Journal of Food Measurement and Characterization最新文献

The purified E.coil-derived patatin is an enzyme with a molecular mass of 40 kDa, it displayed optimal esterase activity (against p-Nitrophenyl acetate, p-NPC₂) at 37 °C and a pH of 9.0 for 25 min. Its enzymatic activity was stable at pH 4.0–9.0 and could retain about 65.8% of its activity at 90 °C for 1 h. The residual activity remained over 80% in 4 weeks’ duration when patatin was freeze-dried or stored in a buffer solution of -80 to 25 °C, the residual activity remained over 80% for 4 weeks. Patatin’s enzymatic hydrolysis ability against p-NPC₂ was enhanced in the presence of K⁺, Mg²⁺, Al³⁺. Most organic solvents had no significant effects on its activity except ethyl acetate. Patatin showed broad specificity to substrates of different carbon chain lengths (C₂-C₁₆), of which the highest was against short carbon chains (C₂-C₄), with the lowest K_m of 1.01 mM and the highest V_max of 49.75 mmol/L·min to p-NPC₂. The patatin also possessed remarkable lipase activity in hydrolyzing oils and high selectivity to animal fats. These results suggested that the recombinant patatin has promising marketable potential in the hydrolysis of important ester or lipid in food, pharmaceutical, biochemical, and biological interests due to its broad substrate specificity and high stability.

In this study, three distinct brands of soybean oils with varying proportions of transgenic and non-transgenic were subjected to analysis. The fluorescence intensity (F) was obtained via a fluorescence spectrophotometer, while the absorption (µ_a) and reduced scattering coefficients (µ’_s) were obtained by through a self-developed double integrating sphere (DIS) system. A quantitative detection method for the adulteration ratio based on fluorescence spectroscopy was proposed which considered the entangling effect of absorption and scattering. The method entails initially conducting principal component analysis (PCA) on the F, µ_a and µ’_s spectra in the range of 350–700 nm, thereby obtaining the first five principal components (PCs) of each kind of spectrum were obtained. Furthermore, the three brands of oil exhibited a discernible clustering tendency when subjected to a three-dimensional PCA mapping approach. The distribution positions of the three spectra in the three plots indicated that they could be considered to complement each other. Following further normalization processing, the PCs were fused and quantitative models were calibrated by using multiple linear regression (MLR), partial least squares regression (PLSR), and support vector regression (SVR). The results indicated that, in comparison to the utilisation of individual spectral characteristics, the fusion of F and µ_a can effectively mitigate the impact of fluorescence internal filtering, thereby improving the prediction accuracy. Furthermore, the combination of F, µ_a and µ’_s can effectively eliminate the interference of scattering on fluorescence, and achieve optimal prediction results. Among them, the MLR model based on F, µ_a and µ’_s could reach the best performance, with determination coefficients of calibration (R²_c) and validation sets (R²_v) reaching 0.959 and 0.947, respectively, while the root mean square error of calibration (RMSEC) and validation sets (RMSEV) were as low as 2.970% and 3.429%, respectively. In comparison, the MLR model based solely on F yielded unsatisfactory results, with R²_c and R²_v were 0.571 and 0.595. It can be concluded that it can greatly improve the accuracy of predicting the adulteration of transgenic in non-transgenic soybean oil by integrating F, µ_a and µ’_s spectroscopy.

The novel bilayer film was developed based on a pea protein isolate (PPI)-sage seed gum (SG) and diverse thickness of Zein-cumin essential oil (CEO) electrospinning fibers layer (0, 15, 30, 45, and 60g/m²). Then the mechanical, structural, barrier, thermal properties, biodegradability, and release behavior of the bilayer active films were evaluated. Increasing the thickness of the Zein-CEO nanofibers significantly improved the tensile strength (TS), elastic modulus, barrier properties against oxygen and water, antimicrobial activity, total phenolic content (TPC), and antioxidant properties (p < 0.05). The PPI-SG/Ze6 remarkably prevented the light transmittance by about 300% higher than the PPI-SG1/Ze0. Adding the Zein-CEO electrospinning nanofibers to the composite film significantly increased the surface hydrophobicity (p < 0.05). Moreover, the percentage of the moisture content (MC), water solubility, and swelling ratio in PPI-SG/Ze6 to the PPI-SG/Ze0 obtained 69.23%, 53.68%, and 55.07%, respectively. The FESEM images exhibited the homogenous and compact structure of the bilayer films, especially in bilayer films containing higher thickness of the nanofiber layer. Besides, the FTIR results confirmed the successful interaction between Zein, CEO, PPI, and SG and the X-ray diffractometer revealed the increase of crystallinity degree in the bilayer films containing higher thickness of the Zein-CEO. According to the DSC curves, adding the thickness of nanofibers, increased the thermal stability and melting temperature of bilayer films, and the CEO release profile represented that the bilayer active films can efficiently control the release of the CEO in different simulant, especially in aqueous simulant. All these findings revealed that developed bilayer biodegradable films would have potential applications in the packaging.

