Natural antioxidants (rosemary and parsley) in microwaved ground meat patties: effects of in vitro digestion.

BACKGROUND: Minimizing food oxidation remains a challenge in several environments. The addition of rosemary extract (150 mg kg-1) and lyophilized parsley (7.1 g kg-1) at equivalent antioxidant activity (5550 µg Trolox equivalents kg-1) to meat patties was assessed in terms of their effect during microwave cooking and after being subjected to an in vitro digestion process. RESULTS: Regardless of the use of antioxidants, cooking caused a decrease of the fat content as compared to raw samples, without noticing statistical differences in the fatty acid distribution between raw and cooked samples [44%, 47% and 6.8%, of saturated fatty acid (SFA), monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA), respectively]. However, the bioaccessible lipid fraction obtained after digestion was less saturated (around 34% SFA) and more unsaturated (35% MUFA +30% PUFA). Cooking caused, in all types of samples, an increased lipid [thiobarbituric acid reactive substances (TBARS)] and protein (carbonyls) oxidation values. The increase of TBARS during in vitro digestion was around 7 mg malondialdehyde (MDA) kg-1 for control and samples with parsley and 4.8 mg MDA kg-1 with rosemary. The addition of parsley, and particularly of rosemary, significantly increased the antioxidant activity (DPPH) of cooked and digested microwaved meat patties. CONCLUSION: Whereas rosemary was effective in minimizing protein oxidation during cooking and digestion as compared to control samples, parsley could only limit it during digestion. Lipid oxidation was only limited by rosemary during in vitro digestion. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Olive and echium oil gelled emulsions: Simulated effect of processing temperature, gelling agent and in vitro gastrointestinal digestion on oxidation and bioactive compounds.

The impact and relative relevance of in vitro gastrointestinal digestion, processing temperature (room temperature or 180 °C), and gelling agent (GA) (carrageenan and alginate) on the bioactive compounds and oxidation status of olive and echium oils gelled formulations with 40% lipid incorporation was assessed. In vitro digestion was not affected by the GA, with >90% lipolysis in all formulations, but was the most relevant variable, promoting oxidation (MDA) regardless of the oil type, GA or temperature applied. Tocopherols and phenolic decreased with digestion, which could be interpreted as a protective response to pro-oxidative conditions during digestion. Temperature decreased olive oil phenolics. Gelification of echium oil using alginate reduced secondary oxidation products formation in comparison with carrageenan, with oxidation degrees after digestion equivalent to those shown with olive oil. The use of alginate with olive oil resulted in the most stable formulations, although not protecting its minor bioactive compounds from thermal degradation.

Fatty acid profile, sterols, and squalene content comparison between two conventional (olive oil and linseed oil) and three non-conventional vegetable oils (echium oil, hempseed oil, and moringa oil).

New sources of bioactive compounds are constantly explored for reformulating healthier foods. This work aimed to explore and characterize the fatty acid profile and sterol content of three non-conventional oils used in functional food products (hempseed oil, moringa oil, and echium oil) and to compare them with two conventional ones (extra virgin olive oil [EVOO] and linseed oil). Oxidative stability was assessed by determining their acidity value and peroxide content. All oils showed adequate values for acidity and oxidation status. Echium and hempseed oils showed a high content of polyunsaturated fatty acids (>70%), especially omega-3 fatty acids, while moringa oil was rich in oleic acid. Echium oil, hempseed oil, and moringa oil presented higher sterol content than EVOO, but lower than that of linseed oil. Sitosterol was the most abundant sterol in all samples (97.88-275.36 mg/100 g oil), except in echium oil, where campesterol (170.62 mg/100 g oil) was the major sterol. Squalene was only found in significant amounts in EVOO. In conclusion, non-conventional oils seem to be interesting sources of bioactive compounds and have great potential for the food industry. PRACTICAL APPLICATION: Non-conventional vegetable oils can be used as alternative sources of lipids in a variety of food products. Additionally, these oils have great potential to be included in the formulation of functional ingredients for the delivery of omega-3 fatty acids, antioxidants, fiber, among others.

Effects of In Vitro Digestion on the Antioxidant Activity of Three Phenolic Extracts from Olive Mill Wastewaters.

