Biological activity and development of functional foods fortified with okra (Abelmoschus esculentus).

The Abelmoschus esculentus plant, better known as okra, is an interesting crop from a nutritional standpoint. The okra plant is native to the African region but can now be found throughout tropical and subtropical areas of the world. This plant, known for its healing abilities, has been used as a traditional medicine to treat several diseases and external ailments, such as wounds or boils. This article reviews the potential health benefits from okra consumption, as well as the bioactive compounds that are suggested to be responsible. Furthermore, the okra plant and its derivatives have been evaluated in the formulation and manufacture of new functional food products. The latest advances in this direction, which includes characterizing the technical properties of functional foods fortified with okra are also presented in this review. A series of bioactive compounds such as flavonoids and catechins have been found in the okra plant, which were associated with numerous biological properties observed in research studies that reported potential anti-diabetic, anti-cancer, anti-hypertensive, and antimicrobial effects, among others, as a result of their consumption. These potential health benefits contribute to the development of new and useful functional foods, with okra (or its derivatives) being used as the highlighted ingredient.

Recent insights on tea metabolites, their biosynthesis and chemo-preventing effects: A review.

Tea manufactured from the cultivated shoots of Camellia sinensis (L.) O. Kuntze is the most commonly consumed nonalcoholic drink around the world. Tea is an agro-based, environmentally sustainable, labor-intensive, job-generating, and export-oriented industry in many countries. Tea includes phenolic compounds, flavonoids, alkaloids, vitamins, enzymes, crude fibers, protein, lipids, and carbohydrates, among other biochemical constituents. This review described the nature of tea metabolites, their biosynthesis and accumulation with response to various factors. The therapeutic application of various metabolites of tea against microbial diseases, cancer, neurological, and other metabolic disorders was also discussed in detail. The seasonal variation, cultivation practices and genetic variability influence tea metabolite synthesis. Tea biochemical constituents, especially polyphenols and its integral part catechin metabolites, are broadly focused on potential applicability for their action against various diseases. In addition to this, tea also contains bioactive flavonoids that possess health-beneficial effects. The catechin fractions, epigallocatechin 3-gallate and epicatechin 3-gallate, are the main components of tea that has strong antioxidant and medicinal properties. The synergistic function of natural tea metabolites with synthetic drugs provides effective protection against various diseases. Furthermore, the application of nanotechnologies enhanced bioavailability, enhancing the therapeutic potential of natural metabolites against numerous diseases and pathogens.

Elderberry Lipophilic and Hydrophilic Bioactive Compounds: Characterization and Extract Encapsulation.

There are few studies on the use of elderberry in the food industry, and its form of application differs between the different studies. Therefore, the objective of this study is to describe a procedure for obtaining a stabilized product with a high content of hydrophilic bioactive compounds (encapsulated elderberry extract). Moreover, the solid residue resulting from the extraction of the polyphenols was characterized, and the lipophilic compounds retained in this residue were analyzed. The results show an important antioxidant activity of the extracts obtained, mainly linked to the high content of anthocyanins, hydroxycinnamic acids, and flavonols. The lipophilic bioactive compounds were characterized by a high content of essential fatty acids and high proportions of tocopherols. The information and results of the present study provide novel information about both lipophilic and hydrophilic compounds for the integral valorization of elderberries to promote a circular economy strategy.

Use of oil mixture emulsion hydrogels as partial animal fat replacers in dry-fermented foal sausages.

