Acoustic Characterization Study of Beef Loins Using Ultrasonic Transducers.

The objective of this study was to non-destructively characterize samples of fresh beef loin by low-intensity ultrasound inspection at various frequencies and to correlate the acoustic parameters of these inspections with quality parameters. In this regard, ultrasonic parameters such as ultrasound pulse velocity (UPV) and variables related to attenuation and frequency components obtained from fast Fourier transform (FFT) were considered. For this, pulsed ultrasonic signal transducers with a frequency of 0.5 and 1.0 MHz were used. Acoustic parameters and those obtained through traditional instrumental analyses (physicochemical and texture) underwent a Pearson correlation analysis. The acoustic determinations revealed numerous significant correlations with the rest of the studied parameters. The results demonstrate that ultrasonic inspection has the ability to characterize samples with a non-destructive nature, and likewise, this methodology can be postulated as a promising predictive tool for determining quality parameters in beef loin samples.

Fish oil/lycopene microcapsules as a source of eicosapentaenoic and docosahexaenoic acids: a case study on spreads.

BACKGROUND: The consumption of omega-3 fatty acids has many beneficial effects for human health, but the intake of foods rich in these fatty acids is not enough to achieve the recommended quantity per person and per day, and their direct addition in foods cause oxidation and unacceptable rancidity and off-flavor. Taking account of all these aspects, this study was aimed to develop stable microcapsules of fish oil (omega-3 polyunsaturated fatty acids) and lycopene (antioxidant) and to investigate their effect on different spreads. RESULTS: The inclusion of different proportions of lycopene in fish oil did not show great benefits in the quality characteristics of emulsions and microcapsules. After the addition of fish oil and fish oil + lycopene microcapsules to dry-cured ham and cheese spreads, no significant differences were found in the proximal composition and oxidative stability, whereas fatty acids composition and sensory analysis were influenced. The eicosapentaenoic and docosahexaenoic acids content increased with the fish oil content in both products, but it decreased significantly after storage in the cheese spreads. Addition of microcapsules did not significantly influence on quantitative-descriptive and acceptability sensory analyses in dry-cured spreads, but it negatively affected the flavor of cheese spreading creams. CONCLUSION: There is no need to add antioxidants to improve the stability of the fish oil microcapsules in the present study, which are appropriate as eicosapentaenoic acid and docosahexaenoic acid vehicles to enrich meat-derived spreading creams. © 2019 Society of Chemical Industry.

Microencapsulation of oil and protein hydrolysate from fish within a high-pressure homogenized double emulsion.

In this study, the effect of high-pressure homogenization on the water-in-oil-in-water (W1/O/W2) double emulsions containing fish protein hydrolysate and fish oil encapsulated within a complex of whey protein concentrate and inulin were investigated in order to produce stable double emulsion. After adequacy of the positive influence of high-pressure homogenization at W1/O (one pass) and W1/O/W2 (three passes), the double emulsions were produced with (H) and without (HS) high-pressure homogenization. H samples were demonstrated lower CI of double emulsion and higher amounts of yield, total oil, encapsulated oil, EPA and DHA of microcapsules in comparison with HS samples. At subsequent step, response surface methodology were applied to optimize the high-pressure homogenization conditions (700-1500 Ba) of double emulsions in terms of minimum CI of emulsions and maximum microencapsulation efficiency and oxidation stability. Optimal conditions were obtained by using high-pressure homogenization at 1000 and 1100 Ba on W1/O and W1/O/W2, respectively.

Improving the lipid profile of ready-to-cook meat products by addition of omega-3 microcapsules: effect on oxidation and sensory analysis.

BACKGROUND: The omega-3 enrichment of ready-to-cook meat products by microencapsulated fish oil (MFO) addition was analyzed. Accordingly, three batches of chicken nuggets were prepared: (i) control (C); (ii) enriched in bulk fish oil (BFO); and (iii) with added MFO. Sensory features, acceptability, oxidative stability and volatile compounds were analyzed. RESULTS: MFO nuggets did not differ from C ones with respect to any sensory trait. BFO showed increased juiciness and saltiness but decreased meat flavor. Acceptability was not affected by enrichment. Consumers were not able to differentiate between C and MFO in a triangle test, although they could clearly identify BFO nuggets. Higher levels of lipid and protein oxidation indicators and of volatile compounds from fatty acid oxidation were found in BFO nuggets compared to C and MFO nuggets. CONCLUSION: Enrichment of ready-to-cook meat products in omega-3 fatty acids with MFO provides both lipid and protein oxidative protection without changes in sensory quality. © 2018 Society of Chemical Industry.

