In this study, the effects of ultrasound- (US-) assisted beef marination on consumer perception and the homogeneity of the solute and mass transfer were evaluated. Marinated and US-treated meat samples (40 kHz, 11 W/cm2 for 20, 40, and 60 min, and storing at 4°C for 7 d) were evaluated by a group of consumers using a structured 9-point hedonic scale of satisfaction. The preferences were analyzed with XLSTAT-Sensory® software. The analysis was performed in conjunction with an energy-dispersive X-ray spectroscopic study to evaluate the sodium transference. The perception analysis indicated that the use of US-assisted marination did not increase the beef acceptability. The sonicated samples showed a more homogeneous distribution of sodium. However, traditional marination (TM) stored for 7 d resulted in greater mass transfer than the US-assisted marination without storage.
Marination is a process by which an aqueous or oily solution containing different ingredients and/or additives (such as salts, polyphosphates, flavorings, and proteins) is incorporated in meat. Marination is performed on any type of meat muscle (pork, beef, chicken, turkey, and lamb) [
However, the injection of brines containing sodium chloride, calcium chloride, polyphosphates, and acids affects the taste of meat [
Acoustic waves applied to solid-liquid systems increase the rate of mass transfer [
The aim of this study was to evaluate the effect of US-assisted beef marination on consumer perception and the relation of US to the homogeneity of the solute and mass transfer in the system.
Samples of bovine muscle
Description of treatments.
Treatment | Marinated type | Marinated time (min) | Storage at 4°C (d) |
---|---|---|---|
T1 | Ultrasound | 60 | 7 |
T2 | Ultrasound | 40 | 7 |
T3 | Ultrasound | 20 | 7 |
T4 | Conventional | 60 | 7 |
T5 | Conventional | 40 | 7 |
T6 | Conventional | 20 | 7 |
T7 | Ultrasound | 60 | 0 |
T8 | Ultrasound | 40 | 0 |
T9 | Ultrasound | 20 | 0 |
T10 | Conventional | 60 | 0 |
T11 | Conventional | 40 | 0 |
T12 | Conventional | 20 | 0 |
A commercial brine solution was prepared for marination of meat (pH 4.8). To produce the brine, seasoning (20 g) containing 2% sodium chloride, 1% monosodium glutamate, 31% garlic, 22% onion, 40% black pepper, 0.99% dextrose, 2% citric acid, 1% silicon dioxide, and 0.01% yellow 5 (tartrazine) was dissolved in 1000 mL of water.
The samples were placed in polypropylene bags, 10 mL of brine was added per 20 g of meat, and the bags were then vacuum-packed. Sample sonication was performed in a US bath (15 × 15 × 10 cm), with a total capacity of 2.25 L. The total amount of water used for sonication was 562.5 mL (Figure
Schematic diagram of the experimental setup.
The effective power introduced to the system by the US was measured using the calorimetric technique described by M. A. Margulis and I. M. Margulis [
In total, 24 consumers aged 17–25 years were recruited. All reported that they consumed beef regularly.
The samples were cooked in an electric skillet (West Bend®, USA) at 176°C for 4 min 30 s on each side. The temperature at the geometrical center of the sample was 72°C. The sample was presented to consumers at 55°C.
The cooked samples were presented in groups of three to the consumers. Plastic containers were coded with three-digit numbers (table from the RAND Corporation [
General acceptability was determined by a scored test with a structured 9-point hedonic scale of satisfaction (1, “I dislike it a lot,” to 9, “I like it a lot”) and an unstructured pleasantness scale of 10 cm with anchors “little” on the left and “a lot” on the right, with a midpoint. The evaluated sensory properties were tenderness (“tough” to “very tender”), juiciness (“dry” to “very juicy”), taste (“weak taste” to “very pronounced taste”), and smell (“weak smell” to “pronounced smell”) [
Four representative treatments were chosen for the study of the mass transfer and the semiquantitative analysis of sodium. The treatments were as follows: T1 = 60 min US, 7 d; T4 = 60 min MT, 7 d; T7 = 60 min US, 0 d; and T10 = 60 min MT, 0 d. Samples measuring 0.5 × 0.5 × 0.5 cm3 were cut under a stereoscope (Carl Zeiss®) and placed in 2.5% glutaraldehyde with Sorensen’s phosphate buffer at pH 7.2 for 4 h, during periods of 5 min vacuum during the first hour of fixing. The samples were rinsed twice in Sorensen’s phosphate buffer at pH 7.0 for 10 min. The samples were then dehydrated with an ethanol series starting at 30% and increasing to 100% for 45 min. The samples were then dried to the critical point with CO2 (Tousimis Samdri® 780A) and coated with gold for 10 min in an ionizer (Jeol Fine Coat Ion Sputter JFC-1100) for observation in a scanning electron microscope (JEOL JSM-6390) operated at 20 kV. The resulting data were mapped by the weight of sodium in the samples.
