Interlaboratory study on lipid oxidation during accelerated storage trials with rapeseed and sunflower oil analyzed by conjugated dienes as primary oxidation products

11 Páginas.-- 5 Figuras.-- 2 Tablas.-- Material suplementarioAccelerated storage tests are frequently used to assess the oxidative stability of foods and related systems due to its reproducibility. Various methods and experimental conditions are used to measure lipid oxidation. Differences between laboratories make it necessary to determine the repeatability and reproducibility of oxidation tests performed under the same conditions. The objective of the present interlaboratory study was to evaluate the outcome of a storage test for two different bulk oils, sunflower oil (SFO) and rapeseed oil (RSO), during a period of 9 weeks at 20°C, 30°C, 40°C, and 60°C. Sixteen laboratories were provided with bottled oils and conducted the storage tests according to a detailed protocol. Lipid oxidation was monitored by the formation of conjugated dienes (CD) and the activation energy (Ea) was determined for comparative purposes and statistically evaluated. An increase in CD formation was observed for both oils when the storage temperature was increased in all laboratories. The Ea,1 ranged from 47.9 to 73.3 kJ mol−1 in RSO and from 27.8 to 62.6 kJ mol−1 in SFO, with average values of 58.2 and 46.8 kJ mol−1, respectively. The reproducibility coefficients were 10.9% and 18.2% for RSO and SFO, respectively. Practical applications: In order to compare results on oxidative stability of foods derived from different studies, the reproducibility of storage tests and methods employed to evaluate the oxidation level should be considered. This study provides fundamental data on the reproducibility of lipid oxidation under accelerated storage conditions and defines important parameters to be considered for the conduction of experiments.Open access funding enabled and organized by Projekt DEAL. We thank Brökelmann + Co – Oelmühle GmbH + Co for the donation of the vegetable oils. The authors gratefully acknowledge Lina Stuthmann from the Food Technology Division, Kiel University and Inge Holmberg from the National Food Institute, Technical University of Denmark for their skillful help.Peer reviewe

Effect of various saturated fatty acids sources on oxidative stability and nutritional profile of DHA-enriched infant follow-on formulas

International audienceInfancy is characterized by significant growth and development that leads to very specific nutritional requirements. During this period, lipids and more particularly long-chain polyunsaturated fatty acids play an important role. To comply with the recommendations, European regulation have recently evolved and now requires fortification of infant follow-on formulas (IFF) with docosahexaenoic acid (DHA) which strongly impacts their oxidative stability. The aim of this study was to improve the lipid profile and oxidative stability of DHA-enriched IFF by using structural and formulation lipid levers. To do so, a model IFF representative of marketed products was formulated and declined by varying the saturated fatty acids sources (refined (POM) or unrefined (RPOM) palm oil, coconut oil (COM), and dairy fat (DFOM)), the emulsifiers (soy lecithin or dairy phospholipids (DPL)) and the structure (droplet size). RPOM-IFF showed a higher stability than POM-IFF. This effect can be attributed to its content of provitamin A compounds (in the form of carotenoids) which act in synergy with tocopherols and have beneficial effects for infant nutrition. The combined use of DPL and DFOM led to a better oxidative stability with a peroxide value twice lower than POM (stabilized with lecithin) after 20 days of storage at 40°C and less important tocopherols degradation. This favorable effect was even reinforced for smaller droplet sizes. Dairy lipids also provide a complex lipid profile and high content of short and medium saturated chain fatty acids which is beneficial for infant nutrition. The introduction of dairy lipids and carotenoids in DHA-enriched IFF composition are interesting levers of stabilization

Comparison of the effect of various sources of saturated fatty acids on infant follow-on formulas oxidative stability and nutritional profile