Near-infrared spectroscopy-based analysis to study sensory parameters on pork loins as affected by cooking methods and conditions.

BACKGROUND: The main objectives of this study were to evaluate the use of near infrared spectroscopy (NIRS) to classify pork loins under different methods and cooking conditions, and to predict sensory attributes of this product. RESULTS: Samples were oven cooked at two temperatures (150 and 180 °C) for different times (45, 60 and 75 min) and confit cooked for different times (120, 180 and 240 min). All cooked loin samples were subjected to a Quantitative Descriptive Analysis by a trained panel. For classification, principal component analysis was performed based on the NIRS database, showing a good discrimination between loins samples subjected to different cooking conditions. Regarding prediction, a data mining technique (multiple linear regression) was applied on a database constructed with data from NIRS and sensory analysis. CONCLUSION: The correlation coefficient and the mean absolute error obtained suggest that the calculated prediction equations of this study are valid to predict the changes in the sensory attributes depending on the cooking method and conditions used for pork loins. © 2018 Society of Chemical Industry.

Non-destructive analysis of sensory traits of dry-cured loins by MRI-computer vision techniques and data mining.

BACKGROUND: Magnetic resonance imaging (MRI) combined with computer vision techniques have been proposed as an alternative or complementary technique to determine the quality parameters of food in a non-destructive way. The aim of this work was to analyze the sensory attributes of dry-cured loins using this technique. For that, different MRI acquisition sequences (spin echo, gradient echo and turbo 3D), algorithms for MRI analysis (GLCM, NGLDM, GLRLM and GLCM-NGLDM-GLRLM) and predictive data mining techniques (multiple linear regression and isotonic regression) were tested. RESULTS: The correlation coefficient (R) and mean absolute error (MAE) were used to validate the prediction results. The combination of spin echo, GLCM and isotonic regression produced the most accurate results. In addition, the MRI data from dry-cured loins seems to be more suitable than the data from fresh loins. CONCLUSIONS: The application of predictive data mining techniques on computational texture features from the MRI data of loins enables the determination of the sensory traits of dry-cured loins in a non-destructive way. © 2016 Society of Chemical Industry.

MRI-computer vision on fresh and frozen-thawed beef: Optimization of methodology for classification and quality prediction.

This study aims to evaluate the capability of Magnetic Resonance Imaging (MRI) and computer vision techniques to classify fresh (raw F) (n = 12) and frozen-thawed (FT) (n = 12) beef and predict physico-chemical, texture and sensory characteristics by optimization the methodology for image analysis (algorithm) and data analysis (regressor), testing different algorithm-regressor combinations. The accuracy of the classification and prediction results especially depend on the algorithm. Different optimum combinations were found for classification (Fractal with CForest, RF or SVM) and prediction of quality parameters of raw FT (Fractal-CForest or Fractal-RF) and cooked FT samples (Classic-RF). Thus, the computational analysis of MRI, especially the algorithm to analyze the image, may be set as a function of the aim (classification or prediction) and of the type of sample (raw or cooked), while the analysed characteristic is not relevant. This study firstly showed the capability of MRI to classify beef (raw F vs. raw FT) and to determine quality characteristics in a non-destructive way.

Improvements in the Procedures to Encapsulate Diverse Bioactive Compounds.

Published articles within the "Microencapsulation of Bioactive Compounds: Techniques and Applications" special issue have been mainly focused on the evaluation of variables affecting the encapsulation of healthy compounds, aiming to achieve accurate quality properties in the encapsulates [...].

Improvements in the methodology for fatty acids analysis in meat products: One-stage transmethylation and fast-GC method.

