Antioxidant activity of hydroxytyrosol in frankfurters enriched with n-3 polyunsaturated fatty acids

The capacity of hydroxytyrosol (HXT) to inhibit lipid oxidation in cooked pork meat batter, oil-in-water emulsions and potential functional frankfurters formulated with a healthier oil combination (as animal fat replacer) was studied during chilling storage, and its effect compared with those produced by synthetic antioxidants (BHA/BHT). Although efficiency varied, HXT was an effective antioxidant during chilling storage in the three food matrices studied. In general the order of inhibition capacity of HXT against lipid oxidation (thiobarbituric acid-reactive substances-TBARS) was cooked meat batter > oil-in-water emulsion > frankfurters, whereas in the case of BHA/BHT (with lower inhibitory activity than HXT) it was cooked meat batter > oil-in-water emulsion, and there was no antioxidative effect in frankfurters. Whereas significant correlations were established between lipid oxidation (TBARS) and antioxidative capacity measured by photochemiluminescence (PCL) in frankfurters supplemented with HXT and BHA/BHT, no significant correlations were found between ferric reducing/antioxidant power assay (FRAP) and TBARS and PCL.     

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 patés 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 patés during chill storage (85days, 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 0.343mg 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.     

Dog rose (Rosa canina L.) as a functional ingredient in porcine frankfurters without added sodium ascorbate and sodium nitrite

The effect of dog rose (Rosa canina L.; RC), rich in polyphenols and ascorbic acid, on lipid and protein oxidation, colour stability and texture of frankfurters was investigated. Four treatments were prepared: with 5 or 30g/kg RC extract and without sodium ascorbate and sodium nitrite (5RC and 30RC, respectively), a positive control (with sodium ascorbate and sodium nitrite; PC) and a negative control (without sodium ascorbate, sodium nitrite or RC extract; NC). Hexanal values were much higher throughout storage in NC compared to RC and PC frankfurters (P<0.001). The RC extracts protected against protein oxidation, but not as efficiently as PC (P<0.05). In the RC treated frankfurters, lower a* values were measured compared to PC due to the lack of sodium nitrite. In conclusion, dog rose can act as a natural antioxidant in frankfurters, but not as full replacer for sodium nitrite.     

Effect of dietary fish oil on fatty acid composition, lipid oxidation and sensory property of chicken frankfurters during storage

Broilers fed with three levels of fish oil (0, 2 and 4%) for 6 weeks were used in the manufacture of chicken frankfurters. The meat samples were vacuum-packed and stored at 0°C for 0, 10, 20 and 30 days. Cooking yield, proximate and fatty acid composition, lipid oxidation, microbial and sensory properties of the meat products were measured. Cooking yield, moisture, fat, protein, ash and cholesterol contents of frankfurters were not affected (P>0.05) by levels of dietary fish oil. Frankfurters processed from chickens fed diets enriched with 2 and 4% of supplemental fish oil had a higher (P<0.05) level of n-3 fatty acids (eicosapentaenoic acid and docosahexaenoic acid), but had a lower level of n-6 fatty acids (P<0.05) than the controls (0% fish oil). TBA values and pH values of meat samples were not affected (P>0.05) by levels of supplemental fish oil in the diets, however, pH values of the vacuum-packaged chicken frankfurters decreased (P<0.05) as the storage time increased. No differences (P>0.05) in total anaerobic plate counts were observed among the fish oil treatments during storage. Supplementation of 2 and 4% fish oil in the diets did not increase (P>0.05) the intensity of fishy flavor in chicken 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.     