The aim of this study was to assess the impact of in vitro digestion on the antioxidant activity of three extracts rich in phenols (two purified organic extracts (A20, A21) and one powdered extract stabilized with maltodextrins (SP)) obtained from olive mill wastewaters (OMWW). The content and composition of phenols and antioxidant activity was determined before and after in vitro digestion. The phenol content of the A20 and A21 samples were higher (>75%) than that of the SP sample before in vitro digestion. After the entire in vitro digestion, 89.3, 76.9, and 50% loss of phenols was found in A20, A21 and SP, respectively. ABTS•+ and ORAC values decreased during in vitro digestion of A20 and A21 samples, while they remained almost constant in SP. IC50 increased during digestion of A20 and A21, evidencing a loss of antioxidant capacity after the intestinal phase; an opposite IC50 trend was noted in SP, confirming the protective role of maltodextrins. For these reasons, SP represents a promising formulation to be used in the food field.

Flax and hempseed oil functional ingredient stabilized by inulin and chia mucilage as a butter replacer in muffin formulations.

The addition of different amounts of a functional ingredient composed of water, inulin, chia seeds, and hemp or flaxseed oil was examined as butter replacer to improve the nutritional value of muffins. Nutritional, technological, and sensory characteristics of the reformulated products were assessed, as well as the stability under storage at room temperature. One control and six modified formulations with three levels of butter replacement (50%, 75%, and 100%) were analyzed. Modified muffins improved their nutritional profile, reducing up to 78% of fat and increasing fiber (up to 62.5%) and omega-3 fatty acids content (from 0.12 g/100 g of product to 0.62 g and 1.55 g in hemp and flaxseed oil samples, respectively). Sensory analysis revealed that flaxseed oil samples were indistinguishable from the control in all evaluated attributes, even in the highest level of replacement. During storage, texture of modified samples behaved similar to the control and no oxidation problems were observed in any of the formulations. Therefore, the functional ingredient proved to be a feasible alternative for replacing butter in muffins, preserving the quality attributes and making them healthier foods. PRACTICAL APPLICATION: Functional ingredients including fiber and low amounts of good-quality sources of fat have a simple manufacturing process, do not require heating, and perform well once incorporated to the matrix. They are versatile and could be incorporated in other bakery products to substitute butter or even oil, to obtain a reduced calorie product and with an enhanced nutritional profile and good sensory properties.

Using canola oil hydrogels and organogels to reduce saturated animal fat in meat batters.

Conventional canola oil and structured canola oil systems, consisting of oil in water hydrogelled emulsions (with 1.5% or 3% kappa carrageenan) and ethylcellulose organogels (12%, with 0%, 1.5% or 3% glycerol monostearate), were used to replace beef fat in emulsion type meat batters. Replacement with regular canola oil increased hardness and lightness (P < .05) of the reformulated products as compared to those with beef fat. Structuring the oil resulted in similar color and texture (P > .05), and lower oxidation values (P < .05) of meat batters. Reformulated products also gave rise to a healthier fatty acid profile, evidenced by a decrease in saturated fatty acids (SFA) from 11.8% to ≈ 2% and an increase in polyunsaturated fatty acids (PUFA) from 0.3% to ≈ 5%. Omega-6 to omega-3 ratio also decreased (16.2 to ≈ 2) when incorporating canola oil into meat batters. Batters formulated with organogels showed improved matrix stability compared to those with hydrogelled emulsions, which showed some coalescence of fat globules and fat losses during cooking, resulting in a reduction of fat content (P < .05).

First international descriptive and interventional survey for cholesterol and non-cholesterol sterol determination by gas- and liquid-chromatography-Urgent need for harmonisation of analytical methods.

