Packaging-specific influence of chitosan on color stability and lipid oxidation in refrigerated ground beef

We examined the influence of chitosan on lipid oxidation and color stability of ground beef stored in different modified atmosphere packaging (MAP) systems. Ground beef patties with chitosan (1%) or without chitosan (control) were packaged either in high-oxygen MAP (HIOX; 80% O₂ + 20% CO₂), carbon monoxide MAP (CO; 0.4% CO + 19.6% CO₂ + 80% N₂), vacuum (VP), or aerobic packaging (PVC) and stored at 1 °C. Chitosan increased (P < 0.05) redness of patties stored in PVC and CO, whereas it had no effect (P > 0.05) in HIOX. Chitosan patties demonstrated lower (P < 0.05) lipid oxidation than controls in all packaging. Control patties in PVC and HIOX exhibited greater (P < 0.05) lipid oxidation than those in VP and CO, whereas chitosan patties in different packaging systems were not different (P > 0.05) from each other. Our findings suggested that antioxidant effects of chitosan on ground beef are packaging-specific.     

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.     

Bioactivity of ellagic acid-, lutein- or sesamol-enriched meat patties assessed using an in vitro digestion and Caco-2 cell model system

Interest exists in the manufacture of functional meat products whereby synthetic antioxidants are replaced with naturally-sourced compounds. Therefore the aim of this study was to determine the bioactivity of pork and beef patties containing ellagic acid (600 μg/g), lutein (200 μg/g) or sesamol (500 μg/g). Cooked pork and beef patties were subjected to an in vitro digestion procedure and the resultant micelles were added to human intestinal Caco-2 cells. Supplementation with micelles from lutein-enriched pork patties protected (P < 0.05) against H₂O₂-induced cell injury whereas the presence of control beef, lutein-enriched beef or ellagic acid-enriched beef, at levels ?20% (v/v), enhanced (P < 0.05) oxidant-induced cytotoxicity. None of the pork patties significantly modulated cellular glutathione content. Micelles from all the enriched pork patties significantly protected against H₂O₂-induced DNA damage. In conclusion, the cytoprotective and genoprotective effects of ellagic acid, lutein, and sesamol, when incorporated into meat systems, depend greatly on the food matrix.     

Role of Melissa officinalis in cholesterol oxidation: Antioxidant effect in model systems and application in beef patties

Cholesterol oxidation products (COPs) constitute a known health risk factor. The antioxidant effect of a lyophilized aqueous Melissa officinalis extract against cholesterol degradation and COPs formation during a heating treatment was evaluated in a model system (180 °C, 0–180 min) at a ratio of 2 mg extract/100 mg cholesterol. Furthermore, the plant extract was subsequently added to beef patties alone or incorporated within an oil-in-water olive oil emulsion to assess its effectiveness during cooking. Melisa extract protected cholesterol from thermal degradation in the model system, yielding higher remaining cholesterol and lower COPs values throughout the whole heating process. Maximum total COPs were achieved after 30 and 120 min of heating for control and melisa-containing samples, respectively. In cooked beef patties, even though the olive oil emulsion was used as flavor-masking approach, melisa extract off-flavor limited the maximum dose which could be added. At these doses (65 μg/g and 150 μg/g without and with the emulsion, respectively), no additional protective effect of melisa over the use of the emulsion was found. Addition of natural extracts into functional foods should definitively take into account sensory aspects.     

Physicochemical and organoleptic characteristics of seasoned beef patties with added glutinous rice flour

This study was conducted to determine if glutinous rice flour (GRF) could be a functional food additive to potentially replace corn starch (CS), soy protein isolate (SPI) and/or sodium tripolyphosphate (STPP) to improve the physicochemical and organoleptic characteristics of seasoned beef patties. GRF had a lower cook loss among the treatment groups due to an increase in fat and moisture retentions (p < 0.05). GRF lowered texture profile values for hardness, gumminess, springiness, and chewiness (p < 0.05) of the patties, which are generally beneficial for this product. The beef patties with GRF were juicier and more tender than the control and other treatments (p < 0.05). Hedonic scores for juiciness, tenderness and overall acceptability were the highest for the beef patties with 1 and 3% GRFs, suggesting that GRF may be an effective functional ingredient to improve the textural quality of seasoned beef patties.     

