Low-sodium dry-cured rabbit leg: A novel meat product with healthier properties

Improving quality and consumer acceptance of rabbit meat: Prospects and challenges

Rabbit meat is an excellent source of high-quality proteins, essential fatty acids, vitamins, and minerals, which can be further improved through various management, preslaughter, and post-slaughter interventions. Rabbit meat consumption is popular in certain regions of the world. The multidimensional role of rabbits as pet, pest, and laboratory animals, lack of proper knowledge among consumers towards the nutritive value of rabbit meat, animal welfare, and ethical issues, sustainable potential, undeveloped marketing, and processing chain, and price parity with available cheap meat and non-meat alternatives, are some constraints in the rabbit meat production. Increasing awareness of the nutritive value, positive health effects of rabbit meat consumption and production chain, development of processed meat products, and proper animal welfare compliance in rabbit production could improve consumer acceptance. The present manuscript reviewed various factors that affect the meat quality and consumer acceptance of rabbit meat for a more sustainable and viable source for global meat supply.

Effects of a Diet of Allium Extract on Growth, Biochemistry, Metabolism, and Gut Microbiota of Rabbits (Oryctolagus cuniculus)

The rabbit farming industry is growing due to the rising demand for healthy, sustainable meat. Rabbit meat's nutritional benefits and low environmental impact appeal to health-conscious consumers. To enhance economic sustainability, efforts focus on reducing disease susceptibility and antibiotic use through improved biosecurity and natural additives, such as organosulphur compounds from Allium plants, which have shown promise in studies for boosting productivity and health. This study aimed to investigate the effects of PTSO supplementation on farm rabbits. Over and after a 76-day period, various parameters were assessed to measure the impacts on rabbit growth, health, biochemical parameters, muscle metabolism, and intestinal microbiota. The rabbit groups received either a control diet or a diet supplemented with Allium extract. The results showed significant improvements in growth performance for rabbits fed with Allium extract, including higher final weights, increased average daily gain (ADG), and lower mortality rates. A biochemical analysis revealed normal values for the parameters measured in the treated group. A muscle analysis evidenced the presence of a few metabolites of PTSO. A gut microbiota analysis indicated distinct differences between the control and treated groups, increasing the presence of some strains that can influence positively the growth of rabbits. This study highlights the potential benefits of PTSO supplementation for improving growth performance, health parameters, and gut microbiota composition in farm rabbits, suggesting its efficacy as a dietary additive.

Perspective of sodium reduction based on endogenous proteases via the strategy of sodium replacement in conjunction with mediated-curing

NaCl is the main curing agent in dry-cured meat products, and a large amount of NaCl addition leads to high salt content of final products. Salt content and composition are important factors affecting the activity of endogenous proteases, which in turn could affect proteolysis as well as the quality of dry-cured meat products. With the increasing emphasis on the relationship between diet and health, reducing sodium content without sacrificing quality and safety of products is a great challenge for dry-cured meat industry. In this review, the change of endogenous proteases activity during processing, the potential relationship between sodium reduction strategy, endogenous proteases activity, and quality were summarized and discussed. The results showed that sodium replacement strategy and mediated-curing had a complementary advantage in influencing endogenous proteases activity. In addition, mediated-curing had the potential to salvage the negative effects of sodium substitution by affecting endogenous proteases. Based on the results, a sodium reduction strategy that sodium replacement in conjunction with mediated-curing based on endogenous proteases was proposed for the future perspective.

Effects of umami substances as taste enhancers on salt reduction in meat products: A review

Sodium is one of the essential additives in meat processing, but excessive sodium intake may increase risk of hypertension and cardiovascular disease. However, reducing salt content while preserving its preservative effect, organoleptic properties, and technological characteristics poses challenges. In this review, the mechanism of salt reduction of umami substances was introduced from the perspective of gustation-taste interaction, and the effects of the addition of traditional umami substances (amino acids, nucleotides, organic acids(OAs)) and natural umami ingredients (mushrooms, seaweeds, tomatoes, soybeans, tea, grains) on the sensory properties of the meat with reduced-salt contents were summarized. In addition, the impacts of taste enhancers on eating quality (color, sensory, textural characteristics, and water-holding capacity (WHC)), and processing quality (lipid oxidation, pH) of meat products (MP) and their related mechanisms were also discussed. Among them, natural umami ingredients exhibit distinct advantages over traditional umami substances in terms of enhancing quality and nutritional value. On the basis of salt reduction, natural umami ingredients improve the flavor, texture, WHC and antioxidant capacity. This comprehensive review may provide the food industry with a theoretical foundation for mitigating salt consumption through the utilization of umami substances and natural ingredients.

