Effect of ascorbic acid on iron release from the emulsifier interface and on the oxidative flavor deterioration in fish oil enriched mayonnaise

Lipid oxidation in emulsions: New insights from the past two decades

Lipid oxidation constitutes the main source of degradation of lipid-rich foods, including food emulsions. The complexity of the reactions at play combined with the increased demand from consumers for less processed and more natural foods result in additional challenges in controlling this phenomenon. This review provides an overview of the insights acquired over the past two decades on the understanding of lipid oxidation in oil-in-water (O/W) emulsions. After introducing the general structure of O/W emulsions and the classical mechanisms of lipid oxidation, the contribution of less studied oxidation products and the spatiotemporal resolution of these reactions will be discussed. We then highlight the impact of emulsion formulation on the mechanisms, taking into consideration the new trends in terms of emulsifiers as well as their own sensitivity to oxidation. Finally, novel antioxidant strategies that have emerged to meet the recent consumer's demand will be detailed. In an era defined by the pursuit of healthier, more natural, and sustainable food choices, a comprehensive understanding of lipid oxidation in emulsions is not only an academic quest, but also a crucial step towards meeting the evolving expectations of consumers and ensuring the quality and stability of lipid-rich food products.

Antioxidant peptides from alternative sources reduce lipid oxidation in 5% fish oil-in-water emulsions (pH 4) and fish oil-enriched mayonnaise

Bioinformatics tools were used to predict radical scavenging and metal chelating activities of peptides derived from abundant potato, seaweed, microbial, and spinach proteins. The antioxidant activity was evaluated in 5% oil-in-water emulsions (pH4) and best-performing peptides were tested in mayonnaise and compared with EDTA. Emulsion physical stability was intact. The peptide DDDNLVLPEVYDQD showed the highest protection against oxidation in both emulsions by retarding the formation of oxidation products and depletion of tocopherols during storage, but it was less efficient than EDTA when evaluated in mayonnaise. In low-fat emulsions, formation of hydroperoxides was reduced 4-folds after 5 days compared to control. The concentration effect of the peptide was confirmed in mayonnaise at the EDTA equimolar concentration. The second-best performing peptides were NNKWVPCLEFETEHGFVYREHH in emulsion and AGDWLIGDR in mayonnaise. In general, the peptide efficacy was higher in low-fat emulsions. Results demonstrated that peptide negative net charge was important for chelating activity.

Antiradical Activity of Hydrolysates and Extracts from Mollusk A. broughtonii and Practical Application to the Stabilization of Lipids

The antiradical properties of hydrolysates and hydrothermal extracts of bivalve mollusks (Anadara broughtonii) from the Far Eastern Region of Russia and their influence on lipid oxidation in mayonnaise were investigated. The radical binding activity of hydrolysates and extracts of A. broughtonii varies from 55% to 89%. The maximum radical-binding activity was observed for acid hydrolysates. The antiradical efficiency of acid hydrolysates is 35%–41% of the BHT (butylhydroxytoluene) index. The antiradical activity depends on the (method of) technological and biotechnological processing of raw materials. Acid and enzymatic hydrolysates and hydrothermal extracts of A. broughtonii in mayonnaise slow down the process of oxidation of lipids and hydrolysis of triglycerides. Acid hydrolysates reduce the speed of oxidation and hydrolysis of lipids in mayonnaise more efficiently than the enzymatic hydrolysates.

Preservation of gallic acid and methyl gallate on purified Kilka fish oil oxidation by Rancimat

Kinetic analysis of gallic acid and methyl gallate in purified Kilka oil was studied in the concentration, range 200-1600 ppm, during autooxidation in Rancimat test at 60°C. The stabilization factor (F), the oxidation rate ratio (ORR), the activity (A), and the mean rate of antioxidant consumption (Winh) were determined. The scavenging activity of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals decreased in the order gallic acid > methyl gallate > α-tocopherol > BHT as observed in Kilka oil. There were no significant differences between the effectiveness and strength and activity of gallic acid and methyl gallate at concentrations 200, 400, and 800 ppm. However, above 800 ppm, the activity of methyl gallate became higher than gallic acid, because methyl gallate despite gallic acid did not participate in any chain propagation reactions.

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

INTRODUCTION

Mayonnaise is an oil in water emulsion (O/W) consisting 70-80% oil. Lipid oxidation is a major cause of quality deterioration in mayonnaise. The effectiveness of antioxidants in a hetrophasic systems is highly dependent on their polarity and partitioning properties.