Studies on tenderization and preparation of enrobed pork chunks in microwave oven

This study was conducted to develop technology for tenderization and production of enrobed pork chunks in a microwave oven. Meat chunks from shoulder cuts of pork were cured in a solution containing salt, sodium tripolyphosphate and sugar for 48 h at 4 ± 1 °C, enrobed with cream based batter and cooked in a microwave oven at 900 MHz. These enrobed chunks (control) were compared with tenderized (treated) enrobed chunks, for which 7.5% cucumis extract, 9% ginger extract and 0.50% papain powder were incorporated in the standard curing solution. Ginger and papain treatments caused significant (P < 0.01) increases in the moisture content and pH of the cooked products compared to the control and cucumis treated samples. Shear force values were significantly (P < 0.01) lower and overall acceptability scores were significantly (P < 0.01) higher in all treated samples compared to the control. During storage at 4 ± 1 °C, the moisture contents and sensory qualities decreased, but TBARS values and microbial counts increased significantly (P < 0.01). Although all products were acceptable up to 15 days of storage, the ginger treated samples had significantly (P < 0.01) lower TBARS and microbial loads and higher sensory attributes than the control, cucumis and papain treated samples. The magnitude of the storage changes were less and acceptability ranking was higher for the ginger treated samples compared with the others. The results indicated that microwaves could be used for the preparation of enrobed pork chunks. The overall acceptability and shelf life of microwave cooked enrobed pork chunk can be further improved using ginger extract in the curing solution.     

Changes in meat quality of ovine longissimus dorsi muscle in response to repeated freeze and thaw

Changes in eating and technological quality attributes of ovine longissimus dorsi muscle during repeated freeze and thaw were investigated. Shear force value, L* value, a* value and fiber diameter decreased (P < 0.05) but lipid oxidation increased (P < 0.05) with repeated freeze–thaw cycles. Sarcomere length and pH decreased (P < 0.05) within the first 10 freeze–thaw cycles but increased (P < 0.05) after 5 further cycles. Total and myofibrillar protein solubility, and intramuscular free fatty acids concentration decreased (P < 0.05) after 1 cycle of freeze and thaw but then increased (P < 0.05) gradually with further cycles. Hardness, chewiness, cohesiveness and resilience of comminuted lamb products decreased (P < 0.05) with increased freeze–thaw cycles. And therefore, repeated freeze and thaw should be minimized in terms of meat color for commercial value and water holding capacity for further processing.     

A comparative study of high pressure sterilisation and conventional thermal sterilisation: Quality effects in green beans

Experiments were conducted to compare the colour, texture and microbiological quality of green beans that had been either high pressure sterilised (HPS) using commercially achievable pressures (a pre-heat to 86 °C followed by two treatments of 2 min at 700 MPa) or were conventionally thermally sterilised (F_o 1 to 3 min with a retort temperature of 115 °C). Samples were assessed immediately after processing and after 7 months of ambient storage. HPS treated samples were generally darker in appearance (L^⁎ values shifted downwards) compared with heat treated (F₀ 3 min) samples. The a^⁎ values for HPS samples were significantly (P < 0.05) higher than F₀ 3 min treated samples after processing but were not significantly different after 7 months storage (P > 0.05). HPS treated samples were typically twice as firm as F₀ 3 min treated samples (P < 0.05). There was some softening over storage but this differential in firmness was maintained after 7 months. Total aerobic and anaerobic plate counts and spore counts after storage were below the limits of detection in all samples apart from one canned sample where leaker spoilage had occurred.Industrial relevanceThermal sterilisation technologies are used to produce ambient stable products but frequently these products suffer deleterious quality changes such as colour and texture modification as a result of processing. There is industrial interest in any technologies with the potential to produce ambient stable products with improved retention of ‘fresh’ characteristics. High pressure sterilisation is a promising method for the production of ambient stable products with improved quality.     

