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.

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.

Microscopic characterization of orchid mycorrhizal fungi: Scleroderma as a putative novel orchid mycorrhizal fungus of Vanilla in different crop systems.

Vanilla is an orchid of economic importance widely cultivated in tropical regions and native to Mexico. We sampled three species of Vanilla (V. planifolia, V. pompona, and V. insignis) in different crop systems. We studied the effect of crop system on the abundance, type of fungi, and quality of pelotons found in the roots using light and electron microscopy and direct sequencing of mycorrhizal structures. Fungi were identified directly from pelotons obtained from terrestrial roots of vanilla plants in the flowering stage. Root samples were collected from plants in crop systems located in the Totonacapan area in Mexico (states of Puebla and Veracruz). DNA was extracted directly from 40 pelotons and amplified using ITS rRNA sequencing. Peloton-like structures were observed, presenting a combination of active pelotons characterized by abundant hyphal coils and pelotons in various stages of degradation. The most active pelotons were observed in crop systems throughout living tutors (host tree) in comparison with roots collected from dead or artificial tutors. Fungi identified directly from pelotons included Scleroderma areolatum, a common ectomycorrhizal fungus that has not been reported as a mycorrhizal symbiont in orchids. Direct amplification of pelotons also yielded common plant pathogens, including Fusarium and Pyrenophora seminiperda, especially in those sites with low colonization rates, and where large numbers of degraded pelotons were observed. This research reports for the first time the potential colonization of Vanilla by Scleroderma, as a putative orchid mycorrhizal symbiont in four sites in Mexico and the influence of crop system on mycorrhizal colonization on this orchid.