OBJECTIVES

The aim of the present study was to determine the effect of a hydrophilic [green tea extract (GTE)] and a lipophilic [tocopherol mixture (TOC)] and BHA on lipid oxidation in mayonnaise during 60 days of storage at 38 °C and to examine the interactions between GTE and TOC, to determine possible synergistic or antagonistic effects in antioxidant activity.

METHODS

The oxidative stability was studied by measuring hydroperoxides, volatile organic compounds (VOCs) and colour of mayonnaise during storage. Comprehensive analysis of VOCs was done by static headspace extraction and separation by two-dimensional gas chromatography time of flight mass spectrometry. Sensory analysis was also carried out to study the effect of storage time and antioxidant type on sensory properties of mayonnaise and to investigate the predictive ability of volatile compounds for sensory terms.

RESULTS AND CONCLUSION

Addition of GTE (500 ppm) and TOC (500 ppm) increased the formation of hydroperoxides and certain VOCs. The combination of GTE with TOC improved the antioxidant efficacy compared to the individual extracts. However, sensory evaluation demonstrated that GTE promoted the development of unpleasant fishy and rancid aroma. The volatile compound methional, was significantly and positively correlated with fishy and rancid flavour. Regarding colour analysis, GTE showed the highest increase in darkening and browning during storage.

Egg white hydrolysate inhibits oxidation in mayonnaise and a model system

The flavor deterioration of mayonnaise is induced by iron, which is released from egg yolk phosvitin under acidic conditions and promotes lipid oxidation. To prevent oxidative deterioration, natural components, rather than synthetic chemicals such as ethylenediaminetetraacetic acid have been required by consumers. In the present study, we evaluated the inhibitory effects of three egg white components with the same amino acid composition, namely egg white protein, hydrolysate, and the amino acid mixture, on lipid oxidation in mayonnaise and an acidic egg yolk solution as a model system. We found that the hydrolysate had the strongest inhibitory effect on lipid oxidation among the three components. The mechanism underlying the antioxidant effect was associated with Fe2+-chelating activity. Thus, egg white hydrolysate may have the potential as natural inhibitors of lipid oxidation in mayonnaise.

Prediction of oxidation parameters of purified Kilka fish oil including gallic acid and methyl gallate by adaptive neuro-fuzzy inference system (ANFIS) and artificial neural network

BACKGROUND

As a result of concerns regarding possible health hazards of synthetic antioxidants, gallic acid and methyl gallate may be introduced as natural antioxidants to improve oxidative stability of marine oil. Since conventional modelling could not predict the oxidative parameters precisely, artificial neural network (ANN) and neuro-fuzzy inference system (ANFIS) modelling with three inputs, including type of antioxidant (gallic acid and methyl gallate), temperature (35, 45 and 55 °C) and concentration (0, 200, 400, 800 and 1600 mg L(-1) ) and four outputs containing induction period (IP), slope of initial stage of oxidation curve (k1 ) and slope of propagation stage of oxidation curve (k2 ) and peroxide value at the IP (PVIP ) were performed to predict the oxidation parameters of Kilka oil triacylglycerols and were compared to multiple linear regression (MLR).

RESULTS

The results showed ANFIS was the best model with high coefficient of determination (R(2)  = 0.99, 0.99, 0.92 and 0.77 for IP, k1 , k2 and PVIP , respectively). So, the RMSE and MAE values for IP were 7.49 and 4.92 in ANFIS model. However, they were to be 15.95 and 10.88 and 34.14 and 3.60 for the best MLP structure and MLR, respectively. So, MLR showed the minimum accuracy among the constructed models.

CONCLUSION

Sensitivity analysis based on the ANFIS model suggested a high sensitivity of oxidation parameters, particularly the induction period on concentrations of gallic acid and methyl gallate due to their high antioxidant activity to retard oil oxidation and enhanced Kilka oil shelf life. © 2016 Society of Chemical Industry.

Effect of fish oil encapsulates incorporation on the physico-chemical and sensory properties of cookies

A great deal of attention has been focused on the various health benefits apparently associated with consumption of fish oil. The incorporation of fish oils in food products is becoming increasingly widespread and a large variety of products is being marketed. However, the use of fish oil as functional nutritional ingredients in foods has been limited by its oxidative susceptibility. In the present study, attempts were made to develop fish oil fortified cookies as healthy snack foods by incorporating fish oil microencapsulate. Microencapsulation of fish oil was done by spray drying. Commercially available milk was used to form micro sized complexes with fish oil. Fish gelatin/maltodextrin were used as a wall material for encapsulation. Fish oil was added in three forms (fish oil as such, fish oil-in-water emulsion and fish oil microencapsulate) for the preparation of cookies. Cookies prepared without incorporating fish oil was served as control. The physical, chemical and sensory attributes of cookies were evaluated. Encapsulation significantly (P < 0.05) decreased lipid oxidation in the cookies. The sensory evaluation of cookies showed significant (P < 0.05) difference in the overall acceptability. Results from this study, demonstrated the possibility of fish oil incorporation into cookies through emulsification and microencapsulation which may increase the intake of omega-3 fatty acids for nutritional benefits.

