Utilization of optimized processing conditions for high yield synthesis of conjugated linoleic acid by L. plantarum AB20-961 and L. plantarum DSM2601 in semi-dry fermented sausage

Effects of using pomegranate peel, beet leaf, and broccoli flower extracts on oxidative stability and physicochemical properties of cooked ground beef during refrigerated storage

Plant extracts gained attention in the meat industry for their role in preventing microbial growth and oxidative deterioration. Antioxidant efficiency of various ratios (0.125, 0.25, 0.5, and 1%) of ethanolic or methanolic pomegranate peel (PP), beet leaf (BL), and broccoli flower (BF) extracts on cooked ground beef was investigated during refrigerated storage. Thiobarbituric acid reactive substances (TBARS), lipid hydroperoxide (LPO), p-anisidine, cooking loss (CL), pH, and color analysis were performed. Results revealed that CL increased (p < .05) with 0.5 and 1% PE or 1% BF extracts, whereas no CL change was observed in other extract applications. Although using 0.5% and 1% of ethanolic or methanolic PP extracts caused lower pH than control (p < .05), no pH difference was found among other treatments. L* values were not affected by extract applications, whereas a* decreased and increased with PP and BL extract addition, respectively (p < .05). Meantime, a* values decreased and b* values increased by elevation in extract ratio (p < .05). In terms of solvent impact, methanolic PP and ethanolic BL extracts caused higher b* (p < .05), whereas no difference in b* was obtained between ethanolic or methanolic BL extracts. TBARS, LPO, and p-anisidine analysis revealed that the highest lipid oxidation was obtained in control (p < .05). PP extract treatments exhibited the lowest lipid oxidation (p < .05). Lipid oxidation gradually increased in control and all extract-incorporated samples during storage (p < .05). In extract-incorporated samples, lipid oxidation decreased with increasing the extract ratio (p < .05). Lipid oxidation was inhibited more by all incorporation ratios for each tested extract compared to control (p < .05). Moreover, using 0.125% PP, 0.5% BL, or 1% BF extracts was more effective in lipid oxidation inhibition than BHT (p < .05). It may be concluded that PP, BL, and BF extracts may be utilized by the meat processors to achieve prolonged shelf life and improved quality features.

Screening and Identification of High-Yielding Strains of Conjugated Linoleic Acid and Optimization of Conditions for the Conversion of CLA

Conjugated linoleic acid (CLA) is a class of naturally occurring octadecadienoic acid in humans and animals and is a general term for a group of conformational and positional isomers of linoleic acid. In order to obtain the development of excellent lactic acid strains with a high production of conjugated linoleic acid, 32 strains with a possible CLA conversion ability were obtained by initial screening using UV spectrophotometry, and then the strains were re-screened by gas chromatography, and finally, the strain with the highest CLA content was obtained. The strains were optimized for cultivation by changing the amount of substrate addition, inoculum amount, and fermentation time. The results showed that the yield of the experimentally optimized strain for the conversion of conjugated linoleic acid could reach 94.68 ± 3.57 μg/mL, which was 74.4% higher than the initial yield of 54.28 ± 2.12 μg/mL of the strain. The results of this study can provide some basis for the application of conjugated linoleic acid production by Lactobacillus paracasei in the fermentation of lactic acid bacteria.

Incorporating bay leaf extract (Laurus nobilis L.) and determining the quality attributes of Turkish fermented sausage (sucuk)

This study aimed at investigating the quality attributes of Turkish fermented sausage (sucuk) incorporated with bay leaf extract obtained as a natural antioxidant and a source of phytochemicals. Five different bay leaf extracts were obtained with distilled water and 60%, 70%, 80%, and 90% ethanol. The total phenolic contents and antioxidant activity values indicated that ultrasound-assisted 70% ethanol extract was the most suitable extract. Furthermore, five groups of sucuks were manufactured with the addition of bay leaf extract (1, 5, and 10 mL/kg), ascorbic acid (500 mg/kg), and control. The extracts were produced similar pH values when compared to control and ascorbic acid samples. The treatments had no significant effect on moisture contents of sucuks. Bay leaf extracts produced comparable color, texture profile analysis, and TBARS values to control and ascorbic acid samples. Biogenic amine contents (mg/kg dry weight) of sucuks including tryptamine (6.43-30.66), 2-phenylethylamine (2.24-32.04), putrescine (2.19-7.98), cadaverine (3.28-12.21), histamine (7.01-11.38), tyramine (3.27-71.07), spermidine (4.44-8.01), and spermine (53.96-68.25) were mostly within the lower ranges typically associated with sucuk. However, the lowest cadaverine values observed at the end of storage in the bay leaf extract added samples indicated that bay leaf extract might be effective in decreasing cadaverine values during storage. The addition of bay leaf extract caused similar sensory attributes to the control and ascorbic acid samples. This study revealed that Turkish fermented sucuks could be effectively incorporated with bay leaf extracts without a negative effect on the quality attributes or consumer acceptability.

