The effect of selected functional additives and heat treatment on nitrosamine content in pasteurized pork ham

The influence of pasteurization and sodium chloride, sodium ascorbate, polyphosphates and sodium nitrite coupled with pasteurization on nitrosamine contents in pork was studied. Nitrosamines: dimethylonitrosamine (DMNA) and diethylonitrosamine (DENA) were extracted from raw material, distilled, condensed in an evaporator under lowered pressure and analyzed chromatographically. An inhibitory effect of NaCl and sodium ascorbate on volatile nitrosamines (DMNA and DENA) was seen. Adding solutions of polyphosphates to the meat caused a slight increase in nitrosamine contents, higher than noted with sodium chloride. The effect of these compounds on nitrosamine formation depended on the presence of polyphosphates and sodium nitrite in the brine. If the brine contained nitrites, the adverse effect of sodium ascorbate and NaCl on nitrosamine formation was weaker. Moreover, a strong inhibitory effect of pasteurization on DMNA and DENA formation was observed.     

Meat nitrosamine contamination level depending on animal breeding factors

The aim of the work was to answer the question how the species, breeding factors and season of the year affect nitrosamine contents in raw meat. The concentrations were assessed in raw pork from gilts, sows, hogs and boars, in beef from heifers, cows, bullocks and bulls, in veal and in horse, ram and goat meat. The studies were conducted in spring, summer, autumn and in winter. Meat contents of nitrosamines (dimethylonitrosamine-DMNA and diethylonitrosamine-DENA) were assessed by Pancholy's method adapted to nitrosamine determination in meat and meat products by Scanlan and Ryes. The levels of DMNA and DENA were determined using a Varian 3400 gas chromatograph coupled to a mass spectrometer (Finnigan MAT ITD. 800). The volatiles were identified by comparing their mass spectra with standards and by comparison of retention times with standards. Quantitative and qualitative analysis was conducted by comparison with N-nitrosamine standard solution chromatograms. The highest nitrosamine (DMNA and DENA) concentrations were found in pork and beef, smaller in horseflesh and the lowest in ram and goat meat and in veal.     

The influence of environment, mode of nutrition and animal species on level of nitrosamine contamination in venison

The work aimed to research occurrence of nitrosamines in raw venison from different game species and mode of nutrition effect on their meat concentrations. Samples of venison from male and female elks, male and female red deer, male and female roe deer, male and female fallow deer, male and female wild boars, male and female brown hares and males and females of wild rabbits shot in Poland during the permissible hunting seasons were used for the experiments after their jointing and cutting. In the experiments conducted on eight species and 16 genera of wild male and female game animals a total of 336 analytical assays were conducted. Twenty-one meat samples of 1 kg each (each from a different animal) were collected respectively from males and females of eight animal species and taken to a laboratory. Meat contents of nitrosamines [dimethylonitrosamine (DMNA) and diethylonitrosamine (DENA)] were assessed by Pancholy's method adapted to nitrosamine determination in meat and meat products by Scanlan and Ryes. The levels of DMNA and DENA were determined using a Varian 3400 gas chromatograph coupled to a mass spectrometer (Finnigan MAT ITD. 800). Quantitative and qualitative analysis was conducted by comparison with N-nitrosamine standard solution chromatograms.     

EFFECT OF SODIUM NITRITE CONCENTRATION ON N-NITROSODIMETHYLAMINE FORMATION IN FRANKFURTERS

The effect of nitrite concentration on N-nitrosodimethylamine (DMNA) formation using frankfurter emulsion was investigated. Sodium nitrite was usually added to the emulsion to give levels of 150, 750, 1050, 1500 and 2500 mg/kg of meat. The frankfurters were cooked with light smoke for either 2 or 4 hr. DMNA was determined in all samples by GLC with an alkali flame ionization detector and confirmed by GLC-MS when sufficient amounts were present. Residual nitrite analysis indicated that about one-half of the sodium nitrite added was still present after processing. 19 μg DMNA per kg meat was found in frankfurters that contained 2500 mg sodium nitrite per kg of meat and processed for 2 hr. Indications of DMNA in levels of 3–14 μg/kg meat were obtained with frankfurters containing 750–1500 mg sodium nitrite per kg meat and processed for either 2 or 4 hr depending on the nitrite level. There appeared to be some tendency for an increase in DMNA formation on increasing processing time.     

