Characterization of Flaxseed Oil Bimodal Emulsions Prepared with Flaxseed Oil Cake Extract Applied as a Natural Emulsifying Agent

Physico-Chemical, Textural and Sensory Evaluation of Emulsion Gel Formulated with By-Products from the Vegetable Oil Industry

The aim of this study was to obtain low fat mayonnaise-like emulsion gels using sesame cake and walnut cake by-products resulting from vegetable oil extraction. The ingredients used to formulate the mayonnaise like emulsion gel samples were corn starch, sesame seed cake (SSC), walnuts seed cake (WSC), lemon juice, sunflower oil, mustard, sugar, salt, gelatin and water. Five different samples were prepared: one control lab sample (M) containing only corn starch and the other ingredients (without SSC and WSC), two samples (SO1 and SO2) with 2 and 4% of SSC (without corn starch and WSC) and two samples (WO1 and WO2) with 2 and 4% of WSC (without corn starch and SSC). Also, an egg-free commercial mayonnaise (CM) was purchased and used for comparison. Physicochemical (fat, protein, moisture, ash, carbohydrate, water activity, emulsion stability, viscosity, density and color), textural (hardness, adhesiveness, springiness, cohesiveness, gumminess and chewiness), and sensory (aspect, color, texture/firmness, flavor, taste and acceptability) attributes of all samples were investigated. The results showed that carbohydrate content decreased in all four seed cakes samples compared to the control sample, while protein and fat content increased in all seed cakes samples, with the largest increases observed in the sesame seed cake samples. It was observed that the CM sample has a carbohydrate content value close to that obtained for the M sample, while the protein content has the lowest value for the CM sample compared to all samples analyzed. The stability of the emulsion gels increased from 70.73% (control sample) to 83.64% for the sample with 2% addition sesame seed cake and to 84.09% for the 2% walnut cake added, due to the coagulation capacity of the added cakes. The type and concentration of oil seeds cake added in emulsion gels affected their textural properties such as hardness, adhesiveness, gumminess, and chewiness. The hardness and adhesiveness of low-fat mayonnaise-like emulsion gels samples decreased with the addition of oil seeds cake. However, the addition of by-products improved the sensory properties of emulsion gels. This study provided a theoretical basis for the food industry's application of oilseed cakes, especially for the development of low-fat mayonnaise.

Improving the structure and properties of whey protein emulsion gel using soluble interactions with xanthan and basil seed gum

Applying hydrocolloids in the structure of protein emulsion gel can improve its properties. Interaction of whey protein concentrate (WPC) (5%) with xanthan gum (XG) and basil seed gum (BSG) at different concentrations (0.2%, 0.4%, and 0.6%) was investigated to improve mechanical and structural properties of emulsion gel. Results illustrated that gums created a stronger structure around the oil droplets, which confocal images approved it. Also, the particle size decreased and uniformed by cooperating 0.6% gum in comparison with WPC (46.87 μm). The lowest and highest hardness values were observed in emulsion gel formed by WPC (1.27 N) and 0.6BSG: WPC (3.03 N), respectively. Also, the increase of gum concentration had a positive on consistency parameter of texture, so the value was 11.48 N s in WPC emulsion gel and it reached 0.6BSG: WPC (25.71 N s) and 0.6XG: WPC (19.96 N s). Evaluating the stability of the treatments by centrifugation indicated that 0.6BSG: WPC (89.10%) and 0.6XG: WPC (74%) had the highest level of stability. Increasing gum concentration increased the consistency and viscosity. Also, the viscoelastic properties of emulsion gel improved by 0.6% BSG. The elastic modulus of the WPC, 0.6XG: WPC, and 0.6BSG: WPC emulsion gels at the same frequency (1 Hz) was 240.90, 894.59, and 1185.61 Pa, respectively. In general, the interaction of WPC solution with hydrocolloids, especially BSG, is suggested to prepare more stable and elastic emulsion gels.

