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.

Food potential of Scenedesmus obliquus biomasses obtained from photosynthetic cultivations associated with carbon dioxide mitigation.

Microalgae are photosynthetic microorganisms that stand out from conventional food sources and ingredients due to their high growth rate and adaptability. In addition to being highly sustainable, significant concentrations of proteins, lipids, and pigments accumulate in their cell structures from photosynthesis. Hence, this study sought to evaluate the food potential of Scenedesmus obliquus biomasses obtained from photosynthetic cultures enriched with 3, 5, 10, 15, 20, and 25% carbon dioxide (CO2) (v/v). Cultivations with 3, 5, and 10% CO2 showed greater amino acids and proteins synthesis; the protein content reached values above 56% of the dry biomass and high protein quality, due to the presence of most essential amino acids at recommended levels for the human diet. The highest concentrations of chlorophylls were found in cultures with 15, 20, and 25% CO2 (24.2, 23.1 and 30.8 mg g-1, respectively), although the profiles showed higher percentages of degradation compounds. Carotenoid concentrations were three times higher in cultures with 3, 5, and 10% CO2 (25.3, 22.7 and 18.1 mg g-1, respectively) and all-trans-ß-carotene was the major compound. Lipid synthesis was intensified at higher CO2 enrichment; the percentages obtained were 14.8% of lipids in the culture with 15% CO2, 15.0% with 20% CO2, and 13.7% with 25% CO2. In addition, greater polyunsaturated fatty acids accumulation and a significant reduction in the n6/n3 ratio were also observed at the highest CO2 concentrations. Our findings showed that CO2 treatments significantly altered all compounds concentrations in S. obliquus biomasses, which presented satisfactory composition for application in foods and as ingredients.

Effect of ultrasound application on the growth of S. xylosus inoculated in by-products from the poultry industry.

A wide variety of by-products are produced by the industry when animals are slaughtered. However, the proteins present in these by-products, are not being fully useable, in the elaboration of value-added products. Staphylococcus xylosus is commonly used as a starter culture in meat products subjected to ripening for a long period, as it produces proteolytic and lipolytic enzymes that improve the sensory quality of the products. Ultrasound (US) has been arousing interest in the meat industry, as it reduces processing time and also improves the technological and sensory quality of meat products. However, the stimulate effect of US on the growth of S. xylosus in by-products from the poultry industry is still unknown. Thus, this study aimed to evaluate the stimulate effect of US on the growth of S. xylosus inoculated in by-products from the poultry industry. S. xylosus was inoculated (5.63 log CFU/g) in sterilized by-products from the poultry, which were then sonicated at 37 °C for 0, 15, 30, and 45 min according to the following parameters: frequencies of 130 and 35 kHz, amplitudes of 50% and 80% and normal and degas operating modes. The sonicated samples were incubated at 37 °C for 0, 24, 48, and 72 h. Soon after sonication, no stimulate effect of US was observed on the growth of S. xylosus. However, after 24 h of incubation, the samples sonicated for 15 and 30 min in normal mode, at 35 and 130 kHz, and amplitudes of 50 and 80% exhibited better stimulate effect at the growth S. xylosus counts (p < 0.01) when compared to the Control, with values of 8.23 and 7.77 log CFU/g, respectively. These results can be exploited to obtain new added-value products, having as raw material by-products from the poultry industry.

Strategy to increase the lipid stability of the microbial oil produced by Umbelopsis isabellina for food purposes: Use of microencapsulation by external ionic gelation.

