Effect of Sodium Erythorbate on Residual Nitrite, pH and Bacterial Growth in Liver Sausage Formulated with Different Levels of Mechanically Separated Pork

Some microbiological, chemical, and physical characteristics of liver sausage formulated with 0, 25, 50, and 75% mechanically separated pork (MSP), 156 ppm sodium nitrite and 0 or 550 ppm sodium erythorbate were studied during refrigerated storage (5°C, 6 days) and subsequent elevated-temperature holding (20–24°C, 48 hr). Growth of inoculated Clostridium sporogenes was inhibited by 156 ppm nitrite in all sausages even after 48 hr at 20–24°C, regardless of MSP level. Growth of aerobic mesophiles and facultative anaerobes at 20–24°C was also inhibited in sausage formulated with 156 ppm nitrite and 550 ppm erythorbate. Erythorbate addition and increased MSP levels resulted in higher Hunter a color values. Residual nitrite, pH values, and total iron content of liver sausage increased with increasing MSP content.     

Effect of Mechanically Separated Pork, Sodium Erythorbate and Sodium Nitrite Combinations on Clostridium sporogenes Survival and Growth in Liver Sausage

Liver sausage formulated with 50 or 75% mechanically separated pork (MSP), 75 or 150 ppm sodium nitrite and 0, 550 or 1100 ppm sodium erythorbate was examined for Clostridium sporogenes PA3679 survival and growth during refrigerated temperature storage (5°C, 6 days) and during subsequent exposure to elevated temperatures (22–24°C, 2 d). Sodium nitrite at 150 ppm inhibited clostridial growth in sausage held at 22–24°C, regardless of MSP content, if 550 ppm sodium erythorbate were also present. Sodium nitrite at 75 ppm combined with erythorbate at 550 and 1100 ppm did not inhibit C. sporogenes growth during simulated temperature mishandling of liver sausage. Residual nitrite decreased (P<0.05) with erythorbate addition but was unaffected by MSP.     

Investigation of mechanisms by which sodium citrate reduces the pink color defect in cooked ground turkey

The principal mechanism by which sodium citrate reduces the pink color defect in cooked ground turkey was investigated. Sodium citrate (SC; 0, 0.125, 0.25, 0.5, 1.0, 2.0 M), sodium nitrite (0.01, 0.1 M), and nicotinamide (0.5, 0.75 M) were combined in solutions of bovine hemin to determine SCs ability to bind heme iron and competitively inhibit pink-color-generating ligands from binding. Additionally, the effects of sodium erythorbate (0, 275, 550 ppm), ferrous iron chloride (0, 0.3, 3.0, 30 ppm), and ferric iron chloride (0, 0.3, 3.0, 30 ppm) on SCs ability to reduce pink cooked color was examined. Absorbance curves of hemin + nitrite and hemin + nicotinamide were relatively unaffected by SC, therefore whether or not SC bound heme iron, that did not appear to be a mechanism for inhibiting the pink color defect. Both ferrous and ferric iron chloride had minimal effects on color values, possibly due to sodium tripolyphosphate chelation ability in the meat system and thus their presence did not enhance SCs ability to reduce the pink color defect. However, sodium erythorbate, a reducing agent, inhibited SCs ability to decrease the pink color defect in samples induced pink with sodium nitrite and nicotinamide. Therefore, it appears SC requires the presence of oxygen and may participate in oxidative processes to reduce the pink color defect.     

L-Ascorbic Acid and Its 2-Phosphorylated Derivatives in Selected Foods: Vitamin C Fortification and Antioxidant Properties

Two carbonated beverages fortified with 30 mg L-ascorbic acid (AsA) equivalents/250 mL in the form of L-ascorbate 2-monophosphate (AsMP) and stored at 25–35°C retained more vitamin C than those with added AsA or L-ascorbate 2-polyphosphate (AsPP). Breads enriched with ferrous iron and fortified with 560 AsA eq./100g flour in the form of AsPP and AsA retained 40% and 5% vitamin C, respectively, after 6 davs at 25°C. Bran (40%) flakes fortified with 0.19% AsA ea. as AsMP and AsPP gave much improved retention of vitamin C during storage for 7 mo at 25–40°C and 7–11% moisture levels. The sodium salts of AsA, AsMP, and AsPP, when injected into whole eye of round beef at 0.18% AsA eq., inhibited hexanal formation after the meat was roasted and stored for 5 days at 5°C. Those sodium salts did not prevent accumulation of peroxides in peanut paste.     