Quality and Flavor Difference in Dry-Cured Meat Treated with Low-Sodium Salts: An Emphasis on Magnesium

The present study aimed to develop low-sodium curing agents for dry-cured meat products. Four low-sodium formulations (SPMA, SPM, SP, and SM) were used for dry-curing meat. The physicochemical properties and flavor of the dry-cured meat were investigated. The presence of Mg2+ ions hindered the penetration of Na+ into the meat. The weight loss, moisture content, and pH of all low-sodium salt groups were lower than those of S. Mg2+ addition increased the water activity (Aw) of SPMA, SPM, and SM. Dry-curing meat with low-sodium salts promoted the production of volatile flavor compounds, with Mg2+ playing a more prominent role. Furthermore, low-sodium salts also promoted protein degradation and increased the content of free amino acids in dry-cured meat, especially in SM. Principal component analysis (PCA) showed that the low-sodium salts containing Mg2+ were conducive to improving the quality of dry-cured meat products. Therefore, low-sodium salts enriched with Mg2+ become a desirable low-sodium curing agent for achieving salt reduction in dry-cured meat products.

The Effect of Lactiplantibacillus plantarum x3-2b Bacterial Powder on the Physicochemical Quality and Biogenic Amines of Fermented Lamb Jerky

In this study, a protective agent was added to prepare a high-activity Lactiplantibacillus plantarum x3-2b bacterial powder as a fermentation agent and explore its effect on the physicochemical quality, biogenic amines, and flavor of fermented lamb jerky. A composite protective agent, composed of 15% skim milk powder and 10% trehalose, was used, and bacterial mud was mixed with the protective agent at a 1:1.2 mass ratio. The resulting freeze-dried bacterial powder achieved a viable count of 5.1 lg CFU/g with a lyophilization survival rate of 87.58%. Scanning electron microscopy revealed enhanced cell coverage by the composite protective agent, maintaining the cell membrane's integrity. Inoculation with x3-2b bacterial powder increased the pH and the reduction in aw, enhanced the appearance and texture of fermented lamb jerky, increased the variety and quantity of flavor compounds, and reduced the accumulation of biogenic amines (phenethylamine, histamine, and putrescine). This research provides a theoretical basis for improving and regulating the quality of lamb jerky and establishes a foundation for the development of bacterial powder for the commercial fermentation of meat products.

New insights in improving sustainability in meat production: opportunities and challenges

Treating livestock as senseless production machines has led to rampant depletion of natural resources, enhanced greenhouse gas emissions, gross animal welfare violations, and other ethical issues. It has essentially instigated constant scrutiny of conventional meat production by various experts and scientists. Sustainably in the meat sector is a big challenge which requires a multifaced and holistic approach. Novel tools like digitalization of the farming system and livestock market, precision livestock farming, application of remote sensing and artificial intelligence to manage production and environmental impact/GHG emission, can help in attaining sustainability in this sector. Further, improving nutrient use efficiency and recycling in feed and animal production through integration with agroecology and industrial ecology, improving individual animal and herd health by ensuring proper biosecurity measures and selective breeding, and welfare by mitigating animal stress during production are also key elements in achieving sustainability in meat production. In addition, sustainability bears a direct relationship with various social dimensions of meat production efficiency such as non-market attributes, balance between demand and consumption, market and policy failures. The present review critically examines the various aspects that significantly impact the efficiency and sustainability of meat production.

Spontaneously growing fungi on the surface and processing areas of matured sheep ham and volatile compounds produced

