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 (41 days 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.     

Effects of replacing pork back fat with vegetable oils and rice bran fiber on the quality of reduced-fat frankfurters

The effects of substituting olive, grape seed, corn, canola, or soybean oil and rice bran fiber on the chemical composition, cooking characteristics, fatty acid composition, and sensory properties of low-fat frankfurters were investigated. Ten percent of the total fat content of frankfurters with a total fat content of 30% (control) was partially replaced by one of the vegetable oils to reduce the pork fat content by 10%. The moisture and ash content of low-fat frankfurters with vegetable oil and rice bran fiber were all higher than the control (P < 0.05). Low-fat frankfurters had reduced-fat content, energy values, cholesterol and trans-fat levels, and increased pH, cooking yield and TBA values compared to the controls (P < 0.05). Low-fat frankfurters with reduced-fat content plus rice bran fiber had sensory properties similar to control frankfurters containing pork fat.     

Effect of total replacement of pork backfat with walnut on the nutritional profile of frankfurters

The nutritional profile of a frankfurter with walnut (25%) (WF) was compared with that of low fat (6%) (LF) and normal fat (16%) (NF) sausages. LF frankfurters did not improve the fatty acid profile as compared with NF (p>0.05), or the indices of atherogenicity (IA) (0.50) or thrombogenicity (IT) (1.12), indicating that the reduction of animal fat produced no cardioprotective effect. However, frankfurter with walnut had a healthy polyunsaturated fatty acid profile, a lower ω-6/ω-3 ratio and lower IA (0.10) and IT (0.15). In addition, WF could be a good source of manganese, iron, copper, potassium and magnesium, supplying 39%, 35%, 34%, 16% and 15% of the respective daily recommended intakes, respectively. Also, there were significant amounts of other bioactive components such as α-,γ- and δ-tocopherol, total dietary fibre, polyphenols and tannins. The amino acid composition of WF indicated a healthier lysine/arginine ratio (0.83) than in LF (1.23) and NF (1.19).     

Utilization of interesterified oil blends in the production of frankfurters

Ten treatments of frankfurters were produced with interesterified oil and oil blends (palm oil, palm stearin, cottonseed oil, hazelnut oil and their mixtures) and were compared to control, produced with all animal fat. Addition of interesterified oil and oil blends affected (p < 0.05) the moisture and fat content and pH values of frankfurters. According to the colour measurements, the brightness value (L^∗) of most of the samples with interesterified oil and oil blends were higher (p < 0.05) than the control. The fatty acid composition of frankfurters was modified. The PUFA/SFA values of frankfurters were increased due to the presence of interesterified oil and oil blends in the formulation. Frankfurters with 100% interesterified cottonseed oil or with interesterified oil blends with 66.6% and 83.4% cottonseed oil had PUFA/SFA ratio higher than 0.4 and are considered better than all others from the health point of view. Frankfurters produced with 100% interesterified cottonseed and hazelnut oil or with interesterified hazelnut oil blends had the same (p > 0.05) scores for sensory attributes with the control, while all other treatments were also acceptable.     

PROCESSING CHARACTERISTICS AND YIELD OF PORK FRANKFURTERS MANUFACTURED FROM GILTS ADMINISTERED EXOGENOUS PORCINE SOMATOTROPIN

Eighteen gilts (75 kg) were injected daily with 0, 2.5, or 5 mg of porcine somatotropin (pST) for either 30 or 31 days prior to slaughter to examine the effects of dose of pST administration to swine on processing characteristics of frankfurters manufactured from pork. Frankfurters were manufactured from New York shoulders (NAMP #404) and formulated with fat from the same carcass to a final product target of 22% fat and 10% added water. Frankfurters from pST- treated gilts had lower smokehouse yields (0.9% decrease; P <.005) and greater shear force peak height (35.4% increase; P < 0.05) compared with the controls. The increased shear force required for skin failure of frankfurters manufactured from pork from pST-treated pigs was not readily explained by other differences due to treatment (e.g., cooking stability, batter proximate composition or salt soluble protein content; all P > 0.05)     

Lipid and protein structure analysis of frankfurters formulated with olive oil-in-water emulsion as animal fat replacer

