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.

Pea Protein Isolate as a Meat Substitute in Canned Pork Pâté: Nutritional, Technological, Oxidative, and Sensory Properties.

This study investigated the feasibility of replacing pork meat with pea protein isolate in canned pâtés at proportions ranging from 12.5% to 50%. The results indicated that protein reformulation did not significantly impact the protein content and lipid oxidation of the pâtés. Reformulated products exhibited a decrease in a∗ values and an increase in b∗ values. These color changes were also sensorially identified in the Check-All-That-Apply (CATA) test, where the reformulated pâtés were associated with attributes such as 'yellow color' and 'unpleasant color', which were inversely related to product acceptance. The protein reformulation reduced the hardness, gumminess, and chewiness parameters of the pâtés. These textural changes were positively reflected in the CATA test, where the reformulated products were characterized by attributes like 'soft texture', 'pleasant texture', and 'good spreadability', which strongly correlated with higher consumer acceptance. Notably, pâtés with 37.5% and 50% substitutions of pork meat with pea protein showed acceptability levels comparable to the control, and those with up to a 25% substitution exhibited superior sensory acceptability. However, the color alteration suggests the need for future optimization, such as using natural colorants. In summary, the results of this study not only validate the feasibility of replacing pork meat with pea protein in pâtés but also offer valuable insights for future investigations to develop more innovative and sustainable meat products.

Replacing Animal Fat with Gels of Psyllium Fiber and Combined Linseed Oil-Psyllium Fiber in Salamis: Impacts on Technological, Nutritional, Oxidative, and Sensory Properties.

This study produced two gels: one solely using psyllium fiber (GP) and another combining this fiber with linseed oil (GL+P). Both gels replaced 15% and 30% of the animal fat content of salamis. The objective was to evaluate the impact of this lipid reformulation on the technological, nutritional, oxidative, and sensory properties of the salamis. The lipid reformulation did not alter the evolution of pH and lactic acid bacteria during processing. The addition of GL+P did not interfere with the product's drying process. However, replacing 30% of animal fat with the GP resulted in greater weight loss and a lower final Aw value. The lipid reformulation minimally affected the color of the salamis but significantly enhanced their nutritional profile. This improvement was marked by a decrease in fat content and an increase in protein. Specifically, in the samples with GL+P, there was a rise in linolenic acid content and a reduction in the n-6/n-3 PUFA ratio. Adding GP did not affect the salamis' oxidative stability and sensory profile. However, substituting 30% of the animal fat with GL+P increased the TBARS values, and volatile compounds derived from lipid oxidation hampered the products' sensory profiles. A reduction in these negative effects was observed when replacing 15% of the fat with GL+P, suggesting this to be the ideal dosage for balancing the nutritional benefits with maintaining the product's oxidative stability.

Elevating meat products: Unleashing novel gel techniques for enhancing lipid profiles.

Rising health concerns and the diet-health link drive demand for healthier foods, prompting meat manufacturers to reformulate traditional products. These manufacturers have reduced fat content to enhance nutritional quality, which is essential for maintaining desired product features. As a result, numerous strategies have emerged over recent decades to decrease fat and enhance the lipid profiles of meat products. Among these strategies, using hydrocolloids, emulsification, encapsulation, or gelation of oils to produce fat substitutes stands out. Using gels allows fat replacers with characteristics similar to animal fat (similar rheological, physical, or appearance properties) but with a much healthier lipid profile (by incorporating highly unsaturated oils). Therefore, this manuscript aims to comprehensively describe the main fat replacers used to prepare meat products. In addition, an in-depth review of the latest studies (2022-2023) that use novel gels to reform meat products has been made, indicating in each case the implications that the reformulation produces at a physicochemical, nutritional, and sensory level. Given the reported results, it seems clear that the strategy of using bigels or emulgels is very promising and allows obtaining nutritionally highly improved meat products without affecting their sensory or physicochemical properties. However, the best conditions to obtain a novel gel suitable for use as a fat substitute for each meat product still need to be studied and correctly defined. Moreover, these advancements can pave the way for more extensive studies on using novel gel techniques in other food industries, expanding their applicability and leading to healthier consumer options across various food categories.

Jabuticaba peel extract and nisin: A promising combination for reducing sodium nitrite in Bologna-type sausages.