The Effects of Irradiation at 1.6 kGy on Quality Characteristics of Commercially Produced Ham and Pork Frankfurters over Extended Storage

ABSTRACT: Commercially produced sliced ham and all-pork frankfurters were obtained from a national meat processor and irradiated at 1.6 kGy. The samples were evaluated for color, lipid oxidation, odor, flavor, and the production of volatiles over an 8-wk storage period. Irradiation processing did not affect color values for the ham or frankfurters. Lipid oxidation as measured by 2-thiobarbituric acid-reactive substances (TBARS) did not increase for either the ham or frankfurters. Irradiation processing increased off-odor scores for the ham but not for frankfurters. On the other hand, off-flavor scores were not significantly different for ham but were higher in frankfurters after irradiation processing. Dimethyl disulfide content increased as a result of irradiation in both the ham and frankfurters but decreased during the 8-week storage period. Irradiation processing resulted in the formation of new volatile compounds in the ham samples including heptane, trans -1-butyl-2-methylcyclopropanone, 2-octene, and toluene, which were not present in nonirradiated ham. In the case of frankfurters, irradiation treatment resulted in the formation of 2-butanone, which was not present in the nonirradiated frankfurters. Most volatile compounds that were affected by irradiation processing of either the ham or frankfurters were increased when compared with nonirradiated controls. Although color and lipid oxidation (TBARS) did not seem to be affected by irradiation processing at 1.6 kGy, changes in odor, flavor, and the production of volatiles are of concern if irradiation is to be used to control microbial growth in ready-to-eat pork products.     

Effectiveness of rosemary essential oil as an inhibitor of lipid and protein oxidation: Contradictory effects in different types of frankfurters

The effect of increasing levels (150, 300 and 600ppm) of rosemary essential oil on lipid and protein oxidation and the increase of non-heme iron (NHI) content during refrigeration (+4°C/60 days) of frankfurters produced with tissues from Iberian pigs (IF) or white pigs (WF), was studied. Frankfurters with no added essential oil were used as controls. Iberian pigs were free-range reared and fed on acorns and pasture whereas white pigs (Large-white×Landrance) were intensively reared and fed on a mixed diet. Large differences were detected between types of frankfurters (Iberian vs white) in terms of fatty acid composition and tocopherols content due to the different feeding background of the animals. The effect of the addition of rosemary essential oil on the oxidative stability of frankfurters depended on the level of added essential oil and the characteristic of the frankfurter. The rosemary essential oil successfully inhibited the development of lipid and protein oxidation in IF with that antioxidant effect being more intense at higher concentrations of essential oil. In WF, 150ppm rosemary essential oil showed an antioxidant effect, significantly reducing the generation of lipid and protein oxidation products. At higher levels (300 and 600ppm) the essential oil had, in general, no effect on lipid oxidation while significantly enhanced the oxidation of proteins and the release of iron from myoglobin. The presence of certain amounts of tocopherols in the frankfurters could have influenced the activity displayed by the added essential oil leading to antioxidant or prooxidants effects though the different fatty acid composition and oxidative status between frankfurters could also have had an effect.     

Effect of preformed konjac gels,with and without olive oil,on the technological attributes and storage stability of merguez sausage

In order to improve the fat content of fresh sausages (merguez), the effects of both reducing beef fat level (by konjac gel-KG) and incorporing olive oil (in a konjac matrix-OKM) on nutritional, quality characteristic and refrigerated storage stability were studied. Fat reductions in merguez sausages of between 53 and 76% were achieved when beef fat was replaced with KG; the proportion reached 34–49% using OKM as a beef fat replacer, where 23 to 36% of total fat in the merguez was from olive oil. The merguez contained substantial amounts of some minerals (Mg and Fe). Sensory analysis revealed no significant differences between the control and the reformulated products, which had relatively low levels of lipid oxidation. Shelf life and biogenic amines of merguez sausage were not affected by formulation during refrigerated storage. Therefore, the use of konjac materials as fat replacers could reduce total caloric energy by replacing/reducing beef fat and improving sausage formulation to achieve healthier merguez products.     

Protein Oxidation in Frankfurters with Increasing Levels of Added Rosemary Essential Oil: Effect on Color and Texture Deterioration

