High-intensity ultrasound as pre-treatment in the development of fermented whey and oat beverages: effect on the fermentation, antioxidant activity and consumer acceptance.

This study aimed to evaluate the effect of high-intensity ultrasound as pre-treatment in the development of fermented whey and oat beverages. Oat malt was produced, incorporated into a whey formulation (35, 50 and 65% v/v of whey) and ultrasonicated (at 40 kHz and 11 W/cm2) for 0, 3 or 10 min, prior to fermentation with L. casei 431. The treatments were identified as 35/65/0, 50/50/0, 65/35/0, 35/65/3, 50/50/3, 65/35/3, 35/65/10, 50/50/10 and 65/35/10, referring to the whey percentage, oat percentage, and the ultrasound time (min), respectively. The beverages 50/50/0 and 50/50/3 registered the highest (P < 0.05) growth with 1.96 and 2.00 log CFU ml, respectively. In general, the final average population of L. casei 431 was 7 to 8.86 log CFU/ml, being this adequate for a probiotic beverage. The highest antioxidant activity was found in the 35/65/3, 35/65/10, 50/50/3 and 50/50/10 beverages without difference (P < 0.05) among them. There was no effect of gender on the acceptance of the probiotic beverages. The best accepted beverage by women was 50/50/3 and both genders disliked the beverage 35/65/10. There was no relationship between the acceptance of the beverages and the consumers' habit by fermented milk beverages. No difference in the preference between the 50/50/0 and the 50/50/3 beverage was found. It is concluded that the probiotic beverage containing 50% whey and 50% oat and ultrasonicated for 3 min generated the highest levels of L. casei 431 growth, high antioxidant activity and good consumer acceptance and preference.

High-Frequency Focused Ultrasound on Quality Traits of Bovine Triceps brachii Muscle.

This aim of this study was to evaluate the effect of high-frequency focused ultrasound (HFFU) on quality traits of bovine Triceps brachii. Four treatments (0, 10, 20, and 30 min) of HFFU (2 MHz and 1.5 W/cm2) were applied to bovine T. brachii muscle. Immediately after treatment, evaluations of color, pH, drip loss, water holding capacity, and shear force in meat were undertaken. The application of HFFU slightly decreased (p < 0.05) the redness of meat. In addition, a significant (p < 0.05) decrease in the shear force of meat was observed after the application of HFFU at 30 min. No effect (p > 0.05) was observed on other color parameters, drip loss, and water holding capacity of meat. Overall, HFFU improved beef tenderness without negative impacts on color, pH, drip loss, and water holding capacity of meat. HFFU offers the option of tenderizing specific muscles or anatomical regions of the beef carcass. These findings provide new insights into the potential application of ultrasound in meat processing.

Fat replacement by pecan nut and oregano oil and their impact on the physicochemical properties and consumer acceptability of frankfurters.

OBJECTIVE: A study was conducted to determine the physicochemical quality and consumer acceptability of beef frankfurter-type sausages formulated with pecan nut paste and Mexican oregano oil (MO) of two varieties, Poliomintha longiflora Gray (Mexican oregano Poliomintha, MOP) or Lippia berlandieri (Mexican oregano Lippia, MOL). METHODS: Frankfurters were processed under six treatment conditions: control (10.67% pork fat), MOP (control + 0.01% MOP), MOL (control + 0.01% MOL), MOP-N (control + 0.01% MOP + 6% pecan nut paste), MOL-N (control + 0.01% MOL + 6% pecan nut paste), and C-N (control + 6% pecan nut paste). The physicochemical properties and the consumer acceptability were determined. RESULTS: The addition of MO and nut did not influence the water holding capacity, drip loss, and luminosity of frankfurters, but those ingredients increased pH and shear force (p<0.05) and decreased redness (p<0.05) of frankfurters. Frankfurters were generally well accepted by consumers. However, general acceptability of sausages decreased with the addition of MO. Control sausages showed the highest acceptability. CONCLUSION: The MO and pecan nut paste do not affect drastically the quality of frankfurters. These results provide evidence that partial replacement of pork fat by pecan nut in frankfurters maintain a consistent physicochemical quality and its commercialization looks promising given consumers' acceptance.