This study aimed to evaluate the influence of partial replacement of animal fat by oil mixture emulsion hydrogels on the quality properties of dry-fermented foal sausages. Three batches were elaborated: control (CON) - 100 % of pork fat; treatments 1 and 2 (T1 and T2) - 50 % of pork fat was replaced by oil mixture emulsions, tigernut (T1) or sesame oils (T2) blended with algal oil. Lipid reformulations reduced (P < 0.001) fat (36.91 % vs about 30 %, for CON and reformulated samples, respectively), and moisture contents (33.57 % vs about 28 %, for CON and reformulated samples, respectively), while darker sausages were obtained. These changes in the both, fat and moisture contents, have an important influence on the texture parameters, since reformulated samples presented higher values of hardness (283-317 N) than control samples (152 N). Both oil emulsion hydrogels favored a decrease (P < 0.001) of saturated fatty acids (34.16 vs 30 g/100 g of fat), an increase (P < 0.001) of mono- (T1) and polyunsaturated (T2) fatty acids (depending on the batch), and an improvement of all health indices as omega-6/omega-3 (n-3/n-6) and polyunsaturated fatty acids/ saturated fatty acid ratios (PUFA/SFA), atherogenic (AI) and thrombogenic (TI) indices and hypocholesterolaemic/hypercholesterolaemic ratio (h/H). T2 seemed to reduce (P < 0.001) the lipid oxidation in the samples, while T1 presented the highest values. On the other hand, the terpenes and terpenoids were the most abundant volatile compounds (VOCs) found in all sausages, mainly due to the use of pepper as flavoring spice. Several differences were observed on the content of different individual VOCs (hydrocarbons, acids, alcohols, aldehydes, etc.) and also in the total VOCs content, due of both, differences in lipid oxidation processes (in accordance with TBARS values) and also the moisture and fat content of the samples. Nevertheless, consumer acceptability resulted to be unaffected (T1) or improved (T2) by the fat reformulation. Thus, overall results pointed out that the use of T2 emulsion hydrogel as a partial animal fat replacer could be a promising strategy to achieve healthier dry-cured foal sausages with high consumers' approval.

Improving oxidative stability of foods with apple-derived polyphenols.

Consumers demand healthy and natural food products. Thus, naturally derived antioxidants are emerging as a promising alternative to the use of present ingredients. Apples and apple derivative products (e.g., apple juice, apple cider, apple sauce, and others) are widely consumed throughout the world for a variety of different reasons and supply a large quantity of polyphenolic compounds. The extraction of polyphenolic compounds from apples and their incorporation into processed foods as naturally sourced ingredients could be a preferred alternative to commonly used commercial antioxidants that are used in many foods. In addition, they could have a positive impact on the environment and on the economy due to the utilization of byproducts generated during processing of apples, like apple pomace. In terms of the extraction procedures for the antioxidant compounds found in apples, the most efficient processes are methods that use ultrasound as the extraction tool. With this technique, greater yields are achieved, and less extraction time is required when compared with other, more conventional, extraction methods. However, parameters such as the extraction solvent, temperature during extraction, and extraction time must be suitably optimized in order to obtain the best performance and the highest antioxidant capacity. From an application standpoint, the use of apple-derived polyphenol extracts as a naturally derived food additive has documented applications for bread, meat, fish, cookies, and juices and there is evidence of increased antioxidant capacity, reduced rate of lipid oxidation, and increased storage time without compromising on sensory properties.

Natural Antioxidants from Endemic Leaves in the Elaboration of Processed Meat Products: Current Status.

During the last few years, consumers' demand for animal protein and healthier meat products has increased considerably. This has motivated researchers of the meat industry to create products that present healthier components while maintaining their safety, sensory characteristics, and shelf life. Concerning this, natural plant extracts have gained prominence because they can act as antioxidants and antimicrobials, increasing the stability and shelf life of processed meat products. It has been observed that the leaves of plant species (Moringa oleifera, Bidens pilosa, Eugenia uniflora, Olea europea, Prunus cerasus, Ribes nigrum, etc.) have a higher concentration and variety of polyphenols than other parts of the plants, such as fruits and stems. In Chile, there are two native berries, maqui (Aristotelia chilensis) and murtilla (Ugni molinae Turcz), that that stand out for their high concentrations of polyphenols. Recently, their polyphenols have been characterized, demonstrating their potential antioxidant and antimicrobial action and their bioactive action at cellular level. However, to date, there is little information on their use in the elaboration of meat products. Therefore, the objective of this review is to compile the most current data on the use of polyphenols from leaves of native plants in the elaboration of meat products and their effect on the oxidation, stability, and organoleptic characteristics during the shelf life of these products.

Encapsulation of Bioactive Phytochemicals in Plant-Based Matrices and Application as Additives in Meat and Meat Products.

