pressure homogenization, ultrasonication and microfluidization etc., are reviewed to produce nanoemulsions with diverse characteristics and functionalities. Scale-up potential and practical challenges of each production method are also discussed. Various properties of nanoemulsions stability, drug solubility, bioavailability and targeted delivery are highlighted. Furthermore, their potential applications in food and beverage sectors including encapsulation of bioactive compounds, packaging, preservation and new product formulation have been elaborated along with real world examples at commercial stage. This review will contribute to providing knowledge about gastrointestinal fate of nanoemulsions, toxicity and safety by in-vitro and in-vivo testing as well as other research evidences. Regulatory aspects and public perception on use of nanoemulsions are also covered. Nevertheless, nanoemulsion presents immense potential for addressing various challenges in food industry. Continued research efforts in formulation design, ingredient selection, its compatibility with food constituents as well as the associated safety issues should be undertaken to unlock new opportunities towards scalability and commercialization.

The primary concern regarding the pineapple juice processing industry is its insufficient stability. The goal of this investigation is to evaluate the storage stability and shelf life of cold plasma (CP) and thermally treated pineapple juice samples (S1, untreated; S2, optimized plasma-treated; S3, extreme plasma-treated; S4, thermally-treated) packed in glass (GL) and polyethylene terephthalate (PET) bottles at 5, 15, and 25°C. The color parameters increased with time and storage temperature. However, the bioactive substances decreased during storage for all the samples. Moreover, all the samples at elevated temperatures showed a higher degradation rate for bioactive compounds and color parameters. The changes in color parameter values across all samples showed zero-order kinetics, while the bioactive compounds followed a 1^st-order kinetics. The application of various packing materials and storage temperatures had a significant impact (p < 0.05) on the microbiological, enzyme inactivation, and biochemical characteristics of the samples. However, there was an insignificant effect (p > 0.05) on the pH, acidity, and soluble solids. CP and thermally-treated samples reduced natural microbiota below the detection limit (<1-log CFU/mL). The sensory quality of S2, S3, and S4 samples remained above the acceptable limit (OA>5) for 120 d at 5 ℃. The shelf-life of the optimized CP-treated juice sample packed in GL bottles was 90, 50, and 25 days at 5, 15, and 25°C, respectively, based on AA≥20 mg/100 mL, OA≥5, ΔE*≤12, and microbial count≤6-log CFU/mL. In conclusion, CP is an effective non-thermal method that may extend the shelf life of pineapple juice packed in GL bottles by up to 90 days in refrigerated conditions (5 °C).

Pulsed light (PL), a relatively new non-thermal technology can be used as a possible substitute to the conventional (thermal and chemical) technology for disinfecting a wide variety of fruits and vegetables. The short-duration light pulses, ranging from 1 to 20 flashes per second with an energy density of about 0.01–50 Jcm⁻², ensure the killing of several disease-causing microorganisms by causing minimal impact on the quality parameters in fruits and vegetables. This technology enhances safety and extends shelf-life period of fruits and vegetables. Furthermore, PL decreases or inhibits the harmful effect of conventional techniques on nutritional components. The review discusses recent research on PL's influence on nutritional and physicochemical parameters and its potential applications for extending the shelf life of fruits and vegetables. This PL technology can be successfully employed alone or in combination with other techniques for enhancing fresh produce life. PL is considered a safe, eco-friendly and non-thermal technique for shelf-life extension. For this review article, keywords such as pulsed light, fruits and vegetables, microbial safety and shelf life were selected and most relevant papers were cited. Thus, the present review article, supported by 70 references, highlights the novel potential of PL treatment and its diverse applications in the fruit and vegetable sector.

This study examined the effect of magneto-induced electric field (MIEF) treatment under varying pH conditions on the physicochemical, structural, and rheological properties of citrus pectin (CP). The results indicate that as the pH increased (to 4.0, 7.0, and 10.0), the molecular weight, degree of esterification, and galacturonic acid content of CP decreased. At pH values of 4.0 and 7.0, MIEF treatment caused fractures in the side chains of CP, while at pH 10.0, the main chain broke. MIEF treatment under these conditions enhanced the steady-state fluid behavior and dynamic viscoelastic properties of CP by promoting increased entanglements of neutral sugar side chains. Overall, the combined effect of pH and MIEF led to the breakdown of the main or side chains of CP, reducing its molecular weight and thereby influencing its rheological properties. In effect, this study provides a green modification technique for CP and its application to functional foods.