Fortification of foods with omega-3 polyunsaturated fatty acids

A $600 million nutritional supplements market growing at 30% every year attests to consumer awareness of, and interests in, health benefits attributed to these supplements. For over 80 years the importance of polyunsaturated fatty acid (PUFA) consumption for human health has been established. The FDA recently approved the use of ω-3 PUFAs in supplements. Additionally, the market for ω-3 PUFA ingredients grew by 24.3% last year, which affirms their popularity and public awareness of their benefits. PUFAs are essential for normal human growth; however, only minor quantities of the beneficial ω-3 PUFAs eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are synthesized by human metabolism. Rather PUFAs are obtained via dietary or nutritional supplementation and modified into other beneficial metabolites. A vast literature base is available on the health benefits and biological roles of ω-3 PUFAs and their metabolism; however, information on their dietary sources and palatability of foods incorporated with ω-3 PUFAs is limited. DHA and EPA are added to many foods that are commercially available, such as infant and pet formulae, and they are also supplemented in animal feed to incorporate them in consumer dairy, meat, and poultry products. The chief sources of EPA and DHA are fish oils or purified preparations from microalgae, which when added to foods, impart a fishy flavor that is considered unacceptable. This fishy flavor is completely eliminated by extensively purifying preparations of n-3 PUFA sources. While n-3 PUFA lipid autoxidation is considered the main cause of fishy flavor, the individual oxidation products identified thus far, such as unsaturated carbonyls, do not appear to contribute to fishy flavor or odor. Alternatively, various compound classes such as free fatty acids and volatile sulfur compounds are known to impart fishy flavor to foods. Identification of the causative compounds to reduce and eventually eliminate fishy flavor is important for consumer acceptance of PUFA-fortified foods.

Oxidative stabilization of mixed mayonnaises made with linseed oil and saturated medium-chain triglyceride oil

Mayonnaises, made with either saturated medium chain triglyceride (MCT) oil or unsaturated purified linseed oil (LSO), were mixed. Raman confocal microspectrometry demonstrated that lipid droplets in mixed mayonnaise remained intact containing either MCT oil or LSO. Peroxide formation during storage was lower in mixed mayonnaise compared to LSO mayonnaise, while in mixed oil mayonnaise the level of peroxides was constantly low. Mixed oil mayonnaise had a lower rate of oxygen consumption than mixed mayonnaise, LSO mayonnaise having the highest rate. The decay of water-soluble nitroxyl radicals showed radicals are formed in the aqueous phase with the same rate independent of the lipids. This was also reflected in decay of α-tocopherol during storage being similar in MCT and LSO mayonnaises, but being stable in mixed oil mayonnaise and mixed mayonnaise. Results suggest that other effects than simply diluting unsaturated triglycerides with saturated triglycerides is causing the oxidative stabilization observed for mixed mayonnaise and mixed oil mayonnaise.

Multiscale structures of lipids in foods as parameters affecting fatty acid bioavailability and lipid metabolism

On a nutritional standpoint, lipids are now being studied beyond their energy content and fatty acid (FA) profiles. Dietary FA are building blocks of a huge diversity of more complex molecules such as triacylglycerols (TAG) and phospholipids (PL), themselves organised in supramolecular structures presenting different thermal behaviours. They are generally embedded in complex food matrixes. Recent reports have revealed that molecular and supramolecular structures of lipids and their liquid or solid state at the body temperature influence both the digestibility and metabolism of dietary FA. The aim of the present review is to highlight recent knowledge on the impact on FA digestion, absorption and metabolism of: (i) the intramolecular structure of TAG; (ii) the nature of the lipid molecules carrying FA; (iii) the supramolecular organization and physical state of lipids in native and formulated food products and (iv) the food matrix. Further work should be accomplished now to obtain a more reliable body of evidence and integrate these data in future dietary recommendations. Additionally, innovative lipid formulations in which the health beneficial effects of either native or recomposed structures of lipids will be taken into account can be foreseen.