Gelled double emulsions as delivery systems for hydroxytyrosol and n-3 fatty acids in healthy pork patties.

Structuring of double emulsion offers the possibility to obtain a system with similar consistency to animal fat which is an interesting approach to improve the fat content of meat products. This article examines the suitability of gelled double emulsions (GDE) for use as a delivery system for n-3 PUFAs and hydroxytyrosol (Hxt) in pork patties. Effect of partial (MF/GDE sample) and total (LF/GDE) replacement of pork backfat with GDE with perilla oil (PO) as lipid phase and Hxt (in W1) on pork patty composition and properties was evaluated. Compared with the control sample (NF/CS), the products with PO contained less SFAs and higher proportions of LNA and ALA, and this difference augmented with the level of GDE. Addition of GDE increased Kramer shear force of cooked patties as the higher percentage of fat replaced was used. Oxidative stability of patties can be interpreted in terms of composition and structural factors, especially in relation with the use of GDE as a fat replacer. Products showed oxidation values greater than 1 after 3 days of refrigeration. NF/GDE and MF/GDE, with similar scores, were the most acceptable for the panellists. This technology is suitable for labelling meat products with nutritional and health claims.

A comprehensive approach to formulation of seaweed-enriched meat products: From technological development to assessment of healthy properties.

Meat consumption is influenced by various kinds of factors, among them health implications. Different strategies can be effective in developing meat-based functional foods. These basically entail reducing the presence of compounds with negative health implications and enhancing the presence of beneficial compounds. This article reviews a comprehensive model for the development of meat-based functional foods based on a presentation of the research achieved in terms of the design and development of qualitatively and quantitatively modified meat products (frankfurters, patties and restructured steaks). These were reformulated to incorporate nutrients associated with three different seaweeds (wakame-Undaria pinnatifida; nori-Porphyra umbilicalis; and sea spaghetti-Himanthalia elongata) as sources of bioactive substances, while simultaneously reducing sodium and fat and improving fatty acid profiles. Those seaweeds were chosen, because in terms of composition and health implications, abundance on Spanish coasts, relatively widespread consumption, and suitability in terms of flavour and colour they are better suited than others for use as ingredients in new products. It also discusses the consequences of the use of this type of meat-based functional foods (combination of pork meat and 5% of each seaweed with or without hypercholesterolaemic agent included in the diets) on growing animals (Wistar male rats), and their effects on different aspects of lipoprotein metabolism, oxidative stress and liver structure. This article, then, reports a comprehensive approach to the production of seaweed-enriched meat products, considering aspects of technological development aimed at achieving the functional effect.

Physicochemical properties and encapsulation of silicon in double emulsions for healthier food applications.

This article analyses the potential use of double emulsions as silicon delivery systems with reference to the influence of the composition of the inner aqueous phase (W1, containing NaCl and sodium caseinate or gelatin) on silicon encapsulation and physicochemical properties of food-grade W1/O/W2. Irrespective of W1, DEs initially showed a well-defined monomodal distribution, with the widest range registering in the sample with gelatin. All samples developed a bimodal distribution during storage (3 ± 2 °C). Heating increased the range of droplet size distribution. DEs exhibited high physical stability (creaming), decreasing over storage; this behaviour was generally unaffected by W1 composition, which maintained similar stability (95-96%) at the end of storage. Viscosity was generally unaffected by formulation, storage time or heating treatment. Si encapsulation efficiency (72.4 and 78.3%) was not affected by W1 composition, while Si encapsulation stability was generally unaffected by either storage or heating. These DEs can be used as potential ingredient (with lower fat content, better fatty acid profile and with the potential Si health benefits) for the development of healthier foods including meat products.

Preparation and impact of multiple (water-in-oil-in-water) emulsions in meat systems.