The physicochemical properties of chitosan-microparticles are related to the crosslinking salts. The effects of sodium-pyrophosphate or sodium-tripolyphosphate and ultrasonication on the formation of phosphate-chitosan microparticles were evaluated. Potentiometric titration curves were used to determine the ionization degree of chitosan by employing the Henderson-Hasselbach equation and milliequivalents. Colloidal formation was validated by turbidity and conductivity at different phosphate-chitosan salt ratios. The ultrasonication effect was characterized by visual appearance, zeta potential, particle size, FTIR, SEM, and EDS analyses. Additionally, the impact of particle size on the cytotoxicity and the encapsulation properties of a curcumin microemulsion was assessed. Chitosan ionization degree was pH dependent and was fully ionized below 4.0. The milliequivalent points were estimated at 0.9 and 1.06 for the two crosslinkers and chitosan, respectively. The maximum turbidity observed during complex formation was 0.5 and 1.0 for the pyrophosphate-chitosan and tripolyphosphate-chitosan samples, respectively, showing a critical conductivity value of 1. FTIR showed the interaction between phosphate salts (PO^–) and chitosan amino groups (NH₃⁺) in the region of 1200–1650 cm^–1. SEM showed that the particle size decreased with ultrasonication. After ultrasonication, the particle size of the phosphate-chitosan microparticles decreased 17-fold but the zeta potential did not change. The phosphate-chitosan complexes did not present cytotoxic activity at concentrations lower than 1000 µg/mL. The pyrophosphate-chitosan and tripolyphosphate-chitosan microparticles have remarkable loading capacities for curcumin, making them promising carriers for nutraceutical and pharmaceutical applications.

A new method based on dielectric properties has been developed to distinguish blended soy sauce from fermented soy sauce. Fifty samples of pure fermented soy sauce and blended soy sauce with different contents of hydrolyzed vegetable protein (HVP) were prepared. The dielectric constant and dielectric loss factor of all soy sauce samples in the 30 MHz–3000 MHz frequency range were measured using an impedance analyzer. The sample set was divided into a correction set and a prediction set using the joint x-y distances (SPXY) algorithm, and the partial least squares (PLS) and support vector machine (SVM) models were adopted to distinguish the different samples. The effects of selecting characteristic variables on model prediction using the full spectra (FS), principal component analysis (PCA), and successive projection algorithm (SPA) were compared. Results indicate that the discriminant effect of the PLS model was better than that of the SVM model overall. The SPA–PLS model had the best predictive performance among the six developmental models. The correlation coefficients of the correction set and prediction set were 0.9205 and 0.9096, respectively. The root mean square error of the calibration set was 1.3699 and that of the prediction set was 1.5950. The study demonstrated that the combination of dielectric spectra and stoichiometry can be utilized to determine whether soy sauce has been adulterated.

Peanut protein (PP)/buckwheat protein (BWP) mixture crosslinked by transglutaminase (TGase) under dual-frequency ultrasound (DFU) field was developed and its structural and functional properties were characterized. The results showed that the optimal DFU parameters for PP-BWP crosslinking were 25 kHz/40 kHz dual-frequency ultrasound working time ratio of 10:10 (s/s), a temperature of 45°C, ultrasonic power density of 125 W/L and time duration of 30 min, resulting in the degree of crosslinking (DC) of 37.7 %, which is 125 % higher than that of the control. The solubility at pH 7.0, oil-holding capacity, and emulsifying capacity of the protein aggregate (peanut protein-buckwheat protein crosslinked by TGase under dual-frequency ultrasound, U-TG-PP-BWP) was significantly (P<0.05) improved compared with protein aggregates formed without ultrasound (TG-PP-BWP); however, the emulsion stability, foaming capacity and form stability decreased. Secondary structure analysis indicated no apparent difference between un-crosslinked protein and U-TG-PP-BWP. After ultrasound treatment, the α-helix decreased by 11.2 % and the β-sheet, β-turn and random coil increased by 7.7 %, 3.4 % and 4.7 %, respectively, in U-TG-PP-BWP compared to TG-PP-BWP. The microstructures showed that U-TG-PP-BWP formed a lamellar structure with many micropores while TG-PP-BWP aggregated into large and tight blocks. SDS-PAGE analysis showed that, compared to PP and BWP, the subunit bands of cross-linked TG-PP-BWP and U-TG-PP-BWP were altered at 14.4–116 kDa, yielding proteins larger than 116 kDa, suggesting covalent cross-linking of the two proteins. In conclusion, the enzymatic cross-linking of proteins can be promoted by DFU, providing a new approach to developing novel plant proteins.