Lipid and protein structural characteristics of frankfurter formulated with olive oil-in-water emulsion stabilized with soy protein isolate (SPI) as pork backfat replacer were investigated using Fourier transform infrared spectroscopy (FT-IR). Proximate composition and textural properties were also evaluated. Different frankfurters were reformulated: F/PF with pork backfat, F/SPI with oil-in-water emulsion stabilized with SPI and F/SPI + SC + MTG with emulsion stabilized with a combination of SPI, sodium caseinate (SC) and microbial transglutaminase (MTG). Replacement of pork backfat with these emulsions produced an increase (P < 0.05) of hardness, springiness, cohesiveness and chewiness but a reduction (P < 0.05) of adhesiveness. F/SPI and F/SPI + SC + MTG frankfurters showed the lowest (P < 0.05) half-bandwidth in the 2922 cm⁻¹ band, which could be related to lipid chains were more ordered than in F/PF. Modifications in the amide I band profile revealed a higher concentration of aggregated intermolecular β-sheets in F/SPI + SC + MTG samples. Lipid and protein structural characteristics could be associated with specific textural properties of healthier frankfurters.     

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.     

Effect of tomato paste and nitrite level on processing and quality characteristics of frankfurters

Fourteen treatments of frankfurters (18% fat) were produced with two levels of sodium nitrite, 0 and 150mg/kg (0.015%), and seven levels (0%,2%,6%,8%,12% and 16%) of tomato paste with 12% soluble solids The higher the tomato paste level the higher the preference of consumers for frankfurters based on their colour. Frankfurters with 16% tomato paste had a sour taste while those with 12% tomato paste were the most acceptable. In a 2nd experiment three treatments of frankfurters (18% fat) were produced with 0, 50 and 100mg/kg of sodium nitrite and 12% tomato paste and a fourth (control) with only 150mg/kg sodium nitrite. Treatments with 12% tomato paste had lower (p<0.05) pH values and residual nitrite, and higher (p<0.05) thiobarbituric acid values, lightness and yellowness than control. Frankfurters with reduced levels of sodium nitrite (50 and 100mg/kg) and 12% tomato paste had the highest (p<0.05) redness. Storage time affected (p<0.05) all quality attributes. The nitrites added to frankfurters can be reduced from 150mg/kg to 100mg/kg in combination with 12% tomato paste without any negative effect on the quality of the product.     

Chemical and sensory quality changes of fish fingers,made from mirror carp (Cyprinus carpio L., 1758), during frozen storage (−18 °C)

The effects of frozen storage at −18 °C on the chemical and sensory qualities of fish fingers produced from unwashed and washed mirror carp (Cyprinus carpio) mince were investigated. The amounts of moisture, crude protein, lipid, crude ash, ω3 polyunsaturated fatty acids (PUFA ω3), and ω6 polyunsaturated fatty acids (PUFA ω6) in fish fingers produced from unwashed mince (UWF) were found to be 68.50%, 15.5%, 6.00%, 2.20% 2.31%, and 55.2%, respectively, while they were found to be 70.23%, 10.8%, 2.14%, 1.80%, 2.28%, and 54.6%, respectively, in carp fingers produced from washed mince (WF). The thiobarbituric acid value (TBA, mg malonaldehyde/kg) was found to be significantly higher in mince of WF than in mince of UWF and increased significantly during frozen storage in both the mince of UWF and WF (p < 0.05). A significant decrease in pH was obtained throughout the washing treatment (p < 0.05). There were no significant differences of pH in either the mince of UWF or WF between the beginning and end of the storage periods (p > 0.05), whereas a sharp increase was observed in the fourth month in both groups. The protein solubilities of the mince of both UWF and WF decreased significantly throughout the storage periods (p < 0.05). Sensory parameters of colour, odour, flavour, and general acceptability for both groups decreased during the frozen storage period (p < 0.05) but were still within acceptable limits. It was also concluded that mirror carp was a good source for fish fingers and that product could be stored for five months in a frozen state without undesirable changes of sensory and chemical qualities.     

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 40 days generally had little effect on the technological characteristics of frankfurters.     

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.     

Practical use of surimi-like material made from porcine longissimus dorsi muscle for the production of low-fat pork patties

This study evaluates the effect of replacing fat with surimi-like material (SLM) made from the porcine longissimus dorsi muscle on the physicochemical and sensory characteristics of pork patties. Pork patties were produced with different levels of fat and SLM using a commercial method. Pork patties produced with 20% SLM had the lowest fat content (1.76%, P < 0.001), and had a higher cooking yield (87.41 vs. 78.57%, P < 0.05) and less shrinkage (4.01 vs. 9.02%, P < 0.001) than patties produced with 20% back-fat (control). Moreover, patties produced with SLM exhibited more acceptable organoleptic characteristics, including tenderness (P < 0.01) and overall acceptability (P < 0.001), than full-fat control patties. These results indicated that SLM cannot only be used as a fat replacer, but that it also improves the physicochemical and sensory characteristics of low-fat pork patties.     