International audienceFortification of infant follow-on formulas (IFF) with docosahexaenoic acid (DHA), which is prone to lipid oxidation, is required by European regulation. This study aimed to identify lipid formulation parameters that improve the nutritional profile and oxidative stability of IFF. Model IFF were formulated using different lipid and emulsifier sources, including refined (POM) or unrefined red palm oil (RPOM), coconut oil (COM), dairy fat (DFOM), soy lecithin, and dairy phospholipids (DPL). After an accelerated storage, RPOM and DFOM with DPL had improved oxidative stability compared to other IFF. Specifically, they had a peroxide value twice lower than POM and 20% less loss of tocopherols for DFOM-DPL. This higher stability was mainly explained by the presence of compounds such as carotenoids in RPOM and sphingomyelin in DFOM-DPL very likely acting synergistically with tocopherols. Incorporation of dairy lipids and carotenoids into DHA-enriched IFF compositions seems promising to enhance their stability and nutritional quality

Effect of some local plant extracts on fatty acid composition of fish (Alestes baremoze) during smoking and sun drying in the Far‐North region of Cameroon

Abstract The objective of this study was to assess the antioxidant activities of three plant extracts (Moringa oleifera leaves, Xylopia aethiopica fruits, and Allium cepa leaves) and to evaluate their effects on the preservation of fish polyunsaturated fatty acids (PUFAs) during smoking and sun‐drying processes. PUFAs are highly prone to oxidation during fish processing. The plant extracts were analyzed for their polyphenol contents and were evaluated for their total antiradical capacity. The polyphenol components of each plant were characterized. The hydroethanolic and aqueous extracts were added to the fish at concentrations of 3, 6, 9, and 12 g/L and 10, 20, 30, and 40 g/L, respectively. Butylated hydroxytoluene (BHT) was used as a positive control at a concentration of 2 g/L to compare the antioxidant effects of the plant extracts. The treated fish was subjected to smoking or sun drying and the fatty acid composition of the fish lipid extract was assessed. The results showed that the total polyphenolic, flavonoid, and tannin contents varied significantly from one plant extract to the other (p < .05). The radical scavenging and FRAP increased significantly with the concentration of the plant extracts (p < .05). An HPLC analysis of the extracts led to the preliminary identification of four hydroxycinnamic acids in M. oleifera and X. aethiopica, one anthocyanin and one flavone glycoside in M. oleifera, and four flavan‐3‐ols in X. aethiopica. Moreover, eight flavonols were preliminarily identified in the three plants. Compared to the control product, these plant extracts significantly protected fish PUFAs from oxidation (p < .05). The aqueous extract of A. cepa at 40 g/L better preserved omega‐3 in fish during smoking and sun drying than the control product. Incorporating the three plant extracts during smoking and sun‐drying processes can effectively preserve the PUFAs in fish. Therefore, these plants are viable sources of natural antioxidants in the preservation of fish products

Optimization of the oxidative stability and lipid profile of DHA-enriched infant follow-on formulas by the introduction of dairy lipids

International audienceInfancy period is a key window of development during which the requirements in lipids and more particularly in long-chain polyunsaturated fatty acids are specific. In order to abide by the recommendations, European regulation now requires a fortification of infant follow-on formulas (IFF) with docosahexaenoic acid (C22:6, DHA) which strongly impacts their oxidative stability. The aim of this study was to optimize the structure and formulation of DHA-enriched IFF in order to improve their lipid profile and oxidative stability. To do so, a model IFF representative of marketed products was formulated and declined by varying the saturated fatty acids sources (refined (POM) or unrefined (RPOM) palm oil, coconut oil (COM), and dairy fat (DFOM)), the emulsifiers (soy lecithin or dairy phospholipids (DPL)) and the structure (droplet size). These model IFF were submitted to an accelerated storage test of 20 days at 40°C during which peroxide values (PV), tocopherols, vitamin A, and fatty acids profiles were monitored. Despite the addition of DHA, all model IFF had quite good oxidative stability with PV lower than 10 meqO2/kg of lipids until 9 days of storage. DFOM and POM had equivalent kinetics of PV increase and tocopherols degradation. Moreover, no significant differences were observed between these two IFF regardless of droplet size (0.4 or 0.7 µm). RPOM was more stable than POM, very likely due to its higher carotenoids content. Regarding emulsifiers, DFOM-DPL (stabilized with DPL) had a PV twice lower than POM (stabilized with lecithin) at 20 days and a tocopherols degradation of 67.5% vs 88.8% for POM. This result translates a more important resistance to oxidative degradation of DFOM-DPL. This favorable effect was even reinforced for smaller droplet sizes. The introduction of dairy lipids but also of carotenoids in DHA-enriched IFF composition are interesting levers of stabilization. Moreover, dairy lipids lead to a more complex lipid profile and a higher content of short and medium-chain saturated fatty acids which is beneficial for infant nutrition