Effect of Iron Form, Temperature, and Inoculation with Clostridium botulinum Spores on Residual Nitrite in Meat and Model Systems

The effect of iron form (ferrous, ferric, heme), temperature and botulinal spores on nitrite level was determined in meat. In model systems, ferritin iron was also included, and ascorbate was used as a reducing agent. Reduced hemoglobin caused the most rapid nitrite depletion in both systems. Ferrous iron caused faster nitrite depletion in model systems than in meat. Ferrous iron reduced nitrite readily in model systems at 27°C, but not at 5°C. Ferritin iron did not affect nitrite level. In meat at 27°C, nitrite depletion was much faster in inoculated samples. Protein-bound nitrite levels were higher in meat with added ionic iron. In cured meat with added ionic iron, iron-NO-protein complexes may form, lowering the amount of nitric oxide (NO) available to inhibit botulinal spore outgrowth.     

Effect of meat ingredients (sodium nitrite and erythorbate) and processing (vacuum storage and packaging atmosphere) on germination and outgrowth of Clostridium perfringens spores in ham during abusive cooling

The effect of nitrite and erythorbate on Clostridium perfringens spore germination and outgrowth in ham during abusive cooling (15 h) was evaluated. Ham was formulated with ground pork, NaNO₂ (0, 50, 100, 150 or 200 ppm) and sodium erythorbate (0 or 547 ppm). Ten grams of meat (stored at 5 °C for 3 or 24 h after preparation) were transferred to a vacuum bag and inoculated with a three-strain C. perfringens spore cocktail to obtain an inoculum of ca. 2.5 log spores/g. The bags were vacuum-sealed, and the meat was heat treated (75 °C, 20 min) and cooled within 15 h from 54.4 to 7.2 °C. Residual nitrite was determined before and after heat treatment using ion chromatography with colorimetric detection. Cooling of ham (control) stored for 3 and 24 h, resulted in C. perfringens population increases of 1.46 and 4.20 log CFU/g, respectively. For samples that contained low NaNO₂ concentrations and were stored for 3 h, C. perfringens populations of 5.22 and 2.83 log CFU/g were observed with or without sodium erythorbate, respectively. Residual nitrite was stable (p > 0.05) for both storage times. Meat processing ingredients (sodium nitrite and sodium erythorbate) and their concentrations, and storage time subsequent to preparation of meat (oxygen content) affect C. perfringens spore germination and outgrowth during abusive cooling of ham.     

Effect of Sodium Nitrite Concentration, Sodium Erythorbate and Storage Time on the Quality of Franks Manufactured from Mechanically Deboned Turkey

The effects of sodium nitrite (0-156 ppm), sodium erythorbate (0 or 550 ppm) and storage time (up to 10 wk at 4°C) were measured on the chemical and sensory properties of turkey franks formulated largely from mechanically deboned turkey (MDT), Residual nitrite in the finished product was proportional to that incorporated at time of formulation and was reduced by using small initial amounts in combination with the maximum allowable erythorbate (550 ppm). Acceptable cured color in turkey franks was achieved with the incorporation of 50 ppm of nitrite. Erythorbate effectively increased cured color development and stability, particularly with smaller amounts of nitrite. Rancidity development in turkey franks was not of major significance. Even so, the presence of erythorbate imposed further control of oxidative changes in lipids. Maximum cured flavor development occurred with 50–100 ppm nitrite.     

Low dose gamma irradiation effects on Clostridium botulinum inoculated turkey frankfurters containing various sodium chloride levels

Low dose gamma irradiation (0, 0·5 and 1·0 Mrad) at two irradiation temperatures (+ 1°C and −30°C) of turkey frankfurters containing various levels of sodium chloride (NaCl; 3·25%, 2·5% or 1·5%) or 1·5% NaCl plus 0·4% sodium tripolyphosphate (TPP) was evaluated for its effect on C. botulinum toxin production in frankfurters held at 27°C. A radiation dose of 0·5 Mrad or greater was sufficient to inhibit botulinal toxin production for 40 days in inoculated frankfurters containing 2·5% or greater concentrations of NaCl, regardless of the irradiation temperature. Neither 0·5 Mrad nor 1·0 Mrad inhibited toxin production in products containing 1·5% NaCl with or without TPP. NaCl should be reduced in processed meats with care; gamma radiation treatments cannot totally compensate for NaCl reduction.     

Characterization of Minced Meat Extracted from Blue Crab Picking Plant By-Products

Blue crab meat was mechanically extracted from picking-room byproducts to produce the following minced meat yields: 3.18%, white; 10.71%, mixed; 6.39%, claw, and 2.62%, leg. Each meat had distinct visual, textural, and flavor attributes. Aerobic plate counts of unpasteurized minced meat ranged from 10⁵ to 10⁷ CFU/g. Extraction within 1.5 hours of picking or icing of by-products prior to mechanical extraction stabilized microbial levels. Meat pasteurized at 80.6°C darkened or blued significantly less than meat processed at 83.3°C. Addition of citric acid-phosphate buffer to meat pasteurized at 80.6°C further reduced darkening of meats.     