The development of plant-based functional food ingredients has become a major focus of the modern food industry as a response to changes in consumer attitudes. In particular, many consumers are switching to a plant-based diet because of their concerns about animal-derived foods on the environment, human health, and animal welfare. There has therefore been great interest in identifying, isolating, and characterizing functional ingredients from botanical sources, especially waste streams from food and agricultural production. However, many of these functional ingredients cannot simply be incorporated into foods because of their poor solubility, stability, or activity characteristics. In this article, we begin by reviewing conventional and emerging methods of extracting plant-based bioactive agents from natural resources including ultrasound-, microwave-, pulsed electric field- and supercritical fluid-based methods. We then provide a brief overview of different methods to characterize these plant-derived ingredients, including conventional, chromatographic, spectroscopic, and mass spectrometry methods. Finally, we discuss the design of plant-based delivery systems to encapsulate, protect, and deliver these functional ingredients, including micelles, liposomes, emulsions, solid lipid nanoparticles, and microgels. The potential benefits of these plant-based delivery systems are highlighted by discussing their use for incorporating functional ingredients into traditional meat products. However, the same technologies could also be employed to introduce functional ingredients into plant-based meat analogs.

A Review on Health-Promoting, Biological, and Functional Aspects of Bioactive Peptides in Food Applications.

Food-derived bioactive peptides are being used as important functional ingredients for health-promoting foods and nutraceuticals in recent times in order to prevent and manage several diseases thanks to their biological activities. Bioactive peptides are specific protein fractions, which show broad applications in cosmetics, food additives, nutraceuticals, and pharmaceuticals as antimicrobial, antioxidant, antithrombotic, and angiotensin-I-converting enzyme (ACE)-inhibitory ingredients. These peptides can preserve consumer health by retarding chronic diseases owing to modulation or improvement of the physiological functions of human body. They can also affect functional characteristics of different foods such as dairy products, fermented beverages, and plant and marine proteins. This manuscript reviews different aspects of bioactive peptides concerning their biological (antihypertensive, antioxidative, antiobesity, and hypocholesterolemic) and functional (water holding capacity, solubility, emulsifying, and foaming) properties. Moreover, the properties of several bioactive peptides extracted from different foods as potential ingredients to formulate health promoting foods are described. Thus, multifunctional properties of bioactive peptides provide the possibility to formulate or develop novel healthy food products.

Nanoencapsulation of Promising Bioactive Compounds to Improve Their Absorption, Stability, Functionality and the Appearance of the Final Food Products.

The design of functional foods has grown recently as an answer to rising consumers' concerns and demands for natural, nutritional and healthy food products. Nanoencapsulation is a technique based on enclosing a bioactive compound (BAC) in liquid, solid or gaseous states within a matrix or inert material for preserving the coated substance (food or flavor molecules/ingredients). Nanoencapsulation can improve stability of BACs, improving the regulation of their release at physiologically active sites. Regarding materials for food and nutraceutical applications, the most used are carbohydrate-, protein- or lipid-based alternatives such as chitosan, peptide-chitosan and ß-lactoglobulin nanoparticles (NPs) or emulsion biopolymer complexes. On the other hand, the main BACs used in foods for health promoting, including antioxidants, antimicrobials, vitamins, probiotics and prebiotics and others (minerals, enzymes and flavoring compounds). Nanotechnology can also play notable role in the development of programmable food, an original futuristic concept promising the consumers to obtain high quality food of desired nutritive and sensory characteristics.

Effect of Aloysia citrodora Essential Oil on Biochemicals, Antioxidant Characteristics, and Shelf Life of Strawberry Fruit during Storage.