Serum concentrations of lathosterol, the plant sterols campesterol and sitosterol and the cholesterol metabolite 5α-cholestanol are widely used as surrogate markers of cholesterol synthesis and absorption, respectively. Increasing numbers of laboratories utilize a broad spectrum of well-established and recently developed methods for the determination of cholesterol and non-cholesterol sterols (NCS). In order to evaluate the quality of these measurements and to identify possible sources of analytical errors our group initiated the first international survey for cholesterol and NCS. The cholesterol and NCS survey was structured as a two-part survey which took place in the years 2013 and 2014. The first survey part was designed as descriptive, providing information about the variation of reported results from different laboratories. A set of two lyophilized pooled sera (A and B) was sent to twenty laboratories specialized in chromatographic lipid analysis. The different sterols were quantified either by gas chromatography-flame ionization detection, gas chromatography- or liquid chromatography-mass selective detection. The participants were requested to determine cholesterol and NCS concentrations in the provided samples as part of their normal laboratory routine. The second part was designed as interventional survey. Twenty-two laboratories agreed to participate and received again two different lyophilized pooled sera (C and D). In contrast to the first international survey, each participant received standard stock solutions with defined concentrations of cholesterol and NCS. The participants were requested to use diluted calibration solutions from the provided standard stock solutions for quantification of cholesterol and NCS. In both surveys, each laboratory used its own internal standard (5α-cholestane, epicoprostanol or deuterium labelled sterols). Main outcome of the survey was, that unacceptably high interlaboratory variations for cholesterol and NCS concentrations are reported, even when the individual laboratories used the same calibration material. We discuss different sources of errors and recommend all laboratories analysing cholesterol and NCS to participate in regular quality control programs.

Influence of a gel emulsion containing microalgal oil and a blackthorn (Prunus spinosa L.) branch extract on the antioxidant capacity and acceptability of reduced-fat beef patties.

The addition of a blackthorn branch extract (Prunus spinosa L.) to a gel emulsion system containing microalgal oil was examined in order to obtain a functional ingredient (APG), for use as fat replacer in beef patties. Chromatographic analysis indicated that catechins were the major polyphenols present in the Prunus spinosa L. extract. The antioxidant capacity increased as a result of the extract addition, as shown by the comparison of the gel emulsions, with and without it (APG and AG, respectively). Beef patties containing APG as fat replacer (modified patties) had a lower fat content (5.3% versus 10.75%), doubled the antioxidant activity and the DHA content, and improved the stability against oxidation by reducing the peroxide content more than two fold when compared to control patties. In addition, instrumental color measured by the CIE L*a*b* system showed no significant difference between control and modified raw patties. Moreover, the sensory acceptability of the new formulation was confirmed by a like/dislike hedonic test.

DHA rich algae oil delivered by O/W or gelled emulsions: strategies to increase its bioaccessibility.

BACKGROUND: The bioaccessibility of bioactive compounds for functional food deserves evaluation. An in vitro gastrointestinal digestion model was applied to provide information about the extent of lipid hydrolysis, oxidative stability and bioaccessibility of algae oil (42% of docosahexaenoic acid; DHA), comparing three lipid delivery systems: bulk oil, soy protein stabilized O/W emulsion and carrageenan gelled emulsion. RESULTS: Lipid digestion kinetics was slightly influenced by the delivery systems. Nevertheless, at the end of intestinal digestion, lipolysis in the three samples ranged between 49% and 52%, showing a partial oil digestion. Lipid oxidation, measured by malondialdehyde, was significantly lower (P < 0.01) in both emulsified oils after intestinal digestion compared to the bulk oil. Bioaccessibility of DHA was 58%, 71% and 84% for bulk oil, O/W emulsion and gelled emulsion, respectively. CONCLUSION: These results suggest that both emulsified delivery systems used in the present study enhanced the solubilization of free fatty acids, in particular omega-3 fatty acids, and therefore their potential intestinal absorption. © 2018 Society of Chemical Industry.

International descriptive and interventional survey for oxycholesterol determination by gas- and liquid-chromatographic methods.