Raw ham is a dried and matured product traditionally made from pork leg, but other animals, such as sheep, can be used. The natural presence of bacteria and fungi in this product influences its characteristics throughout the process. This study analysed the fungal populations present during raw sheep hams' processing. Two types of products were developed: without and with the addition of seasonings. Mycological analyses were carried out from the ingredients, seasonings, facilities air, as well as on the surfaces of the hams and the air in the chamber throughout the maturation period (0, 45, 90, and 180 days) using 18 % dichloran glycerol agar and the data were submitted to Principal Component Analysis. Volatile compounds were evaluated at the end of the sheep ham manufacturing process through a gas chromatograph coupled to a mass spectrometer. At 45 days of aging, a more remarkable similarity was observed between the fungi present on the non-seasoned hams and those in the ripening chamber's air, while the seasoned hams showed a more evident relation with those fungi present in the spices. With time, the fungi in the air of the ripening chamber started to be influenced by Aspergillus ser. Aspergillus and Aspergillus ser. Rubri already installed in the seasoned hams at 45 days, and then it probably dispersed the non-seasoned ones due to the airborne spores, becoming the most prevalent in both treatments at 90 days. At the end of ripening, the mycobiota of both raw hams was composed mainly by xerophilic species of Aspergillus section Aspergillus. The total fungal count was 5.78 log CFU/cm2 for the non-seasoned and 7.19 log CFU/cm2 for the seasoned ones. A potentially ochratoxigenic Aspergillus ser. Circumdati was detected at the end of aging in raw, unseasoned hams. In conclusion, seasoning directly influences the species developing on the surface of seasoned hams throughout the ripening process, and indirectly affects the mycobiota of the non-seasoned hams when sharing the same ripening chamber. The presence of fungi in the matured sheep ham seems to contribute to the formation of volatile compounds, which are related to the sensory quality of these products.

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.

Quality improvement of prerigor salted ground chicken breast with basic amino acids at low NaCl level

The prerigor salting effect is known to provide superior meat processing quality. Based on the urgent need for low salt meat products, the present study was undertaken to evaluate the prerigor salting effect when basic amino acids were introduced at 1% NaCl level. Ground chicken breast meat was salted with NaCl and basic amino acids at 30 min, 60 min, and 90 min postmortem for prerigor treatments. Compared to the 1% NaCl (w/w) treatment, the introduction of 0.06% basic amino acids (w/w) in the prerigor significantly led to an increase in myofibril fragmentation, myofibrillar protein solubility, emulsion activity, storage modulus change rate, gel water-holding capacity and hardness (P < 0.05). Furthermore, smaller and more uniformly sized droplets were produced in emulsion by basic amino acids. Individual basic amino acids had different prerigor salting effects, and it was indicated that basic amino acids could play a positive role in the prerigor salting effect when NaCl was reduced.

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.

Influence of Lactobacillus helveticus ZF22 and TR1-1-3 strains on the aromatic flavor of fermented sausages

In this study, five strains isolated from traditional Inner Mongolian air-dried meat products were used, two Lactobacillus helveticus strains, ZF22 and TR1-1-3, with potent antibacterial activity, acid, salt, and nitrite tolerance, were selected for this study. Lactic acid bacteria (LAB) (Lactobacillus helveticus ZF22 and TR1-1-3) were inoculated into fermented sausages at 10⁷ CFU/g and their volatiles were studied during fermentation and storage. Clustering heat map and principal component analysis (PCA) were used to identify differentiating flavor components in uninoculated and inoculated sausages. The results showed that 72 volatile flavor substances were identified during the fermentation of the fermented sausages and that inoculation with Lactobacillus helveticus ZF22 and TR1-1-3 increased the proportion of acids, ketones and alkanes. Moreover, the clustering heat map demonstrated that esters such as ethyl isobutyrate, ethyl acetate, and ethyl valerate were more abundant in TR1-1-3 and ZF22 than ZR. The PCA analysis showed that the volatile compounds of the three fermented sausages were distributed in separate quadrants, suggesting that the volatile compound compositions of the three fermented sausages differed significantly. Our findings suggest that inoculating fermented sausages with Lactobacillus helveticus TR1-1-3 and ZF22 can improve flavor by enhancing the type and amount of flavor compounds.

Effect of Biogenic Amine-Degrading Lactobacillus on the Biogenic Amines and Quality in Fermented Lamb Jerky

This study compares five types of lamb jerky, namely, CO (without starter culture), PL-4 (with producing putrescine, cadaverine, histamine, and tyramine), BL4-8 (degrading putrescine, cadaverine, histamine, and tyramine), CL4-3 (degrading putrescine and tyramine), and X3-2B (degrading histamine and tyramine). A study was performed to examine the effects of starter culture on the physical−chemical quality, flavor, and biogenic amines (BAs) during fermentation and ripening. At the end of fermentation, the pH value of the BL4-8 group (4.75) was significantly lower than that of other groups (p < 0.05). After high-temperature roasting, the water activity (0.55), water content (22.6%), nitrite residue (0.41 mg/kg), and TBARS value (0.27 mg/100 g) of the X3-2B group were significantly lower than those of other groups (p < 0.05). The findings show that adding starter BL4-8, CL4-3, and X3-2B can increase the variety and content of flavor in the product. The levels of histamine, putrescine, and tyramine were significantly lower in the BL4-8, CL4-3, and X3-2B groups than in CO and PL-4 groups. This study shows that BL4-8, CL4-3, and X3-2B are potential starters for fermented meat products.