The aim of this paper was to prepare and characterise multiple emulsions and assess their utility as pork backfat replacers in meat gel/emulsion model systems. In order to improve the fat content (in quantitative and qualitative terms) pork backfat was replaced by a water-in-oil-in-water emulsion (W1/O/W2) prepared with olive oil (as lipid phase), polyglycerol ester of polyricinoleic acid (PGPR) as a lipophilic emulsifier, and sodium caseinate (SC) and whey protein concentrate (WP) as hydrophilic emulsifiers. The emulsion properties (particle size and distribution, stability, microstructure) and meat model system characteristics (composition, texture, fat and water binding properties, and colour) of the W1/O/W2, as affected by reformulation, were evaluated. Multiple emulsions showed a well-defined monomodal distribution. Freshly prepared multiple emulsions showed good thermal stability (better using SC) with no creaming. The meat systems had good water and fat binding properties irrespective of formulation. The effect on texture by replacement of pork backfat by W1/O/W2 emulsions generally depends on the type of double emulsion (associated with the hydrophilic emulsifier used in its formulation) and the fat level in the meat system.

Healthier oils stabilized in konjac matrix as fat replacers in n-3 PUFA enriched frankfurters.

Nutritional, sensory and technological properties of frankfurters as affected by reformulation processes designed to reduce fat content and improve fatty acid profile were investigated. Healthier oils stabilized in oil in water emulsion or in konjac matrix gel were used as fat replacers. Results showed that improved fat content by the replacement of pork backfat with konjac gel and by the addition of healthier oils stabilized by various different systems, both resulted in products with very similar characteristics. From a nutritional standpoint, reformulated frankfurters with konjac gel and/or added a healthier oil combination may claim "reduced fat content" and/or "high omega 3 fatty acid content" according to European Regulation, since they could contain less than 30% of the fat in the reference product and more than 0.6 g of ALA/100 g and more than 80 mg of the sum of EPA plus DHA per 100 g, respectively. Chill storage over 40days generally had little effect on the technological characteristics of frankfurters.

Enriched n-3 PUFA/konjac gel low-fat pork liver pâté: lipid oxidation, microbiological properties and biogenic amine formation during chilling storage.

Low-fat pork liver pâtés enriched with n-3 PUFA/konjac gel were formulated by replacing (totally or partially) pork backfat by a combination of healthier oils (olive, linseed and fish oils) and konjac gel. Lipid oxidation, microbiological changes and biogenic amine (BA) formation were studied in healthier-lipid pâtés during chill storage (85 days, 2 °C). Increasing unsaturated fatty acid levels favoured lipid oxidation, although the levels reached were low throughout the storage period, ranging from 0.113 to 0.343 mg malonaldehyde/kg sample. Neither the formulation nor the time in storage affected the microbial load. Biogenic amine contents of products (the sum of initial concentrations and amines formed during storage) varied according to the type of BA but were far below levels that could constitute a consumer health hazard.

Low-fat pork liver pâtés enriched with n-3 PUFA/konjac gel: dynamic rheological properties and technological behaviour during chill storage.

Low-fat pork liver pâtés enriched with n-3 PUFA/konjac gel were formulated by replacing (total or partially) pork backfat by a combination of healthier oils (olive, linseed and fish oils) and konjac gel. Dynamic rheological properties and technological behaviour of pâtés during chill storage (2 °C, 85 days) were analysed. Cooking yields were affected (P<0.05) by formulation, with percentages ranging between 88 and 98%. According to the frequency sweep test, pâtés presented a gel/emulsion-like pattern with a loosely-structured network and the consistency of a viscoelastic gel. Thermal processing caused the formation of a protein gel network with a considerable element of emulsion-like characteristics. Pâtés became lighter and less red (P<0.05) during chill storage. Purge losses of around 1% were observed at the end of the storage period, irrespective of formulation. Textural parameters of pâtés were affected by formulation and storage time. The results suggest that the replacement of pork back fat by oil-in-water emulsion and the incorporation of konjac gel could provide a mixture of ingredients that effectively mimics the normal animal fat content in pâtés.