The development of protein oxidation as assessed by the total carbonyl content and its influence on color and texture deterioration during the refrigerated storage (+4 °C/60 d) of frankfurters, were studied. The effect of the addition of a rosemary essential oil at different levels (150, 300, and 600 ppm) on the protein oxidative stability of the frankfurters was also evaluated. Frankfurters with no added essential oil were used as controls. The amount of carbonyls from protein oxidation significantly increased during refrigerated storage, and this increase was significantly higher in control frankfurters than in those treated with 300 and 600 ppm. Rosemary essential oil at levels of 300 and 600 ppm successfully protected the heme molecule from degradation and significantly inhibited the increase of nonheme iron (NHI) in refrigerated stored frankfurters. Color changes were directly related to oxidation processes because frankfurters with added antioxidants (300 and 600 ppm) suffered less color modifications than the controls. The addition of rosemary essential oil enhanced texture characteristics of frankfurters by reducing hardness, adhesiveness, gumminess, chewiness, and controlling the lost of elasticity during refrigeration. Statistically significant correlations were calculated between protein oxidation and instrumentally measured parameters, suggesting that the alteration of protein functionality caused by oxidation likely affected color and texture characteristics of frankfurters.     

Antioxidant and Antimicrobial Activity of Rosemary Extract in Chicken Frankfurters

ABSTRACT:  The antioxidant and antimicrobial effects of commercially available oil-soluble rosemary extracts VivOX 20 and VivOX 4 were investigated against lipid oxidation and microbial growth in vacuum-packed chicken frankfurters. The content of the main active ingredient, carnosic acid, in extracts was 20% and 4% (w/w), respectively. For comparison, the activity of commercially available preservative Robin LI LS was also tested. The control was chicken frankfurters made without test additives. Antioxidant activity tests were performed at 3 storage temperatures (4, 12, 25 °C), using the Rancimat method. Antimicrobial effect was investigated by aerobic plate count. Results showed that both rosemary preparations possess antioxidant and antimicrobial properties that may make them useful in the food industry. In chicken frankfurters with added VivOX 20 and VivOX 4, higher oxidative stability was exhibited at all storage temperatures, as in frankfurters with Robin LI LS. Addition of VivOX 20, VivOX 4, and Robin LI LS also significantly reduced the aerobic plate count, compared to controls, stored at 4 or 12 °C.     

Grape seed flour is a viable ingredient to improve the nutritional profile and reduce lipid oxidation of frankfurters

In this study, grape seed flour (GSF) obtained from wine by-products was incorporated into frankfurters at seven concentrations (0, 0.5, 1, 2, 3, 4, and 5%) and the effects occurred on physical, nutritional and sensory characteristics of the products were investigated. The colour values (L*, a* and b*) of frankfurters generally decreased (p < 0.05) on account of the increasing amount of GSF. The utilization of this flour also led to a decline in the oxidation level of the products (p < 0.05), probably due to its antioxidant content. The increment of GSF in the frankfurters enhanced the protein, total dietary fibre and water holding capacity of the treatments (p < 0.05). Although the level of GSF above 0.5% reduced overall acceptability, the frankfurters containing the level up to 2% received scores above the average. The evaluation of wine by-products in the production of healthier and functional frankfurters has been achieved by the study, but further research is necessary to improve palatability of the products.     

Effects of anka rice, nitrite, and phosphate on warmed-over flavor and palatability characteristics in roast beef

Effects of anka rice, nitrite, and phosphate used in surface curing of roast beef on chemical analysis, lipid oxidation, sensory evaluation, physical measurements, and microbial growth after refrigerated storage were studied. TBA values indicated that nitrite retarded lipid oxidation and inhibited development of warmed-over flavor; however, anka rice had a flavor masking effect on oxidation; and phosphate did not improve physical measurements due to surface curing but slightly inhibited oxidation. There was a synergistic effect among anka rice, nitrite, and phosphate in some measurements.     

Volatile N-nitrosamines in meat products: Potential precursors,influence of processing,and mitigation strategies

Meat products can be contaminated with carcinogenic N-nitrosamines, which is ascribed to the reaction between a nitrosating agent, originating from nitrite or smoke, and a secondary amine, derived from protein and lipid degradation. Although in model systems it is demonstrated that many amine containing compounds can be converted to N-nitrosamines, the yield is dependent of reaction conditions (e.g., low pH and high temperature). In this article, the influence of the composition of the meat products (e.g., pH, a_w, spices) and processing (e.g., ageing, ripening, fermentation, smoking, heat treatment and storage) on the presence and availability of the amine precursors and the N-nitrosamine formation mechanism is discussed. In addition, this article explores the current N-nitrosamine mitigation strategies in order to obtain healthier and more natural meat products.     