Assessment of the protein quality of fourteen soybean [Glycine max (L.) Merr.] cultivars using amino acid analysis and two-dimensional electrophoresis

The protein quality of commercial soybeans varieties can be determined from their total protein content, their amino acid composition and from the ratio of glycinin to β-conglycinin, the major seed storage protein components. In this study 14 commercial soybean cultivars were assessed. There were significant differences in storage protein composition (P < 0.05) and in their valine, proline and phenylalanine contents (P < 0.01 to P < 0.001). Mean protein values among these varieties ranged from 29.8% to 36.1%. The total amino acid nitrogen (AAN) ranged from 89.6 to 95.1 g AA/16 g of nitrogen, corresponding to nitrogen values from 16.5 to 17.9 g AAN/100 g protein. All varieties contained a good balance of essential amino acids (EAA₉), limited only in methionine. Two-dimensional gel electrophoretic (2-DE) separations, led to the establishment of high-resolution proteome reference maps, enabling polypeptide chain identification and calculation of the ratio of the constituent glycinin and β-conglycinin storage proteins of soybean. This method enables the assessment of the genetic variability of the soybean cultivars, which can then be correlated with their protein quality and food processing properties. These three methods can be used as very effective tools for assisting plant breeders in their selection of high quality soybean varieties.     

Effect of modified atmosphere packaging,storage period,and storage temperature on the residual nitrate of sliced-pastırma,dry meat product,produced from fresh meat and frozen/thawed meat

The amount of nitrite in sliced-pastirma made, from fresh or frozen (which was stored at −18 °C for 240 days and then thawed at 10 °C for 24 h) M. Longissimus dorsi muscle was determined. Sliced-pastirma samples were stored in modified atmosphere packages (50% N₂ + 50% CO₂) at 4 and 10 °C for 150 days, and the amount of residual nitrite was measured after 0, 30, 60, 90, and 150 days of storage. The residual nitrite of pastirma samples made with frozen/thawed meat was higher than that of the pastirma made from fresh meat at both 0 day and at the end of the storage (150 days). The storage temperature (p < 0.01), storage period (p < 0.01) and the storage period × the storage temperature interaction (p < 0.01) had significant effects on the amount of the residual nitrite.     

Effect of an outdoor rearing system on the welfare,growth performance,carcass and meat quality of a slow-growing rabbit population

The effect of Outdoor or Indoor housing systems on the growth, welfare and carcass and meat quality of a local rabbit population was investigated. The slaughter age was 103 ± 2 days. Open-field tests showed an effective capacity of the Outdoor group to combat stressors. Compared to Indoor rabbits, Outdoor rabbits showed better growth performance and higher slaughter weight (SW) (2535 vs 2137 g; P < 0.01). Outdoor housing conditions increased the physical activity of rabbits and their hind legs were more developed (36.1% vs 34.9%; P < 0.01). Slaughter yield was lower in Outdoor rabbits (57.8% vs 58.4% SW; P < 0.05) due to the higher skin proportion (17.2% vs 15.6% SW; P < 0.05). Outdoor rabbit meat showed lower L1 value (L. lumborum: 55.6 vs 59.2; P < 0.01; B. femoris: 53.0 vs 55.5; P < 0.01) and cooking loss (L. lumborum: 15.9% vs 18.1%; P < 0.05). Outdoor rabbit hind leg meat was characterized by lower water (74.5% vs 75.1%; P < 0.01) and higher protein (22.9% vs 22.6%; P < 0.01) and fat (1.4% vs 1.1%; P < 0.01) contents; lipids were lower in SFA and higher in MUFA. Outdoor rearing seems to be a possible alternative housing system that allays the ethical concerns of modern consumers while also providing good meat quality.     