Effects of Green Tea and Grape Seed and TBHQ on Physicochemical Properties of Baladi Goat Meats

The effect of natural extracts of green tea or commercial grape seed in combination with synthetic tert methyl-butylhydroquinone at different concentrations on lipid oxidation and the redness of goat meats stored at 5°C for 9 days was evaluated. Fresh boneless Baladi goat meats were ground and mixed at varying concentrations of green tea or grape seed extract alone or combined with tert methyl-butylhydroquinone. The color values of raw goat meat and the thiobarbituric acid-reactive substance values of raw and cooked goat meats were determined following 0, 3, 6, and 9 days of storage at 5°C. The antioxidant activity of the plant extracts and the tert methyl-butylhydroquinone ranged from 4.6–10.2 h induction time using an oxidative stability instrument. Thiobarbituric acid-reactive substance values ranged from 0.21 to 1.21 and 0.31 to 4.57 mg malondialdehyde/kg (goat meat) for the raw and cooked goat meats, respectively. Tert methyl-butylhydroquinone and plant extracts significantly decreased lipid oxidation of the goat meats, with a higher level of addition being more effective in minimizing lipid oxidation. Grape seed extract significantly increased the redness, while green tea extract decreased it; no effect of tert methyl-butylhydroquinone on the redness of goat meats was observed. This study has shown that inclusion of natural extracts of green tea and grape seed in goat meat could reduce lipid oxidation during its storage.     

Humectants improve myosin extractability and water activity of raw, cured intermediate moisture meats

Glycerol, propylene glycol and sorbitol were incorporated into salt-based intermediate moisture meats manufactured from porcine M. longissimus thoracis and bovine M. biceps femoris by dry curing and air drying at 4°C. Moisture content and water activity (a(w)) in cured pork were reduced by the addition of propylene glycol and sorbitol. Propylene glycol was more effective than sorbitol in lowering a(w). The extractability of myosin heavy chain, used as an index of alteration of myofibrillar protein, decreased in intermediate moisture porcine meats with the addition of salt and was unaffected by sorbitol. However, use of glycerol and propylene glycol in cured and air-dried pork increased the extractability of myosin heavy chain. Whereas intact myofibrils could not be extracted from salt-cured, air-dried beef, myofibrils could be made from air-dried beef cured in the presence of 10% glycol, 5% propylene glycol and 4% sorbitol. Such myofibrils contracted immediately on addition of Mg(2+)-ATP. In addition, even after storafe for 5 months, including 30 days at 25°C, myosin heavy chain could be extracted from meat cured with this combination of humectants. In comparison with salt curing alone, curing meat with the above three humectants together, plus salt, results in intermediate moisture meats more like fresh meat.     

Survival and growth of Clostridium perfringens in commercial no-nitrate-or-nitrite-added (natural and organic) frankfurters, hams, and bacon

The popularity of "preservative-free" foods among consumers has stimulated rapid growth of processed meats manufactured without sodium nitrite. The objective of this study was to quantify the potential for Clostridium perfringens growth in commercially available processed meats manufactured without the direct addition of nitrite or nitrate. Commercial brands of naturally cured, no-nitrate-or-nitrite-added frankfurters (10 samples), hams (7 samples), and bacon (9 samples) were obtained from retail stores and challenged with a three-strain inoculation (5 log CFU/g) of C. perfringens. Reduced inhibition (P < 0.05) was observed in seven brands of frankfurters, six brands of hams, and four brands of bacon when compared with each respective sodium nitrite-added control. In naturally cured and truly uncured commercial frankfurters, growth over time was approximately 4.7 log, while conventionally cured frankfurters exhibited growth at 1.7 log. Naturally cured ham and bacon products exhibited growth at 4.8 and 3.4 log, respectively, while their conventionally cured counterparts exhibited growth at 2.6 and 2.3 log, respectively. These products also demonstrated variation in growth response. The results indicate that commercially available natural/organic naturally cured meats have more potential for growth of this pathogen than do conventionally cured products. Natural and organic processed meats may require additional protective measures in order to consistently provide the level of safety from bacterial pathogens achieved by conventionally cured meat products, and which is expected by consumers.     

Comparison of Ferric Glycinate to Ferrous Sulfate in Model Infant Formulas: Kinetics of Vitamin Losses

Ferric glycinate prooxidant properties were compared with those of ferrous sulfate in a powdered casein-based infant formula. About 60 ppm of either iron source were added separately to the experimental formula. Fortified formulas were then stored at 20°C, 37°C or 45°C for 12, 9 or 7 months, respectively. The samples were assayed periodically during storage for vitamins A, E, B₁, B₂ and C evaluation. Ferric glycinate fortification yielded a 30-50% deterioration of the rate constant values of those obtained for ferrous sulfate addition. A 10-30% increase in activation energy values was also observed when ferric glycinate replaced ferrous sulfate as iron source. Results demonstrated lower prooxidant properties of iron when added to this infant formula as ferric glycinate than when ferrous sulfate was present.     