Plant-based beverages can be a healthier alternative for people with dietary restrictions, however, enhancement of their shelf life without affecting their nutritional value is quite complicated. High-pressure processing (HPP) might be a better solution for this concern. In this study, the impact of HPP (100–600 MPa) and thermal processing (63 °C, 30 min) on the shelf life and quality of coconut-cashew nut milk (CCM) beverage was analyzed for 21 days at refrigerated condition (4 ± 2 °C). Among the processing conditions, HPP at 550 MPa for 2 min was found to be suitable to ensure microbial safety and overall quality of CCM beverage. The HPP treatment provided better retention of total phenolic content (4.16 mg gallic acid equivalent (GAE)/g) and antioxidant capacity (74.80%) than thermal processing. Both HPP and thermal processing exhibit a similar content of total carbohydrates and fat, however, a significant (p < 0.05) decrease in protein was observed in HPP-treated samples. Further, HPP-treated samples showed higher K, Ca, and P contents. Microstructure analysis revealed the formation of aggregates in HPP-treated samples during storage, which was further confirmed by an increase in average particle size and zeta potential. The study revealed that HPP could be a better alternative technology to achieve a high shelf life for plant-based beverages without affecting their quality and sensory parameters.

Finger millet seed coat and endosperm are abundant sources of phytonutrients. This study aimed to investigate the application of extrusion technology to convert finger millet seed coat and endosperm into instant ingredients and to assess their physicochemical, nutritional, phenolic, antioxidant and product-forming qualities. Extrusion significantly enhanced sedimentation values in both the extruded finger millet seed coat (ESC) (355%) and the endosperm-rich fraction (EEF) (353%). Proximate analysis showed no significant changes in the protein content, whereas the total dietary fiber decreased (63%) in ESC and increased (23%) in EEF. Total phenolic content was retained by 57% and 74% in ESC and EEF, respectively, while the flavonoid content remained relatively high in ESC (70%) and EEF (81%). The major phenolics identified were catechin (CAT) and p-catechuic acid (PCAT). In ESC, free cat and p-cat were retained by 56% and 24%, respectively, whereas bound cat retained by 42%, and p-cat exhibited an increase of 118%. Conversely, EEF showed no significant changes in free cat, while free p-cat was retained by 76%, and the bound cat and p-cat were retained by 46% and 50%, respectively. The extruded fractions showed a reduction in antioxidant activity in both ESC and EEF. Pasting properties were decreased on extrusion in EEF. Instant beverages prepared using ESC and EEF exhibited acceptable organoleptic properties. In conclusion, through extrusion technology it is possible to develop functional food ingredients rich in antioxidants and phenolic compounds from finger millet.

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This study investigated the effect of pulsed infrared (PIR) radiation as a novel thermal process (low energy consumption) on the decontamination of A spergillus flavus (A. flavus) spores in saffron. Some physicochemical properties including energy consumption, antioxidant activity, total phenolic content, and overall saffron quality. The experimental parameters included PIR power levels (250, 350, and 450 W), sample distances from the radiation source (10, 20, and 30 cm), treatment time (0–20 min), and PIR pulse (1, 2, and 3 pulses/s). Optimal conditions were identified at 350 W PIR power, 10 cm distance, 1.5 min of irradiation, and a pulse frequency of 3 pulses/s, achieving a maximum reduction of 3.769 Log CFU/g (%76.92 reduction) in A. flavus spores. It was observed that PIR utilizes 50% less energy than IR due to its pulsed nature, making it an energy-efficient method. PIR had a less pronounced (%28.8 less) effect on the IC₅₀ of Sargol Negin saffron compared to IR (P < 0.05). The Double Weibull model provided the best fit for predicting microbial population dynamics. Before this study, the application of PIR for decontamination of A. flavus spores in saffron had not been reported. The findings suggest that the PIR method effectively reduce microbial contamination while maintaining the quality of saffron, making it a viable option for ensuring food safety and quality.