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.

Protein Oxidation in Muscle Foods: A Comprehensive Review

Muscle foods and their products are a fundamental part of the human diet. The high protein content found in muscle foods, as well as the high content of essential amino acids, provides an appropriate composition to complete the nutritional requirements of humans. However, due to their special composition, they are susceptible to oxidative degradation. In this sense, proteins are highly susceptible to oxidative reactions. However, in contrast to lipid oxidation, which has been studied in depth for decades, protein oxidation of muscle foods has been investigated much less. Moreover, these reactions have an important influence on the quality of muscle foods, from physico-chemical, techno-functional, and nutritional perspectives. In this regard, the loss of essential nutrients, the impairment of texture, water-holding capacity, color and flavor, and the formation of toxic substances are some of the direct consequences of protein oxidation. The loss of quality for muscle foods results in consumer rejection and substantial levels of economic losses, and thus the control of oxidative processes is of vital importance for the food industry. Nonetheless, the complexity of the reactions involved in protein oxidation and the many different factors that influence these reactions make the mechanisms of protein oxidation difficult to fully understand. Therefore, the present manuscript reviews the fundamental mechanisms of protein oxidation, the most important oxidative reactions, the main factors that influence protein oxidation, and the currently available analytical methods to quantify compounds derived from protein oxidation reactions. Finally, the main effects of protein oxidation on the quality of muscle foods, both from physico-chemical and nutritional points of view, are also discussed.

Use of Meat-Bone Paste to Develop Calcium-Enriched Liver Pâté

The production technology of meat-bone paste and its effect on chemical, mineral and amino acid compositions of liver pâté were studied. The liver was replaced by meat-bone paste in the concentration of 5, 10, 15, 20, and 25% for the production of experimental samples. The compositional analysis of pâté manufactured with meat-bone paste showed that the reformulation did not influence the content of moisture (~56%), fat (~28%), or protein (~11%) while producing a significant increase of ash and a decrease of carbohydrates in comparison with control pâtés. The higher amounts of minerals of bone-meat paste, including calcium (3080 mg/100 g), magnesium (2120 mg/100 g), phosphorous (2564 mg/100 g), and iron (7.30 mg/100 g), explained the higher amount of both ash and these minerals in the reformulated samples compared to the control samples. The total caloric value (~300 kcal/100 g) was also unaffected by the addition of bone-meat paste. The content of both essential and non-essential amino acids decreased with the inclusion of meat-bone paste, although this decrease was lower in essential (6280 mg/100 g in control vs. 5756 mg/100 g in samples with 25% of meat-bone paste) than in non-essential amino acids (6080 mg/100 g in control vs. 3590 mg/100 g in samples with 25% of meat-bone paste). This fact is due to several essential amino acids not showing differences between control and reformulated samples, while in non-essential amino acids, these differences were greater. The results of this study showed that meat-bone paste addition is a good strategy to produce liver pâté enriched in minerals and with minimum influence on the content of the other important nutrients. Therefore, these results can be used for the design of new liver pâté with an increased nutritional significance by using meat industry by-products. According to the balance of minerals, the use of 15% of meat-bone paste to reformulate liver pâté is the best strategy used in the present research. However, additional studies on the stability (during storage), shelf-life, and sensory acceptability of these reformulated pâtés should be carried out.

A Review: Microbial Diversity and Function of Fermented Meat Products in China

Fermented meat products have a long history in China. These products exhibit a characteristic unique flavor, compact meat quality, clear color, long shelf life and wide variety and are easy to transport. During the processing and storage of fermented meat products, microorganisms are present and exhibit diverse characteristics. Microorganisms can accelerate the degradation of proteins and fats to produce flavor compounds, inhibit the growth and reproduction of heterozygous bacteria, and reduce the content of chemical pollutants. This paper reviews the microbial diversity of Chinese ham, sausage, preserved meat, pressed salted duck, preserved fish and air-dried meat and provides analyses of the microbial compositions of various products. Due to the differences in raw materials, technology, auxiliary materials, and fermentation technology, the microbial species found in various fermented meat products in China are different. However, most fermented meat products in China are subjected to pickling and fermentation, so their microbial compositions also have similarities. Microorganisms in fermented meat products mainly include staphylococci, lactobacilli, micrococci, yeasts, and molds. The study of microbial diversity is of great significance for the formation of quality flavor and the safety control of fermented meat products, and it provides some theoretical reference for the study of fermented meat products in China.

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.