The quantification of fatty acids (FA) in meat products is frequently carried out by two-stage methylation procedures followed by long gas chromatography (GC) runs. This work aimed to simplify this methodology by means of a one-stage transmethylation method and a fast GC run, evaluating the influence of sample preparation, reagents and type of heating on the amount of FA in different meat products and optimizing a fast GC-FID (flame ionization detector) run. This allowed to establish the optimum combination of parameters (methanol + chlorotrimethylsilane, lyophilized samples and oven heating) to achieve the quantification of the highest possible amount of FA and to reduce the time of GC run from 60 to 10 min. The quality evaluation of this method obtained satisfactory results. Thus, the quantification of FA in meat products was achieved in a straightforwardly and quickly way by using a one-stage transmethylation procedure followed by a fast GC-FID run.

1H NMR to analyse the lipid profile in the glyceride fraction of different categories of Iberian dry-cured hams.

The extraordinary organoleptic qualities of Iberian ham derive from the singular producing pig breed and from the traditional rearing conditions, both of which define its lipid content and composition. In this work 1H NMR spectroscopy is used for the first time to analyse the lipid profile of Iberian hams as determinant of quality. Quantification of fatty acids is readily obtained from the spectra, with the monounsaturated fatty acids standing out, especially in the higher quality hams. Unprecedently, triacylglyceride hydrolysis products formed during the curing process can also be directly detected and quantified. Furthermore, chemometric analysis of the NMR data allows to classify Iberian hams according to the pig's crossbreed and feeding regime. Principal component analysis shows fatty acid unsaturation and triacylglyceride hydrolysis as discriminating variables. 1H NMR spectroscopy has thus revealed as a convenient and powerful tool for the lipid analysis and classification of Iberian hams and for detection of fraud.

Recent Developments in the Microencapsulation of Fish Oil and Natural Extracts: Procedure, Quality Evaluation and Food Enrichment.

Due to the beneficial health effects of omega-3 fatty acids and antioxidants and their limited stability in response to environmental and processing factors, there is an increasing interest in microencapsulating them to improve their stability. However, despite recent developments in the field, no specific review focusing on these topics has been published in the last few years. This work aimed to review the most recent developments in the microencapsulation of fish oil and natural antioxidant compounds. The impact of the wall material and the procedures on the quality of the microencapsulates were preferably evaluated, while their addition to foods has only been studied in a few works. The homogenization technique, the wall-material ratio and the microencapsulation technique were also extensively studied. Microcapsules were mainly analyzed for size, microencapsulation efficiency, morphology and moisture, while in vitro digestion, flowing properties, yield percentage and Fourier transform infrared spectroscopy (FTIR) were used more sparingly. Findings highlighted the importance of optimizing the most influential variables of the microencapsulation procedure. Further studies should focus on extending the range of analytical techniques upon which the optimization of microcapsules is based and on addressing the consequences of the addition of microcapsules to food products.

Contents and composition of individual phospholipid classes from biceps femoris related to the rearing system in Iberian pig.

During dry-cured ham processing, phospholipids (PL) are the main substrates of lipolysis and oxidation. However, the published data on individual PL classes in the pig muscle are inconsistent. This study determined the PL class contents and composition in biceps femoris of Iberian pigs according to the rearing system (Montanera vs Pienso). Phosphatidylcholine (PC), phosphatidylethanolamine (PE), cardiolipin (CL) and sphingomyelin contents were higher in the Montanera pigs than in the Pienso pigs. Total PL and PC, PE, phosphatidylinositol + phosphatidylserine and CL contained higher levels of oleic acid and slightly higher levels of n-3 polyunsaturated fatty acids (PUFA) but lower levels of n-6 PUFA in the Montanera pigs than in the Pienso pigs. The rearing system had no effect on the plasmalogen content but influenced aldehyde composition, mainly in PE and in total PL. These results can partially explain the differences in sensory properties of dry-cured ham between the Montanera and Pienso systems.

Optimization of the image acquisition procedure in low-field MRI for non-destructive analysis of loin using predictive models.