Valorization of wastes and by-products of nuts, seeds, cereals and legumes processing

Wastes and by-products of nuts, seeds, cereals and legumes carry a unique potential for valorization into value-added ingredients due to their protein, dietary fiber, antioxidant, vitamin and mineral contents. The most crucial factor in the recovery of value-added ingredients and bioactives from the wastes and by-products is the utilization of the most efficient extraction technique. This work is an overview of the classification of wastes and by-products of nuts, seeds, cereals and legumes processing, the methods used in the extraction of valuable compounds such as proteins, dietary fibers, phenolics, flavonoids and other bioactives. This chapter provides insights on the promising applications of extracted ingredients in various end products. A special emphasis is given to the challenges and improvement methods for extraction of value-added compounds from wastes and by-products of nuts, seeds, cereals and legumes processing.

Effect of Flaxseed Oil Cake Extract on the Microbial Quality, Texture and Shelf Life of Gluten-Free Bread

Extending the shelf life of gluten-free bread (GFB) is a challenge. Mainly due to the ingredients used and their characteristics, GFB has numerous drawbacks such as unsatisfactory texture and rapid staling beyond a low nutritional value. In the present study, flaxseed oil cake extract (FOCE) was used to replace water (25-100%) in GFB formulations in order to test FOCE's potential to reduce GFB staling and extend microbial stability. Texture (TPA test), water activity (LF NMR), acidity (pH measurements) and microbiological quality of GFBs were tested. Moreover, the content of a lignan with broad health-promoting potential, secoisolariciresinol diglucoside (SDG), in GFB with FOCE was analyzed. The results showed that the use of FOCE enriched experimental GFB in valuable SDG (217-525 µg/100 g DM) while not causing adverse microbiological changes. A moderate level (25-50%) of FOCE did not change the main texture parameters of GFB stored for 72 h, the quality of which was comparable to control bread without FOCE. Meanwhile, higher proportions of FOCE (75-100% of water replacement) shortened GFB shelf life as determined by water activity and texture profile, suggesting that GFB with FOCE should be consumed fresh. To summarize, FOCE at moderate levels can add value to GFBs without causing a drop in quality, while still fitting in with the idea of zero waste and the circular economy.

Structural Characterization and Functional Properties of Flaxseed Hydrocolloids and Their Application

Flaxseed is an excellent source of valuable nutrients and is also considered a functional food. There are two types of hydrocolloids in flaxseed: flaxseed gum and proteins. Flaxseed gum exhibits emulsifying and foaming activities or can be used as a thickening and gelling agent. Due to its form of soluble fiber, flaxseed gum is related to many health benefits. Flaxseed proteins have various functional properties based on their physicochemical properties. While albumins possess the emulsion-forming ability, globulins better serve as foaming agents. Flaxseed proteins may also serve as a source of functional peptides with interesting biological and health-related activities. Functional properties and health-related benefits predetermine the application of these hydrocolloids, mainly in the food industry or medicine. Although these properties of flaxseed hydrocolloids have been recently and extensively studied, they are still not widely used on the industrial scale compared to other popular plant gums and proteins. The aim of this review was to present, discuss and highlight the recent discoveries in the structural characteristics and functional and biological properties of these versatile hydrocolloids with respect to factors affecting their characteristics and offer new insights into their potential applications as comparable alternatives to the other natural hydrocolloids or as the sources of novel functional products.

Development and Characterization of a Low-Fat Mayonnaise Salad Dressing Based on Arthrospira platensis Protein Concentrate and Sodium Alginate

The food industry is constantly reformulating different foods to fulfill the demands of the consumers (natural ingredients and good sensory quality). The present work aimed to produce low-fat mayonnaises using 30.0, 22.5, and 15.0% oil, 1% soy protein isolate (SPI) or spirulina (Arthrospira platensis) protein concentrate (SPC), and 2% sodium alginate. The physical properties (thermal stability, rheological behavior, and particle size), the sensory attributes (appearance, texture, taste, and acceptability), the purchase probability, and amino acid availability (after a simulated digestion) were evaluated. The mayonnaises demonstrated good thermal stability (>90%) using 22.5 and 15% oil, all products showed shear-thinning behavior and a consistency index of 20–66 Pa·s. The reduction of oil from 30 to 15% increased the particle size from 6–9 µm to 10–38 µm. The most acceptable product was the formulated with SPI and 22.5% oil (8.3 of acceptability and 79% of purchase probability). Finally, the addition of proteins improved the total essential amino acids compared to a commercial product (28 and 5 mg/25 g, respectively). In summary, it was possible to obtain well accepted products with high purchase probability using low concentrations of oil and vegetable proteins.