Increasing numbers of laboratories develop new methods based on gas-liquid and high-performance liquid chromatography to determine serum concentrations of oxygenated cholesterol metabolites such as 7α-, 24(S)-, and 27-hydroxycholesterol. We initiated a first international descriptive oxycholesterol (OCS) survey in 2013 and a second interventional survey 2014 in order to compare levels of OCS reported by different laboratories and to define possible sources of analytical errors. In 2013 a set of two lyophilized serum pools (A and B) was sent to nine laboratories in different countries for OCS measurement utilizing their own standard stock solutions. In 2014 eleven laboratories were requested to determine OCS concentrations in lyophilized pooled sera (C and D) utilizing the same provided standard stock solutions of OCS. The participating laboratories submitted results obtained after capillary gas-liquid chromatography-mass selective detection with either epicoprostanol or deuterium labelled sterols as internal standards and high-performance liquid chromatography with mass selective detection and deuterated OCS as internal standard. Each participant received a clear overview of the results in form of Youden-Plots and basic statistical evaluation in its used unit. The coefficients of variation of the concentrations obtained by all laboratories using their individual methods were 58.5-73.3% (survey 1), 56.8-60.3% (survey 2); 36.2-35.8% (survey 1), 56.6-59.8, (survey 2); 61.1-197.7% (survey 1), 47.2-74.2% (survey 2) for 24(S)-, 27-, and 7α-hydroxycholesterol, respectively. We are surprised by the very great differences between the laboratories, even under conditions when the same standards were used. The values of OCS's must be evaluated in relation to the analytical technique used, the efficiency of the ample separation and the nature of the internal standard used. Quantification of the calibration solution and inappropriate internal standards could be identified as major causes for the high variance in the reported results from the different laboratories. A harmonisation of analytical standard methods is highly needed.

Volatiles formation in gelled emulsions enriched in polyunsaturated fatty acids during storage: type of oil and antioxidant.

Gelled emulsions with carrageenan are a novel type of emulsion that could be used as a carrier of unsaturated fatty acids in functional foods formulations. Lipid degradation through volatile compounds was studied in gelled emulsions which were high in polyunsaturated oils (sunflower or algae oil) after 49 days of storage. Aqueous Lavandula latifolia extract was tested as a natural antioxidant. Analysis of the complete volatile profile of the samples resulted in a total of 40 compounds, classified in alkanes, alkenes, aldehydes, ketones, acids, alcohols, furans, terpenes and aromatic hydrocarbons. During storage, the formation of the volatile compounds was mostly related to the oxidation of the main fatty acids of the sunflower oil (linolenic acid) and the algae oil (docosahexaenoic acid). Despite the antioxidant capacity shown by the L. latifolia extract, its influence in the oxidative stability in terms of total volatiles was only noticed in sunflower oil gels (p < 0.05), where a significant decrease in the aldehydes fraction was found.

Linseed oil gelled emulsion: A successful fat replacer in dry fermented sausages.

Different levels of animal fat replacement by a high omega-3 content carrageenan gelled emulsion in dry fermented sausages were studied in order to improve their fatty acid composition. Percentages of fat replacement were 26.3% (SUB1), 32.8% (SUB2) and 39.5% (SUB3). α-linolenic acid (ALA) content increased up to 1.81, 2.19 and 2.39g/100g (SUB1, SUB2, and SUB3 products) as compared to the Control (0.35g/100g), implying an increment in polyunsaturated fatty acids (PUFA) supply (up to 10.3%) and reductions in omega-6/ omega-3 ratio (75, 82 and 84%, respectively). Peroxides and TBARs values were not affected (P>0.05) by the fat modification and a slight low formation of volatile aldehydes derived from lipid oxidation was detected. Fat replacement did not cause relevant modifications on the instrumental color properties and no sensory differences (P>0.05) were found between Control and SUB2 products (32.8%) for taste and juiciness, pointing out the viability of this formulation for human consumption.

Cholesterol and stigmasterol within a sunflower oil matrix: Thermal degradation and oxysterols formation.

The characteristics of the lipid matrix surrounding sterols exert a great influence in their thermal oxidation process. The objective of this work was to assess the oxidation susceptibility of equal amounts of cholesterol and stigmasterol within a sunflower oil lipid matrix (ratio 1:1:200) during heating (180°C, 0-180min). Remaining percentage of sterols was determined and seven sterol oxidation products (SOPs) were analysed for each type of sterol along the heating treatment. Evolution of the fatty acid profile and vitamin E content of the oil was also studied. Overall oxidation status of the model system was assessed by means of Peroxides Value (PV) and TBARS. PV remained constant from 30min onwards and TBARS continued increasing along the whole heating treatment. Degradation of both cholesterol and stigmasterol fitted a first order curve (R(2)=0.937 and 0.883, respectively), with very similar degradation constants (0.004min(-1) and 0.005min(-1), respectively). However, higher concentrations of oxidation products were found from cholesterol (79µg/mg) than from stigmasterol (53µg/mg) at the end of the heating treatment. Profile of individual oxidation products was similar for both sterols, except for the fact that no 25-hydroxystigmasterol was detected. 7α-Hydroxy and 7-keto-derivatives were the most abundant SOPs at the end of the treatment. PUFA and vitamin E suffered a significant degradation along the process, which was correlated to sterols oxidation.