糖基化血红蛋白着色剂在肉制品中的应用

将不同发色剂添加到熟肉饼中,通过测定不同组别的色差值来判断发色剂的发色效果。结果表明,添加血红蛋白着色剂的两组(经过腌制和不经腌制)发色效果都比较好,与添加亚硝酸钠的组分比较,颜色差别不显著(P>0.05),因此从发色效果上看血红蛋白着色剂能完全替代亚硝酸钠在肉制品中起发色作用。     

Determination of the maximum feasible proportion in the substitution of meat substances by protein isolates in combined meat products

The author discusses the experimental data obtained during studies on male Wistar rats on the biological value of combined meat products (20 samples) including soybean protein isolate, sodium caseinate, and blood plasma proteins. The replacement proportions were 0, 12.5, 25, 50 and 100%. A definite dependence was ascertained between the biological value of total proteins in combined meat products and the replacement proportions. The replacement of meat proteins by soybean protein isolate (not over 25%), by sodium caseinate (by 50%) and by blood plasma proteins (not over 25%) and by a mixture containing 3 proteins (soybean, lactic, plasma) did not reduce the biological value of these combined meat products as compared to control.     

Reducing the sodium content in meat products: The effect of the formulation in low-sodium ground meat patties

This study investigated the effect of formulation on quality characteristics of low-sodium ground meat patties. The variation in sodium content was achieved by varying the NaCl content. The formulation variables studied were sodium and fat content and the use of phosphate. The patties were made using 50% or 60% meat in the formulations. Formulation affected the perceived saltiness of ground meat patties. Fat and lean meat content affected perceived saltiness, but their effects were opposite. When the fat content was increased the perceived saltiness increased, but when the meat content increased the perceived saltiness decreased. However, the effect of fat content on perceived saltiness was less than the effect of meat content. The use of phosphate effectively decreased cooking loss, particularly of high-fat-low-sodium patties. The same firmness could be reached with lower sodium content when phosphate was used.     

Influence of the addition of mechanically recovered meat on the physico-chemical properties of meat model blends

The physico-chemical properties of meat model blends (basic composition: fresh lean pork, pork back fat, 2% NaCl, water with ice), with added mechanically recovered pork (MRM), were studied. Fresh MRM was added at levels of 10% and 20% substitution of meat protein with or without further substitution by 10% sodium caseinate or soya isolate. The addition of MRM to meat blends caused an increase in the pH, the water-holding capacity, the viscosity, the dominant wavelength and colour purity. No effects on emulsifying capacity were observed but thermal cooking losses and lightness of colour were reduced. The addition of blends of MRM and soya isolate or sodium caseinate caused lower values of the investigated features than those observed when only MRM was used.     

Studies of levels of biogenic amines in meat samples in relation to the content of additives

The impact of meat additives on the concentration of biogenic amines and the quality of meat was studied. Fresh white and red meat samples were fortified with the following food additives: citric and lactic acids, disodium diphosphate, sodium nitrite, sodium metabisulphite, potassium sorbate, sodium chloride, ascorbic acid, α-tocopherol, propyl 3,4,5-trihydroxybenzoate (propyl gallate) and butylated hydroxyanisole. The content of spermine, spermidine, putrescine, cadaverine, histamine, tyramine, tryptamine and 2-phenylethylamine was determined by capillary isotachophoretic methods in meat samples (fresh and fortified) during four days of storage at 4°C. The results were applied to estimate the impact of the tested additives on the formation of biogenic amines in white and red meat. For all tested meats, sodium nitrite, sodium chloride and disodium diphosphate showed the best inhibition. However, cadaverine and putrescine were characterised by the biggest changes in concentration during the storage time of all the additives. Based on the presented data for the content of biogenic amines in meat samples analysed as a function of storage time and additives, we suggest that cadaverine and putrescine have a significant impact on meat quality.     

Effect of sodium lactate on thermal inactivation of Listeria monocytogenes and Salmonella in ground chicken thigh and leg meat

The effect of sodium lactate on thermal inactivation D- and z-values of Listeria monocytogenes and Salmonella was determined for chicken thigh and leg meat. At 55 to 70 degrees C, the D-value of L. monocytogenes in ground chicken thigh and leg meat with the addition of 4.8% sodium lactate (4.8 g sodium lactate per 100 g of meat) was 53 to 75% higher than that in the meat without sodium lactate. No significant difference was found for the D-values of Salmonella at 55 to 70 degrees C between the meat with and that without sodium lactate (4.8%. wt/wt). The z-values of both L. monocytogenes and Salmonella were not affected by sodium lactate (4.8%). The results from this study are useful for predicting thermal process lethality of L. montocytogenes and Salmonella in formulated chicken thigh and leg meat products.     

烹制时间对狮子头营养品质和挥发性风味物质的影响

为探究烹制时间对狮子头营养品质和挥发性风味物质的影响,该文对不同烹制时间条件下狮子头的基础营养成分、色泽、卡路里、质构、嫩度和挥发性风味物质指标进行研究.结果 表明,不同烹制时间对狮子头的营养品质和挥发性风味物质含量影响显著(P<0.05).烹制过程使狮子头中水分含量增加显著(P<0.05).与原料肉相比,烹至120 ...     

