Effects of ultrasound versus pasteurization on whey–oat beverage processing: quality and antioxidative properties

The consumption of functional beverages is rapidly increasing. The improvement in the functional properties of whey after the application of ultrasound is due to the release of bioactive peptides that have antioxidant properties, among others. Bioactive peptides with antioxidant activity have also been found in oats, stimulating the study of whey beverages formulated with oats to obtain functional products. The aim of this study was to determine the influence of ultrasound (24 kHz) at 20 °C for 15 min at 23 W and 154 W on the quality and functional properties of whey–oat (50:50 v/v) beverages and compare it with pasteurization at 65 °C for 30 min (LTLT). Non-significant effect (p > 0.05) of ultrasound intensity (23 W and 154 W) was observed on the physicochemical characteristics and the proximal composition of the whey–oat beverages. The sonicated beverages showed a greater tendency to green and yellow color (p < 0.05), higher fat content (p < 0.05), and less ash and carbohydrates (p < 0.05) than the pasteurized beverage. The antioxidant activity of the mM Trolox equivalent/mL of the sonicated beverages was higher (p < 0.05) (4.24 and 4.27 for 23W and 54 W, respectively) compared to that of the pasteurized beverage (4.12). It is concluded that ultrasound is superior to pasteurization in improving the antioxidant activity of whey–oat beverages without having a detrimental impact on the proximal composition and physicochemical quality. Future studies should evaluate more functional parameters and determine the shelf life of sonicated whey–oat beverages

Anisotropy and chemical composition of ultra-high energy cosmic rays using arrival directions measured by the Pierre Auger Observatory

The Pierre Auger Collaboration has reported evidence for anisotropy in the distribution of arrival directions of the cosmic rays with energies $E>E_{th}=5.5\times 10^{19}$ eV. These show a correlation with the distribution of nearby extragalactic objects, including an apparent excess around the direction of Centaurus A. If the particles responsible for these excesses at $E>E_{th}$ are heavy nuclei with charge $Z$, the proton component of the sources should lead to excesses in the same regions at energies $E/Z$. We here report the lack of anisotropies in these directions at energies above $E_{th}/Z$ (for illustrative values of $Z=6,\ 13,\ 26$). If the anisotropies above $E_{th}$ are due to nuclei with charge $Z$, and under reasonable assumptions about the acceleration process, these observations imply stringent constraints on the allowed proton fraction at the lower energies

Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO

Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principle calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI. Supplemental material in the ancillary file

Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

A measurement of the cosmic-ray spectrum for energies exceeding $4{\times}10^{18}$ eV is presented, which is based on the analysis of showers with zenith angles greater than $60^{\circ}$ detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above $5.3{\times}10^{18}$ eV, the "ankle", the flux can be described by a power law $E^{-\gamma}$ with index $\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)}$ followed by a smooth suppression region. For the energy ($E_\text{s}$) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find $E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19}$ eV.Comment: Replaced with published version. Added journal reference and DO

Efficacy of Ultrasonic-Assisted Curing Is Dependent on Muscle Size and Ultrasonication System

Ultrasound-assisted marinade is a promising technology for reducing the time of traditional immersion marination. This study evaluated the effect of the ultrasonic system (bath or probe, amplitude 50 or 100%) and muscle sample size (3 or 5 cm3) on physicochemical quality, yield (salt content, fresh weight, and relative fresh weight), and bacteria counts associated with pork. The results showed a significantly high salt (p &lt; 0.0001) content in 3 cm3 (11.54%) and 5 cm3 (8.88%) samples after 24 h marination by immersion. The 3 cm3 cubes marinated in a 100% probe system for 20 min presented an amount of salt (9.55%) that was quite close to the controls. The 3 cm3 samples treated by immersion and in a 50% probe system gained more relative weight (in relation to the initial weight, 7.45 and 6.64%, respectively) after 7 d at 4 &deg;C. Meanwhile the 5 cm3 cubes marinated by immersion gained 8.1%. The other treatments showed a weight loss after treatment. Although significant differences were found in the fresh weight and in water holding capacity (WHC) in the 3 and 5 cm3 meat samples, the relative fresh weight is a real measure of weight gain, more relevant for the industry. Thus, the samples with the highest salt transfer experienced a phenomenon of &ldquo;dehydration&rdquo;, retaining less water. The 3 and 5 cm3 cubes marinated by immersion presented orange color tones due to the long processing time, while the probe system produced redder and brighter tones. Ultrasound as a technology to assist in marinades is not efficient for bacteria control of mesophilic, psychrophilic, or coliform. However, a significant increase in lactic acid bacteria (LAB) counts may bring benefits for meat preservation during refrigerated storage

The Physicochemical, Microbiological, and Structural Changes in Beef Are Dependent on the Ultrasound System, Time, and One-Side Exposition

The effect of high-intensity ultrasound (HIU) system (bath, 37 kHz and 90 W/cm2; or probe, 24 kHz and 400 W) and application time (25 or 50 min, one-side exposition) on the properties of bovine Longissimus lumborum after 7 d of storage at 4 &deg;C was studied. The bath system significantly increased the lightness of the muscle, while other color parameters (a*, b*, hue, and chroma) were not different from the control. The water holding capacity and shear force decreased significantly (3.1&ndash;5% and 0.59&ndash;0.72 kgf, respectively) in sonicated meat independently of the system, favoring the tenderization of the muscle after storage. Microstructural changes observed in the HIU-exposed surface provided evidence of a higher area of interfibrillar spaces (1813 vs. 705 &micro;m2 in the control), producing tenderization of the muscle, compared with the control. HIU significantly increased counts of total aerobic and coliform bacteria, especially after 50 min of ultrasonication. HIU also increased lactic acid bacterial counts in the bath system. Single-sided muscle exposition to ultrasound may produce sufficient significant changes in muscle properties, which could decrease long treatment times that would be needed for the exposition of both sides. HIU in bath systems increases tenderness by modifying meat ultrastructure, with no significant changes in physicochemical parameters. Nevertheless, microbiological quality may need to be considered during the process due to a slight increase in bacterial counts

The Effect of High-Intensity Ultrasound on the Physicochemical and Microbiological Properties of Mexican Panela Cheese

High-intensity ultrasound could be an alternative to pasteurization for cheeses made with fresh raw milk, the properties of which must be preserved as part of their intangible cultural heritage, such as Panela cheese in Mexico. This research aimed to study the effect of the amplitude (50% and 100%) and application time (0, 5, and 10 min) of ultrasound treatment of fresh raw milk, on the yield and microbiological and physicochemical qualities of Panela cheese after 24 h of storage at 4 &deg;C. The yield was increased to 24.29% with 10 min of ultrasonication, although the amount of exudate was higher in the ultrasonic product than in the control (20.33%). As the ultrasonication time increased, the yellowness (b*) increased significantly, while the hue angle decreased (with values close to 90&deg;), resulting in evident yellow tones in cheeses made with milk treated for 10 min. The pH significantly increased from 6.6 to 6.74 with 5 min of ultrasound, but decreased to 6.37 with 10 min of ultrasonication. Although no significant differences were found in fat content, the protein significantly increased with 5 min of sonication, but it decreased markedly when ultrasound was applied for 10 min. Ultrasound treatment with amplitudes of 50% effectively decreased the counts of coliform bacteria regardless of ultrasonication time. However, the mesophilic bacteria increased by a 0.9 log with an amplitude of 100% and 10 min treatment. The results showed that ultrasound improved the yield and microbial, nutritional, and physicochemical properties of Panela cheese