Impact of Heat Moisture Treatment and Hydration Level of Flours on the Functional and Nutritional Value-Added Wheat-Barley Blended Breads

The impact of heat moisture treatment (HMT) of flours on the techno-functional and nutritional patterns of binary flour bread matrices (wheat/barley, WT/CB, 60:40, w/w) was investigated in untreated (?) and HMT (+) samples made at 160 and 170 dough yield (DY) levels. Assessment was performed by determining viscoelastic (stress relaxation test) and mechanical (double compression test) behaviours, volume (seed displacement), colour (Photoshop system), crumb grain (digital image analysis), starch digestibility (enzyme hydrolysis) and staling kinetics (Avrami equation), bioaccessible polyphenol content (digestive enzymatic mild extraction) and anti-radical activity (DPPH●). A superior functional profile was provided by HMT of CB flour in the blend WT?CB+ when hydrated at DY 170 compared to the untreated control WT?CB?. The sample exhibited a similar specific volume, more cohesive, springier, more resilient crumb, with similar rate and extent of crumb firming on ageing, and similar colour pattern but finer and more uniformly sized cell structure, and deserved similar sensory ratings as the control WT?CB? concerning cell uniformity, smoothness and typical smell and taste. Digestible starch kinetic curves of blended breads pointed out samples WT?CB+ and WT+CB+ as matrices expliciting a lower degree and slower rate of starch hydrolysis when mixed at low and high DY, respectively. A similar anti-radical activity for composite bread matrices was evidenced regardless of either HMT or DY.     

Enhancement of Bioactive Compounds and Antioxidant Activities of Olive (<Emphasis Type="Italic">Olea europaea</Emphasis> L.) Leaf Extract by Instant Controlled Pressure Drop

In this work, the effect of Détente Instantanée Contrôlée (DIC) (French for instant controlled pressure drop) on the total polyphenol, flavonoids, α-tocopherol contents, and antioxidant activities of olive leaves was studied. Olive leaf extracts were pre-treated at one cycle DIC under 0.1 MPa pressure for 11 s and followed by an extraction with 95% ethanol at 55 °C during 3 h. The phenolic compounds, flavonoïds, oleuropein, and α-tocopherol contents were determined, showing 66.63 mg gallic acid equivalent (GAE)/g db, 12 mg catechin equivalent (CE)/g db, 43.9 mg/g db, and 0.15 mg/g db for the untreated leaves against 239.37 mg GAE/g db, 28 mg CE/g db, 70.3 mg/g db, and 0.59 mg/g db for DIC-treated leaves, respectively. Therefore, DIC allows more availability of bioactive compounds contributing to a high antiradical activity (DPPH) compared to a synthetic antioxidant butylated hydroxytoluene (BHT). Both extracts showed a total antioxidant capacity (method of phosphomolybdenum) greater than that of the standard BHT. Likewise, both extracts have a reducing power (FRAP test) significant concentration-dependent. The DIC-treated leaves showed a higher antioxidant capacity compared to that of untreated leaves. Thus, DIC could be an effective treatment to promote the extraction of bioactive molecules of high antioxidant activities from olive leaves.     

Assessing Changes in Enriched Maize Flour Formulations After Extrusion by Means of FTIR,XRD, and Chemometric Analysis

Spectral analysis employing multivariate techniques was employed to differentiate plain maize flours from formulations containing maize with added milled chia or quinoa seeds for producing cereal breakfast extrudates. The physicochemical changes of the enriched formulations due to processing stages and formulation were evaluated by using FTIR and chemometric analysis, which allowed a rapid and non-destructive discrimination between sample processing and compositional aspects. Specific IR frequencies were selected which provided highest sample discrimination. Selected IR absorbance relationships at those specific wavenumbers were useful to track changes promoted by extrusion for carbohydrates, proteins, and lipids. The complexes between amylose and lipids, that takes place during extrusion, underwent distinctive changes as confirmed by XRD. The crystallinity loss, after extrusion (with an average value of 50%), shows evidence of amylose-lipid complexes formation of type E_h and V_h. Correlations between the textural behavior, composition, and selected FTIR indices were obtained.     

