Lipid Oxidation in Oil‐in‐Water Emulsions Rich in Omega‐3: Effect of Aqueous Phase Viscosity, Emulsifiers, and Antioxidants

Unveiling the power of bene (Pistacia atlantica) hull scum: Boosting oxidative stability with methanolic extract and ferrous ions

This study investigated the antioxidant potential of Bene hull methanolic extract (BHME) in mitigating lipid oxidation in vegetable oils across four systems (oil-in-water emulsions and bulk oils, both with and without Fe+2). The BHME's free radical-scavenging assay and ferric reducing abilities were compared with natural (α-tocopherol, CEX) and synthetic (BHT) antioxidants. The research analyzed different BHME concentrations (0, 400, 800, and 1600 ppm) and evaluated the effects of storage time on lipid oxidation, monitored through Peroxide Value (PV) and Carbonyl Value (CV) measurements. An array of statistical analyses, including ANOVA and a robust Support Vector Machine (SVM) model were employed to predict oxidation dynamics. The findings revealed that BHME demonstrated significant antioxidant activity, comparable to BHT, with both showing similar IC50 values (7.59 μg/ml and 7.45 μg/ml, respectively. In emulsions, PV increased 2.5 times at 800 ppm and 13 times at 1600 ppm compared to bulk oils. The presence of Fe+2 led to a 40 % higher PV in emulsions. CV values rose by 35 and 56 units at 800 and 1600 ppm, respectively, and increased six fold over the storage period. The SVM model showed high predictive accuracy, with R2 values exceeding 0.97. Response surface graphs indicated that storage time had a more pronounced effect on PV and CV than antioxidant concentration. This study highlights BHME's potential as an effective natural antioxidant, particularly in bulk oils, and demonstrates the utility of SVM for analyzing lipid oxidation. These findings provide valuable insights for improving the oxidative stability and shelf life of lipid-based food products.

Stimuli-responsive antioxidant Pickering emulsions stabilized by functionalized cellulose nanocrystals

Stimuli-responsive antioxidant Pickering emulsions play crucial role in many industrial areas. This study demonstrated for the first time oil-in-water Pickering emulsions with outstanding antioxidation and responsive demulsification stabilized by functionalized cellulose nanocrystals (CNCs). Dialdehyde cellulose nanocrystals (DACs) were first prepared through the oxidation of CNCs with periodate, followed by the grafting of p-aminophenols (PAPs) onto their surfaces through Schiff base reaction, affording PAP grafted DACs (DAC-g-PAP) via dynamic covalent linkage. The degree of the oxidation (DO) of DACs had a significant effect on the yield of the targeting DAC-g-PAP nanoparticles. High DO (≥40 %) potentially led to the degradation of DACs during the grafting of PAP. The introduced PAP endowed DACs with excellent radical scavenging capability, thereby providing antioxidant properties while improving the hydrophobicity. DAC-g-PAP nanoparticles were then applied as Pickering emulsifiers to prepare oil-in-water Pickering emulsions. The resultant Pickering emulsions indicated exceptional antioxidant and pH-responsiveness together with good freezing-thaw stability. The structures of DAC-g-PAP nanoparticles were thoroughly characterized in this study.

Exploring Phenolic Compounds in Crop By-Products for Cosmetic Efficacy

Phenolic compounds represent a group of secondary metabolites that serve essential functions in plants. Beyond their positive impact on plants, these phenolic metabolites, often referred to as polyphenols, possess a range of biological properties that can promote skin health. Scientific research indicates that topically using phenolics derived from plants can be advantageous, but their activity and stability highly depend on storage of the source material and the extraction method. These compounds have the ability to relieve symptoms and hinder the progression of different skin diseases. Because they come from natural sources and have minimal toxicity, phenolic compounds show potential in addressing the causes and effects of skin aging, skin diseases, and various types of skin damage, such as wounds and burns. Hence, this review provides extensive information on the particular crops from which by-product phenolic compounds can be sourced, also emphasizing the need to conduct research according to proper plant material storage practices and the choice of the best extracting method, along with an examination of their specific functions and the mechanisms by which they act to protect skin.

Oxidative stability of Pickering emulsions

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Oxidative stability of O/W Pickering emulsions depends on their interfacial layer.

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Solid particles can reduce Pickering emulsion oxidation by creating a thick interface.

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Manipulating the charge of the interface can control Pickering emulsion oxidation.

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Adding antioxidants to solid particles can reduce oxidation in Pickering emulsions.

In recent years, Pickering emulsions have been the focus of growing interest because of their possible role as alternatives to conventional emulsions. Some reviews have investigated the physical stability of Pickering emulsions, but the oxidative stability of these emulsions remains largely unexplored. In this review, the oxidation mechanism and factors affecting lipid oxidation rates in Pickering emulsions are discussed. Then, different food-grade solid particles are evaluated for their ability to stabilize Pickering emulsions. Finally, several strategies are reviewed for improving the oxidative stability of Pickering emulsions. These strategies are based on efforts to manipulate the physical and chemical properties of the interfacial layer, increase the concentration of antioxidants at the interfacial layer through incorporating them into solid particles, cause oil droplets to crowd at high packing fractions, trap oil droplets in a gel network and increase the viscosity of the continuous phase.

