Emulsion gels containing n-3 fatty acids and condensed tannins designed as functional fat replacers

Antioxidant-Enhanced Alginate Beads for Stabilizing Rapeseed Oil: Utilizing Extracts from Post-Distillation Waste Residues of Rosemary

An eco-friendly extraction process of polyphenols from conventional dried rosemary tissues and post-distillation waste residues was applied using β-cyclodextrin as a co-solvent. The aqueous extracts were characterized by measuring the total phenolic content, and their phenolic compounds were identified and quantified by LC-MS. Sodium alginate solutions (2% w/w) with/without incorporation of rosemary aqueous extracts were prepared and used for the preparation of O/W emulsions containing 20% rapeseed oil and an 80% water phase. Hydrogel beads were then stored at 20 °C for 28 days. The quality of encapsulated oil during storage was evaluated by measurements of the peroxide value, p-anisidine value, free fatty acids, total oxidation value, and fatty acid composition, whilst the aqueous phase of the beads was analyzed for its total extractable phenolic content (TEPC). The experimental findings indicate that the incorporation of aqueous extracts from post-distillation rosemary residues in emulsion-filled hydrogel beads resulted in the lowest level of oxidation products in the encapsulated rapeseed oil (PV = 10.61 ± 0.02 meq/Kg oil, p-AnV = 4.41 ± 0.09, and FFA = 0.14 ± 0.00, expressed as % oleic acid content), indicating an acceptable oil quality until the end of the storage period.

Olive Pomace Oil Structuring for the Development of Healthy Puff Pastry Laminating Fats: The Effect of Chilling Storage on the Quality of Baked Products

Developing puff pastry (PP) laminating fats (LFs) with sustainable structured olive pomace oil (OPO) could contribute to its increased valorization. This study evaluated the physicochemical stability of four OPO-based LFs or margarines and the performance of their baked PP counterparts during two months of chilling storage at 4 °C. LF samples, developed at the laboratory scale, contained 41% (LF1 and LF2) OPO and 31% (LF3 and LF4) OPO together with 10% cocoa butter when using two static initial crystallization conditions (room temperature for LF1 and LF3, freezer for LF2 and LF4) before storage. During the storage period, the proximate composition, thermal and dynamic rheological properties, firmness and spreadability, oil-binding capacity, color, and lipid oxidation of the four LF samples were examined, along with the baking performance and textural properties of the PP counterparts. The initial cooling rate had minimal significance. Cocoa butter negatively influenced post-crystallization processes occurring in OPO-based LF3 and LF4, resulting in increased hardness and reduced performance after 18 days of storage, attributed, at least partially, to a high amount of 1,3-dipalmitoyl-2-oleoyl-glycerol (POP), mainly from cocoa butter. Conversely, OPO-based LF1 and LF2 maintained their quality and were stable for two months without apparent granular crystal formation.

Advances in preparation and application of food-grade emulsion gels

Emulsion gel is a semi-solid or solid material with a three-dimensional net structure produced from emulsion through physical, enzymatic, chemical methods or their combination. Emulsion gels are widely used in food, pharmaceutical and cosmetic industries as carriers of bioactive substances and fat substitutes due to their unique properties. The modification of raw materials, and the application of different processing methods and associated process parameters profoundly affect the ease or difficult of gel formation, microstructure, hardness of the resulting emulsion gels. This paper reviews the important research undertaken in the last decade focusing on classification of emulsion gels, their preparation methods, the influence of processing method and associated process parameters on structure-function of emulsion gels. It also highlights current status of emulsion gels in food, pharmaceutical and medical industries and provides future outlook on research directions requiring to provide theoretical support for innovative applications of emulsion gels, particularly in food industry.