High-intensity ultrasound applied on cured pork: Sensory and physicochemical characteristics.

This research aimed to evaluate the physicochemical characteristics and their relationship with sensory properties of cured porcine m. longissimus lumborum assisted by high-intensity ultrasound (HIU, 37 kHz, 22 Wcm-2). An experiment was designed with three factors at two levels each: type of curing (immersion or ultrasound-assisted -UA-), immersion time (30 or 90 min), and steak thickness (1.27 or 2.54 cm). After treatment and 7 days of storage at 4°C, the percentage of salt, pH, CIE L* a* b* color, water holding capacity (WHC), and shear force were determined in the samples. A quantitative descriptive analysis was performed using eight trained panelists. The HIU significantly increased the percentage of NaCl (p < .0005) and decreased the color saturation of the meat (p < .05), but did not affect the luminosity, redness (a*), yellowness (b*), pH, WHC, or shear force (all p > .05). The thickness of the steak had significant effects on almost all of the evaluated variables. Samples with 1.27 cm thickness had lower shear force, higher WHC and salt percentage (p < .0001). In agreement with this, the sensory profiles showed that the 1.27 cm samples treated with HIU for 30 min were perceived as less tough (more tender) and juicier.

Bacterial control and structural and physicochemical modification of bovine Longissimus dorsi by ultrasound.

A multifactorial study to evaluate the effect of three ultrasound intensities (16, 28 and 90 Wcm-2), two sonication times (20 and 40 min), and two storage times (0 and 7 days at 4 °C) on physicochemical properties, microbiological counts, and microstructure of bovine Longissimus dorsi was performed. The results showed that ultrasound (US) did not modify luminosity (P = 0.42), redness (a*, P = 0.45), or yellowness (b*, P = 0.94). However, the hue angle increased with US treatment and during storage (P = 0.04), showing an important degradation in the color of meat treated with 16 Wcm-2. The pH and shear force decreased during storage at 4 °C (P = 0.01). Although US did not have any significant effects on the tenderness of the meat, the interfibrillar areas increased drastically in samples treated with 16, 28 and 90 Wcm-2 (P < 0.0001). US was effective in controlling mesophilic and psychrophilic bacteria during storage at 4 °C when intensities of 90 Wcm-2 were used (P < 0.0001), whereas decontamination of coliform bacteria was efficient independently of ultrasonication intensity, as long as a long sonication time (40 min) was used.

Ultrasound and meat quality: A review.

High intensity ultrasound (HIU) offers an alternative to traditional methods of food preservation, and is regarded as a green and promising emerging technology. Ultrasound generates acoustic cavitation in a liquid medium, developing physical forces that are considered the main mechanism responsible for changes in exposed materials. In meat, ultrasound has been successfully used to improve processes such as mass transfer and marination, tenderization of meat and inactivation of microorganisms. It is also an alternative to traditional meat ageing methods for improving the quality properties of meat. Moreover, the combination of ultrasonic energy with a sanitizing agent can improve the effect of microbial reduction in foods. This review describes recent potential applications of ultrasound in meat systems, as well as physical and chemical effects of ultrasound treatment on the conservation and modification of processed meat foods. Finally, the ultrasound application parameters must be deep explored and established before the method can be scaled to industrial levels.