Effect of cooking on the chemical composition of low-salt, low-fat Wakame/olive oil added beef patties with special reference to fatty acid content.

Changes in chemical composition, with special reference to fatty acids, as affected by cooking, were studied in low-salt (0.5%)/low-fat patties (10%) with added Wakame (3%) and partial or total replacement of pork backfat with olive oil-in-water emulsion. The addition of Wakame and olive oil-in-water emulsion improved (P < 0.05) the binding properties and the cooking retention values of moisture, fat, fatty acids and ash, which were close to 100%. Partial and total replacement of animal fat with olive oil-in-water emulsion reduced (P < 0.05) saturated fatty acids (SFAs), while total replacement also reduced (P < 0.05) polyunsaturated fatty acid (PUFAs) contents. The fatty acid concentration in cooked patties was affected by product formulation. Unlike the case of all animal fat patties, when olive oil was added the cooking process increased (P < 0.05) SFAs, monounsaturated fatty acids (MUFAs) and PUFA n-3 (linolenic acid) and n-6 (linoleic acid) contents. Cooked formulated patties with seaweed and partial or total replacement of pork backfat by oil-in-water emulsion and with seaweed added were less calorie-dense and had lower SFAs levels, while samples with olive oil had higher MUFAs levels.

A healthier oil combination and konjac gel as functional ingredients in low-fat pork liver pâté.

Healthier lipid pâtés were formulated by reducing the fat content and/or replacing the pork backfat by a healthier oil combination (olive, linseed and fish oils) and konjac gel (0-15%). The reformulation results were evaluated by composition (proximate analysis and fatty acid profile), technological properties (emulsion stability, colour, and texture), microbiological and sensory parameters of the pâtés. Pâtés with partial or total replacement of pork backfat had lower levels of saturated fatty acids (SFA) (27.4% and 21.3%) and monounsaturated fatty acids (MUFA) (49.8% and 42.5%), and higher levels of polyunsaturated fatty acids (PUFA) (22.4% and 35.6%) compared with control pâtés (32.2%, 58.2% and 9.04% respectively). The n-6/n-3 PUFA ratio was decreased from 6.78 (in control pâtés) to 0.79 and 0.48 when partial and total pork backfat respectively was replaced by a healthier oil combination. Although emulsion stability was affected by the formulation, in general all pâtés had good fat and water binding properties. The fat reduction produced a softer and more spreadable pâté, although no effect on penetration parameters was observed after by pork fat replacement by a healthier oil combination. The addition of 15% of konjac gel produced stiffer structures (as compared with 0 and 7%) which are very close to those of the control samples. No microbiological limitations were produced by the reformulation process, obtaining pâtés with acceptable sensory characteristics, similar to the control sample.

Quality characteristics of low-salt restructured poultry with microbial transglutaminase and seaweed.

Characteristics of restructured poultry steaks as affected by addition of Sea Spaghetti seaweed (3% dry matter) combined with NaCl reduction and a microbial transgutaminase/caseinate (MTGase/caseinate) system as a cold binding agent were studied during chill storage. The incorporation of Sea Spaghetti caused a slight (P<0.05) increase in purge loss but reduced cooking loss in the products. Addition of MTGase/caseinate did not affect water binding properties. The added seaweed and the MTGase/caseinate system both increased (P<0.05), the Kramer shear force (KSF) of raw products, making them easier to handle. No such effect was observed in cooked products. Products with Sea Spaghetti had higher levels (P<0.05) of total viable counts and lactic acid bacteria, and also higher levels of tyramine and spermidine. All products were judged acceptable by a sensory panel. During chill storage no important changes were found in the target properties due to composition.

Technological and sensory characteristics of reduced/low-fat, low-salt frankfurters as affected by the addition of konjac and seaweed.