Oleaginous microorganisms, including the fungus Umbelopsis isabellina, have emerged as a biotechnological alternative to obtain polyunsaturated fatty acid-rich oils, which are strongly linked to energy purposes (biofuel) than the food industry. Considering the composition of microbial oil and its use by the food industry, it is necessary to investigate strategies that increase its lipid stability. Ergo, this pioneering study aimed to microencapsulate the oil produced by Umbelopsis isabellina and evaluate its oxidative stability throughout the storage period against factors such as temperature and luminosity. The microbial oil was microencapsulated through the external ionic gelation technique, producing an encapsulation efficiency of 80% and proving to be a suitable method because it maintained oil composition. Combining microencapsulation and refrigerated storage led to the best effects on storage time, increasing the evaluated lipid stability through the peroxide values and conjugated diene formation. Moreover, saturated and monounsaturated fatty acid content increased, and polyunsaturated fatty acid content decreased during storage for both the free and microencapsulated oil, regardless of storage temperature, although microencapsulation reduced the changes. The results primarily demonstrate how microencapsulation prolongs the oxidative stability and unsaturated fatty acid content of the microbial oil by reducing its reactions to external environmental factors, thus facilitating its use in the food industry.

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.

Lipid oxidation and sensory characterization of Omega-3 rich buffalo burgers enriched with chlorogenic acids from the mate (Ilex paraguariensis) tree harvesting residues.

A freeze-dried extract from the bark of mate branches (BMBE) containing high chlorogenic acids (CGA) content (30 g 100 g-1) was produced. Then, chia oil was mixed with 7.5% BMBE and sonicated for 0, 10, and 20 min. Chia oil with or without the addition of BMBE was hydrogelled and used to produce buffalo burgers with 50% reduction in animal fat. CGA levels and the nutritional, oxidative, and sensory properties of the burgers were analyzed. A reduction of ~30% fat and an increase above 60% PUFA/SFA ratio was observed for the reformulated raw and cooked burgers. In addition, the Omega-6/Omega-3 PUFA ratio of the burgers decreased from 20.8 (raw) and 31.9 (cooked) to values lower than 2. The addition of BMBE enriched the burgers with CGA, preventing an increase in lipid oxidation caused by chia oil. The addition of BMBE-enriched hydrogelled chia oil not subjected to sonication did not affect the sensory properties of the burgers.

Viability of microencapsulated Lactobacillus acidophilus by complex coacervation associated with enzymatic crosslinking under application in different fruit juices.

The objective of this study was to produce microcapsules containing Lactobacillus acidophilus LA-02 by complex coacervation followed by crosslinking with transglutaminase and to evaluate the effect of their addition on different fruit juices, as well as the probiotic viability of L. acidophilus and its effect on fruit juices during storage. To this end, L. acidophilus was microencapsulated by complex coacervation, followed by crosslinking with transglutaminase at different concentrations. Probiotics, in their free and microencapsulated forms, were added to orange juice and apple juice at concentrations of 10% and 30%. The obtained microcapsules were characterized in terms of morphology. The viability of probiotics and the effects of their addition on fruit juices were assessed and the juices characterized (with respect to pH and total soluble solids) during 63 days of storage at 4 °C. Orange juice proved to be more suitable for the addition of probiotics, and the survival of probiotics was directly related to pH. The microcapsules had a protective effect on L. acidophilus, prolonging their survival, and the crosslinking process proved to be adequate and promising, ensuring probiotic viability. Thus, the complex coacervation process associated with induced enzymatic crosslinking provided protection for L. acidophilus in different fruit juices, showing an adequate methodology for adding probiotics to this adverse food matrix, guaranteeing the survival of L. acidophilus for up to 63 days, and generating products with innovative and promising probiotic appeal.

Jabuticaba peel extract obtained by microwave hydrodiffusion and gravity extraction: A green strategy to improve the oxidative and sensory stability of beef burgers produced with healthier oils.

Hydrogelled emulsions (HE) from chia and linseed oils (1:1) were made with different concentrations (0, 6, 8, and 10%) of jabuticaba peel extract (JPE) obtained by microwave hydrodiffusion and gravity (MHG) extraction. Burgers (20% fat) were produced with the replacement of 60% of fat by HEs. The oxidative profile and the sensory quality of raw and cooked burgers were evaluated for 120 days (-18 °C). The JPE exhibited 1.72 mg/mL of phenolic compounds and 57,741.67 µmol TE/mL of antioxidant capacity. In addition, the MHG extraction eliminated the mesophilic bacteria from the jabuticaba peel. The burgers made with HE and without the addition of JPE showed a 5-fold increase in TBARS values when compared to the control. On the other hand, the addition of 10% JPE to HE was effective to maintain the lipid oxidation similar to the control until the 60th day of storage. Besides, the incorporation of JPE into HE reduced the sensory defects caused by the lipid reformulation.