Strawberry fruits are highly susceptible to cold burning, resulting in low storage periods at low temperatures. Plant extracts or essential oils (EOs) can potentially be used as preservatives in fruits throughout the refrigerated period. In the present study, the biochemicals, antioxidant characteristics, and shelf life of treated strawberries with Aloysia citrodora essential oil (ACEOs) were evaluated during keeping time. The treatments were produced as follows: T1, control; T2, 250 ppm ACEOs; T3, 500 ppm ACEOs; and T4, 750 ppm ACEOs. Total soluble solids (TSS), weight loss, titratable acidity (TA), antioxidant activity (DPPH assay), total phenolic (TPC), flavonoid and anthocyanin contents (TFC), and enzymes activity (peroxidase and ascorbate peroxidase) were evaluated during the refrigerated period (5 °C with relative humidity of 85-90% for 20 days). The results revealed that weight loss and TA were reduced in all treatments during storage, being that the rates were lower in samples treated with ACEOs. TPC, TFC, TSS, antioxidant, and enzymes activity were higher in treated fruits than control.

Omega-3-Rich Oils from Marine Side Streams and Their Potential Application in Food.

Rapid population growth and increasing food demand have impacts on the environment due to the generation of residues, which could be managed using sustainable solutions such as the circular economy strategy (waste generated during food processing must be kept within the food chain). Reusing discarded fish remains is part of this management strategy, since they contain high-value ingredients and bioactive compounds that can be used for the development of nutraceuticals and functional foods. Fish side streams such as the head, liver, or skin or the cephalothorax, carapace, and tail from shellfish are important sources of oils rich in omega-3. In order to resolve the disadvantages associated with conventional methods, novel extraction techniques are being optimized to improve the quality and the oxidative stability of these high-value oils. Positive effects on cardiovascular and vision health, diabetes, cancer, anti-inflammatory and neuroprotective properties, and immune system improvement are among their recognized properties. Their incorporation into different model systems could contribute to the development of functional foods, with market benefits for consumers. These products improve the nutritional needs of specific population groups in a scenario where noncommunicable diseases and pandemic crises are responsible for several deaths worldwide.

Physicochemical, Thermal and Rheological Properties of Pectin Extracted from Sugar Beet Pulp Using Subcritical Water Extraction Process.

The objective of this study was to characterize the properties of pectin extracted from sugar beet pulp using subcritical water (SWE) as compared to conventional extraction (CE). The research involved advanced modeling using response surface methodology and optimization of operational parameters. The optimal conditions for maximum yield of pectin for SWE and CE methods were determined by the central composite design. The optimum conditions of CE were the temperature of 90 °C, time of 240 min, pH of 1, and pectin recovery yield of 20.8%. The optimal SWE conditions were liquid-to-solid (L/S) ratio of 30% (v/w) at temperature of 130 °C for 20 min, which resulted in a comparable yield of 20.7%. The effect of obtained pectins on viscoamylograph pasting and DSC thermal parameters of corn starch was evaluated. The contents of galacturonic acid, degree of methylation, acetylation, and ferulic acid content were higher in the pectin extracted by SWE, while the molecular weight was lower. Similar chemical groups were characterized by FTIR in both SWE and CE pectins. Color attributes of both pectins were similar. Solutions of pectins at lower concentrations displayed nearly Newtonian behavior. The addition of both pectins to corn starch decreased pasting and DSC gelatinization parameters, but increased ΔH. The results offered a promising scalable approach to convert the beet waste to pectin as a value-added product using SWE with improved pectin properties.

ɛ-polylysine coating with stinging nettle extract for fresh beef preservation.

Combination effects of ɛ-polylysine coating (0.5 and 1%) and stinging nettle extract (3, 6 and 9%) on quality properties and shelf life of beef meat (2 × 2 × 2 cm) was evaluated at 4 °C for 12 days. The results indicated that ɛ-polylysine (ε-PL) coating with stinging nettle extract (SNE) had no significant effects on ash, fat, protein and moisture content among packaged beef samples in polyethylene bags (in atmosphere condition). At the end of storage, beef samples coated with 1% ε-PL and 9% SNE had significantly lower TBARS and TVB-N values compared to those found in control. Furthermore, 1% ε-PL coating with SNE 9% showed the highest inhibitory effects against molds and yeast, total viable counts (TVC) and coliforms during storage. However, sensory evaluation showed that samples coated with 1% ε-PL and 6% SNE had the highest scores for overall acceptability compared to the other groups. Based on the obtained results, ε-PL coating with SNE could be effectively used for extending the beef meat shelf life without negative effects on sensory attributes.