Study of the hard-to-cook property of stored yam tubers (Dioscorea dumetorum) and some determining biochemical factors

In an attempt to investigate the hard-to-cook phenomenon in Dioscorea dumetorum tubers during storage, selected physical and chemical characteristics were monitored. A 3 × 5 factorial experiment with storage conditions (15 °C, 59% RH; 30 °C, 75% RH; 45 °C, 86% RH) and storage period (0, 2, 4, 7 and 14 days) as variables was carried out. Changes in cooked hardness, water absorption, water-holding capacity and solid loss of steeped tubers as well as phytate, total phenols and lignin contents were monitored. Water uptake and solid loss of steeped tubers decreased significantly (P ⩽ 0.05) with storage period, suggesting that storage affects cell wall membrane permeability of the tubers. Cooked hardness analyses indicated significant difference (P ⩽ 0.05) between fresh and stored tubers and its rate varied with storage time and storage conditions. Cooked hardness values correlated negatively (r = −0.922–0.857, P ⩽ 0.05, d.f. = 146) with phytate and total phenols. A multiple mechanism for D. dumetorum tubers hardening is presented which includes phytate loss as a minimal contributor to cooked hardness during the first days of storage and total phenol loss via a lignification-like mechanism as a major contributor.     

Protective role of Lactobacillus fermentum R6 against Clostridium perfringens in vitro and in chicken breast meat under temperature abuse conditions

Six bacterial species were evaluated to determine their inhibitory effects on Clostridium perfringens in vitro (brain heart infusion broth) and in situ (chicken breast meat) under temperature abuse conditions (4 ± 1 °C for 12 h, followed by 7 h at 28 ± 1 °C and then 4 ± 1 °C for 53 h). During abusive storage, rapid growth of C. perfringens from vegetative cell and spore inocula was observed, exhibiting a 2.68–3.37 log CFU/mL (or g) increase in bacterial counts. In the presence of Pediococcus pentosaceus P1 or Lactobacillus fermentum R6, the counts of C. perfringens remained unchanged in the samples containing vegetative cells at the end of storage (P < 0.05); for those containing spores, the germination and outgrowth were also effectively inhibited, decreasing in bacterial counts of > 1.9 log CFU/mL (or g) compared to those of the control (P < 0.05). The pH of chicken meat was slightly declined by 0.09 in the presence of L. fermentum (P > 0.05), and the inhibitory effect against C. perfringens was ascribed to non-acid antimicrobial substances. These results indicate a potential solution for bio-protecting chicken meat from C. perfringens growth.Industrial relevanceClostridium perfringens is a common pathogen that contaminates meat and meat products, but the organism cannot multiply under cold chain conditions at 4 °C. However, it was reported that temperature abuses commonly occurred during the transportation, storage or retail display of the food chill chain. During the abusive storage, C. perfringens could grow rapidly, which may lead to food poisoning. It is a serious problem for food safety.In this study, Lactobacillus fermentum R6 was found to show effective inhibition on both the growth of C. perfringens vegetative cells and the germination and outgrowth of its spores in chicken meat (P < 0.05) under temperature abuse conditions, and also it had a minimal effect on the pH of the meat (P > 0.05). The results reveal a potential technology for bio-protecting chicken meat from C. perfringens growth.     

Incorporating essential oils of marjoram and rosemary in the formulation of beef patties manufactured with mechanically deboned poultry meat to improve the lipid stability and sensory attributes

The effect of addition of essential oils of marjoram (Origanum marjorana L.) and rosemary (Rosmarinus officinalis L.) at concentration of 200 mg/kg to beef patties formulated with 200 g/kg mechanically deboned poultry meat (MDPM) was studied. The proximate composition, lipid oxidation, sensory characteristics and microbial counts of beef patties manufactured with 200 g/kg MDPM (percentage of lean portion) were assessed during frozen storage at ?18 °C. Beef patties formulated with MDPM (200 g/kg) showed significant (P < 0.05) reduction in protein content and significant (P < 0.05) increase in fat content. Incorporating MDPM in beef patties formulation significantly (P < 0.05) increased the TBARS (Thiobarbituric acid reactive substance) values and significantly (P < 0.05) reduced the flavor and overall acceptability scores. Addition of essential oils of marjoram and rosemary at level of 200 mg/kg significantly (P < 0.05) reduced the TBARS and significantly (P < 0.05) increased the sensory scores of beef patties during frozen storage period. Overall, the study indicated the potential use of natural herbal essential oils to protect against lipid oxidation and improve the sensory attributes of beef patties formulated with MDPM.     