EFFECT OF FRANKFURTER CURE INGREDIENTS ON N-NITROSODIMETHYLAMINE FORMATION IN A MODEL SYSTEM

The effect of cure ingredients on the nitrosation of dimethylamine was investigated in a model system containing sodium nitrite. The ingredients used were: sodium chloride, sodium nitrate, glucono-δ-lactone (GDL), sodium acid pyrophosphate (SAPP), sodium erythorbate (NaEry), sodium ascorbate (NaAsc), ascorbic acid (AscH) and sodium tripolyphosphate (STPP). Under conditions approximating those used in the processing of frankfurters, CDL by itself was found to increase the formation of dimethylnitrosamine (DMNA), whereas reductants reduced the amount formed. Of the reductants, NaAsc or NaEry, in combination with other cure ingredients have similar inhibitory activity. The use of NaCl, NaNO₃ and SAPP had little or no effect on DMNA formation.     

Immunofluorescence detection of pea protein in meat products

In this study we developed an immunofluorescence method to detect pea protein in meat products. Pea protein has a high nutritional value but in sensitive individuals it may be responsible for causing allergic reactions. We produced model meat products with various additions of pea protein and flour; the detection limit (LOD) of the method for pea flour was 0.5% addition, and for pea protein it was 0.001% addition. The repeatabilities and reproducibilities for samples both positive and negative for pea protein were all 100%. In a blind test with model products and commercial samples, there was no statistically significant difference (p > 0.05) between the declared concentrations of pea protein and flour and the immunofluorescence method results. Sensitivity was 1.06 and specificity was 1.00. These results show that the immunofluorescence method is suitable for the detection of pea protein in meat products.     

Effects of meat preheating and wrapping on the levels of polycyclic aromatic hydrocarbons in charcoal-grilled meat

The contamination of polycyclic aromatic hydrocarbons PAHs by thermally treated high-protein foods, such as charcoal-grilled meat products, is due to the generation by direct pyrolysis of food nutrients and the direct deposition of PAHs from smoke produced through incomplete combustion of the thermal agents. This study investigated the effects on the PAH (BaP, BbFln and Fln) contents by using two different types of treatments, preheating (steam and microwave) and wrapping (aluminium and banana leaf) of the meat samples prior to charcoal grilling. PAHs were extracted through tandem solid-phase extraction. The results showed that the applied preheating and wrapping treatments on the samples strongly affect the PAHs levels in the charcoal-grilled meat. No carcinogenic PAHs (BaP and BbFln) were detected in the samples after steam and microwave preheating or aluminium wrapping treatments. Significant reductions of Fln content, of up to 46% and 81% in beef and chicken samples, respectively, were observed in the study.     

Effect of selected generally recognized as safe preservative sprays on growth of Listeria monocytogenes on chicken luncheon meat

The ability of selected generally recognized as safe (GRAS) chemical preservatives to reduce populations or inhibit growth of Listeria monocytogenes on chicken luncheon meat was evaluated. Slices of luncheon meat were treated by evenly spraying onto their surfaces 0.2 ml of a solution of one of four preservatives (sodium benzoate, sodium propionate, potassium sorbate, and sodium diacetate) at one of three different concentrations (15, 20, or 25% [wt/vol]). Each slice was then surface inoculated with a five-strain mixture of 10(5) CFU of L. monocytogenes per ml, held at 4, 13, or 22 degrees C, and assayed for L. monocytogenes immediately after inoculation and at 3, 7, 10, and 14 days of storage. Initial reductions of L. monocytogenes populations ranged from 0.78 to 1.32 log10 CFU g(-1) at day 0 for sodium benzoate- or sodium diacetate-treated meat, whereas reductions for the sodium propionate or potassium sorbate treatments were only 0.14 to 0.36 log10 CFU g(-1). After 14 days of storage at 4 degrees C, L. monocytogenes populations on all treated slices were 1.5 to 3 log10 CFU g(-1) less than on the untreated slices. At 13 degrees C and after 14 days of storage, L. monocytogenes populations were 3.5 and 5.2 log10 CFU g(-1) less on luncheon meat slices treated with 25% sodium benzoate or 25% sodium diacetate, respectively, and ca. 2 log10 CFU g(-1) less when treated with 25% sodium propionate or 25% potassium sorbate than on untreated control slices. Only sodium diacetate was highly inhibitory to L. monocytogenes on meat slices held at 22 degrees C for 7 days or longer. Untreated luncheon meat held at 22 degrees C was visibly spoiled within 10 days, whereas there was no evidence of visible spoilage on any treated luncheon meat at 14 days of storage.     