Application of Pomegranate by-Products in Muscle Foods: Oxidative Indices, Colour Stability, Shelf Life and Health Benefits.

In recent years, considerable importance is given to the use of agrifood wastes as they contain several groups of substances that are useful for development of functional foods. As muscle foods are prone to lipid and protein oxidation and perishable in nature, the industry is in constant search of synthetic free additives that help in retarding the oxidation process, leading to the development of healthier and shelf stable products. The by-products or residues of pomegranate fruit (seeds, pomace, and peel) are reported to contain bioactive compounds, including phenolic and polyphenolic compounds, dietary fibre, complex polysaccharides, minerals, vitamins, etc. Such compounds extracted from the by-products of pomegranate can be used as functional ingredients or food additives to harness the antioxidant, antimicrobial potential, or as substitutes for fat, and protein in various muscle food products. Besides, these natural additives are reported to improve the quality, safety, and extend the shelf life of different types of food products, including meat and fish. Although studies on application of pomegranate by-products on various foods are available, their effect on the physicochemical, oxidative changes, microbial, colour stabilizing, sensory acceptability, and shelf life of muscle foods are not comprehensively discussed previously. In this review, we vividly discuss these issues, and highlight the benefits of pomegranate by-products and their phenolic composition on human health.

Recent Discoveries in the Field of Lipid Bio-Based Ingredients for Meat Processing.

Current culture and pace of lifestyle, together with consumer demand for ready-to-eat foods, has influenced the food industry, particularly the meat sector. However, due to the important role that diet plays in human health, consumers demand safe and healthy food products. As a consequence, even foods that meet expectations for convenience and organoleptic properties must also meet expectations from a nutritional standpoint. One of the main nutritionally negative aspects of meat products is the content and composition of fat. In this sense, the meat industry has spent decades researching the best strategies for the reformulation of traditional products, without having a negative impact in technological processes or in the sensory acceptance of the final product. However, the enormous variety of meat products as well as industrial and culinary processes means that a single strategy cannot be established, despite the large volume of work carried out in this regard. Therefore, taking all the components of this complex situation into account and utilizing the large amount of scientific information that is available, this review aims to comprehensively analyze recent advances in the use of lipid bio-based materials to reformulate meat products, as well as their nutritional, technological, and sensorial implications.

Plant Extracts Obtained with Green Solvents as Natural Antioxidants in Fresh Meat Products.

Plants are rich in bioactive compounds (BACs), mainly polyphenols, which are valuable choices to replace synthetic antioxidants in meat products. These natural antioxidants from plants, in the form of extracts and essential oils (EOs), have been obtained from different sources such as fruits (dragon fruit, guarana, pomegranate), vegetables, (cabbage, onion), herbs, and spices (epazote, ginger, rosemary, sage, thyme, turmeric, winter savory) by several extraction processes. However, in the context of current directives there is a notable incentive for "green" solvents to replace organic ones and conventional techniques, in order to avoid harm to the environment, operator, and consumer health. In addition, the recycling of co-products from the processing of these plant materials allow us to obtain valuable BACs from under-exploited materials, contributing to the revalorization of these wastes. The resulting extracts allow us to maintain the quality of meat products, exhibiting similar or better antioxidant properties compared to those shown by synthetic ones. Their incorporation in fresh meat products would maintain the oxidative stability, stabilizing colour parameters, decreasing the formation of metmyoglobin, lipid, and protein oxidation and the generation of lipid-derived volatile compounds, without affecting sensory attributes. In addition, these novel ingredients contribute to improve both technological and functional characteristics, thus diversifying the offer of so-called "wellness foods". In this review, the application of plant extracts as natural antioxidants in several fresh meat products is presented, showing their efficacy as scavenging radicals and imparting additional health benefits.

Beetroot and radish powders as natural nitrite source for fermented dry sausages.