This study investigated the effect of a 50% reduction in sodium nitrite and the addition of nisin (200 mg/kg) and different concentrations (0, 0.5%, 0.75%, and 1%) of jabuticaba peel extract (JPE) on the main attributes affected by this chemical additive in Bologna-type sausages. The modified treatments showed approximately 50% lower residual nitrite than the control throughout the storage (60 days at 4 °C). The proposed reformulation did not affect the color (L*, a*, and b*), and the ΔE values (< 2) demonstrated high color stability during storage. Physicochemical (TBARS and volatile compounds) and sensory analyses performed to evaluate oxidative stability indicated that JPE exhibited antioxidant activity comparable to sodium nitrite. The microbiological quality of the reformulated products was similar to the control, but further studies should be conducted to assess the effect of this reformulation strategy on the growth of pathogenic microorganisms impacted by nitrite.

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.

Higher CO2 during controlled atmosphere storage of unshelled 'Barton' pecans or carnauba wax coating: Effect on the quality after long-term storage at two temperatures.

Pecan nuts, a healthy food, have shown an increased demand for consumption. Therefore, there must be a certain level of care to avoid quality losses, which are primarily influenced by storage conditions and time. This study evaluates the effects of long-term controlled atmosphere (CA) storage with low O2 partial pressure (pO2 - 2 kPa), combined or not with high CO2 (pCO2 - 40 or 80 kPa), carnauba wax coating (CW), and ambient atmosphere (AMB; control) at 10 and 20 °C, on unshelled 'Barton' pecan nut quality. Color, water activity (Aw), moisture content (MC), and oxidation markers, such as peroxide value (PV), acidity value (AV), TBARS, and volatile compounds (VC) were evaluated. Storage up to twelve months at 10 °C and with CA (regardless of the temperature) ensured higher luminosity and color parameter b* ("golden") and a lower a* parameter ("reddish"). The MC ranged from 2.8 to 3.6%, irrespective of storage conditions, for up to twelve months, which is suitable. The AMB at 10 °C ensured lower AV, TBARS, and PV compared to the CW treatment. Furthermore, CA with low pO2 and high pCO2, even at 20 °C, guaranteed lower AV, TBARS, and PV. Storage at 20 °C increased characteristic VCs of lipid oxidation (aldehydes, acids, alcohols, ketones, lactones, and esters, especially with CW coating). However, all conditions at 10 °C and with pCO2 (even associated at 20 °C) reduced the presence of these VCs. The CW used as a coating on the pecans did not show satisfactory results and should not be recommended for pecan storage at these applied conditions. Our findings showed that low pO2 and high pCO2 maintain better pecan quality than O2 ambient (20 kPa), even at temperatures above refrigeration (20 °C). Nevertheless, there were no significant differences between 40 and 80 kPa CO2.

Raspberry Extract as a Strategy to Improve the Oxidative Stability of Pork Burgers Enriched with Omega-3 Fatty Acids.

Hydrogelled emulsions (HEs) of linseed oil and pea protein (PP) were produced with four levels (0, 5, 7.5, and 10%) of raspberry extract obtained by a green extraction technique (microwave hydrodiffusion and gravity-MHG). HEs were applied in burgers to replace 50% of pork backfat content. The products' technological, nutritional, oxidative, microbiological, and sensory properties were evaluated. Besides reducing the fat level by approximately 43%, the reformulation reduced the n-6/n-3 PUFA ratio to healthy levels, decreased the diameter reduction by 30%, and increased the cooking yield by 11%. Including 7.5 and 10% of raspberry extract in the HEs decreased the oxidative defects caused by the enrichment of the burgers with omega-3 fatty acids. In addition, the raspberry extract did not cause alterations in the mesophilic aerobic count and the burgers' sensory profile.

Improving the textural and nutritional properties in restructured meat loaf by adding fibers and papain designed for elderly.

This study aimed to evaluate the effects of dietary fibers (apple, oat, pea, and inulin) in meat loaves treated with papain enzyme. In the first step, dietary fibers were added to the products at the level of 6%. All dietary fibers decreased the cooking loss and improved the water retention capacity throughout the shelf life of the meat loaves. Besides, the dietary fibers increased the compression force of meat loaves treated with papain, mainly oat fiber. The dietary fibers decreased the pH, especially the treatment with apple fiber. In the same way, the color was changed mainly by the apple fiber addition, resulting in a darker color in both raw and cooked samples. TBARS index increased in meat loaves added with both pea and apple fibers, mostly for the last one. In the next step, the combination of inulin, oat, and pea fibers was evaluated in the meat loaves treated with papain, combining fibers up to 6% total content likewise decreased cooking and cooling loss and increased the texture of the papain-treated meat loaf. The addition of fibers improved the acceptability of the texture-related samples, except for the three-fiber mixture (inulin, oat, and pea), which was related to a dry, hard-to-swallow texture. The mix of pea and oat fibers conferred the best descriptive attributes, possibly related to improved texture and water retention in the meat loaf, and comparing the use of isolated oat and pea, the perception of negative sensory attributes was not mentioned, such as soy and other off-flavors. Considering these results, this study showed that dietary fibers combined with papain improved the yielding and functional properties with potential technological use and consistent nutritional claims for elderly.