This paper reports the effect of an edible seaweed, Sea Spaghetti (Himanthalia elongata), on the physicochemical (emulsion stability, cooking loss, colour, texture, residual nitrite and microstructure) and sensory characteristics of reduced- and low-fat, low-salt (NaCl) frankfurters prepared with konjac gel as a fat substitute. The effects on emulsion stability of substituting konjac gel for pork backfat were conditioned by the proportion of the substitution. Incorporation of a combination of Sea Spaghetti/konjac gel (accompanied by reduction in salt) increased (P<0.05) cooking loss and reduced (P<0.05) emulsion stability in the gel/emulsion systems. Incorporation of Sea Spaghetti/konjac gel produced a decrease (P<0.05) of lightness (L*) and redness (a*) values and an increase (P<0.05) of yellowness (b*) as compared to the other samples. The effect of adding seaweed on the texture parameters of low-salt frankfurters varied depending on the proportion of konjac gel used in the formulation. Morphological differences in frankfurter microstructure were observed as fat content was reduced and konjac gel increased. Incorporation of a combination of Sea Spaghetti/konjac gel caused the formation of a more heterogeneous structure, in which the seaweed was integrated in the meat protein matrix.

Nutritional and antioxidant properties of different brown and red Spanish edible seaweeds.

This article reports a study of the nutritional composition, total dietary fiber (TDF), mineral contents, fatty acid and amino acid profiles, polyphenolic concentration and antioxidant activity of three Spanish seaweeds: two brown seaweeds (Himanthalia elongata and Undaria pinnatifida) and one red (Porphyra umbilicalis). TDF and ash were the most abundant components in the brown seaweeds, while TDF and protein were the main components in the red one. In all seaweeds, the lipid contents were very low but the polyunsaturated fatty acid contents were high. Although the red seaweed contained significantly (p < 0.05) more protein content than the brown ones, all three contained all the essential amino acids at levels comparable to FAO/WHO requirements. The brown seaweeds contained significantly more minerals than the red one; they are a rich source of K, Na, Ca and Mg and present a beneficial Na/K ratio. Himanthalia elongata displayed remarkably high polyphenolic content, endowing it with appreciable antioxidant activity. These seaweeds offer considerable potential as functional food ingredients due to components like dietary fiber, minerals and trace elements, protein and lipids, which produce many different kinds of biological activities, and also to their high antioxidant capacity.

Composition and antioxidant capacity of low-salt meat emulsion model systems containing edible seaweeds.

The study was designed to determine the influence of the addition of edible seaweeds, Sea Spaghetti (Himanthalia elongata), Wakame (Undaria pinnatifida), and Nori (Porphyra umbilicalis), on fatty acid composition, amino acid profile, protein score, mineral content and antioxidant capacity in low-salt meat emulsion model systems. The addition of seaweeds caused an increase (P<0.05) in n-3 polyunsaturated fatty acids (PUFA) and a decrease (P<0.05) in the n-6/n-3 PUFA ratio. The thrombogenic index significantly decreased (P<0.05) in Nori and Wakame meat samples. Meat systems made with added seaweeds had lower (P<0.05) sodium contents than control samples. In general, addition of seaweeds to products increased (P<0.05) the concentrations of K, Ca, Mg and Mn. The presence of Nori caused an increase (P<0.05) in levels of serine, glycine, alanine, valine, tyrosine, phenylalanine and arginine, whereas Wakame and Sea Spaghetti produced no significant changes in amino acid profiles in the model systems. The inclusion of Sea Spaghetti increased the sulphur amino acid score by 20%. The added seaweeds supplied the meat samples with soluble polyphenolic compounds, which increased the antioxidant capacity of the systems. The polyphenol supply and antioxidant increase were greatest (P<0.05) in the samples containing Sea Spaghetti.

Design and nutritional properties of potential functional frankfurters based on lipid formulation, added seaweed and low salt content.