Development of β-Cyclodextrin/Konjac-Based Emulsion Gel for a Pork Backfat Substitute in Emulsion-Type Sausage

Emulsion gel has been used to replace animal fats in meat products. Konjac is a widely used gelling agent; however, its low emulsion stability limits its use in meat products. This study aimed to examine the quality characteristics of β-cyclodextrin (CD)-supplemented konjac-based emulsion gel (KEG) (CD-KEG) and its application as a fat substitute in emulsion-type sausages. The supplementation of CD increased hydrogen bonds and hydrophobic interactions with konjac and oil in the gels, respectively. Additionally, CD increased the structural complexity and strength of KEG. Since adding more than 6% of CD to KEG did not increase the gel strength, 6% CD-added KEG was adopted to substitute for pork backfat in manufacturing low-fat emulsion-type sausages. The following formulations of the sausages were prepared: pork backfat 20% (PF20); pork backfat 10% + KEG 10% (KEG10); KEG 20% (KEG20); pork backfat 10% + CD-KEG 10% (CD-KEG10); CD-KEG 20% (CD-KEG20); and pork backfat 5% (PF5). The CD-KEG20 formulation exhibited higher viscosity and viscoelasticity than KEG20, which suggested that CD improves the rheological properties and the thermal stability of meat batter. Additionally, CD-KEG20 showed similar emulsion stability, cooking yield and texture parameters compared with PF20. Therefore, 6% CD-added KEG is a suitable fat substitute for preparing low-fat emulsion-type sausages.

Antioxidant and emulsifying properties of a galactose-rich heteropolysaccharide from Plinia cauliflora peels

In this study functional properties of a galactose-rich heteropolysaccharide (GH) were accessed. The bands of a galactose-rich polysaccharide were found in FTIR spectra, including those from the fingerprint region. GH was characterized as a dark-red material (L* 25.86 ± 0.75, a* 9.46 ± 1.01, b* 0.65 ± 0.14, Chroma 9.48 ± 1.02) with antioxidant activity of 21.5 ± 0.08, 12.1 ± 0.06 and 0.46 ± 0.04 mmol Trolox Eq mg^-1 GH in FRAP, DPPH and ABTS, respectively. GH presented 44.9% of esterification degree and 10.73 ± 0. 01 mg of GAE g^-1. The production parameters of GH emulsions (GH concentration, time and ultrasound power) were optimized using a 2³ Central Composite Rotatable Design (CCRD). Emulsion droplets presented particle size (d µm) varying from 0.823 ± 0.065 to 1.926 ± 0.151, polydispersity index (PDI) from 0.10 ± 0.05 to 0.40 ± 0.01 and zeta potential from -29.25 ± 3.98 to -33.75 ± 1.77. Finally, the high emulsifying activity (EA) (96.67%) and emulsion stability (ES) (97.44%) allow suggesting that GH is a promising polysaccharide for food applications.

Novel Gluten-Free Bread with an Extract from Flaxseed By-Product: The Relationship between Water Replacement Level and Nutritional Value, Antioxidant Properties, and Sensory Quality