Correlation of triacylglycerol oligopolymers and oxidised triacylglycerols to quality parameters in extra virgin olive oil during storage

The evaluation of the effect of storage on extra virgin olive oil is usually achieved basing on the concurrence of many analytical methods. With the aim of reducing the number of determinations to carry out, the levels of triacylglycerol oligopolymers and oxidised triacylglycerols, determined by high-performance size-exclusion chromatography (HPSEC) analysis of the polar compounds of the oil, have been evaluated. The obtained results highlighted that the oxidised triacylglycerols were significantly correlated (p < 0.001) in a positive way with peroxide value and K₂₃₂ and in a negative way with total phenols and induction time, hence they can give indications about the primary oxidation level of the oil. The triacylglycerol oligopolymers, instead, were found to be significantly and positively correlated (p < 0.001) with K₂₇₀ that denotes the secondary oxidation of an oil. On the contrary, significant negative correlations (p < 0.001) between triacylglycerol oligopolymers and both the contents of carotenoids and chlorophylls, whose contents in the oil seriously diminish when the secondary oxidation is high, were found.     

Lipid and protein oxidation of α-linolenic acid-enriched pork during refrigerated storage as influenced by diet supplementation with olive leaves (Olea europea L.) or α-tocopheryl acetate

The objective of this study was to evaluate the effect of diet supplementation with olive leaves or α-tocopheryl acetate on lipid and protein oxidation of raw and cooked n− 3 enriched-pork during refrigerated storage. Enrichment of pork with α-linolenic acid through diet supplementation with linseed oil enhanced (p ≤ 0.05) lipid oxidation in both raw and cooked chops but had no effect (p > 0.05) on protein oxidation during refrigerated storage while decreasing (p ≤ 0.05) the sensory attributes of cooked pork. Diet supplementation with olive leaves or α-tocopheryl acetate had no effect (p > 0.05) on the fatty acid composition of pork but decreased (p ≤ 0.05) lipid oxidation while exerting no effect (p > 0.05) on protein oxidation in both raw and cooked α-linolenic acid-enriched chops stored and chilled for 9 days. Moreover, olive leaves and α-tocopheryl acetate supplemented at 10 g/kg and 200 mg/kg diet, respectively, exerted (p ≤ 0.05) a beneficial effect on the sensory attributes of cooked α-linolenic acid-enriched pork chops.     

Breed effect on quality veal production in mountain areas: emphasis on meat fatty acid composition

This study was designed to compare the quality of veal produced from ‘Tudanca × Charolais’ cross (n = 6) and Limousin (n = 6) breeds when allowed to feed freely on mountain pastures and suckle naturally from birth to 7 months of age. After 80 days of age calves also had access to concentrate (maximum of 3 kg/day), while mothers did not. At slaughter, Limousin calves were heavier (P < 0.01) and provided better carcass yield (P < 0.05) and conformation (P < 0.001) than Tudanca calves. Tudanca beef provided higher fat content (P < 0.05) was less tough (P < 0.05), and was scored as more tender and juicy (P < 0.1) with higher acceptability than Limousin beef (P < 0.1). In general, Tudanca had a better fatty acid profile than Limousin beef, especially in terms of the content of polyunsaturated (P < 0.05), long-chain polyunsaturated fatty acids (P < 0.05) and their n−6/n−3 ratios (P < 0.1), as well as vaccenic acid (P < 0.1) and the overall trans-18:1 isomer profile.     