The aim of this paper was to design and analyse the nutritional composition (fatty acid profile, cholesterol, mineral and amino acid content) of low-fat frankfurters enriched with n-3 polyunsaturated fatty acids (PUFA) (using algal oil to add 400mg of docosahexanoic acid - DHA/100g of product) as affected by the addition of seaweed (5.5% Himanthalia elongata) and the partial substitution (50%) of animal fat by olive oil (as a source of monounsaturated fatty acids - MUFA) or combinations of olive oil and seaweed. Reduction of NaCl level was also studied. The presence of algal oil produced frankfurters with high long-chain n-3 PUFA contents. The partial substitution of the pork fat by olive oil reduced (P<0.05) saturated fatty acids (SFA) and promoted (P<0.05) MUFA. A healthier lipid formulation (algal and olive oils and the reducing animal fat) produced a good balance of MUFA/SFA, PUFA/SFA and n-6/n-3 ratios. Although adding seaweed had little effect on the lipid and amino acid profiles of frankfurters, it does constitute a means to produce low-sodium products with important dietary fibre content, with better Na/K ratios and rich in Ca.

Influence of adding Sea Spaghetti seaweed and replacing the animal fat with olive oil or a konjac gel on pork meat batter gelation. Potential protein/alginate association.

Standard and modulated differential scanning calorimetry (DSC, MDSC) and dynamic rheological thermal analysis (DRTA) were used to in situ simulate the batter gelation process. Texture profile analysis (TPA) and conventional quality evaluations were applied to processed products. Sea Spaghetti seaweed addition was highly effective at reinforcing water/oil retention capacity, hardness and elastic modulus in all formulations. Olive oil substituting half pork fat yielded a presumably healthier product with slightly better characteristics than control. A konjac-starch mixed gel replacing 70% of pork fat produced a similar product to control but with nearly 10% more water. DSC revealed the currently unknown phenomenon that Sea Spaghetti alginates apparently prevented thermal denaturation of a considerable protein fraction. MDSC confirmed that this mainly concerned non-reversing effects, and displayed glass transition temperatures in the range of 55-65°C. DRTA and TPA indicated however much stronger alginate-type gels. It is tentatively postulated that salt-soluble proteins associate athermally with seaweed alginates on heating to constitute a separate phase in a thermal composite-gelling process.

Low-fat frankfurters enriched with n-3 PUFA and edible seaweed: Effects of olive oil and chilled storage on physicochemical, sensory and microbial characteristics.

This article reports a study of the physicochemical, sensory and microbiological characteristics of low-fat (10%) and n-3 PUFA-enriched frankfurters as affected by addition of seaweed (5% Himanthalia elongata), partial substitution (50%) of animal fat by olive oil and chilled storage (41days at 2°C). The presence of seaweed improved water and fat binding properties, reduced (P<0.05) lightness and redness and increased (P<0.05) the hardness and chewiness of low-fat frankfurters enriched with n-3 PUFA. The effect of olive oil on those characteristics was less pronounced than that of seaweed. Replacing pork backfat with olive oil in frankfurters produced acceptable sensory characteristics, similar to control, while addition of seaweed resulted in less acceptable products, due mainly to the special flavour of the seaweed. Formulation and storage time affected the total viable count and lactic acid bacteria count. Frankfurters containing olive oil and seaweed had the highest total viable count from day 14 of storage, with lactic acid bacteria becoming the predominant microflora.

Influence of different types and proportions of added edible seaweeds on characteristics of low-salt gel/emulsion meat systems.

The effects of three different types of edible seaweeds, Sea Spaghetti (Himanthalia elongata), Wakame (Undaria pinnatifida), and Nori (Porphyra umbilicalis) added at two concentrations (2.5% and 5% dry matter) on the physicochemical and morphological characteristics of gel/emulsion systems were evaluated. The addition of seaweeds improved (P<0.05) water- and fat-binding properties except in the case of Nori added at 2.5%. Hardness and chewiness of the cooked products with added seaweed were higher (P<0.05), and springiness and cohesiveness were lower (P<0.05) than in control samples. Colour changes in meat systems were affected by the type of seaweed. The morphology of sample differed depending on the type of seaweed added, and this is the result of differences in physical and chemical characteristic of the seaweed powder used. In general, products formulated with the brown seaweeds (Sea Spaghetti and Wakame) exhibited similar behaviour, different from that of products made with the red seaweed Nori.