Evaluating different levels of papain as texture modifying agent in bovine meat loaf containing transglutaminase.

In this study, bovine meat loaves were produced with different levels of papain (0.00125%, 0.0025%, 0.00375%, and 0.005%) combined with transglutaminase (1%). The effect of this reformulation on pH, instrumental color, water activity, proximate composition, texture, yield, and scanning electron microscopy (SEM) of meat loaves was investigated. In addition, the enzymatic activity of papain was also analyzed. The papain addition increased the pH and the yield of the samples. The hardness was progressively reduced with the increase of papain level. Such changes could be seen through the images recorded by SEM, where an extremely fragmented structure was observed in treatments with higher papain concentration. Papain showed an optimum temperature of 80 °C. This study allowed to observe an intense proteolytic effect in all treatments, despite the papain concentration. Therefore, lower levels should be applied so that the product does not alter its sensory characteristics, such as soft and crumbly texture.

Hydrogelled emulsion from linseed oil and pea protein as a strategy to produce healthier pork burgers with high technological and sensory quality.

Hydrogelled emulsions (HEs) produced with linseed oil and different levels of pea protein (PP) (0, 5, 10, 15, and 20%) were used to replace 50% of animal fat in burgers. The effect of this lipid reformulation on the nutritional, technological, oxidative, microbiological, and sensory quality of the burgers was evaluated during their refrigerated storage (4 °C for 12 days). The reformulated burgers displayed a reduction of >40% in fat and an increase of up to 10% in protein content. Lipid reformulation also increased the PUFA/SFA ratio and reduced the n-6/n-3 PUFAs ratio and the atherogenicity and thrombogenicity indices of the lipid fraction of the burgers. Including 5 and 10% of PP in the HEs made it possible to obtain burgers of high technological quality and with a sensory profile similar to full-fat products. PP was also efficient in reducing the increase in the lipid oxidation caused by the enrichment with n-3 PUFAs.

High-power ultrasound, micronized salt, and low KCl level: An effective strategy to reduce the NaCl content of Bologna-type sausages by 50.

This study evaluated the combination of high-power ultrasound (HPU), micronized salt (MS), and low KCl levels as a strategy to produce reduced sodium Bologna-type sausages. Samples with 50% NaCl reduction were produced with regular salt (RS) or MS and 0.5% KCl. The sausages were sonicated for 0 or 27 min in an ultrasonic bath (25 kHz, 60% amplitude, normal mode, 20 °C) immediately after filling. The sodium reformulation strategy was effective in compensating for the defects in the emulsion stability and texture profile caused by the NaCl reduction. Besides, the combination of HPU, MS, and KCl did not cause major impacts on the evolution of pH, Eh, and TBARS values of the sausages during storage (21 days at 4 °C). The use of MS and KCl also allowed a reduction by 50% of the NaCl content (< 42% Na; Na/K ratio: 1.2 to 1.3) of the samples without affecting the salty taste, which was enhanced by the HPU treatment.

Effect of Transglutaminase Treatment on the Structure and Sensory Properties of Rice- or Soy-Based Hybrid Sausages.

Partial substitution of meat with non-protein sources in hybrid meat products generally leads to a decrease in texture attributes and, consequently, in sensory acceptance. In this study, we investigated the effects of transglutaminase (TG) at two concentrations (0.25% and 0.5%) on the physicochemical, textural, and sensory properties of hybrid sausages formulated with concentrated soy or rice proteins. TG caused a reduction in the heat treatment yield of hybrid sausages, particularly those made with rice protein. pH and color parameters were marginally affected by TG addition. Texture parameters increased substantially with TG, although escalating the TG level from 0.25% to 0.5% did not result in a proportional improvement in texture parameters; in fact, for rice-based hybrid sausages, no difference was achieved for all attributes, while only cohesiveness and chewiness were improved for soy-based ones. TG enhanced the sensory attributes of soy-based hybrid sausages to a level comparable to control meat emulsion, as evidenced by ordinate preference score and projective mapping. Our findings suggest that TG is a viable strategy for enhancing texture and sensory parameters in hybrid sausages, particularly for plant proteins that exhibit greater compatibility with the meat matrix.