Emulsion Gels Formed by Electrostatic Interaction of Gelatine and Modified Corn Starch via pH Adjustments: Potential Fat Replacers in Meat Products

The application of emulsion gels as animal fat replacers in meat products has been focused on due to their unique physicochemical properties. The electrostatic interaction between proteins and polysaccharides could influence emulsion gel stability. This study aimed to evaluate the physicochemical properties of emulsion gels using starch and gelatin as stabilizers, promoting electrostatic attraction via pH adjustment. Three systems were studied: emulsion gel A (EGA) and emulsion gel B (EGB), which have positive and negative net charges that promote electrostatic interaction, and emulsion gel C (EGC), whose charge equals the isoelectric point and does not promote electrostatic interactions. There was no significant difference in proximate analysis, syneresis and thermal stability between samples, while EGA and EGB had higher pH values than EGC. The lightness (L*) value was higher in EGA and EGB, while the yellowness (b*) value was the highest in EGC. The smaller particle size (p < 0.05) in EGA and EGB also resulted in higher gel strength, hardness and oxidative stability. Microscopic images showed that EGA and EGB had a more uniform matrix structure. X-ray diffraction demonstrated that all the emulsion gels crystallized in a β′ polymorph form. Differential scanning calorimetry (DSC) revealed a single characteristic peak was detected in both the melting and cooling curves for all the emulsion gels, which indicated that the fat exists in a single polymorphic state. All emulsion gels presented a high amount of unsaturated fatty acids and reduced saturated fat by up to 11%. Therefore, the emulsion gels (EGA and EGB) that favored the electrostatic protein-polysaccharide interactions are suitable to be used as fat replacers in meat products.

Karakterisasi Fisiko-Kimia Biji dan Kulit Ari Kacang Bogor Asal Jampang-Sukabumi Jawa Barat

The traditional cultivation and limited use of bambara groundnut (Vigna subterranea) seed and coat have encouraged the development of this commodity. The aim of this research was to characterize the seed and coat of bambara groundnut from Jampang, Kab. Sukabumi, West Java. Analysis on bambara groundnut seed including proximate analysis, in vitro protein digestibility, starch content, and dietary fiber, as well as analysis on its coat including anthocyanin, total phenolic, antioxidant activity, phytic acid and tannin, were examined in this study. The results showed that bambara groundnut seed from Jampang-Sukabumi contained 16.53% proteins, 3.04% ash, 7.83% fats and 55.22% carbohydrates in dry basis (db). The carbohydrates consisted of starch 52.71% and dietary fiber 7.47% (db). The protein had an in vitro protein digestibility of 41.65% db. The purple seed coat contained of 1.51% anthocyanin, 25.85 mg/g total phenolic content (as gallic acid equivalent), antioxidant activity at 82.75% inhibition of free radical DPPH, 6.37 mg/g phytic acid, and 96.79 mg/g tannin (as tannic acid equivalent) in dry basis. The relatively high content of tannin and antioxidant activity but very low phytic acid content, make the bambara seed coat a potential source for tannin, meanwhile the bambara groundnut is potential as a nutrition source.

Application of Emulsion Gels as Fat Substitutes in Meat Products

Although traditional meat products are highly popular with consumers, the high levels of unsaturated fatty acids and cholesterol present significant health concerns. However, simply using plant oil rich in unsaturated fatty acids to replace animal fat in meat products causes a decline in product quality, such as lower levels of juiciness and hardness. Therefore, it is necessary to develop a fat substitute that can ensure the sensory quality of the product while reducing its fat content. Consequently, using emulsion gels to produce structured oils or introducing functional ingredients has attracted substantial attention for replacing the fat in meat products. This paper delineated emulsion gels into protein, polysaccharide, and protein–polysaccharide compound according to the matrix. The preparation methods and the application of the three emulsion gels as fat substitutes in meat products were reviewed. Since it displayed a unique separation structure, the double emulsion was highly suitable for encapsulating bioactive substances, such as functional oils, flavor components, and functional factors, while it also exhibited significant potential for developing low-fat or functional healthy meat products. This paper summarized the studies involving the utilization of double emulsion and gelled double emulsion as fat replacement agents to provide a theoretical basis for related research and new insight into the development of low-fat meat products.

Engineering Emulsion Gels as Functional Colloids Emphasizing Food Applications: A Review