The aim of this study was to investigate the use of radish and beetroot powders as potential substitutes of nitrite in fermented dry sausages due to their high nitrate content (around 16,000 and 14,000 mg/kg, respectively). Six treatments were prepared and evaluated during the ripening process and storage time: C1 (control with 150 mg/kg sodium nitrite and 150 mg/kg sodium nitrate), C2 (control without sodium nitrite/nitrate), R05 (0.5% radish powder), R1 (1% radish powder), B05 (0.5% beetroot powder) and B1 (1% beetroot powder). The addition of vegetable powders influenced moisture content, weight loss and water activity of sausages. Nitrite was formed from radish and beetroot powders during the ripening process, especially in R1 and B1 treatments. Beetroot powder affected colour, pigments and lactic acid bacteria counts. The results of pH, colour, lipid oxidation, nitrite and nitrate analysis suggest R1 treatment as a potential nitrite replacer obtained from a simple and feasible drying process.

Red pitaya extract as natural antioxidant in pork patties with total replacement of animal fat.

The antioxidant effects of red pitaya extract (PE) were evaluated in pork patties for 18 days at 2 °C. The following treatments were prepared: control (CON, without antioxidant), sodium erythorbate (ERY, 500 mg kg-1), PE low dose (PEL, 250 mg kg-1), PE medium dose (PEM, 500 mg kg-1), and PE high dose (PEH, 1000 mg kg-1). No significant effect was observed on chemical composition and cooking loss with the addition of PE, while a significant effect was noticed in cohesiveness (P < 0.05). The intense pink colour of PE enhanced the colour stability during storage (9.33, 7.92 and 7.69 vs. 6.77 for PEH, PEM and PEL vs. CON, respectively; (P < 0.05). TBARS (1.21 vs. 2.44 mg MDA/kg) and carbonyl values (5.45 vs. 6.87 nmol carbonyl/mg) of treated samples were lower than those observed in CON. Similar values were found between samples with PE and ERY. PE improved colour acceptance and the preference of pork patties. Therefore, PE is a very effective natural antioxidant by delaying colour and oxidative deterioration.

Combined effects of ε-polylysine and ε-polylysine nanoparticles with plant extracts on the shelf life and quality characteristics of nitrite-free frankfurter-type sausages.

In this study, ɛ-polylysine (ɛ-PL) or ɛ-polylysine nanoparticle (ɛ-PLN) combined with plants extracts (including green tea, olive leaves and stinging nettle extracts) were used as nitrite replacers in frankfurter-type sausages. The sausage samples were wrapped in polyethylene bags (in vacuum conditions) and their physicochemical, microbiological and sensory properties were evaluated during 45 days of refrigerated storage. The results showed that the incorporation of ɛ-polylysine had no significant effects on proximate composition of sausages. However, ɛ-PL and ɛ-PLN sausages had significantly (P < 0.05) lower lightness, redness and higher yellowness compared to control samples. At the end of storage, sausages formulated with ɛ-PLN had significantly (P < 0.05) higher contents of phenolic compounds and lowest TBARS values. Microbiological counts also indicated that ɛ-PLN displayed significantly higher inhibitory effects. Higher sensory indices were obtained in ɛ-PLN sausages. Based on the obtained results, ɛ-PLN was effective to improve frankfurter-type sausages shelf life. Therefore, these ingredients could be useful for frankfurter-type sausages production as nitrite replacers.

Healthy beef burgers: Effect of animal fat replacement by algal and wheat germ oil emulsions.

The present study aimed to reformulate beef burgers to make them healthier through total replacement of pork backfat by algal (Al) and/or wheat germ (WG) oils emulsions. The addition of oils emulsions increased the protein and decreased the proportions of lipids in the burgers between 26% and 38%. Colour and technological parameters were not affected by the addition of oils, but increased all TPA parameters. α-tocopherol (Vitamin E) increased in reformulated samples. The wheat germ oil reduced the SFA concentration. The use of algal and/or wheat germ oils emulsions increase PUFA concentration. Beef burgers containing algal oil can be claimed as "high omega-3 content". Both oils improved the n-6/n-3 and PUFA/SFA nutritional ratios. Sensory differences were observed in the flavour and overall quality parameters. The formulations containing algal oil emulsion were similar to the Control. As a general conclusion, the use of algal oil emulsion as pork backfat substitute improve nutritional characteristics of burger without affecting technological or sensory properties.