Effect of pectin on the properties of nanoemulsions stabilized by sodium caseinate at neutral pH

The effect of different concentrations of low methoxyl pectin (LMP) on lipid oxidation and physical stability of sodium caseinate (CAS) stabilized nanoemulsions under neutral pH was investigated. The addition of pectin at low concentration (≤ 0.10 wt%) had no significant effect on the average size of nanoemulsions, but a slight size increase and phase separation were observed at higher concentrations of pectin (≥ 0.25 wt%). This result suggests that LMP can not adsorb at the oil/water interfacial CAS membrane at neutral pH. However, in the presence of LMP, the physical stability of nanoemulsions against high salt concentrations and freeze-thaw cycles was significantly enhanced. Moreover, nanoemulsions containing pectin have a better ability to inhibit lipid and protein oxidation than nanoemulsions without pectin after 3 weeks, and the lowest lipid hydroperoxide content was observed for nanoemulsions containing 0.25 wt% pectin.

Use of vegetables for enhancing oxidative stability of omega-3 oils in the powdered state

The preliminary study examined the effectiveness of various vegetables for the stabilisation of omega-3 oil powders against oxidative deterioration. Purees made from different vegetables (mushroom, brussels sprouts, broccoli, cauliflower, snow peas, tomato, and garlic) were employed for preparation of vegetable-tuna oil emulsions, which were subsequently freeze-dried into powders. Oxipres® data showed that vegetable-tuna oil powders had longer induction periods than neat tuna oil. During accelerated oxidation storage (40 °C/4weeks), eicosapentaenoic and docosahexaenoic acids in the vegetable-tuna oil powders were protected against oxidation, and there were lower levels of headspace secondary and tertiary oxidation products. Whole vegetable purees were suitable protective matrices for omega-3 oils. Of the various vegetable purees examined for protective effects against omega-3 oxidation, mushroom, brussels sprouts, broccoli, and cauliflower were superior to snow peas, garlic and tomato. The antioxidant properties of phytonutrients inherent in various vegetables are likely contributors to protection of omega-3 oil powders against oxidation.

Tocopherols as antioxidants in lipid-based systems: The combination of chemical and physicochemical interactions determines their efficiency

Lipid oxidation is a major concern in the food, cosmetic, and pharmaceutical sectors. The degradation of unsaturated lipids affects the nutritional, physicochemical, and organoleptic properties of products and can lead to off-flavors and to the formation of potentially harmful oxidation compounds. To prevent or slow down lipid oxidation, different antioxidant additives are used alone or in combination to achieve the best possible efficiency with the minimum possible quantities. In manufactured products, that is, heterogeneous systems containing lipids as emulsions or bulk phase, the efficiency of an antioxidant is determined not only by its chemical reactivity, but also by its physical properties and its interaction with other compounds present in the products. The antioxidants most widely used on the industrial scale are probably tocopherols, either as natural extracts or pure synthetic molecules. Considerable research has been conducted on their antioxidant activity, but results regarding their efficiency are contradictory. Here, we review the known mechanisms behind the antioxidant activity of tocopherols and discuss the chemical and physical features that determine their efficacy. We first describe their chemical reactivity linked with the main factors that modulate it between efficient antioxidant capacity and potential prooxidant effects. We then describe their chemical interactions with other molecules (phenolic compounds, metals, vitamin C, carotenes, proteins, and phospholipids) that have potential additive, synergistic, or antagonist effects. Finally, we discuss other physical parameters that influence their activity in complex systems including their specific interactions with surfactants in emulsions and their behavior in the presence of association colloids in bulk oils.

Lipid oxidation in emulsions and bulk oils: a review of the importance of micelles

Lipid oxidation is a major cause of quality deterioration in food products. In these foods, lipids are often present in a bulk or in emulsified forms. In both systems, the rate, extent and pathway of oxidation are highly dependent on the presence of colloidal structures and interfaces because these are the locations where oxidation normally occurs. In bulk oils, reverse micelles (association colloids) are present and are believed to play a crucial role on lipid oxidation. Conversely, in emulsions, surfactant micelles are present that also play a major role in lipid oxidation pathways. After a brief description of lipid oxidation and antioxidants mechanisms, this review discusses the current understanding of the influence of micellar structures on lipid oxidation. In particular, is discussed the major impact of the presence of micelles in emulsions, or reverse micelles (association colloids) in bulk oil on the oxidative stability of both systems. Indeed, both micelles in emulsions and associate colloids in bulk oils are discussed in this review as nanoscale structures that can serve as reservoirs of antioxidants and pro-oxidants and are involved in their transport within the concerned system. Their role as nanoreactors where lipid oxidation reactions occur is also commented.

A comprehensive review on polarity, partitioning, and interactions of phenolic antioxidants at oil-water interface of food emulsions

There has been a growing interest in developing effective strategies to inhibit lipid oxidation in emulsified food products by utilization of natural phenolic antioxidants owing to their growing popularity over the past decades. However, due to the complexity of emulsified systems, the inhibition mechanism of phenolic antioxidants against lipid oxidation is rather complicated and not yet fully understood. In order to highlight the importance of polarity of phenolic antioxidants in emulsified systems according to the polar paradox, this review covers the recent progress on chemical, enzymatic, and chemoenzymatic lipophilization techniques used to modify the polarity of antioxidants. The partitioning behavior of phenolic antioxidants at the oil-water interface, which can be influenced by the presence of synthetic surfactants and/or antioxidant emulsifiers (e.g., polysaccharides, proteins, and phospholipids), is discussed. In addition, the emerging phenolic antioxidants among phenolic acids, flavonoids, tocopherols, and stilbenes applied in food emulsions are elaborated. As well, the interactions of polar-nonpolar antioxidants are stressed as a promising strategy to induce synergistic interactions at oil-water interface for improved oxidative stability of emulsions.