The food industry generates a great amount of food waste and by-products, which in many cases are not fully valorized. Press cakes, deriving from oilseeds extraction, represent interesting co-products due to their nutritional value, high biopolymers content, and the presence of bioactive phytochemicals. Gluten-free breads (GFBs) are products that have disadvantages such as unsatisfactory texture, low nutritional value, and short shelf life, so natural additives containing proteins and hydrocolloids are in demand to increase GFBs value. In this study, extract from flaxseed by-product (FOCE-Flaxseed Oil Cake Extract) was used to replace water (25-100%) in GFBs formulations and their nutritional value, antioxidant properties, and sensory features were investigated. The results showed that GFBs with FOCE had an elevated nutritional and nutraceutical profile (up to 60% more proteins, significantly increased K, Mg, and P levels). Moreover, the addition of FOCE improved the technological parameters (increased specific volume, number of cells and height/width ratio, reduced density, average size, and perimeter of cells), antioxidant potential, and overall sensory quality of GFBs. This study showed an encouraging way of using a by-product that, due to its high content of proteins, polysaccharides, minerals, and antioxidants, can add value to GFBs.

A Concise Review on Taro Mucilage: Extraction Techniques, Chemical Composition, Characterization, Applications, and Health Attributes

Taro (Colocasia esculenta) is an important source of carbohydrates as an energy source and is used as a staple food throughout the world. It is rich in mucilage and starch granules, making it a highly digestible ingredient. Mucilage can act as a matrix and a thickening, binding, emulsifying, or foaming agent in food, pharmaceutical, and several other fields of research. Moreover, mucilage can be extracted from several living organisms and has excellent functional properties, such as water-holding, oil-holding, and swelling capacities. Therefore, these remarkable functional properties make mucilage a promising ingredient with possible industrial applications. Furthermore, several extraction techniques, including enzyme-assisted, ultrasonication, microwave-assisted, aquatic, and solvent extraction methods, are used to obtain quantitative amounts of taro mucilage. Coldwater extraction with ethanol precipitation can be considered an effective and cost-effective technique to obtain high-quality mucilage with suitable industrial applications, whereas the ultrasonication method is more expensive but results in a higher amount of mucilage than other emerging techniques. Mucilage can also be used as a fat replacer or reducer, dye remover, coating agent, and antioxidating agent. Therefore, in this review, we detail the key properties related to the extraction techniques, chemical composition, and characterization of taro mucilage, along with its suitable applications and health benefits.

Black Cumin (Nigella sativa L.) Seed Press Cake as a Novel Material for the Development of New Non-Dairy Beverage Fermented with Kefir Grains

In recent years, there has been a growing interest from the food industry in new products that are increasingly desired by consumers because of the functional ingredients they contain. This category certainly includes fermented plant-based beverages, which combine the properties of plant substrates with the beneficial effects of fermentation on human health. In our study, two trial variants containing 20% and 30% black cumin (Nigella sativa L.) seed press cake (BCPC) were inoculated with kefir grain cultures and then incubated at 25 °C for 24 h. The resulting beverages were stored under refrigeration (6 °C) for 28 days. During storage, pH, total free amino acids, reducing sugars, changes in the microbial population, viscosity, textural parameters, and color were measured on days 1, 5, 7, 14, 21, and 28. Throughout the storage period, the number of lactic acid bacteria, as well as yeasts, exceeded the recommended minimum level. Numerous changes in product parameters were observed in the tested beverages as a result of fermentation compared to non-fermented products. This study indicates the possibility of using BCPC as a valuable matrix for the production of a functional kefir-like beverage.

The Application of Spray-Dried and Reconstituted Flaxseed Oil Cake Extract as Encapsulating Material and Carrier for Probiotic Lacticaseibacillus rhamnosus GG

Agro-industrial by-products are promising source of biopolymers, including proteins and polysaccharides. This study was designed to evaluate the flaxseed oil cake extract (FOCE) as natural encapsulating material and carrier for probiotic Lacticaseibacillus rhamnous GG (LGG). The powders were obtained using three spray drying inlet temperatures (110 °C, 140 °C, 170 °C), and reconstituted. The influence of temperature on water activity, morphology, chemical composition, flowability and cohesiveness of the powders was estimated. For all variants, the survival of bacteria during spray drying, and simulated passage through the gastrointestinal tract was evaluated. The preservation of LGG probiotic features such as cholesterol reduction, hydrophobicity and adhesion to mucin were examined. Results revealed that all physicochemical and functional characteristics of the powders were affected by the inlet temperature. This study demonstrated that FOCE is an appropriate matrix for spray drying (due to flaxseed proteins and polysaccharides) providing high survivability of bacteria (89.41-96.32%), that passed meaningfully through the simulated gastrointestinal tract (4.39-5.97 log reduction), largely maintaining their probiotic properties, being a promising environmentally-friendly carrier for probiotic LGG.