Production of Conjugated Linoleic Acid (CLA) by Lactiplantibacillus plantarum: A Review with Emphasis on Fermented Foods

The term Conjugated Linoleic Acid (CLA) refers generically to a class of positional and geometric conjugated dienoic isomers of linoleic acid. Among the isomers of linoleic acid cis9, trans11-CLA (c9, t11-CLA) and trans10, cis12-CLA (t10, c12-CLA) are found to be biologically active isomers, and they occur naturally in milk, dairy products and meat from ruminants. In addition, some vegetables and some seafoods have also been reported to contain CLA. Although the CLA levels in these natural sources are insufficient to confer the essential health benefits, anti-carcinogenic or anti-cancer effects are of current interest. In the rumen, CLA is an intermediate of isomerization and the biohydrogenation process of linoleic acid to stearic acid conducted by ruminal microorganisms. In addition to rumen bacteria, some other bacteria, such as Propionibacterium, Bifidobacterium and some lactic acid bacteria (LAB) are also capable of producing CLA. In this regard, Lactiplantibacillus plantarum (formerly Lactobacillus plantarum) has demonstrated the ability to produce CLA isomers from linoleic acid by multiple enzymatic activities, including hydration, dehydration, and isomerization. L. plantarum is one of the most versatile species of LAB and the bacterium is widely used in the food industry as a microbial food culture. Thus, in this review we critically analyzed the literature produced in the last ten years with the aim to highlight the potentiality as well as the optimal conditions for CLA production by L. plantarum. Evidence was provided suggesting that the use of appropriate strains of L. plantarum, as a starter or additional culture in the production of some fermented foods, can be considered a critical factor in the design of new CLA-enriched functional foods.

Advances in research on microbial conjugated linoleic acid bioconversion

Conjugated linoleic acid (CLA) is a functional food ingredient with prebiotic properties that provides health benefits for various human pathologies and disorders. However, limited natural CLA sources in animals and plants have led microorganisms like Lactobacillus and Bifidobacterium to emerge as new CLA sources. Microbial conversion of linoleic acid to CLA is mediated by linoleic acid isomerase and multicomponent enzymatic systems, with CLA production efficiency dependent on microbial species and strains. Additionally, complex factors like LA concentration, growth status, culture substrates, precursor type, prebiotic additives, and co-cultured microbe identity strongly influence CLA production and isomer composition. This review summarizes advances in the past decade regarding microbial CLA production, including bacteria and fungi. We highlight CLA production and potential regulatory mechanisms and discuss using microorganisms to enhance CLA content and nutritional value of fermented products. We also identify primary microbial CLA production bottlenecks and provide strategies to address these challenges and enhance production through functional gene and enzyme mining and downstream processing. This review aims to provide a reference for microbial CLA production and broaden the understanding of the potential probiotic role of microbial CLA producers.

Bifidobacterium animalis A12, a Probiotic Strain That Promotes Glucose and Lipid Metabolism, Improved the Texture and Aroma of the Fermented Sausage

Bifidobacterium animalis A12 was used for the development of fermented sausage. The growth activity, tolerance, and enzyme activity of B. animalis A12 and its contribution to the texture and flavour of fermented sausages were evaluated. Additionally, the sensory texture, flavour components, and amino acid nutrients during the fermentation process were assessed. B. animalis had high tolerance to NaCl and nitrite, and B. animalis A12 had protease and lipase activities. The pH value of sausage fermented with B. animalis A12 was lower than that of sausage fermented without any fermentation strain. Hexanal, heptanal, decanal, cis-2-decanal, and 4-methoxy-benzaldehyde are the unique aldehydes flavour components of fermented sausages in the A12 group. The highest content of volatile flavour substances and amino acids, and the color and texture characteristics of fermented sausage in the experimental group at 18 h were better than those at other times. These results suggest that B. animalis A12 has the potential to be used as a starter culture for im-proving flavour and texture in fermented sausage.