Increasing omega-3 levels through dietary co-extruded flaxseed supplementation negatively affects pork palatability

To clarify the impact of feeding co-extruded flaxseed on carcass quality and pork palatability, 96 pigs (48 barrows and 48 gilts) were fed three different levels of flaxseed (0%, 5% and 10% of dietary intake) for 76 days. Carcass quality and meat quality characteristics of pure loin muscle and ground pork (20% fat) were evaluated. Fat hardness and belly firmness decreased (P < 0.001) with increasing co-extruded flaxseed. Pigs fed co-extruded flaxseed levels had higher lean yield (P = 0.045) and total lean content (P = 0.034). Loin from barrows had higher fat content compared to gilts (P < 0.001). Co-extruded flaxseed supplementation increased (P < 0.001) omega-3 content in loin and ground pork. Pork flavour intensity and off-flavour intensity scores lowered (P < 0.001) with increasing levels of co-extruded flaxseed, being more accentuated (P = 0.023) in reheated pork chops from barrows. Diet affected all texture and flavour sensory characteristics (P < 0.05) as tissue levels of omega-3 fatty acids increased, likely as a result of increased lipid oxidation.     

Effects of nutritional level on pork quality and gene expression of μ-calpain and calpastatin in muscle of finishing pigs

The study was designed to investigate the effects of nutritional level (control diet (CD), 14.19% crude protein, 13.81 MJ of DE/kg; low nutritional level diet (LND), 11.08% crude protein, 12.55 MJ of DE/kg) on pork quality and gene expression of μ-calpain and calpastatin in muscle of finishing pigs. The LND treatment increased drip loss (P < 0.05), had a trend to increase intramuscular fat (IMF) content (P = 0.09), decreased Warner–Bratzler shear force (WBSF) of pork (P < 0.05), improved mRNA level of μ-calpain (P < 0.05) in skeletal muscle, but had no effect on gene expression of calpastatin, compared with the CD treatment. These data suggest that a moderately reduced energy and protein diet increased pork tenderness and intramuscular fat. The increase in tenderness by LND treatment may be partly due to increased gene expression of μ-calpain in muscle.     

Utilization of Pork Collagen Protein in Emulsified and Whole Muscle Meat Products

ABSTRACT: Effects of pork collagen in emulsified and whole muscle products were evaluated. Eight frankfurter treatments (0%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, and 3.5% pork collagen) and 4 ham treatments (0%, 1%, 2%, and 3% pork collagen) were formulated. Frankfurters and hams were evaluated for cooked yields, purge, color, texture, and sensory characteristics. Incorporation of pork collagen at 1% and above significantly ( P < 0.05) increased cooked and chilled yields in frankfurters but did not have any effect in hams. Purge was significantly ( P < 0.05) reduced in both frankfurters and hams after 4 wk of storage. Sensory difference testing showed no significant difference up to 2% usage level of pork collagen in both frankfurters and hams ( P > 0.05).     

Effects of diet enriched with restructured meats,containing Himanthalia elongata, on hypercholesterolaemic induction,CYP7A1 expression and antioxidant enzyme activity and expression in growing rats