Changes in fatty acids and polar material of restructured low-fat or walnut-added steaks pan-fried in olive oil.

The study aims to determine the influence of pan-frying on the fatty acid composition and fat content and alteration of functional restructured beef steaks. Low-fat (L, 2% fat), 20% walnut-added (W, 13% fat) and medium fat (M, 13% fat) steaks were prepared and fried in extra virgin olive oil. Pan-frying increased fat in L and W steaks and decreased it in M ones. Raw L and M steaks showed similar fatty acid profiles while W ones contained a lower percentage of saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) but a higher percentage of polyunsaturated fatty acids (PUFA). The fatty acid profile of fried steaks was between that of the raw steaks and olive oil. Several fatty acids (g fatty acid/100g edible steaks) were affected (p<0.001) by the frying×meat-formulation interaction. Linoleic and linolenic acid contents did not decrease in fried W steaks, but decreased (p<0.05) when data were expressed on a dry matter basis. Frying increased SFA, MUFA and ω-6 PUFA contents in L samples while it decreased SFA and increased ω-6 PUFA in M steaks. Before and after frying, W steaks had atherogenic and thrombogenic indexes at least three times lower than their counterparts. Both indexes decreased in fried L samples while only the AI in M ones. Polar material content (PM) increased only in L samples. No relevant differences were found between PM of the fried steaks and that of their corresponding used oils. Results suggest that pan-frying improves the fatty acid composition of L and M steaks with minor changes in PM. The high retention of lipids observed in the W samples permits consumption of ω-3 PUFA- and ω-6 PUFA-enriched meat with a very low content of alteration compounds.

Composition and physicochemical characteristics of restructured beef steaks containing walnuts as affected by cooking method.

The study was conducted to determine the influence of various cooking methods - conventional oven, microwave oven, electric grill and pan-frying on the composition and physicochemical characteristics of restructured beef steaks formulated as low fat (L, 2.0% fat), medium fat (M, 13.0% fat) and 20% added walnut (W, 12.6% fat). Composition, retention coefficients for different compounds, cooking loss (CL) and texture were affected by both formulation and cooking. There was considerable retention of moisture, fat and minerals (as ash) in W samples after cooking. CL was highest (P<0.05) in M sample and lowest (P<0.05) in W samples. Microwaved restructured steaks had higher (P<0.05) kramer shear force (KSF) and bind strength (BS), while pan-fried and conventionally oven-cooked steaks had lower (P<0.05) KSF. The thiobarbituric acid-reactive substances (TBARS) content was low in all restructured steaks but was affected by both cooking and formulation. Although cooking can change the proximal composition of steaks, lipid retention (>90%) was greatest in the case of the W sample, thus assuring that the ultimate objective of these restructured meats, namely to provide a source of walnut and walnut fat, would be successful.

Characteristics of restructured beef steak with different proportions of walnut during frozen storage.

Physicochemical (thawing loss, cooking loss, surface shrinkage, texture, colour and lipid oxidation) and sensory properties of restructured beef steak with different levels of added walnut (0%, 10% and 20%) were determined at various times during frozen storage up to 128 days. Cooking loss (CL), Kramer shear force (KSF) and binding strength (BS) of restructured beef decreased (P<0.05) as the proportion of walnut increased. Walnut enhanced (P<0.05) lightness and yellowness and reduced (P<0.05) redness. Frozen storage did not affect (P>0.05) CL, KSF and BS of restructured beef steak. Redness decreased (P<0.05) over storage for all samples. Lipid oxidation of restructured beef steak containing walnut was not a limiting factor for frozen stability of meat products. Frozen storage had no effect (P>0.05) on the sensory quality of restructured beef steak.