COMPARISON OF GROUND VERSUS MECHANICALLY DESINEWED BEEF IN FRANKFURTERS

Six formulations of frankfurters were processed from three sources of lean (USDA choice minor cuts, USDA choice flanks and USDA utility triangles) that were comminuted by two systems (grinding and mechanical desinewing). Total frankfurter yields during smoking, chilling and reheating were not affected by formulation. Mechanical desinewing was effective in removing connective tissue from choice minor cut and utility triangle beef and reducing the incidence of gelling out in frankfurters made from choice minor cuts. Desinewing improved the ease in casing peelability only for frankfurters made from choice flanks. Sensory and physical characteristics were affected more by source of lean than by method of comminution. Frankfurters prepared from choice flanks had higher tenderness ratings, finer texture scores and lighter color than frankfurters made from choice minor cuts and utility triangles.     

Effects of red beet extracts on protein and lipid oxidation,colour, microbial,sensory properties and storage stability of Turkish pastırma

Lipid oxidation and discoloration are two important problems in the storage of pastırma, a meat product. In this research, the usability of lyophilized red beet water extract (LRBWE) in cemen paste and its effects on the pastırma quality (especially colour, protein and lipid oxidation, microbial and sensory properties) were investigated during storage. Two trials were conducted; in trial 1, LRBWE was obtained, its various properties were designated and effects on the cemen paste of these extracts (0.0%, 0.4%, 0.6%, 0.8% 1.0% and 1.2%) were determined. In trial 2, pastırma with cemen paste containing 0.8%, 1.0% and 1.2% LRBWE were produced and stored at 4 ± 1 °C for 150 days. The LRBWE did not influence protein oxidation of pastırma, whereas increasing LRBWE level led to a decrease in lipid oxidation (P < 0.01), and an increase in redness (a1) value (P < 0.01) and sensory properties (P < 0.01) of sliced pastırma compared with control pastırma. These results revealed that the addition of 1.0% or 1.2% LRBWE to cemen paste was effective to improve the colour stability, lipid oxidation, microbial and sensory quality of pastırma during storage.     

Influence of canola-olive oils, rice bran and walnut on functionality and emulsion stability of frankfurters

Fat content of frankfurters (20 g/100 g) was replaced with canola and canola-olive oils. Rice bran (RB) and walnut (WE) were added (2.5 g/100 g) to emulsions as macronutrients. Changes in energy values, color, emulsion stability and lipid oxidation of frankfurters during storage were investigated. ANOVA model was highly significant for color parameters and energy values (P < 0.001). The canola-olive oil replacement led to a high capacity to hold water and fat exudates in frankfurters, reporting higher emulsion stabilization parameters than regular frankfurters. The addition of RB led to an increase of cooking and fat exudates, indicating high emulsion instability possible due to interactions between RB fiber and fat-protein binders. Walnut addition reported low cooking loss values, and a significant capacity for emulsion stabilization in comparison with regular and RB frankfurters. Lipid oxidation increased from days 0-7 in all frankfurters, declining afterwards until end of storage. TBARS was not influenced by type of emulsions control, but significant (P < 0.05) differences were observed in vegetable oil emulsions made with RB; as well as between RB and WE added to either vegetable oil emulsions. These results suggest the use of these natural ingredients as valuable promoters of healthy meat products.     

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 400 mg of docosahexanoic acid – DHA/100 g 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.     

Investigating quality attributes and consumer acceptance of uncured, no-nitrate/nitrite-added commercial hams, bacons, and frankfurters