Investigation of methods to detect mechanically recovered meat in meat products - II: Gel electrophoresis

This study investigated the use of sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) as a method for differentiating between mechanically recovered and hand deboned meat. Twenty-nine samples of mechanically recovered meat (MRM), including some heat treated samples, were obtained. The samples were derived from several animal species and processed using different machine types and a range of processing conditions. They were examined using SDS-PAGE and the separation patterns obtained compared with those of hand deboned meat (HDM) reference samples. There were obvious differences in the relative intensities of several bands within the profiles obtained which distinguished MRM from HDM. These were more obvious for red meat than poultry meat samples. A few differences were found between MRM samples produced using different machines but no apparent differences between samples produced using different machine operating conditions were observed. The technique was tested using composite MRM-HDM mixtures. It was possible to suggest an order of percentage incorporation of MRM at levels of down to 5–10% for red meat and 25% for poultry meat. With further development and refinement, it may be possible to use the technique to detect and possibly quantify MRM present in all types of meat products, including cooked meat products.     

Reducing sodium intake from meat products

Sodium intake exceeds the nutritional recommendations in many industrialized countries. Excessive intake of sodium has been linked to hypertension and consequently to increased risk of stroke and premature death from cardiovascular diseases. The main source of sodium in the diet is sodium chloride. It has been established that the consumption of more than 6g NaCl/day/person is associated with an age-increase in blood pressure. Therefore, it has been recommended that the total amount of dietary salt should be maintained at about 5-6g/day. Genetically salt susceptible individuals and hypertensives would particularly benefit from low-sodium diets, the salt content of which should range between 1 and 3g/day. In industrialized countries, meat products and meat meals at home and in catering comprise one of the major sources of sodium, in the form of sodium chloride. Sodium chloride affects the flavour, texture and shelf life of meat products. The salt intake derived from meat dishes can be lowered by, whenever possible, adding the salt, not during preparation, but at the table. In most cases, salt contents of over 2% can be markedly lowered without substantial sensory deterioration or technological problems causing economical losses. Salt contents down to 1.4% NaCl in cooked sausages and 1.75% in lean meat products are enough to produce a heat stable gel with acceptable perceived saltiness as well as firmness, water-binding and fat retention. A particular problem with low-salt meat products is, however, that not only the perceived saltiness, but also the intensity of the characteristic flavour decreases. Increased meat protein content (i.e. lean meat content) in meat products reduces perceived saltiness. The required salt content for acceptable gel strength depends on the formulation of the product. When phosphates are added or the fat content is high, lower salt additions provide a more stable gel than in non-phosphate and in low-fat products. Small differences in salt content at the 2% level do not have marked effects on shelf life of the products. By using salt mixtures, usually NaCl/KCl, the intake of sodium (NaCl) can be further reduced.     

Specific degradation of myosin in meat by bromelain

The specificity of bromelain and papain for degradation of actin and myosin in meat was compared. Meat was treated with 0·1% enzyme for 0–60 min at 24°C and proteins, extracted with 6 urea containing 2% sodium dodecylsulfate (SDS) solution, were separated by SDS-polyacrylamide gel electrophoresis (PAGE). The profile of the extracted proteins clearly indicated that papain degrades myosin and actin at similar rates, whereas bromelain degrades myosin preferentially. This distinction could be useful in the development of freeze-dried meat products in which toughening of the meat due to the formation of high molecular weight aggregates from myosin cross-linking is minimized.     

不同加热方法对牦牛肉中矿物质和维生素含量的影响

研究了水煮、微波、烘烤和油炸加热方法对牦牛背最长肌(longissimus muscle,LM)和后小腿肉(shank hind,SH)维生素和矿物质含量的影响。结果表明:与生肉(对照组)相比较,水煮牦牛肉的钠、磷、钾和硫胺素含量显著减少(p<0.05)。水煮加热方法对维生素保留率最低,而烘烤加热最高。四种加热方法中牦牛肉钙、铁、锰和钴保留率无显著差异(p>0.05),而钠、镁、磷和钾的保留率差异显著(p<0.05);加热对硫元素几乎没有损失。综合考虑四种加热方法对牦牛肉维生素和矿物质的保留率,烘烤是牦牛肉较好的加热方法,建议在肉品加工企业和家庭烹饪中应用。     

天然虾青素对鸭肉品质和脂质氧化稳定性的影响

研究天然虾青素对肉鸭的感官、肉质和储藏稳定性的影响。试验选择108只出壳健康商品樱桃谷肉鸭,随机分为2组,分别饲喂添加0mg/kg(对照组)和10mg/kg虾青素(试验组)的饲粮。结果表明:饲喂虾青素可显著改善肉鸭胫掌、喙的颜色,并可在肝脏、胸肌和腿肌中沉积,可显著降低胸肌鲜样和冰冻样中的丙二醛(MDA)含量。