Effect of ultrasound on proteolysis and the formation of volatile compounds in dry fermented sausages.

Ultrasound (US) is an emerging technology capable of affecting enzymes and microorganisms, leading to the release of amino acids and the formation of volatile compounds. The effect of different exposure times (0, 3, 6, and 9 min) of US (25 kHz, 128 W) on the proteolysis and volatile compounds of dry fermented sausages during processing (day 0 and 28) and storage (day 1 and 120) was investigated. Lower alanine, glycine, valine, leucine, proline, methionine, and tyrosine levels were observed at the beginning of manufacture for the sample subjected to 9 min of US (p < 0.05) when compared to the control. During the storage period, the samples subjected to US exposure for 3 and 6 min exhibited higher free amino acid levels. A greater formation of hexanal, pentanal, and hexanol was observed in the US-treated samples when compared to the control (p < 0.05), as well as other derivatives from the oxidation reactions during the storage. The use of US (25 kHz and 128 W) in the manufacture of dry fermented sausages can affect the proteolysis and the formation of compounds derived from lipid oxidation during the storage.

Use of prebiotic sources to increase probiotic viability in pectin microparticles obtained by emulsification/internal gelation followed by freeze-drying.

The aim of this study was to investigate the influence of hi-maize, inulin, and rice bran in the survival of Lactobacillus acidophilus LA-5 in pectin microparticles obtained by internal gelation and subjected to freeze-drying. For this, the development of a matrix capable of extending Lactobacillus acidophilus viability to develop new functional foods was emphasized. Microparticle size, encapsulation efficiency, probiotic survivability after gastrointestinal simulation, and storage stability were analyzed. The pectin + inulin encapsulation matrix presented the highest encapsulation efficiency (68.1%) compared to the other treatments. Microparticle sizes ranged from 166 ± 2 µm (pectin + hi-maize) to 345 ± 9 µm (pectin + inulin). The microparticles added from the different prebiotics showed better microorganism protection when compared to treatment without prebiotics, which presented greater viability in the gastrointestinal simulation. Under storage conditions of 25 °C and -18 °C, the microparticles containing hi-maize, inulin, and rice bran maintained the probiotic microorganisms viable for longer periods than the pectin microparticles. At 7 °C, the pectin + rice bran treatment stood out from the other treatments, as it was able to maintain probiotic stability during 120 days of storage.

Is it possible to reduce the cooking time of mortadellas using ultrasound without affecting their oxidative and microbiological quality?

This study evaluated the reduction of cooking time of mortadellas using ultrasound (US, 25 kHz) and the effects on the oxidative and microbiological quality of the product. Three cooking conditions were studied: control, cooking time traditionally adopted by the meat industry; TUS and TWUS: cooking with and without US application and 50% reduction of the traditional cooking time, respectively. The application of US did not increase the peroxide, conjugated dienes, and TBARS indices and did not accelerate the protein oxidation. In addition, no significant changes were observed in the color of the mortadellas subjected to ultrasonic-assisted cooking. TUS and control presented a similar mesophilic, psychrotrophic and lactic acid bacteria counts during storage. The ultrasonic-assisted cooking provided a faster increase and higher homogeneity in the internal temperature of the mortadellas. Therefore, the US can be considered a promising technology to improve the cooking process of mortadellas.

Development of nanoemulsions containing Physalis peruviana calyx extract: A study on stability and antioxidant capacity.