The use of low-field magnetic resonance imaging (LF-MRI) scanners has increased in recent years. The low economic cost in comparison to high-field (HF-MRI) scanners and the ease of maintenance make this type of scanner the best choice for nonmedical purposes. However, LF-MRI scanners produce low-quality images, which encourages the identification of optimization procedures to generate the best possible images. In this paper, optimization of the image acquisition procedure for an LF-MRI scanner is presented, and predictive models are developed. The MRI acquisition procedure was optimized to determine the physicochemical characteristics of pork loin in a nondestructive way using MRI, feature extraction algorithms and data processing methods. The most critical parameters (relaxation times, repetition time, and echo time) of the LF-MRI scanner were optimized, presenting a procedure that could be easily reproduced in other environments or for other purposes. In addition, two feature extraction algorithms (gray level co-occurrence matrix (GLCM) and one point fractal texture algorithm (OPFTA)) were evaluated. The optimization procedure was validated by using several evaluation metrics, achieving reliable and accurate results (r > 0.85; weighted absolute percentage error (WAPE) lower than 0.1%; root mean square error of prediction (RMSEP) lower than 0.1%; true standard deviation (TSTD) lower than 2; and mean absolute error (MAE) lower than 2). These results support the high degree of feasibility and accuracy of the optimized procedure of LF-MRI acquisition. No other papers present a procedure to optimize the image acquisition process in LF-MRI. Eventually, the optimization procedure could be applied to other LF-MRI systems.

Fish Oil Microcapsules as Omega-3 Enrichment Strategy: Changes in Volatile Compounds of Meat Products during Storage and Cooking.

This work aims to analyze the effects of processing and storage on the volatile compound profile of different meat products enriched in ω-3 polyunsaturated fatty acids (PUFA). Monolayered (Mo) and multilayered (Mu) microcapsules of fish oil were tested. The profiles of volatile compounds were analyzed by solid-phase microextraction (SPME) coupled with gas chromatography-mass spectrometry (GC-MS). The enrichment with Mo significantly increases the abundance of volatile compounds from lipid oxidation and markers of ω-3 PUFA oxidation, which may be related to the multilayer structure of chitosan-maltodextrin in Mu that achieves greater fish oil protection than the simple coating of maltodextrin in Mo. Besides, the changes in volatile compounds during storage depends on the type of fish oil microcapsules and the meat products, having an increased abundance of ω-3 PUFA oxidation markers in dry-cured sausages added with Mo. However, the enrichment of these meat products with Mo and Mu does not modify the usual variations in the volatile compound profile during culinary cooking. Thus, the addition of multilayer fish oil microcapsules may be a suitable option for enrichment of meat products in ω-3 PUFA without modifying the abundance of volatile compounds, including oxidation markers.

Evaluation of fresh meat quality by Hyperspectral Imaging (HSI), Nuclear Magnetic Resonance (NMR) and Magnetic Resonance Imaging (MRI): A review.

The development of non-destructive methodologies based on Hyperspectral Imaging (HSI), Nuclear Magnetic Resonance (NMR) and Magnetic Resonance Imaging (MRI) techniques to determine quality characteristics of fresh meat has been reviewed in this study. It has been focused primarily on research published in the last decade, and has placed particular attention on the instrumentation, data acquisition and main applications of each technique, finding a wide variety of possibilities for systems and methodologies as well as evidence of accurate and promising results. Most samples analysed were pork and beef, followed by lamb and chicken, with few studies on fresh meat from rabbit and duck. The overall evaluation is that work has been performed primarily in an experimental way but generally still lacks real application in the meat industry. In that respect, these non-destructive techniques should be improved, especially regarding speed, price and influence of external factors.

Influence of pre-cure freezing on the profile of volatile compounds during the processing of Iberian hams.

BACKGROUND: This work was designed to study the effect of pre-cure freezing of raw thighs from Iberian pigs on the profile of volatile compounds during the processing of hams. RESULTS: Generation of volatile compounds during Iberian ham processing was similar in both pre-cure frozen and refrigerated hams, the main differences being at the final stage. The levels of 2-methylbutanal, 2-methyl-1-butanol, 2,3-butanediol and 2-heptanol were significantly higher in dry-cured hams that were pre-cure frozen than in refrigerated ones, whereas the content of most detected esters was statistically lower in pre-cure frozen than in refrigerated hams. CONCLUSION: The effect of pre-cure freezing of Iberian ham on the profile of volatile compounds during ripening was not remarkable. Few differences were found in the final product, which would not greatly modify the aroma and flavour features of the dry-cured hams.

Lipid digestion and oxidative stability in ω-3-enriched meat model systems: Effect of fish oil microcapsules and processing or culinary cooking.

