Green technologies applied to low-NaCl fresh sausages production: Impact on oxidative stability, color formation, microbiological properties, volatile compounds, and sensory profile.

The influence of different concentrations of NaCl (2.5% and 1.75%), basic electrolyzed water (BEW), and ultrasound (US, 25 kHz, 159 W) on the quality of fresh sausages was studied. During storage at 5 °C, TBARS, pH, Eh, aw, nitrous pigments, and bacterial evolution were evaluated at three specific time intervals: 1d, 15d, and 30d. At the same time, the volatile compounds and sensory profile were specifically assessed on both the 1d and 30d. Notably, sausages with 1.75% NaCl and BEW displayed higher pH values (up to 6.30) and nitrous pigment formation, alongside reduced Eh (as low as 40.55 mV) and TBARS values (ranging from 0.016 to 0.134 mg MDA/kg sample), compared to the 2.5% NaCl variants. Protein content ranged between 13.01% and 13.75%, while lipid content was between 18.23% and 18.86%, consistent across all treatments. Psychrotrophic lactic bacteria showed a significant increase in low-NaCl sausages, ranging from 5.77 to 7.59 log CFU/g, indicative of potential preservative benefits. The sensory analysis favored the TUSBEW70 treatment for its salty flavor on the 30th day, reflecting a positive sensory acceptance. The study highlights that employing US and BEW in sausage preparation with reduced NaCl content (1.75%) maintains quality comparable to higher salt (2.5%) counterparts. These findings are crucial for meat processing, presenting a viable approach to producing healthier sausages with reduced sodium content without compromising quality, aligning with consumer health preferences and industry standards.

Do ultrasound form spontaneously nitrous pigments in nitrite-free pork meat batter?

The effects of ultrasound (US) on myoglobin modification, nitrous pigment formation, color, and total and free sulfhydryl content in nitrite-free pork meat batter were assessed. Five treatments were elaborated: Control (without US); TUS10'12 and TUS20'12 (sonication at 25 kHz, at 12 °C for 10 and 20 min, respectively); TUS10'18 and TUS20'18 (sonication at 25 kHz, at 18 °C for 10 and 20 min, respectively). Sonication for 20 min at 12 °C increased OxyMb and DeoxyMb pigments while reducing MetMb levels. This US condition also yielded higher red color indices and lower yellow color indices. Moreover, TUS20'12 exhibited enhanced nitrous pigment formation and decreased FerrylMb and free sulfhydryl (SH) values, indicating reduced oxidation in OxyMb and DeoxyMb pigments. In conclusion, the findings demonstrate that US can impart a cured color to nitrite-free meat products.

Combined effect of ultrasound and basic electrolyzed water on the microbiological and oxidative profile of low-sodium mortadellas.

Ultrasound (US) and basic electrolyzed water (BEW) are considered emerging technologies; however, few studies have addressed the combination of both technologies in emulsified meat products. This study aimed to evaluate the individual and combined effect of US (25 kHz; 175 W; 20 min) and BEW (pH 10.99; -92.33 mV) on the microbiological and oxidative profile of low-sodium mortadellas (30% of NaCl reduction) stored for 90 days at 5 °C. The use of BEW alone increased the pH and reduced the redox potential of mortadellas, while the US did not affect these parameters. The combined application of US and BEW reduced the lactic acid bacteria counts by up to 0.36 log CFU/g. In addition, BEW stimulated the growth of lipolytic bacteria. The treatments subjected to US application alone showed a lower growth rate of lipolytic bacteria, lower lipid and protein oxidation, and higher ΔE* values. Therefore, the application of US and BEW may be a promising strategy to improve the microbiological and oxidative quality of mortadella during storage.

Effects of ultrasonic-assisted cooking on the volatile compounds, oxidative stability, and sensory quality of mortadella.

Ultrasound is a form of green technology that has been applied efficiently to improve processes in the food industry. This study evaluated the application of ultrasound to reduce the cooking time of mortadella. The volatile compounds, oxidative stability, and sensory quality of mortadella were evaluated. Four cooking conditions were used, as follows: Control, corresponding to the cooking time traditionally used in the meat industry; TUS100 and TUS50: cooking with US (25 kHz) and 50% reduction of the cooking time of Control, using 100% (462 W) and 50% (301 W) amplitude, respectively; and TWUS: cooking without the application of US and 50% reduction of the cooking time of Control. TUS100 and TUS50 showed an increase of 10.8% and 29.4%, respectively, in the total amount of terpenes on the first day of storage in relation to the Control. The presence of nonane on the 60th day only in the US-treated samples (0.22 × 106 vs 0.11 × 106 for TUS100 and TUS50, respectively) indicated that the US treatment may have induced higher oxidation in mortadella. The oxidative stability index ranged from 274 to 369 days for TUS100 and the Control, respectively. The treatments TWUS and TUS50 showed a lower sensory quality at the end of storage. On the other hand, TUS100 presented sensory quality similar to the Control, demonstrating that ultrasonic-assisted cooking using a 100% amplitude is an alternative to reduce the cooking time without affecting the product quality.