Microencapsulation of Propolis in Protein Matrix Using Spray Drying for Application in Food Systems

Propolis presents several health benefits due to the presence of bioactive compounds, mainly phenolic compounds; however, its application in food is limited due to undesirable odor and low water solubility. The bioactive compounds are usually susceptible to degradation by exposure to light, heat, or oxygen or by interaction with other compounds, which may limit its biological activity. The study aimed the propolis extract microencapsulation using rice, pea, soybean, and ovoalbumin proteins as wall material by spray drying and to analyze their in vitro digestion. The propolis extract presented a high concentration of apigenin. Encapsulation efficiency was greater than 70%, and it was maintained the antioxidant activity of propolis (88% inhibition of DPPH for propolis extract and >?73% for the microparticles). The DSC, ATR-FTIR, and X-ray diffraction techniques confirmed the encapsulation. The microparticles showed different shapes, sizes, and physical characteristics. The microparticles encapsulated with pea protein could be used in formulations of Minas Frescal cheese due to the controlled released, whereas the other microparticles could be used in pudding formulations.     

Microencapsulation of Curcumin by a Spray-Drying Technique Using Gum Arabic as Encapsulating Agent and Release Studies

Curcumin is a natural yellow pigment extracted from dried roots of turmeric, used in food applications. Despite its applicability in food products, this phenolic compound is also used in the pharmaceutical field. It is reported to have health benefits such as anticancer, antitumor, and antiviral effects. However, curcumin is a very unstable compound. Therefore, this work proposes the microencapsulation of curcumin, in order to protect it and to improve its stability and solubility in water, by spray-drying, using the gum arabic as an encapsulating agent in three different concentrations 10, 15, and 20% (weight/volume (w/v)). Emulsions were prepared with coconut oil and used to prepare the curcumin microparticles. For this purpose, different analysis and studies were performed. A product yield ranging from 44 to 52% and from 29 to 42% was obtained for the production of microparticles without and with curcumin, respectively. The curcumin microcapsules and empty capsules were characterized and evaluated. All the microparticles presented a spherical form, had a diameter around 7–9 μm (considering a volume distribution), and had a rough surface. The efficiency of encapsulation was between 75 and 85%, being higher for the particles prepared with higher concentrations of encapsulating agents. Considering the controlled release studies, the microcapsules were prepared with different concentrations of gum arabic but showed similar release profiles. However, it was also concluded that increasing the amount of gum arabic used in the formulation of the microparticles, the amount of curcumin released in the first minutes decreases; therefore, the release tends to be slower (63.2% of the release varied between 25.5 and 69.0 min). Fitting the experimental results to a linearized equation of the Weibull model, it was possible to obtain a good correlation coefficient (R² varying from 0.94 to 0.97), indicating that this model adapts to the experimental data obtained.

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Graphical Abstract SEM images for the microparticles prepared with curcumin using gum arabic, as encapsulating agent and experimental and Weibull model release profiles

     

Nondestructive Prediction of Tilapia Fillet Freshness During Storage at Different Temperatures by Integrating an Electronic Nose and Tongue with Radial Basis Function Neural Networks

This study developed principal component analysis and radial basis function neural networks (PCA-RBFNNs) for predicting freshness in tilapia fillets stored at different temperatures by integrating an electronic nose and electronic tongue. Total volatile basic nitrogen (TVB-N), total aerobic counts (TAC), and K value increased at 0, 4, 7, and 10 °C, while sensory scores decreased significantly. The electronic nose and tongue acquired the volatiles and dissolved chemical compounds in the stored samples. Gas chromatography-mass spectrometry (GC-MS) verified the changes in gas species and contents in fillets stored for different periods of time at different temperatures. PCA-RBFNNs based on data fusion were developed and presented good performance for prediction of TVB-N, TAC, K value, and sensory score in tilapia fillets. The established PCA-RBFNNs based on feature variables of the electronic nose and tongue is a promising method to predict changes in the freshness of fillets stored from 0 to 10 °C in the cold chain.     