Stability of avocado oil during heating: comparative study to olive oil.

The stability of the saponifiable and unsaponifiable fractions of avocado oil, under a drastic heating treatment, was studied and compared to that of olive oil. Avocado and olive oil were characterised and compared at time 0h and after different times of heating process (180°C). PUFA/SFA (0.61 at t=0) and ω-6/ω-3 (14.05 at t=0) were higher in avocado oil than in olive oil during the whole experiment. Avocado oil was richer than olive oil in total phytosterols at time 0h (339.64; 228.27mg/100g) and at 9h (270.44; 210.30mg/100g) of heating. TBARs was higher in olive oil after 3h, reaching the maximum values in both oils at 6h of heating treatment. Vitamin E was higher in olive oil (35.52 vs. 24.5mg/100g) and it disappeared earlier in avocado oil (at 4 vs. 5h). The stability of avocado oil was similar to that of olive oil.

Anti-proliferative effect of Melissa officinalis on human colon cancer cell line.

Melissa officinalis L. (Lamiaceae) is consumed as a traditional herbal tea in the Mediterranean region. The cytotoxic effect of the 50% ethanolic and aqueous extract, determined by the MTT and NR assays, was evaluated in vitro on Human Colon Cancer Cell Line (HCT-116), using Triton 10% as positive control. The 50% ethanolic extract showed significant differences after 72 h of treatment, reducing cell proliferation to values close to 40%, even the lowest dose tested (5 µg/ml). In the MTT assay, the same extract caused the lowest cell viability with 13% at a concentration of 1,000 µg/ml after 72 h of treatment, being a value lower than Triton 10%. The antioxidant activity was also confirmed evaluating the capacity of the extracts to scavenge ABTS and DPPH radicals, and IC(50) values were highly correlated with the total phenolic and flavonoid content. Bioassay guided fractionation led to the isolation of an anti-proliferative compound, rosmarinic acid. Its structural elucidation was performed by HPLC/DAD/ESI/MS analysis. High dose of rosmarinic acid (1,000 µg/ml) was clearly cytotoxic against HCT-116 cells, with a significant decrease in cell number since the earliest time point (24 h).

Effect of fish and oil nature on frying process and nutritional product quality.

UNLABELLED: The modifications on a lean fish (cod-Gadus morhua) and a fatty fish (farmed salmon-Salmo salar) after the application of pan-frying using 2 types of oil with different lipid profile (extra virgin olive oil and sunflower oil) was the aim of this study. Fat content and total energetic value increased significantly after the frying process only in the lean fish, without relevant changes in the fatty fish. Extra virgin olive oil led to a higher fat absorption rate than sunflower oil in both fish. Frying hardly affected the lipid profile of farmed salmon regardless the oil used, however it drastically changed in fried cod compared to raw cod. Omega-6/omega-3 ratio increased from 0.08 in raw cod to 1.01 and 6.63 in fried cod with olive oil and sunflower oil, respectively. In farmed salmon, the omega-6/omega-3 ratio was 0.38 (raw), and 0.39 to 0.58 in fried salmon. The amount of EPA + DHA slightly decreased with frying in salmon, and increased in cod. The type of oil has more influence in the nutritional fish quality for the lean fish compared to that of the fatty fish. The use of extra virgin olive oil was efficient to avoid a significant increase of the lipid oxidation intensity during frying in cod but not in salmon. PRACTICAL APPLICATION: Food modifies its composition and nutritional value with the application of cooking technologies. As most food table composition tables are based on raw food products, this article contributes with interesting data on pan-fried fish composition, which may improve the approach to achieve a real intake of healthy nutrients as omega 3 fatty acids.

Selenium, iodine, omega-3 PUFA and natural antioxidant from Melissa officinalis L.: a combination of components from healthier dry fermented sausages formulation.

