Effect of natural antioxidants on lipid oxidation in mayonnaise compared with BHA, the industry standard

Exploring the antioxidant potential of nekemias species extracts on edible oils: In vitro assessment and lipid oxidation inhibition

Synthetic antioxidants have long been used to protect edible oils from oxidation. However, concerns about their potential health risks and environmental impact have led to a growing interest in natural antioxidants. In this study, we explore the antioxidant properties of extracts from four Nekemias plant species: Nekemias grossedentata (AGR), Nekemias megalophylla (AME), Nekemias chaffanjonii (ACH), and Nekemias cantoniensis (ACA) by obtaining the values for different tests. We investigate their bioactive compound content and evaluate their antioxidant capabilities on six edible oils categorized into three lipid systems based on their fatty acid compositions: oleic acid, linoleic acid, and linolenic acid. Our findings demonstrate that AGR and AME extracts, rich in bioactive compounds, exhibit strong antioxidant activities in vitro, effectively inhibiting lipid oxidation, especially in oleic acid-rich oils like camellia oil. The antioxidant effects of these extracts are comparable to synthetic antioxidants such as TBHQ and superior to natural antioxidant Tea Polyphenols (TP). While the extracts also show antioxidant potential in linoleic and linolenic acid systems, the stability of their effects in these oils is lower than in oleic acid system. These results suggest that Nekemias species extracts have the potential to serve as natural additives for extending the shelf life of edible oils, contributing to the exploration of natural antioxidants.

Influence of the packaging systems on the phenolic profile and antioxidant properties of wine pomace used as seasoning in chicken meat

White wine pomace products (wWPP) represent an innovative strategy as a functional food ingredient to be used as a seasoning both for their technological and functional properties. Nevertheless, the bioactive compounds of wWPP used as a seasoning could be modified during storage. The seasoning in the meat, regardless of the storage method used, modified its phenolic profile and in its bioaccessible fractions, while maintaining a high total antioxidant capacity and total polyphenol content. The contact of the seasoning with the meat can be considered safe as it does not show cytotoxicity in the Caco-2 cells. Additionally, the ability to modulate the cell oxidative stress of the bioaccessible fractions and the potential benefits on microbiota by the colonic fermentation fraction, suggest its potential use as a functional ingredient, without being affected by storage. These results are novel and may help to establish the value of this product as a functional ingredient.

Effect of Vinegar on the Oxidative Stability of Mayonnaise During its Storage

Mayonnaise is an emulsion of oil that is susceptible to lipid oxidation, which can cause spoilage and the formation of harmful compounds. This study aims to evaluate the impact of Syrian apple and grape vinegar on the oxidative stability of mayonnaise and compare the use of natural antioxidants to synthetic ones such as butylated hydroxyanisole and butylated hydroxytoluene. The study measured total phenol content, radical scavenging activity, and identified some phenolic compounds by High Performance Liquid Chromatography (HPLC). The rancidity of mayonnaise was examined using peroxide value and thiobarbituric acid number. The fatty acids content in the mayonnaise samples was examined using gas chromatography. Vinegar samples containing high concentrations of phenolic antioxidants showed high ability to scavenge free radicals. The antioxidants in vinegar protected the mayonnaise samples from primary and secondary oxidation, and there was no statistically significant difference between the ratio of unsaturated fatty acids in the samples containing vinegar at the beginning and at the end of the storage period. The study shows the significance of using vinegar to protect mayonnaise from deterioration and increase its shelf life, in addition to its role as a dressing.

Loss-of-function of triacylglycerol lipases are associated with low flour rancidity in pearl millet [Pennisetum glaucum (L.) R. Br.]