Detection of Viable <Emphasis Type="Italic">Vibrio cholerae</Emphasis> Cells in Seafood Using a Real-Time Visual Loop-Mediated Isothermal Amplification Combined with Propidium Monoazide

Vibrio cholerae is an important foodborne pathogen causing severe intestinal infectious diseases that have high incidence and mortality. Almost all of rapid testing methods including immunological and molecular assays for V. cholerae are incapable of distinguishing live cells from dead ones, which may overestimate the number of bacteria and result in many false positive results. To address the problems, live cell-specific dye such as propidium monoazide (PMA) is employed. The loop-mediated isothermal amplification (LAMP) assay is a nucleic acid amplification method that is fast, specific, and sensitive. In this study, we developed a real-time visual LAMP assay using PMA dye to detect thyA gene, thereby identifying viable V. cholerae cells. The results showed that only V. cholarae strains could be detected, and there was no cross-reaction with non-V. cholarae strains. Besides, the sensitivity of the PMA-LAMP assay was 1.1 × 10² CFU/mL and the entire reaction could be accomplished within 1 h. The sensitivity was on par with that of the PMA-qPCR assay. The detection limit in different artificially inoculated samples was 5 CFU/25 g materials for the tested pathogens. In the practical test, the PMA-LAMP assay performed well in comparison with PMA-qPCR and the culture method. Hence, PMA-LAMP assay can provide a highly effective and rapid approach for detecting viable V. cholerae.     

Investigation of Chlorpyrifos and Its Transformation Products in Fruits and Spices by Combining Electrochemistry and Liquid Chromatography Coupled to Tandem Mass Spectrometry

The identification of transformation products (TPs) of pesticides in food is a crucial task difficult to tackle, due to the lack of standards. In this work, we present a novel methodology to synthesize five main TP standards of the insecticide chlorpyrifos (CPF) and to investigate their occurrence in selected fruits and spices. TPs were electrochemically (EC) synthesized using a boron-doped diamond electrode (BDD) and identified by EC coupled online to mass spectrometry, LC-MS/MS, and high-resolution mass spectrometry. CPF and its TPs were analyzed in the food samples by LC-MS/MS on multiple reaction monitoring (MRM) after dispersive solid-phase extraction. A good recovery of 83–103% for CPF and 65–85% for TPs was obtained. Matrix effects, which cause signal suppression, ranged between 81 to 95% for all targeted analytes. The limit of detection and quantification for CPF were 1.6–1.9 and 4.9–5.7 μg/kg, respectively. Among investigated samples, CPF was determined in fresh lemon (104 μg/kg), fenugreek seed (40 μg/kg), and black pepper (31 μg/kg). CPF content in all samples was lower than the EU maximum residue level (MRL). The most frequently detected TPs were diethylthiophosphate and diethylphosphate. Other TPs, CPF oxon and trichloropyridinol, were also detected. Hence, EC is a versatile tool to synthesize TP standards which enables the determination of contaminants and residues in foodstuffs even if no commercial standards are available.     

Loquat Bruise Detection Using Optical Coherence Tomography Based on Microstructural Parameters

Slight postharvest bruises of loquats remarkably affect the quality and shelf life of the fruits, but they are difficult to identify using visual inspection. Sub-surface structural changes in cells caused by mechanical injury or impact can be detected using spectroscopy-based methods from different angles. Optical coherence tomography (OCT), a non-destructive technology, can acquire cross-sectional images to analyze sub-surface structures of loquats, thus offering the potential to identify fruit bruises. This study proposes an automated OCT image processing method for extracting large cells from loquat images, which involves a series of steps including image denoising, boundary detection, filtering, binarization, segmentation, and region selection. Parenchyma cells in loquat tissue were visualized and characterized, and the five-cell morphological parameters, including total cell surface area, average cell surface area, average cell Feret diameter, equivalent diameter, and cell amount were measured. The bruised and non-bruised loquat groups showed significant differences in the total cell surface area and cell amount, suggesting that these two parameters might be used as indictors for bruise identification. No significant differences in other parameters were observed between the two groups. The microcosm approach proposed in this study sheds some light on ways to improve fruit quality evaluation. Overall, combined with appropriate image processing, OCT is an efficient and non-destructive tool for loquat bruise detection. The proposed strategy might also be expanded to other agricultural applications.