A new formulation of dry fermented sausage, including ingredients that improve the nutritional and health benefits of this type of product is presented. Se yeast (2g/kg), iodized salt (26g/kg), linseed:algae (3:2) emulsion (62.5g/kg), and lyophilized water extract of Melissa officinalis L. as a source of natural antioxidants (686mg/kg), yielded dry fermented sausages with technological and sensory properties similar to traditional ones. From the nutritional standpoint, a 50g portion of this product would give 100% of the recommended daily intake for Se, 70% of DRI for iodine, and 40% and 100% of the reference intake for alpha-linolenic and EPA+DHA, respectively. The omega-6/omega-3 ratio decreased from 15.7 in the control product to 1.96 in the modified one. Despite the high PUFA content, no oxidation was detected by TBARS (<0.15mgMDA/kg) and volatile compounds, showing the effectiveness of the natural antioxidants from M. officinalis. The modified formulation presented good acceptability for panelists with similar appearance, odor, taste and juiciness as the control products.

Effect of lyophilized water extracts of Melissa officinalis on the stability of algae and linseed oil-in-water emulsion to be used as a functional ingredient in meat products.

Previous work pointed out the possibility to enhance the nutritional value of meat products using long chain omega-3 PUFA enriched emulsions. Oil-in-water emulsions elaborated with a mixture of algae and linseed oils (15:10) in order to be used as functional ingredient were stabilized with BHA (butylhydroxyanisol) or with a lyophilized water extract of Melissa officinalis L. (Lemon balm). The lipid profile of the oil mixture showed a high amount of DHA (31.7%), oleic (25.4%) and alpha-linolenic acid (12.7%) resulting in a very low omega-6/omega-3 ratio (0.12). The lyophilized extract of M. officinalis showed a high antioxidant activity (being 62ppm of the lyophilized water extract of Melissa equivalent to 200ppm of BHA, using the DPPH assay as reference), and high total phenolic content. Studying the oxidation process in the emulsions during 15days at room temperature, it could be concluded that this extract was as efficient as BHA in order to control the thiobarbituric acid reactive substances (TBARS) formation.

Validation of a gas chromatography-mass spectrometry method for the analysis of sterol oxidation products in serum.

A validated gas chromatography-mass spectrometry (GC-MS) detection method for the quantitative analysis of sterol oxidation products (SOPs) in serum is described. After a lipid extraction procedure with chloroform-methanol, a cold saponification and purification by solid phase extraction, oxysterols were derivatized to form trimethyl-sylil-ethers which were subjected to GC-MS analysis. Calibration curves for cholesterol oxidation products showed determination coefficient (R(2)) of 1.0, with low values for the coefficient of variation of the response factors (< 1%). Detection and quantification limits were below 5 ng/mL and 10 ng/mL, respectively. Recovery data were between 77.65% and 110.29% (CV < 10% for all compounds). Good results were obtained for within- and between-day repeatability, with values below 10%. In conclusion, the method performed is suitable for the determination and quantification of SOPs in serum.

Levels of phytosterol oxides in enriched and nonenriched spreads: application of a thin-layer chromatography-gas chromatography methodology.

The content of phytosterol oxidation products (POPs) in enriched and nonenriched commercial spreads was evaluated by thin-layer chromatography-gas chromatography (TLC-GC). Oxides of beta-sitosterol, campesterol, and stigmasterol were produced by thermo-oxidation (7-hydroxy, 7-keto, and epoxy derivatives) and chemical synthesis (triol derivatives), which were then separated and identified by TLC-GC. Their identification was further confirmed by GC-mass spectrometry (GC-MS). The total amounts of phytosterols found were 6.07 and 0.33 g/100 g of sample in phytosterol-enriched and nonenriched spread, respectively, whereas the total POPs contents were 45.60 and 13.31 mg/kg of sample in the enriched and nonenriched products. The main POPs found were the 7-keto derivatives of all phytosterols analyzed; 7-ketositosterol was the most abundant one (14.96 and 5.93 mg/kg of sample in phytosterol-enriched and nonenriched spread). No beta-epoxy and triol derivatives were detected in both types of samples. The enriched spread presented a lower phytosterol oxidation rate (0.07%) than the nonenriched one (0.41%).