Optimization of the oxidative stability and lipid profile of DHA-enriched infant follow-on formulas by the introduction of dairy lipids

International audienceInfancy period is a key window of development during which the requirements in lipids and more particularly in long-chain polyunsaturated fatty acids are specific. In order to abide by the recommendations, European regulation now requires a fortification of infant follow-on formulas (IFF) with docosahexaenoic acid (C22:6, DHA) which strongly impacts their oxidative stability. The aim of this study was to optimize the structure and formulation of DHA-enriched IFF in order to improve their lipid profile and oxidative stability. To do so, a model IFF representative of marketed products was formulated and declined by varying the saturated fatty acids sources (refined (POM) or unrefined (RPOM) palm oil, coconut oil (COM), and dairy fat (DFOM)), the emulsifiers (soy lecithin or dairy phospholipids (DPL)) and the structure (droplet size). These model IFF were submitted to an accelerated storage test of 20 days at 40°C during which peroxide values (PV), tocopherols, vitamin A, and fatty acids profiles were monitored. Despite the addition of DHA, all model IFF had quite good oxidative stability with PV lower than 10 meqO2/kg of lipids until 9 days of storage. DFOM and POM had equivalent kinetics of PV increase and tocopherols degradation. Moreover, no significant differences were observed between these two IFF regardless of droplet size (0.4 or 0.7 µm). RPOM was more stable than POM, very likely due to its higher carotenoids content. Regarding emulsifiers, DFOM-DPL (stabilized with DPL) had a PV twice lower than POM (stabilized with lecithin) at 20 days and a tocopherols degradation of 67.5% vs 88.8% for POM. This result translates a more important resistance to oxidative degradation of DFOM-DPL. This favorable effect was even reinforced for smaller droplet sizes. The introduction of dairy lipids but also of carotenoids in DHA-enriched IFF composition are interesting levers of stabilization. Moreover, dairy lipids lead to a more complex lipid profile and a higher content of short and medium-chain saturated fatty acids which is beneficial for infant nutrition

Pea and lupin protein ingredients : New insights into endogenous lipids and the key effect of high-pressure homogenization on their aqueous suspensions

The incorporation of plant protein ingredients in foods is a means to promote the transition to vegetable proteins. Pea and lupin meet sustainability demands and their protein ingredients display promising technological properties, yet sometimes poor functionalities. However, the involved mechanisms are still unclear, partly because comprehensive and systematic characterization of those ingredients in terms of composition and physicochemical properties is still lacking. In this work, commercial protein fractions of pea and lupin (one isolate and one concentrate for each) were thoroughly characterized. A high-pressure homogenization (HPH) treatment was applied to their aqueous suspensions (pH 7.0) to improve their dispersibility. Although isolates displayed a higher protein content (up to 72 g/100 g (d.m.) against 39 g/100 g (d.m.) for the concentrates, with respective specific N factors), their solubility (i.e., the proteins remaining in the supernatant after centrifugation) was lower than for the concentrates (15–49 wt% of the total proteins, against 65 wt%). Substantial amounts of endogenous lipids in the powders were measured after chloroform/methanol extraction (3.4–10.3 g/100 g (d.m.)), of which about half were phospholipids. For all ingredients, detailed microscopic investigations (including confocal fluorescence microscopy), and light scattering measurements showed that HPH was useful to break down large powder grains. Thus, it altered the colloidal structures present, released endogenous lipid assemblies and enhanced protein solubility. Those new insights into the non-protein composition of plant protein fractions and their behaviour in aqueous media are key for improving their functionalities and facilitating food products’ rational formulation