The aim of this study was to develop and evaluate the physicochemical and antioxidant stability of nanoemulsions containing a Physalis peruviana calyx extract (CPp-NE) and free extracts under different storage conditions (7 and 25 °C) and with absence or incidence of light for 120 days. The calyx extracts were prepared with ethanol 60% and characterized for later preparation of the nanoemulsions by spontaneous emulsification. The formulations presented nanometric sizes, low polydispersity index, negative zeta potential, acid pH, rutin content (11 µg·mL-1), and encapsulation efficiency of 85%. Regarding the stability, the droplet size and PdI of the CPp-NE stored at refrigeration temperature in the dark, room temperature in the dark, and refrigeration temperature with light incidence were stable for 120 days and with no visible changes in the formulations. The antioxidant capacity was related to the reducing capacity, and the best results were found for nanoemulsions stored at room temperature and in absence of light. In addition, CPp-NE presented higher antioxidant and reducing capacity in relation to the free extracts.

The effect of enzymatic crosslinking on the viability of probiotic bacteria (Lactobacillus acidophilus) encapsulated by complex coacervation.

Lactobacillus acidophilus were encapsulated by complex coacervation followed by transglutaminase crosslinking, aiming to improve the resistance of the microcapsules and improve the protection for probiotics. Subsequently, microcapsules were dried by freeze drying. The encapsulation efficiency, morphology, thermal resistance, gastrointestinal simulation and storage stability were analysed for wet and dry forms. The treatments offered high encapsulation efficiency (68.20-97.72%). Transglutaminase maintained the structure rounded, multinucleate and homogeneous distribution of probiotics in the microcapsules. In relation to the thermal resistance, in general, microencapsulation was effective in protecting and crosslinked microcapsules demonstrated greater protection for probiotics, obtaining viable cell counts of up to 10 log CFU g-1, approximately. On exposure to the simulated gastrointestinal tract, microencapsulation coupled to crosslinking demonstrated good results and the dry form was more efficient in the protection and the treatment with greater amount of transglutaminase was highlighted (9.07 log CFU g-1). As for storage, probiotic viability was maintained for up to 60 days in freezing temperature, with counts of up to 9.59 log CFU g-1. The results obtained in the present work are innovative and present a promising alternative for the protection of probiotics and their addition in food products.

Hydrogelled emulsion from chia and linseed oils: A promising strategy to produce low-fat burgers with a healthier lipid profile.

Burgers (20% pork back fat) were produced with the replacement of 0, 20, 40, 60, 80, and 100% of pork back fat by hydrogelled emulsion (HE) from chia and linseed oils. No changes (P > .05) were observed for the moisture retention, diameter reduction, and cooking loss of the treatments, with a significant increase in the lipid retention (P < .05). Hardness increased (P < .05) with increasing the lipid replacement level, and a significant color difference (ΔE) was detected between the treatments and the control. In addition to reducing animal fat, a healthier fatty acid profile was reached after the lipid reformulation of the burgers, thus allowing the burgers to be labeled with health claims. The sensory tests (acceptance and Check-All-That-Apply) indicated that it is possible to replace up to 60% of pork back fat by HE.

Scenedesmus obliquus metabolomics: effect of photoperiods and cell growth phases.

Environmental factors directly affect the growth and composition of microalgal biomass. Therefore, the present work analyzed the metabolomics (amino acids, organic acids, and fatty acids) of the microalga Scenedesmus obliquus cultivated in 24:0 and 12:12 (light:dark) photoperiods and different phases of cell growth. Furthermore, the metabolites were related to protein, lipid, and chlorophyll contents at the end of cultivation. The highest biomass concentration (4020 mg L- 1) and protein (47.3%) were obtained in culture under constant illumination. The cultivation 12:12 (light:dark) photoperiod triggered higher production of lipids (23.0%) and chlorophylls (26.4 mg g- 1) by S. obliquus. Microalgal metabolites were greatly affected by photoperiod and by phase of cell growth. Thus, metabolite production could be related to both the environmental conditions under which cultivation occurred and to the different concentrations of products (proteins, lipids, and chlorophylls) present in the S. obliquus biomass.

Volatile compounds and sensory profile of burgers with 50% fat replacement by microparticles of chia oil enriched with rosemary.