Preventive effects of caffeic acid on lipids,lipoproteins and glycoproteins in isoproterenol induced myocardial infarcted rats

Dietary phenolic compound intake has been reported inversely related to the incidence of cardiovascular diseases. The aim of this research was to understand the preventive effects of caffeic acid, a phenolic acid on lipids, lipoproteins and glycoprotein components in isoproterenol induced myocardial infarcted rats. Rats were pretreated with caffeic acid (15 mg/kg body weight) daily for a period of 10 days. After pretreatment, rats were induced myocardial infarction by subcutaneous injection of isoproterenol (100 mg/kg body weight). Isoproterenol induced myocardial infarcted rats showed significant (P < 0.05) decreased levels of heart phospholipids and significant (P < 0.05) increased levels of serum and heart cholesterol, triglycerides, free fatty acids and serum phospholipids. Isoproterenol also significantly (P < 0.05) increased low density and very low density lipoprotein cholesterol and significantly (P < 0.05) decreased high density lipoprotein cholesterol levels. The activity of liver 3-hydroxy-3methyl glutaryl-coenzyme-A-reductase was significantly (P < 0.05) increased and lecithin cholesterol acyl transferase activity was significantly (P < 0.05) decreased in isoproterenol induced myocardial infarcted rats. In addition, the levels of glycoprotein components in the serum and heart were significantly (P < 0.05) increased in myocardial infarcted rats. Pretreatment with caffeic acid positively altered all the above mentioned biochemical parameters studied in isoproterenol induced myocardial infarcted rats.In conclusion, caffeic acid protected the rat's heart from the deleterious effects of lipids, lipoproteins and glycoproteins by its antilipidemic and antiglycative effects in isoproterenol induced myocardial infarcted rats. A diet containing caffeic acid may be beneficial to myocardial infarction.     

Effects of chestnut tannins on carcass characteristics,meat quality,lipid oxidation and fatty acid composition of rabbits

Seventy two male Bianca Italiana rabbits were used to study the effects of the inclusion (0%, 0.5%, and 1.0%) of a natural extract of chestnut wood (Silvafeed ENC) in the diet on productive traits, carcass characteristics, meat quality, lipid oxidation and fatty acid composition of rabbit meat. Results showed ENC had no significant effect on live weight, productive traits, hot carcass weight, dressing percentage, skin weight, pH, cooking losses, shear force and colour. The iron content was higher in Longissimus thoracis et lumborum (LTL) muscle of rabbit fed the ENC 1.0% diet than the control group. TBARS average values in the group ENC 0.5% were significantly lower (P < 0.05) than in the control and ENC 1.0% groups. Myristic acid (C14:0; P < 0.01), palmitoleic acid (C16:1 cis-9; P < 0.05) and pentadecanoic acid (C15:0; P < 0.01) contents were lower in LTL muscle of rabbits fed the ENC 1.0% diet, whereas the palmitic acid (C16:0) content was higher (P < 0.05) in the rabbits of this group. Moreover, the rabbits fed with the ENC 0.5% diet had lower (P < 0.01) levels of trans-vaccenic acid (C18:1 trans-11) compared to rabbits fed with the control diet. No significant differences were observed in saturated (SFA), monounsaturated (MUFA), polyunsaturated (PUFA) fatty acids, as well as in PUFA/SFA and n − 6/n − 3 ratios among the groups.     

Influence of freezing and dehydration of olive leaves (var. Serrana) on extract composition and antioxidant potential

In this work, the effect of the methods used for the freezing and drying of olive leaves on the polyphenol content and antioxidant capacity of the extracts was addressed. Thus, different methods were used to dry olive leaves (fresh or frozen by conventional (? 28 °C) or N₂ freezing): hot air drying at 70 or 120 °C and freeze drying. The extracts were characterized by determining the phenolic content, antioxidant capacity and HPLC-DAD/MS–MS profile.Drying had a significant (p < 0.05) influence on the antioxidant potential of olive leaf extracts. Both the drying and freezing methods significantly (p < 0.05) influenced the concentration of the main polyphenols identified. Hot air drying provided a higher phenolic content, especially in oleuropein, than freeze drying. Thus, drying at 120 °C was the best processing condition. Freezing reduced the antioxidant potential as compared to fresh leaves, probably due to oxidase activation, although its influence was not dependent on the freezing method.