The current study aimed to produce functional stirred yogurt by incorporating varying amounts of sapote extract (SE) and orange blossom honey. The findings revealed that augmenting yogurt with SE and honey led to a substantial rise in the total phenolic (TPC), total flavonoid compounds (TFC), and antioxidant activity. The physicochemical characteristics showed a favorable shift for the treatments that utilized honey and SE with significant changes observed in total solids (TS), acidity, and pH. In contrast, total protein (TP) and fat content remained unchanged. Sensory analysis indicated that the yogurt augmented with honey and SE had superior flavor, body and texture, and overall acceptability compared to the control sample. However, the addition of SE had an impact on the color of the product. Incorporating honey with SE enhanced the rheological qualities of the product, specifically viscosity and water-holding capacity. There was a decrease in the count of lactic acid bacteria following the addition of honey and SE.

Bacterial community shapes the quality of fermented vegetables through metabolism; however, no information is available on the dynamics of the microbiota and metabolites in dry-pickled radish. Herein, the study aim to reveal the changes in bacterial communities, volatile metabolites, and nonvolatile metabolites, and to speculate how the core bacterial flora affects metabolites by high-throughput sequencing, metabolomics, and flavoromics. During the initial fermentation (d1–d14), the bacterial flora and metabolites of radish considerably changed. The relative abundance of Weissella, Lactiplantibacillus, and Staphylococcus increased, whereas that of Pseudomonas and Lactococcus considerably decreased (p < 0.05). Kyoto encyclopedia of genes and genomes (KEGG) function prediction indicated that functions related to bacterial division and proliferation were high at the start of fermentation, after which functions related to the metabolism and biosynthesis of amino acids, carbohydrates, and nucleic acids increased. Among metabolites, the contents of ethanol, dimethyl disulfide, dimethyl trisulfide, carboxylic acids and derivatives (CAAD, mainly amino acids), and fatty acyls (FAC) increased, whereas those of isothiocyanates and 1-methyl-2-pyrrolidinethione decreased significantly (p < 0.05). During the middle and final stage of fermentation (d14–d42), the bacterial flora and metabolites gradually stabilized. Weissella, Lactiplantibacillus, and Staphylococcus populations correlated positively with the contents of alcohols, sulfides, CAAD, and FAC, and negatively with the content of isothiocyanates. Therefore, Weissella, Lactiplantibacillus, and Staphylococcus may regulate the synthesis and metabolism of amino acids and organic acids by producing enzymes, such as phenylalanine hydroxylase (EC 1.14.16.1), isocitrate dehydrogenase (EC 1.1.1.41), and glutamate mutase (EC 5.4.99.1). This study provides a theoretical basis for improving and standardizing the quality of dry-pickled radish.

Removal of 3-monochloropropane-1,2-diol esters (3-MCPDEs) from edible oils is essential for better quality food consumption due to its detrimental effects on human health. Herein, we present a simple strategy for the in situ growth of a ternary metal–organic framework (Fe–Mn–MOF/N4) with nanocellulose (NC) extracted from almond shells using sulfuric acid (ASS) as a support for 3-MCPD adsorption in spiked extra virgin olive (EVO) oil. The sugar-based deep eutectic solvent (SDES) was also employed as co-solvent to enhance the active sites of the synthesized MOF, thereby increasing the adsorption capacity of the primary solid adsorbents, such as MOF and NC-ASS. The Fe–Mn–MOF/N4 achieved 85% removal of 3-MCPD under optimal conditions (6 h, 40 °C, 60 mg dose of Fe–Mn-MOF/N4, 1 g of NC-ASS, and 200 µL of SDES) via an indirect method. The adsorption performance, analyzed using Langmuir and Freundlich isotherm models, showed excellent adsorption capacity while maintaining the quality of EVO oil within acceptable limits after treatment. Importantly, Fe–Mn–MOF/N4 could be reused up to five times, with an adsorption efficiency of 48.3% after the final cycle, demonstrating its sustainability. However, further optimization is needed to prevent the gradual decline in adsorption efficiency and to meet the regulatory standards. This method offers a sustainable, effective solution for 3-MCPDE reduction, highlighting the potential of MOF-based materials to enhance food safety by reducing harmful contaminants in edible oils and food products.

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