The Friedman test, based on medians, with pairwise multiple comparisons using the Nemenyi test was used to analyze the effect of the US treatment on consumer perception. An agglomerative hierarchical clustering (AHC) with type proximity of similarity and Pearson’s correlation coefficient with the simple linkage method were performed. For the study of preferences, a clustering of consumers was performed to create classes for the global appreciation variable associated with the four properties evaluated in the sensory test. That is, a hierarchical ascendant classification (HAC) and a principal component analysis (PCA) of the sensory properties were used to construct the external preference mapping (EPM) quadratic model. The software XLSTAT-Sensory version 2015.6.01 (Addinsoft) was used. Semiquantitative analysis of variance (ANOVA) with a mean comparison test (Tukey,
The content of sodium in beef samples showed a statistically significant difference (
Content of sodium in beef samples
Treatment | Sodium (% in weight) |
---|---|
60 min MT, 7 d | |
60 min MT, 0 d | |
60 min US, 7 d | |
60 min US, 0 d | |
MT, marinated traditionally; US, ultrasound; d, storage days at 4°C. The content of sodium is the average of three experiments. Means in a column without a common superscript letter differ (
The results in Table
Distribution of sodium in beef samples
Leal-Ramos et al. [
US-assisted extraction is a technology that is cheap, efficient, and easy to operate. Its advantages can be attributed to the acoustic cavitations produced on solvents, achieving a higher penetration of solvents in the sample matrix. In addition, cavitation increases the contact surface between solid and liquid phases. As a result, solutes are rapidly distributed [
The brine had a pH of 4.8, an acid profile probably due to the citric acid component. The initial pH of the samples before any treatment was 5.8. However, the pH of both traditionally marinated and sonicated samples at 7 d after storage was 6.2, due to sodium salt addition during the marination process. There was a slight difference between marinated types and times (
The means of the ranges (Table
Multiple comparisons of beef samples
Samples | Summation of ranges | Means of ranges |
---|---|---|
60 min US, 0 d | 114.000 | |
40 min MT, 0 d | 116.000 | |
40 min US, 0 d | 122.000 | |
20 min US, 0 d | 123.500 | |
40 min MT, 7 d | 140.000 | |
60 min MT, 0 d | 154.000 | |
20 min MT, 7 d | 163.500 | |
20 min MT, 0 d | 170.000 | |
40 min US, 7 d | 175.000 | |
20 min US, 7 d | 179.500 | |
60 min US, 7 d | 190.500 | |
60 min MT, 7 d | 224.000 | |
MT, marinated traditionally; US, ultrasound; d, storage days at 4°C. Significance level is 0.05. Values in columns with different letters are statistically different (
Results per class and grouping of beef samples
Class | Samples per class | Interclass variance | Treatment |
---|---|---|---|
1 | 5 | 58.600 | 60 min US, 0 d |
40 min US, 0 d | |||
20 min US, 0 d | |||
60 min US, 7 d | |||
40 min US, 7 d | |||
| |||
2 | 3 | 45.333 | 60 min MT, 0 d |
40 min MT, 0 d | |||
20 min MT, 0 d | |||
| |||
3 | 3 | 35.333 | 20 min US, 7 d |
60 min MT, 7 d | |||
40 min MT, 7 d | |||
| |||
4 | 1 | 0.000 | 20 min MT, 7 d |
MT, marinated traditionally; US, ultrasound; d, storage days at 4°C.
Categorization of beef samples
The data variability of the results mapped in Figure
Sensory space of beef samples
The treatments with the greatest acceptance were as follows: T1 60 min US, 7 d; T4 60 min MT, 7 d; T6 20 min MT, 7 d; and T10 60 min MT, 0 d. These treatments had positive values for both principal components (Figure
The US waves acting on the meat surface enable the introduction of the brine from US cavitation [
Muscular tissue has lower ionic strength during the traditional marination process compared with brining, reaching equilibrium status by osmosis. This explains why there were no differences in consumer preferences between traditional marination for 60 min with storage and the US-assisted marination with storage.
Equilibrium status was also reported by Sánchez et al. [
Another factor that seems to have a critical influence on consumer preferences is storage time (7 d). At 48 h postmortem, meat is still fresh, and during the storage period, proteolysis caused by calpains contributes to increased tenderness and taste. This proteolysis process can persist up to 10–14 d postmortem in beef [
External preference mapping (Figure
Preferences and satisfaction (%) of beef samples
The percentage of satisfied consumer judges (Figure
Microchannels are generated inside meat samples and affect the tenderness because of cell disruption [
The data in Figure
The data in this study confirm that US offers a positive alternative to traditional marination techniques because the US-treated meat presented a homogeneous distribution of the brine solutes in the meat. Even though the preliminary perception analysis showed that the use of US-assisted marination does not increase the sensory properties of beef, a quantitative descriptive sensory analysis with a trained panel should be considered to evaluate the perception of specific properties in meat in homogeneous and heterogeneous distributions of brine. The acceptability of the marinated product depends on the largest mass transfer to the meat, not on the homogeneity and heterogeneity of the solute distribution.
The authors declare that there is no conflict of interests regarding the publication of this paper.
The authors acknowledge the Electron Microscopy Unit of the “Colegio de Postgraduados (COLPOS)” (Postgraduate College of Agriculture), México, for assistance with scanning electron microscopy.