Efectos fisiológicos de los péptidos bioactivos derivados de las proteínas del lactosuero en la salud: Una revisión / Physiological health effects of whey protein-derived bioactive peptides: A review

RESUMEN El lactosuero es un subproducto derivado de la elaboración de queso. La calidad de la composición química de las proteínas del lactosuero las convierte en un sustrato ideal para la generación de péptidos con actividad biológica. La presente revisión tiene por objetivo analizar y discutir los efectos fisiológicos de los péptidos bioactivos derivados de las proteínas del lactosuero (PBDL) en la salud. Asimismo, este trabajo muestra detalladamente las estructuras químicas de las secuencias de los PBDL capaces de ejercer efectos favorables in vitro e in vivo e influir positivamente en los sistemas cardiovascular, endócrino e inmunológico. Sin embargo, las metodologías para generar PBDL de manera controlada, la dosificación y las concentraciones óptimas han sido poco exploradas. Por lo que es importante llevar a cabo investigación de frontera que permita avanzar el umbral del conocimiento vislumbrando la posibilidad de utilizar los PBDL como coadyuvantes en la prevención y tratamiento de enfermedades.

ABSTRACT Whey is a by-product of cheese production. The relevant chemical composition of whey proteins makes them an ideal substrate to release peptides with biological activity. The objective of this manuscript was to analyze and discuss the effects of whey-derived proteins bioactive peptides in health. Moreover, this review shows in detail sequences able to benefit human systems. Several in vitro and in vivo studies showed the capacity of these bioactive peptides to positively influence cardiovascular, endocrine and immune systems. However, the methodologies to obtain them in a controlled way, as well as dose and optimum concentrations have been scarcely explored. Therefore, it is necessary to conduct new research to improve knowledge that focuses on the possibility of using whey-derived bioactive peptides in the prevention and treatment of diseases.

Ultrasound as a potential process to tenderize beef: Sensory and technological parameters.

In this study, the effects of high intensity ultrasound (HIU), applied after storage, on the physical, microstructural, and sensory characteristics of beef were evaluated. Samples of four beef m. Longissimus dorsi muscle were stored in vacuum at 4 °C for 0, 7 or 14 days and then ultrasonicated (40 kHz, 11 W/cm2) for 60 min. Beef stored for 7 d prior to ultrasonication displayed increased pH and luminosity, reduced redness and saturation value, higher hue angle, and variable changes in water holding capacity. Shear force of sonicated meat was lower than that of control samples at all storage times. HIU also increased the tenderness and fragmentation of meat (P < 0.05) measured by texture profile analysis. The microstructure of sonicated meat showed a visible reduction in the size of fascicles, greater interfibrillary spaces, and thinner endomysium. These effects were enhanced with the storage of meat previous to HIU treatment. Meat stored for 14 d and then treated with ultrasound was perceived to have a more intense fresh meat smell and oily flavor (P < 0.05). However, it was also perceived to be a paler grayish brown color compared to control samples stored for the same duration. Ultrasonicated meat also presented a greater intensity of metallic taste (P < 0.05) and a more tender and moist texture (P < 0.05). Overall, application of HIU of meat after meat was stored affects textural and microstructural properties and accelerates aging without negative impacts on other technological and sensory attributes. Therefore, HIU application after storage has potential as a safe method for tenderizing bovine meat when handled under the conditions in this study.

Comparison of fatty acid content of fresh and frozen fillets of rainbow trout (Oncorhynchus mykiss) Walbaum

The aim of this study was to evaluate and compare the percentage content of fatty acids (FA) of 54 rainbow trout fresh and frozen fillets. Frozen fillets were stored at -15ºC for 45 and 90 days. Saturated (SFA), monounsaturated (MUFA), polyunsaturated (PUFA), omega-6 (n-6) and omega-3 (n-3) fatty acids were determined by gas chromatograph coupled to mass spectrometry. The results indicated that during frozen storage, SFA and MUFA content increased by 32.63 and 9.25%, respectively, while PUFA content decreased by 25.3%, n-6 by 12.4% and n-3 by 32.55%. These changes were more significant (P ≤ 0.05) during the first 45 d of storage. It was concluded that the frozen storage had a negative impact on meat quality of rainbow trout due to the reduction of PUFA, n-3/n-6, polyene index and PUFA/ SFA and the increase of the SFA, and atherogenic and thrombogenic indexes, which meant a substantial loss of nutritional value in the fillets of rainbow trout.