Meat and pork consumptions are very high in Spain. Seaweeds are rich in fibre, minerals, and bioactive substances. Due to the growing demand for healthier meats, this work studied the effect of diets containing restructured pork (RP) enriched with Himanthalia elongata (Sea Spaghetti) on: (1) cholesterolaemia; (2) liver cytochrome P450 7A1 (CYP7A1) expression; (3) liver antioxidant enzyme activities and gene expression; (4) the liver antioxidant substrate concentrations. Four groups of 10 Wistar rats each were fed a mix of 85% AIN-93 M rodent diet and 15% freeze-dried RM for 35 days. The control group (C) consumed control RP; the Sea Spaghetti (SS) group, RP with 5% Sea Spaghetti. Animals on added cholesterol diets (CholC and CholSS) consumed their basal C and SS diets enriched with cholesterol and cholic acid as hypercholesterolaemic agent. Food intake was significantly affected by the alga × cholesterol interaction and by dietary cholesterol (both p < 0.001). Plasma cholesterol was significantly affected by the cholesterol × alga interaction (p < 0.05). CholC rats showed significantly higher plasma cholesterol (p < 0.001) than did their C counterparts, whilst serum cholesterol of CholSS was significantly lower (p < 0.05) than that of CholC. The glutathione peroxide (GSSG) concentrations and all mRNA expressions were significantly affected by the cholesterol × alga interaction (at least p < 0.05). SS vs C group showed significant (at least p < 0.05) increases in superoxide dismutase (Mn-SOD and Cu,Zn-SOD), glutathione peroxidase (GPx) and decrease of glutathione reductase (GR) expressions, and increased GR activity, GSSG and the redox index. CholSS vs CholC showed significant (at least p < 0.05) increases of CYP7A1, GR and Cu,Zn-SOD expression but decreases in catalase, Mn-SOD and GPx expression, and increase of GR activity. In conclusion, Sea Spaghetti could be widely used in RP design. Its addition to non-cholesterol enriched RP diet reduced oxidation mechanisms. SS-RP partially blocked the effect of the hypercholesterolaemic agent, giving rise to a new balance of the antioxidant enzyme expression.     

The effect of corn distiller's dried grains with solubles, ractopamine, and conjugated linoleic acid on the carcass performance, meat quality, and shelf-life characteristics of fresh pork following three different storage methods

The objective of this study was to evaluate dietary corn distiller's dried grains with solubles (DDGS), ractopamine hydrochloride (RAC), and conjugated linoleic acid (CLA) on growth performance, carcass and fat quality, and shelf-life of fresh pork from finishing pigs. Barrows (n = 72) were fed one of eight treatments consisting of two diet sources (corn-soy and corn-soy + 20% DDGS), two levels of RAC (0 and 7.4 ppm), and two levels of CLA (0 and 0.6%) for 28 days. Loins were portioned (n = 3) into one of three storage conditions (fresh, cold, frozen); each followed with seven days of retail display. Feeding RAC improved ADG and G:F (P < 0.05), whereas DDGS decreased belly fat firmness (P < 0.05). Dietary DDGS increased total polyunsaturated fatty acids in jowl and belly samples and increased Iodine Value (IV) (P < 0.05), but addition of CLA decreased IV. Dietary DDGS, RAC, or CLA had minimal impact on pork quality following varied storage methods.     

Acceptability of low-fat frankfurters as influenced by the feeding of elevated levels of monounsaturated fats to growing-finishing swine

The effects of high levels of oleic acid in the diet on the physical, chemical and sensory traits of frankfurters were examined. Frankfurters were formulated at three fat levels (10, 20 and 25%) from pork trimmings from each dietary treatment. The control frankfurters were the most springy, firm, flavorful and palatable and had the most intense flavor (P < 0·05). However, low-fat frankfurters produced from the high-oleate treatments were comparable to the control in all sensory characteristics (P > 0·05). The 10 and 25% fat frankfurters were rated highest and lowest, respectively, for juiciness, springiness, firmness, flavor, flavor intensity and overall palatability (P < 0·05). Sensory panelists detected off-flavors in the 25% fat frankfurters more frequently than in the 10% fat frankfurters (P < 0·05). 2-Thiobarbituric acid values were not affected by treatment and were acceptable after storage at 2°C for 24 weeks (P < 0·05).     

Quality characteristics of Dutch-style fermented sausages manufactured with partial replacement of pork back-fat with pure, pre-emulsified or encapsulated fish oil

Dutch-style fermented sausages were manufactured with 15% and 30% pork back-fat substitution by pure or commercial encapsulated fish oil, either added as such or as pre-emulsified mixture with soy protein isolate. Adding commercial encapsulated fish oil was the most important factor influencing the chemical composition. The fat content was not significantly different between products (p > 0.05). The n−6/n−3 ratio decreased from 8.49 in controls to 0.90-2.47 in modified products. Lipid oxidation parameters (propanal and hexanal) showed much higher values for sausages with pure fish oil than for products with encapsulated oil. For the latter, lipid oxidation was similar to controls. Products with encapsulated or pre-emulsified oil were significantly firmer than products from other treatments in physical and sensory analysis (p < 0.05). Overall, it is technologically feasible to enrich dry fermented sausages with n−3 fatty acids from fish oil and the application of commercial encapsulated fish oil seems to be the best in retaining overall quality.