Ultrasound and low-levels of NaCl replacers: A successful combination to produce low-phosphate and low-sodium meat emulsions.

Meat emulsions were made with 50% of phosphate level commonly used in the meat industry, and 0, 25, and 50% NaCl reduction. In addition, salt replacers (KCl, CaCl2, or MgCl2) were used in the formulations with 25 and 50% salt reduction, corresponding to 10 and 20% of the total amount of salts added, respectively. After embedding in casings, the samples were sonicated (25 kHz and 230 W) in an ultrasonic bath (US) at 20 °C for 0, 18, and 27 min. The addition of CaCl2 or MgCl2 impaired (P < .05) the technological properties of the low-sodium samples. Defects caused by NaCl reduction were not eliminated by 18-min US. However, the combination of KCl and 27-min US eliminated the technological defects caused by the 50% NaCl reduction, with no major impact on lipid oxidation during storage (21 days/4 °C), as observed in the TBARS and sensory profile results. Therefore, it is possible to produce low-phosphate and low-sodium meat emulsions.

Ultrasound assisted maceration for improving the aromatization of extra-virgin olive oil with rosemary and basil.

Aromatization of extra-virgin olive oil (EVOO) with aromatic plants is commonly used to enrich the oil with aromatic and antioxidant compounds. Ultrasound can be an alternative to accelerate this process. The objective of this work was to determine if ultrasound is able to accelerate EVOO aromatization with rosemary and basil and how it affects the migration of volatile and other compounds, the oxidative stability and the antioxidant capacity of the aromatized products. Ultrasound parameters (amplitude, time, and temperature of extraction) were optimized for each herb with central composite designs. Free fatty acid, peroxide value, K232, K270, ΔK, fatty acid profile, total phenolics, antioxidant capacity, polar compounds, oxidative stability and volatile compounds profile were evaluated in all samples. Physical effects of ultrasound on the herbs were observed by scanning electron microscopy. In the optimization, variables related to the oxidative processes were minimized and compounds migration and oxidative stability were maximized. Results were 70.09% amplitude, 36.6 min and 35 °C for rosemary and 95.98% amplitude, 9.9 min and 30 °C for basil. These conditions were compared to 7 and 15 days of conventional maceration (CM). Aromatization of EVOO with rosemary, both by ultrasound assisted maceration (UAM) or CM, improved total phenolics, terpenes, esters, ketones, stability and induction times, as well as decreased the values for the quality parameters. The use of UAM accelerated the process to 37 min. However, aromatization with basil by CM increased the values for the quality parameters and reduced the total phenolics, the antioxidant capacity and the induction and stability times. UAM with basil reached better results than those observed for CM, in only 10 min. In conclusion, rosemary is more appropriate than basil for EVOO aromatization, and UAM was the best choice to accelerate the processes when compared to CM.

Ultrasound: A new approach to reduce phosphate content of meat emulsions.

Meat emulsions with a reduction of 0, 25, 50, 75, and 100% of phosphate levels were produced. Soon after filling, the pieces were sonicated in an ultrasonic bath (normal mode, 60% amplitude, 25 KHz frequency, 230 W acoustic power, and 33 W L-1 volumetric power) for 0, 9, and 18 min. The technological, oxidative, and sensory quality was evaluated. The reduction of the phosphate content in the non-sonicated samples led to a decrease in the cooking yield and emulsion stability and impaired the texture profile, and the oxidative and sensory quality of the samples. Although the 9-min ultrasound treatment was not effective to compensate for defects caused by the phosphate reduction, the application for 18 min improved the technological quality and did not increase the lipid oxidation. In addition, it allowed reducing most of the sensory defects caused by the reduction of 50% of the phosphate level. Therefore, the US can be useful to produce low-phosphate meat emulsions.

Ultrasound: A promising technology to improve the technological quality of meat emulsions.

The use of ultrasound (US) has proven to be an effective tool in the preparation of emulsions. However, the cavitation phenomenon leads to an increase in temperature, which can affect the emulsion stability and the texture. Thus, different US operating modes (degas, normal, and sweep) were applied in meat emulsions for 5.5 min, at 25 kHz frequency and 60% amplitude, and the temperature behavior, yield, emulsion stability, texture, and lipid and protein oxidation were evaluated. The results showed that the wave propagation mode in the US bath exerts a great influence on the increase of temperature of meat emulsions. The distribution of cavitation in normal operating mode significantly favored (P < .001) a higher yield (88.7%) and emulsion stability, with good values of cohesiveness (0.76), hardness (26.9 N), and chewiness (26.1 N), not increasing lipid and protein oxidation. Therefore, this study has proven that that the use of normal US operating mode improved the technological quality of meat emulsions.