Recent advances in the development of healthier meat products.

Meat products are an excellent source of high biological value proteins, in addition to the high content of minerals, vitamins, and bioactive compounds. However, meat products contain compounds that can cause a variety of adverse health effects and pose a serious health threat to humans. In this sense, this chapter will address recent strategies to assist in the development of healthier meat products. The main advances about the reduction of sodium and animal fat in meat products will be presented. In addition, strategies to make the lipid profile of meat products more nutritionally advantageous for human health will also be discussed. Finally, the reduction of substances of safety concern in meat products will be addressed, including phosphates, nitrites, polycyclic aromatic hydrocarbons, heterocyclic aromatic amines, as well as products from lipid and protein oxidation.

Effect of high-power ultrasound and bamboo fiber on the technological and oxidative properties of phosphate-free meat emulsions.

The combination of high-power ultrasound (HPU) and bamboo fiber (BF) was investigated as a strategy to produce phosphate-free meat emulsions. The samples were made with the addition of 0 and 0.25% of alkaline phosphate and 0, 2.5, and 5% BF. Immediately after filling, the samples were sonicated for 0 or 27 min at normal mode, 25 kHz, 60% amplitude, and 20 °C. The samples made with BF and without phosphate showed higher emulsion stability compared to the control made with phosphate. The addition of 2.5% BF effectively compensated for the texture changes due to the absence of phosphate. HPU improved the effect of BF on the texture of meat emulsions by increasing cohesiveness. No significant impact of HPU and BF was observed on the oxidative quality of the samples. However, the instrumental assays and the sensory evaluation demonstrated that the absence of phosphate increased the lipid oxidation of the samples from the beginning of storage.

Production of Collagens and Protein Hydrolysates with Antimicrobial and Antioxidant Activity from Sheep Slaughter By-Products.

This work aimed to produce collagens and hydrolysates with antimicrobial and antioxidant activity from sheep slaughter by-products. The by-products (sheep and lamb) were treated and extracted. The collagens were hydrolyzed with the enzyme Alcalase®. The spectra of collagens and hydrolysates were similar (amide bands I, II, III, A, B). The bands presented by the collagens (α1, α2, ß) were characteristic of type I collagen. The hydrolysates showed molecular weight peptides equal to/lower than 15 kDa. Collagens had a denaturation temperature of 39.32 (lamb) and 36.38 °C (sheep), whereas the hydrolysates did not undergo thermal transition. Hydrolysates showed lower values of antioxidant activity (AA) than the collagens. The collagens from lamb and from sheep displayed an AA of 13.4% (concentration of 0.0002%) and 13.1% (concentration of 0.0005%), respectively. At the concentration of 0.0020%, the lamb hydrolysates displayed an AA of 10.2%, whereas the sheep hydrolysates had an AA of only 1.98%. Collagen also showed higher antimicrobial activity compared to hydrolysates, requiring a lower concentration to inhibit the microorganisms tested. Sheep slaughter by-products proved to be a viable source for obtaining protein hydrolysates and collagens with antimicrobial and antioxidant activity, which can be applied in the development of nutraceuticals beneficial to human health.

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.

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.

Sodium reformulation and its impact on oxidative stability and sensory quality of dry-cured rabbit legs.

The aim of this study was to evaluate the oxidative stability and sensory quality of dry-cured rabbit legs produced with a reduction or replacement of 50% of NaCl by KCl and with the addition of monosodium glutamate (MG). Oxidative stability was evaluated during 90 days of storage at 20 °C by determining pH, redox potential (Eh), and TBARS while overall liking and sensory profile were measured at the beginning of storage. The results indicated that oxidative stability of the dry-cured rabbit legs was not affected by the sodium reformulation. However, TBARS values increased about 15-fold during storage in all treatments. Dry-cured rabbit legs produced with KCl showed lower scores (P < 0.05) for the overall liking and flavor attributes as "astringent flavor", "bitter taste" and "metallic flavor". The addition of MG to products with 50% NaCl reduction provided a liking and a sensory profile similar to the product with 100% NaCl.