This study evaluates the addition of monolayered (MO) and multilayered (MU) fish oil microcapsules to meat model systems and determines the effects of processing and culinary cooking. Adding MO and MU increased the content of EPA and DHA and the level of secondary oxidation products but being far away from the oxidation values that generate anomalous flavours. However, it did not lead to oxidative damage of the enriched batches or affect the moisture and lipid content during processing and/or culinary cooking. The type of fish oil microcapsules, the processing and/or culinary cooking and the type of meat matrix influenced the fatty acid digestion. The highest bioaccessibility of EPA and DHA occurred in cooked samples enriched with MO after processing and before culinary cooking. To optimize EPA and DHA enrichment and bioaccessibility, the type of fish oil microcapsules may be selected as a function of the type of added meat products.

Evaluating the use of fish oil microcapsules as omega-3 vehicle in cooked and dry-cured sausages as affected by their processing, storage and cooking.

This work evaluated the use of monolayered (Mo) and multilayered (Mu) fish oil microcapsules as vehicles of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in cooked and dry-cured meat products as affected by the storage and culinary heating or dry-cured processing. Proximate composition, oxidation, EPA and DHA quantity, acceptability and morphology were evaluated. Mo and Mu microcapsules increased the quantity of EPA and DHA, leading to cooked and dry-cured products susceptible to be labeled as "source of omega-3 fatty acids", without influencing physico-chemical characteristics, oxidative stability, acceptability or usual changes that take place during the culinary heating or dry-cured processing. The storage at refrigeration influenced on usual modifications on lipid oxidation and hedonic scores, but overall quality of the meat products enriched seems not to be impaired after storing. Thus, it could be indicated the viability of Mo and Mu as vehicles to enrich meat products subjected to low and high temperature for manufacturing, storage at refrigeration and culinary heating.

Effect of Omega-3 Microcapsules Addition on the Profile of Volatile Compounds in Enriched Dry-Cured and Cooked Sausages.

The main goal of the present study was evaluating the effect of enriching meat products (cooked (C-SAU) and dry-cured sausages (D-SAU)) with monolayered (Mo) and multilayered (Mu) fish oil microcapsules on the profile of volatile compounds, with special interest in lipid oxidation markers. For that, Solid-Phase Microextraction (SPME) and Gas Chromatography-Mass Spectrometry (GC-MS) were used. Significant differences were found in the volatile compound profile between Mo and Mu, which was been reflected in the meat samples. Thus, in general, volatile compounds from lipid oxidation have shown higher abundance in Mo and C-SAU and D-SAU enriched with this type of microcapsule, indicating that the wall of Mu (chitosan-maltodextrine) might protect the encapsulated bioactive compounds more effectively than that of Mo (maltodextrine). However, this finding is not reflected in the results of previous studies evaluating the sensory perception and oxidation stability of C-SAU and D-SAU, but it should be considered since unhealthy oxidation products can be formed in the enriched meat products with Mo. Thus, the addition of Mu as an omega-3 vehicle for enriching meat products may be indicated.

Monitoring the Processing of Dry Fermented Sausages with a Portable NIRS Device.

This work studies the ability of a MicroNIR (VIAVI, Santa Rosa, CA) device to monitor the dry fermented sausage process with the use of multivariate data analysis. Thirty sausages were made and subjected to dry fermentation, which was divided into four main stages. Physicochemical (weight lost, pH, moisture content, water activity, color, hardness, and thiobarbiruric reactive substances analysis) and sensory (quantitative descriptive analysis) characterizations of samples on different steps of the ripening process were performed. Near-infrared (NIR) spectra (950-1650 nm) were taken throughout the process at three points of the samples. Physicochemical data were explored by distance to K-Nearest Neighbor (K-NN) cluster analysis, while NIR spectra were studied by partial least square-discriminant analysis; before these models, Principal Component Analysis (PCA) was performed in both databases. The results of multivariate data analysis showed the ability to monitor and classify the different stages of ripening process (mainly the fermentation and drying steps). This study showed that a portable NIR device (MicroNIR) is a nondestructive, simple, noninvasive, fast, and cost-effective tool with the ability to monitor the dry fermented sausage processing and to classify samples as a function of the stage, constituting a feasible decision method for sausages to progress to the following processing stage.