Application of oligosaccharides in meat processing and preservation

In recent decades, consumer preference and attention to foodstuff presented as healthy and with desirable nutritional information, has increased significantly. In this field, the meat industry has a challenging task since meat and meat products have been related to various chronic diseases. Functional ingredients have emerged in response to the increasing demand for healthier and more nutritious foods. On this matter, oligosaccharides such as fructooligosaccharides (FOS), xylooligosaccharides (XOS), galactooligosaccharides (GOS), and chitooligosaccharides (COS) have been presented as suitable ingredients for the meat industry with the aim of obtaining healthier meat derivatives (e.g. with low fat or sugar content, reduced amount of additives, and desirable functional properties, etc.). However, studies considering application of such oligomers in the meat sector are scarce. In addition, a large number of issues remain to be solved related both to obtaining and characterizing the oligosaccharides available in the industry and to the effect that these ingredients have on the features of meat products (mainly physicochemical and sensory). The study of new oligosaccharides, the methodologies for obtaining them, and their application to new meat products should be promoted, as well as improving knowledge about their effects on the properties of functional meat foods.

Functional and Clean Label Dry Fermented Meat Products: Phytochemicals, Bioactive Peptides, and Conjugated Linoleic Acid

Consumer demand for specific dietary and nutritional characteristics in their foods has risen in recent years. This trend in consumer preference has resulted in a strong emphasis in the meat industry and scientific research on activities aimed at improving the nutritional value of fermented meat products. These types of meat products are valued by modern consumers due to their nutritional value resulting, among others, from the method of production. One of the major focuses of the current innovations includes the incorporation of bioactive compounds from plant-based food, in relation to the replacement of additives that may raise concerns among consumers (mainly nitrate and nitrite) as well as the modification of processing conditions in order to increase the content of bioactive compounds. Many efforts have been focused on reducing or eliminating the presence of additives, such as curing agents (nitrite or nitrate) in accordance with the idea of “clean label”. The enrichment of fermented meat products in compounds from the plant kingdom can also be framed in the overall strategies of functional meat products design, so that the meat products may be used as the vehicle to deliver bioactive compounds that may exert benefits to the consumer.

Underlying evidence for the health benefits of fermented foods in humans

Fermented foods (FFs) have been a part of our diets for millennia and comprise highly diverse products obtained from plants and animals all over the world. Historically, fermentation has been used to preserve food and render certain raw materials edible. As our food systems evolve towards more sustainability, the health benefits of FFs have been increasingly touted. Fermentation generates new/transformed bioactive compounds that may occur in association with probiotic bacteria. The result can be specific, advantageous functional properties. Yet, when considering the body of human studies on the topic, whether observational or experimental, it is rare to come across findings supporting the above assertion. Certainly, results are lacking to confirm the widespread idea that FFs have general health benefits. There are some exceptions, such as in the case of lactose degradation via fermentation in individuals who are lactose intolerant; the impact of select fermented dairy products on insulin sensitivity; or the benefits of alcohol consumption. However, in other situations, the results fail to categorically indicate whether FFs have neutral, beneficial, or detrimental effects on human health. This review tackles this apparent incongruity by showing why it is complex to test the health effects of FFs and what can be done to improve knowledge in this field.

Development of Healthier and Functional Dry Fermented Sausages: Present and Future

In recent years, consumer perception about the healthiness of meat products has changed. In this scenario, the meat industry and the scientific and technological areas have put their efforts into improving meat products and achieving healthier and functional formulations that meet the demands of today’s market and consumers. This article aims to review the current functional fermented meat products, especially on sausage development. Firstly, an emphasis is given to reducing and replacing traditional ingredients associated with increased risk to consumer’s health (sodium, fat, and nitrites), adding functional components (prebiotics, probiotics, symbiotics, and polyphenols), and inducing health benefits. Secondly, a look at future fermented sausages is provided by mentioning emerging strategies to produce innovative healthier and functional meat products. Additional recommendations were also included to assist researchers in further development of healthier and functional sausages.

Functional bacterial cultures for dairy applications: towards improving safety, quality, nutritional and health benefit aspects

Traditionally, fermentation was used to preserve the shelf life of food. Currently, in addition to favouring food preservation, well standardized and controlled industrial processes are also aimed at improving the functional characteristics of the final product. In this regard, starter cultures have become an essential cornerstone of food production. The selection of robust microorganisms, well adapted to the food environment, has been followed by the development of microbial consortia that provide some functional characteristics, beyond their acidifying capacity, achieving safer, high‐quality foods with improved nutritional and health‐promoting properties. In addition to starters, adjunct cultures and probiotics, which normally do not have a relevant role in fermentation, are added to the food in order to provide some beneficial characteristics. This review focuses on highlighting the functional characteristics of food starters, as well as adjunct and probiotic cultures (mainly lactic acid bacteria and bifidobacteria), with a specific focus on the synthesis of metabolites for preservation and safety aspects (e.g. bacteriocins), organoleptic properties (e.g. exopolysaccharides), nutritional (e.g. vitamins) and health improvement (e.g. neuroactive molecules). Literature reporting the application of these functional cultures in the manufacture of foods, mainly those related to dairy production, such as cheeses and fermented milks, has also been updated.