Pearl millet is an important cereal crop of semi-arid regions since it is highly nutritious and climate resilient. However, pearl millet is underutilized commercially due to the rapid onset of hydrolytic rancidity of seed lipids post-milling. We investigated the underlying biochemical and molecular mechanisms of rancidity development in the flour from contrasting inbred lines under accelerated aging conditions. The breakdown of storage lipids (triacylglycerols; TAG) was accompanied by free fatty acid accumulation over the time course for all lines. The high rancidity lines had the highest amount of FFA by day 21, suggesting that TAG lipases may be the cause of rancidity. Additionally, the high rancidity lines manifested substantial amounts of volatile aldehyde compounds, which are characteristic products of lipid oxidation. Lipases with expression in seed post-milling were sequenced from low and high rancidity lines. Polymorphisms were identified in two TAG lipase genes (PgTAGLip1 and PgTAGLip2) from the low rancidity line. Expression in a yeast model system confirmed these mutants were non-functional. We provide a direct mechanism to alleviate rancidity in pearl millet flour by identifying mutations in key TAG lipase genes that are associated with low rancidity. These genetic variations can be exploited through molecular breeding or precision genome technologies to develop elite pearl millet cultivars with improved flour shelf life.

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.

Free-Radical-Mediated Formation Mechanism of Polar Polymeric Triglycerides in Vegetable Oil Studied by Electron Spin Resonance and High-Performance Liquid Chromatography

The free-radical-mediated formation mechanism of polar polymeric triglycerides (TAGs) was derived based on the formation of lipid-derived radicals and the degradation of TAGs in palm oil (PO), rapeseed oil (RO), and sunflower oil (SO). The experimental spectra were simulated by alkoxyl, alkyl, and 5-dimethyl-1-pyrroline N-oxide (DMPO)-oxidized adducts. DMPO-oxidized adducts were the main radical adducts in the initial stage. Then, alkyl radical adducts became the dominating radical adducts after 12 min in PO and RO. The intensity of alkyl radical adducts was the highest in SO. Therefore, based on the bimolecular reaction, polar polymeric TAGs were mainly bonded by -C-O-O-C- in the initial stage and then by -C-C- and -C-O-C- after 30 min. Besides, according to the correlation analysis between the amounts of polar polymeric TAGs and the degradation of TAGs, the main structures of polar polymeric TAGs in PO, RO, and SO were POL-LOP, POL-OOP, and POO-OOP; OLL-LnLO, OLLn-OLnO, OOO-OLO, and OLLn-OOO; and LLL-LLO, LLL-LLL, and OLL-LLO, respectively.

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.

Untargeted and Targeted Metabolomic Profiling of Australian Indigenous Fruits

Selected Australian native fruits such as Davidson's plum, finger lime and native pepperberry have been reported to demonstrate potent antioxidant activity. However, comprehensive metabolite profiling of these fruits is limited, therefore the compounds responsible are unknown, and further, the compounds of nutritional value in these native fruits are yet to be described. In this study, untargeted and targeted metabolomics were conducted using the three fruits, together with assays to determine their antioxidant activities. The results demonstrate that targeted free and hydrolysed protein amino acids exhibited high amounts of essential amino acids. Similarly, important minerals like potassium were detected in the fruit samples. In antioxidant activity, Davidson's plum reported the highest activity in ferric reducing power (FRAP), finger lime in antioxidant capacity (ABTS), and native pepperberry in free radical scavenging (DPPH) and phosphomolybdenum assay. The compounds responsible for the antioxidant activity were tentatively identified using untargeted GC×GC-TOFMS and UHPLC-QqQ-TOF-MS/MS metabolomics. A clear discrimination into three clusters of fruits was observed using principal component analysis (PCA) and partial least squares (PLS) analysis. The correlation study identified a number of compounds that provide the antioxidant activities. GC×GC-TOFMS detected potent aroma compounds of limonene, furfural, and 1-R-α-pinene. Based on the untargeted and targeted metabolomics, and antioxidant assays, the nutritional potential of these Australian bush fruits is considerable and supports these indigenous fruits in the nutraceutical industry as well as functional ingredients for the food industry, with such outcomes benefiting Indigenous Australian communities.