ABSTRACT:  Increasing demands for natural, organic, and/or preservative-free foods have resulted in the consumer availability of uncured, no-nitrate/nitrite-added processed meat and poultry products. A comprehensive understanding about the quality and sensory attributes of commercially available uncured products is unclear. The objective of this study was to determine if quality and sensory differences exist between uncured and cured meat products. Five different commercial brands (Brands A to E; 4 uncured, no-nitrate/nitrite-added, and 1 nitrite-added) of 3 product types (hams, frankfurters, and bacons) were obtained from retail supermarkets. The samples were evaluated for color, pigment content, pH, lipid oxidation, residual nitrate and nitrite content, and consumer acceptance. All brands from all product types evaluated, except for 1 bacon (Brand B), had cured color, aroma, and flavor attributes similar to the nitrite-added control (Brand E). All product types and brands contained residual nitrate and residual nitrite except for Brands B and D bacons (< 1 ppm nitrite). Lipid oxidation as measured by 2-thiobarbituric acid reactive substances revealed a large variation in the occurrence of lipid oxidation both between and within product types, with frankfurters reporting the highest levels. Color measurements indicated the majority of the brands within each product type were similar to the control. Consumer sensory ratings for surface/lean color, aroma, flavor, texture, and overall acceptance determined that variation existed. Brand E (nitrite-added control) and 1 uncured, no-nitrate/nitrite-added brand for each product type were not different ( P > 0.05) for overall acceptance and received higher scores ( P < 0.05) than all other brands within each product type.     

Prooxidant effects of the combination of green tea extract and sodium nitrite for accelerating lipolysis and lipid oxidation in pepperoni during storage

Abstract: The individual and interactive effects of green tea (GT) extract and sodium nitrite (NT) on lipolysis and lipid oxidation were investigated in pepperoni during processing and storage (4 °C). Pepperoni was treated with GT at concentrations of 0.02%, 0.05%, 0.1%, 0.2%, 0.5%; and NT from 0.003% to 0.015% in increments of 0.003%; and a combination of 0.05% GT and 0.009% NT (GT/NT). The pH, color, residual nitrite, fatty acid (FA), and 2‐thiobarbituric acid reactive substances (TBARS) values were measured. The results showed inhibitory effects on TBARS value were concentration dependent. The largest effect was at 0.05% for GT and 0.009% for NT. Adding 0.05% GT significantly decreased (P < 0.05) the TBARS values but did not affect color values during storage. NT (0.009%) was more effective than GT (0.05%) for maintaining lower TBARS values (P < 0.05). Total fatty acids were not affected by 0.05% GT and 0.009% NT treatments. However, adding GT/NT showed a significant prooxidant effect (P < 0.05) in pepperoni, which accelerated lipolysis and lipid oxidation significantly (P < 0.05) during storage, with depletion of nitrite. This suggests that adding GT and an appropriate amount of NT into pepperoni could promote lipolysis and lipid oxidation during storage, as compared to NT alone. Practical Application: When using GT extract as an antioxidant in industrial production of pepperoni, the interaction effect with NT should be considered, as it may lead to a prooxidant effect during refrigerated storage.     

EXTENDING THE CHILLED SHELF LIFE OF VACUUM-PACKAGED GROUND BEEF USING ASCORBIC ACID, NITRITE OR SALT

The objective of this study was to extend the shelf life of ground beef in chilled conditions. Samples were treated with 2% salt, 2% salt  +  500-ppm ascorbic acid, or 2% salt  +  100-ppm sodium nitrite. The control sample did not contain any additives. Protein, nitrite, moisture contents, pH, thiobarbituric acid (TBA) value, color attributes and microbial counts of samples were determined. Samples were vacuum packaged and stored in refrigeration, and chemical and microbial analyses were performed throughout storage. The pH of samples decreased during storage, and the sample having 2% salt and 500-ppm ascorbic acid had the greatest pH decline. TBA values generally increased ( P <  0.05) with storage time. Samples having 2% salt  +  500-ppm ascorbic acid had the lowest TBA value. On a given storage day, samples having 2% salt  +  100-ppm sodium nitrite had lower microbial microbial count than other samples, indicating the antibacterial effect of nitrite. A significant storage time  ×  treatment interaction ( P <  0.05) existed for almost all quality parameters studied.

PRACTICAL APPLICATIONS

Ground beef has commercial importance for the meat industry in Turkey. Meat processors have difficulties in marketing ground beef because of its relatively low shelf life. By adding ascorbic acid or salt, it is possible to extend shelf life and preserve its color, and to limit lipid oxidation, which will collectively help to increase market share of ground beef.