This study aimed to investigate the effect of ohmic (OH) and microwave heating (MH) pre-treatments on the aqueous extraction of tomato seed oil. As these thermal techniques disrupt the cell structure resulting in enhanced leaching, extractability was expected to be increased. Aqueous phase extraction of tomato seed pretreated with OH (14 V/cm), MH (540 W) and combination of ohmic heating and microwave heating (OH+MH) to compare the oil extractability. Physiochemical parameters have been determined for the extracted oil showing significant differences (p <0.01). The extractability of the oil was more in OH+MH comparing with OH and MH pre-treatments separately. SEM images of OH+MH treated samples showed the cellular damage resulting in high oil recovery. GCMS analysis of the oil samples disclosed the presence of linoleic acid and oleic acid as major contributors in OH+MH (52.15 %; 27.74 %) samples compared with the control (42.05 %; 12.14 %). Therefore, combination of ohmic heating and microwave heating is a novel green approach to improving oil extractability from tomato seeds because it combines efficient electrical and microwave energy, reducing processing time and energy consumption while minimizing the use of chemical solvents.

Practical application

The research was conducted to utilize the waste from tomato processing industry. The tomato seed having an adequate amount of oil. The extraction process was done using water as a solvent. This can be probably eliminating the problem associated with organic solvents e.g. hexane causing an environmental problem, but the lower oil yield was overcome with the help of the pretreatment process. The emerging technologies namely ohmic and microwave were used as a pretreatment to enhance the lower extractability of oil. These technologies have more advantages in terms of least energy utilization, rapid processing time, solvent free extraction and enhanced quality of the oil. This research helps to maximize utilization of tomato seed waste to confer worthwhile byproduct at a large-scale level.

Prepared dishes are popular among consumers due to their convenience, but microorganisms in dishes have the potential to cause spoilage and even lead to foodborne illnesses, rendering microbial control a critical step in production. This paper reviews microbial control techniques commonly used in prepared dishes, including conventional thermal techniques; novel thermal processing, including microwave (MW) and radio frequency (RF) heating; and non-thermal treatment, such as high-pressure processing (HPP) and irradiation. In addition, it summarizes the applications of these techniques in prepared dishes and analyzes factors affecting microbial inactivation, providing guidance for the optimization of these techniques. These technologies are compared in terms of technical characteristics, commercial applicability, the dish types for which they are suitable, etc. Traditional thermal treatment is currently the main processing method used for the industrial microbial control of prepared dishes, while other novel processing technologies have their own characteristics. MW has poor penetration ability, RF is suitable for dishes with a regular shape and consistent thickness, HPP (generally 300–600 MPa) is unsuitable for dishes containing air bubbles, and low-dose irradiation (<10 kGy) is preferred only for the pasteurization of prepared dishes due to food safety concerns. Finally, the challenges and countermeasures associated with their application in prepared dishes are discussed. Further studies and continuous improvements of microbial control techniques are of great significance to produce safe and high-quality prepared dishes.

The aim of this study was to investigate if vibroacoustic methods may be used for the non-destructive determination of beef during its aging process. The vibroacoustic method was based on the observation of mechanical changes in the meat during the aging process and was compared with reference data obtained by Warner-Bratzler shear force measurement as well as sensory testing of the tenderness using a ten-part scale. To evaluate the mechanical properties, transfer functions were used representing the time dependency of the signal and thus the viscoelastic behaviour. In this study, a total of 31 roastbeef samples from 16 different young bulls and two older cows were examined from day of slaughter to day 21 of cold storage with regard to their tenderness. For this purpose, vibroacoustic measurements were carried out on the unprocessed/raw meat at intervals of 1–3 days. The reference measurements using sensor technology and Warner-Bratzler shear force measurement were carried out on the first (day of slaughter) and last (21st day) day on slices of roast beef cooked with saturated steam. In the results of all three methods, the shear force measurement, the sensory test and the vibroacoustic method, showed that roastbeef from the same animal but different halves produced different results. Basically, it is possible to predict the tenderness of roastbeef by taking measurements at the beginning of the maturing process for the end of the maturing period using vibroacoustic methods: Data analysis led to a trend function that roughly reflects the actual tenderness, which is generally higher than the real tenderness represented by the shear-force measurement. In order to obtain a better resolution for recording the mechanical changes during the aging process, the measurements should be carried out at shorter intervals.