Gels are functional materials with well-defined structures (three-dimensional networks) assembled from the dispersed colloids, and capable of containing a large amount of water, oil, or air (by replacing the liquid within the gel pores), known as a hydrogel, oleogel, and aerogel, respectively. An emulsion gel is a gelled matrix filled with emulsion dispersion in which at least one phase, either continuous phase or dispersed phase forms spatial networks leading to the formation of a semisolid texture. Recently, the interest in the application of gels as functional colloids has attracted great attention in the food industry due to their tunable morphology and microstructure, promising physicochemical, mechanical, and functional properties, and superior stability, as well as controlled release, features for the encapsulated bioactive compounds. This article covers recent research progress on functional colloids (emulsion gels), including their fabrication, classification (protein-, polysaccharide-, and mixed emulsion gels), and properties specifically those related to the gel-body interactions (texture perception, digestion, and absorption), and industrial applications. The emerging applications, including encapsulation and controlled release, texture design and modification, fat replacement, and probiotics delivery are summarized. A summary of future perspectives to promote emulsion gels' use as functional colloids and delivery systems for scouting potential new applications in the food industry is also proposed. Emulsion gels are promising colloids being used to tailor breakdown behavior and sensory perception of food, as well as for the processing, transportation, and targeted release of food additives, functional ingredients, and bioactive substances with flexibility in designing structural and functional parameters.

Phenolics Dynamics and Infrared Fingerprints during the Storage of Pumpkin Seed Oil and Thereof Oleogel

Cold-pressed pumpkin seed oil is a valuable source of bioactive molecules, including phenolic compounds. Oleogels are designed for trans and saturated fats substitution in foods, but also demonstrate protection and delivery of bioactive compounds. Consequently, the present work aimed to assess individual phenolic compounds dynamics and infrared fingerprints during the ambient storage of pumpkin seed oil and thereof oleogel. For oleogels production, a 5% ternary mixture of waxes, composed by 3% beewax, 1% sunflower wax and 1% rice bran wax, was used. Phenolic compounds were extracted by traditional liquid–liquid extraction, followed by HPLC-MS quantification. FTIR (400–4000 cm−1) was used for characterizing and monitoring the oxidative stability of all samples and for the evaluation of intermolecular forces between oleogelator mixtures and oil. Specific wavenumbers indicated oxidative processes in stored sample sets; storage time and sample clustering patterns were revealed by chemometrics. Isolariciresinol, vanillin, caffeic and syringic acids were quantified. The main changes were determined for isolariciresinol, which decreased in liquid pumpkin seed oil samples from 0.77 (T1) to 0.13 mg/100 g (T4), while for oleogel samples it decreased from 0.64 (T1) to 0.12 mg/100 g (T4). However, during the storage at room temperature, it was concluded that oleogelation technique might show potential protection of specific phenolic compounds such as syringic acid and vanillin after 8 months of storage. For isolariciresinol, higher amounts are registered in the oleogel (0.411 mg/100 g oil) than in the oil (0.37 mg/100 g oil) after 5 months of ambient temperature storage (T3). Oxidation processes occurred after 5 months storage for both oil and oleogel samples.

The Effect of Emulsifying Protein and Addition of Condensed Tannins on n-3 PUFA Enriched Emulsions for Functional Foods

This paper examines the effect of the type of the emulsifying protein (EP) (sodium caseinate (SC) and whey protein isolate (WPI)) on both oil-in-water liquid-like emulsions (Es) and the corresponding cold gelled emulsions (GEs), and also the effect of addition of carob extract rich in condensed tannins (T). The systems, intended as functional food ingredients, were studied in various different respects, including rheological behaviour, in vitro gastrointestinal digestion with determination of the release of non-extractable proanthocyanidins (NEPA) from T, antioxidant activity and lipolysis. EP significantly affects the rheological behaviour of both Es and GEs. T incorporation produced a structural reinforcement of GEs, especially in the case of SC. The digests from Es displayed a higher antioxidant activity than those from GEs. T lipase inhibition was observed only in the formulations with WPI. Our results highlight the importance, in the design of functional foods, of analyzing different variables when incorporating a bioactive compound into a food or emulsion in order to select the better combination for the desired objective, owing to the complex interplay of the various components.

Protein-based hydrogelled emulsions and their application as fat replacers in meat products: A review

Recent consumers' concerns about diet and its health benefits has triggered a reduction in consumption of foods rich in sugar, fat, salt, and chemical additives. As a result, an expanded market for functional foods has arisen. In particular, high-fat foods normally composed by saturated fatty acids, cholesterol and trans-fatty acids have been reformulated to be healthier. The primary source of saturated fat ingested by humans includes meats and their by-products that have animal fat as lipid source. The reformulation of these products therefore represents an important strategy to make them healthier for human consumption. Substituting solid fat by unsaturated oils usually affects the texture of the products, and therefore, new structuring methods must be developed to provide vegetable oils a similar characteristic to solid fats and improve their functional and health-related properties. Among these structural models, gelled emulsions (GE) show great potential to be used as healthier lipid ingredients in low-calorie and reduced-fat products, including healthier meat products. This review addresses the GE properties to be used as structuring agent, their in vitro bioaccessibility in meat products and effect on technological, sensorial, microstructural and microbiological characteristics.