Direct incorporation of rosemary leaves into chia oil (CO) was performed by ultrasound-assisted extraction (UAE) and conventional maceration extraction (CME). CO was microencapsulated and used in burgers, as follows: control (20% pork back fat (PBF)); HCO (10% PBF + 7.5% water +2.5% unencapsulated CO); HM1 (10% PBF + 10% CO microparticles); HM2 (10% PBF + 10% CO microparticles enriched by UAE) and HM3 (10% PBF + 10% CO microparticles enriched by CME). The volatile compounds and the sensory properties (Check-All-That-Apply and overall acceptability) of burgers were evaluated at days 1 and 120 of frozen storage. The control, HCO, and HM1 groups were characterized for volatile compounds produced by lipid and protein oxidation, and sensory descriptors related to lipid oxidation. HM2 and HM3 groups presented an increase in terpenic volatiles and were characterized by the descriptors herbal and pleasant aroma and ideal texture. In addition, liking scores were positively correlated to the descriptors that characterized the HM2 and HM3 groups.

Oxidative stability of burgers containing chia oil microparticles enriched with rosemary by green-extraction techniques.

In the first part of this study, the oxidative stability of chia oils enriched with rosemary by ultrasound-assisted extraction (UAE) and by a conventional maceration extraction (CME) was evaluated. In the second part, chia oil enriched with rosemary by UAE or CME was microencapsulated and used to replace 50% fat in burgers. The oxidative and sensory quality of burgers were evaluated during 120 days of storage at -18 °C. Chia oil enriched with rosemary by UAE presented a higher oxidative stability compared to CME. Higher Eh and TBARS values were found in burgers containing chia oil microparticles without rosemary. The burgers produced with chia oil microparticles enriched with rosemary by UAE showed greater oxidative stability than other treatments, mainly after cooking. Furthermore, the incorporation of rosemary antioxidants to chia oil reduced the sensory defects caused by the lipid reformulation.

Application of electrolyzed water for improving pork meat quality.

The microbiological and oxidative qualities of pork loin sprayed with different types (slightly acidic, acidic and basic) and combinations of electrolyzed water (EWs) were evaluated. The EWs were applied at two temperatures (18° and 30°C) and pressures (30 and 45psi) and the volume corresponded to approximately 10% water commonly used in carcass washing. EW after spraying exhibited a chlorine concentration between 15 and 25ppm. The application of acidic EW (AEW) alone or in combination with basic EW (BEW) decreased (P<0.05) the microbial counts shortly after spraying. In addition, the combination of BEW+AEW (30psi) reduced the mesophilic and psychrotrophic bacteria counts throughout the refrigerated storage (P<0.05). The EWs did not increase the lipid oxidation of the samples. On the other hand, a high protein oxidation was observed in the samples sprayed with AEW and slightly acidic EW (SAEW), while BEW was effective to reduce the oxidation reactions. Therefore, the results showed that the combination BEW+AEW may be a viable alternative to reduce the volume of water used at slaughter and to improve the microbiological quality of pork meat.

Is it possible to produce a low-fat burger with a healthy n-6/n-3 PUFA ratio without affecting the technological and sensory properties?

Burgers subjected to lipid reformulation were made by replacing 50% of the fat component by microparticles containing chia (CO) and linseed (LO) oils obtained by external ionic gelation. The microparticles presented high n-3 PUFAs levels and were resistant to the pH and temperature conditions commonly used in burger processing. The lipid reformulation did not affect hardness and improved important technological properties, such as cooking loss and fat retention. In addition to reducing the fat content of burgers by up to 50%, the lipid reformulation led to healthier PUFA/SFA and n-6/n-3 ratios, and lower atherogenicity and thrombogenicity indices. The burgers with CO microparticles showed a higher lipid oxidation and a lower sensory quality compared to the other treatments. However, the substitution of pork back fat by LO microparticles did not impair the sensory quality of burgers. Therefore, the microencapsulation of n-3 PUFA-rich oils by external ionic gelation can be considered an effective strategy to produce healthier burgers.