Engineering miscellaneous particles from media-milled defatted walnut flour as novel food-grade Pickering stabilizers

Media milling, an efficient and organic solvent-free method without the use of chemical modification, has been developed to engineer novel walnut-based miscellaneous colloidal particles. The defatted walnut flour particles (DWFPs), which were prepared by a novel continuous phase transition extraction method operated under low temperature (i.e., 50-65 °C) followed by 6-h media milling, were spherical shape with an average size of 753.0 ± 27.8 nm. These particles were mainly composed of proteins (55.6 ± 0.2 wt%) and carbohydrates (24.0 ± 0.2 wt%) and demonstrated the ability to form a gel-like network structure in Pickering emulsions (PEs). The visual observation and confocal laser scanning microscopy (CLSM) showed that the PE droplets stabilized by DWFPs had a good stability over a prolonged storage time (i.e., 3-month storage). Increasing particle concentration (c) in aqueous phase led to the increased emulsified phase volume, decreased oil droplet sizes, and increased storage moduli G' for the viscoelastic responses. As the oil volume fraction (ϕ) increased, the emulsified phase volume fraction and droplet size increased while their rheological properties shifted from fluid-like to gel-like behaviors. The method developed in this study is significant in value-added utilization of walnut products and provides a new insight into facile fabrication of stable food-grade Pickering emulsions-based functional foods using miscellaneous particle stabilizers from walnut extracts.

The Influence of Flaxseed Oil Cake Extract on Oxidative Stability of Microencapsulated Flaxseed Oil in Spray-Dried Powders

The objective of the study was to investigate the application of flaxseed oil cake extract (FOCE) for oxidative stabilization of flaxseed oil in spray-dried emulsions. Two variants of powders with 10% and 20% of flaxseed oil (FO), FOCE, and wall material (maltodextrin and starch Capsul^®) were produced by spray-drying process at 180 °C. The oxidative stability of FO was monitored during four weeks of storage at 4 °C by peroxide value (PV) and thiobarbituric acid-reactive substances (TBARS) measurements. Additionally, the fatty acids content (especially changes in α-linolenic acid content), radical scavenging activity, total polyphenolics content, color changes and free amino acids content were evaluated. Obtained results indicated that FOCE could be an adequate antioxidant dedicated for spray-dried emulsions, especially with a high content of FO (20%). These results have important implications for the flaxseed oil encapsulation with natural antioxidant agents obtained from plant-based agro-industrial by product, meeting the goals of circular economy and the idea of zero waste.

Formulation and Evaluation of Spray-Dried Reconstituted Flaxseed Oil-in-Water Emulsions Based on Flaxseed Oil Cake Extract as Emulsifying and Stabilizing Agent

Spray drying of emulsions is a promising way of increasing their durability, offering the possibility of reconstitution, with the addition of water. The present study aimed to examine the properties of flaxseed oil cake extract (FOCE) as an emulsifying and stabilizing agent for spray-dried reconstituted oil-in-water emulsions. Maltodextrin: starch: flaxseed oil emulsions with FOCE or distilled water as liquid phases, and 10% and 20% of oil were spray-dried at 180 °C. The solubility, flowability, cohesiveness, bulk, and tapped densities of the spray-dried powders were analyzed. Additionally, the characteristics of initial and reconstituted emulsions, such as stability, creaming index, color, particle size, and rheological properties were evaluated. Results showed that FOCE could be an adequate emulsifier for spray-dried emulsions with a high oil content providing high stability after reconstitution, when compared to emulsions based only on maltodextrin–starch wall material with water as the liquid phase. This study showed an encouraging way for producing natural and plant-based spray-dried oil-loaded emulsions for food applications.