An Approach to Manufacture of Fresh Chicken Sausages Incorporated with Black Cumin and Flaxseed Oil in Water Gelled Emulsion

In order to investigate the use of oil in water gelled emulsion (GE) prepared with healthier oil combinations as beef fat replacer in the fresh chicken sausage formulations, four batches of fresh sausages were produced. The first batch was control (C) sample formulated with %100 beef fat, other batches were codded as GE50, GE75, and GE100 respective to the percentage of beef fat replaced with GE. The addition of GE to sausage formulation resulted in an increment in moisture and protein contents while a decrement was observed in fat content (p<0.05). pH, cooking yield and water holding capacity values of GE added samples were found lower than C (p<0.05). GE addition caused lower CIE L* values in samples, however, this trend was not observed in CIE a* and CIE b* values. Initially, the lowest peroxide and the highest TBARS values were recorded in GE100 samples on the 0^th d (p<0.05). Peroxide and TBARS values were in the limits. The texture of samples was softened while total saturated fatty acid content reduced up to 52.61% with the incorporation of GE (p<0.05). Taken together, our results showed that GEs can be used as fat replacers in meat product formulations without causing undesirable quality changes.

Exhausted Woods from Tannin Extraction as an Unexplored Waste Biomass: Evaluation of the Antioxidant and Pollutant Adsorption Properties and Activating Effects of Hydrolytic Treatments

Exhausted woods represent a byproduct of tannin industrial production processes and their possible exploitation as a source of antioxidant compounds has remained virtually unexplored. We herein report the characterization of the antioxidant and other properties of practical interest of exhausted chestnut wood and quebracho wood, together with those of a chestnut wood fiber, produced from steamed exhausted chestnut wood. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing/antioxidant power (FRAP) assays indicated good antioxidant properties for all the materials investigated, with exhausted chestnut wood, and, even more, chestnut wood fiber exhibiting the highest activity. High efficiency was observed also in the superoxide scavenging assay. An increase of the antioxidant potency was observed for both exhausted woods and chestnut wood fiber following activation by hydrolytic treatment, with an up to three-fold lowering of the EC₅₀ values in the DPPH assay. On the other hand, exhausted quebracho wood was particularly effective as a nitrogen oxides (NO_x) scavenger. The three materials proved able to adsorb methylene blue chosen as a model of organic pollutant and to remove highly toxic heavy metal ions like cadmium from aqueous solutions, with increase of the activity following the hydrolytic activation. These results open new perspectives toward the exploitation of exhausted woods as antioxidants, e.g., for active packaging, or as components of filtering membranes for remediation of polluted waters.

Design of gel structures in water and oil phases for improved delivery of bioactive food ingredients

Gels are viscoelastic systems built up with a liquid phase entrapped in a three-dimensional network, which can behave as carriers for bioactive food ingredients. Many attempts have been made to design gel structures in the water phase (hydrogels, emulsion gels, bigels) or oil phase (organogels, bigels) in order to improve their delivery performances. Hydrogels are originated from proteins or polysaccharides, which are suitable for the delivery of hydrophilic ingredients. Organogels are mainly built up with the self-assembling of gelator molecules in the oil phase, and they offer good carriers for lipophilic ingredients. Emulsion gels and bigels, containing both aqueous and oil domains, can provide accommodations for lipophilic and hydrophilic ingredients simultaneously. Gel structures (e.g. rheology, texture, water holding capacity, swelling ratio) can be modulated by choosing different gelators, modifying gelation techniques, and the involvement of other ingredients (e.g. oils, emulsifiers, minerals, acids), which then alter the diffusion and release of the bioactive ingredients incorporated. Various studies have proved that gel-based delivery systems are able to improve the stability and bioavailability of many bioactive food ingredients. This review provides a state-to-art overview of different gel-based delivery systems, highlighting the significance of structure-functionality relationship, to provide advanced knowledge for the design of novel functional foods.