Effect of Acid and Alkaline Pyrophosphate Blends on the Natural Flora of a Cooked Meat System

Cooked pork sausage was prepared by using tetrasodium pyrophosphate (TSPP) and sodium acid pyrophosphate (SAPP) at 0 and 0.4% of the meat weight either separately or in different combinations. Samples were vacuum packaged and held in a refrigerated display case at 5°C for 21 days. Samples were also stored at room temperature (20-22°C) for 24 and 48 hr. Neither phosphate had an effect on microbial counts during refrigerated storage up to 21 days, but SAPP caused significantly lower counts of mesophilic and facultative anaerobic organisms after 48 hr of temperature abuse. The organisms affected were streptococci or very similar coccobacilli.     

Cholesterol Oxidation Products in Some Muscle Foods

Cholesterol oxidation products were estimated in some meat products by capillary gas chromatography after trimethylsilylation. Peak identities were confirmed by mass spectrometry. Freeze-dried pork, stored in contact with air at 22°C for ca. 3 yr, revealed 7α- and 7β-hydroxycholesterol, 7-ketocholesterol, α- and β-epoxide and cholestane-triol. The total concentration of oxidation products reached almost half of the remaining cholesterol content with 7-ketocholesterol as the predominant species. Some oxidation products were noted at a few ppm levels in broiled beef steaks, but not in precooked beef products. As rancidity development advanced in comminuted and cooked meats during storage, the oxidation of cholesterol became apparent.     

Detection of Pork in Processed Meat by an Enzyme-linked Immunosorbent Assay Using Antiswine Antisera

An antiserum to autoclaved porcine muscle extract was raised in sheep and tested for the detection of pork in mixtures of pork in mutton (P/ S) or beef (P/B) heated at 70, 100, and 120°C for 30 min using a competitive enzyme-linked immunosorbent assay (ELISA) method. The results indicated that the antiserum detected low percentages of pork (1%) mixed in beef and in mutton (0.5%) even when the meat mixtures were heated at 70, 100 or 120°C for 30 min, which correspond to heat treatments of commercially processed meat products. Regression analysis showed a high positive correlation (r > 0.99) between absorbance (OD) values and different percentages of experimental or commercially processed P/B meat mixtures. It was concluded that the combination of anti-porcine sera raised in sheep and the ELISA method can be used for the detection of low percentages of pork in processed meats.     

Effect of Freezing Temperature on Weight Loss and Quality Characteristics of Beef Liver, Kidney, Heart, and Tongue

Temperature at which variety meats were frozen (—126°C, -34°C, - 18°C, -8°C) had little effect on weight loss, color, appearance, odor or tenderness of beef liver, kidney, heart and tongue, before, during or after thawing and retail display. Freezing of variety meats at -34°C, as opposed to -126°C: (a) appeared to minimize weight losses associated with thawing, retail display and/or application of pressure; (b) did not materially affect color of meat surfaces during retail display; (c) might improve overall appearance enough to increase retail caselife; and (d) did not affect off-odor incidence or tenderness of variety meats.     

DSC study on the influence of meat source, salt and fat levels, and processing parameters on batters pressurisation

 Hydrostatic high-pressure/temperature treatments were conducted at low (10 °C) and high temperatures (60, 70, and 80°C) on different types of meat batters. Pressure-induced effects on proteins were intensified by sodium chloride molarity at low and high temperatures. Treatments at 10°C under pressurisation yielded net thermal destabilisation effects on meat proteins pertaining either to muscle or batter systems. Heating at usual cooking temperature of 70°C under pressure yielded net stabilising effects on meat batter proteins. Overheating at 80°C was needed for entire protein denaturation. Pork and chicken meats were very similar in behaviour but chicken batters exhibited relatively higher thermal- and pressure-induced protein denaturation. Both kinds of physical destabilisation/stabilisation of proteins by pressure-induced effects increased with pressure level. Received: 30 December 1999 / Revised version: 14 February 2000     

Chemical sprays as a method for improvement in microbiological quality and shelf-life of fresh sheep and goat meats during refrigeration storage (5-7°C)

The shelf-life of meats from freshly slaughtered sheep and goat carcasses at 5-7?°C was extended after spraying (pressure 3 kg/cm(2)) the carcasses with solution 'B' containing potassium sorbate, sodium acetate, sodium citrate, sodium lactate each at 2.5% and sodium chloride at 5% (prepared w/v in potable water), when compared with solution 'A' (without potassium sorbate). Solution B treatment inhibited Bacillus spp. to minimum and were not detected up to sixth day. It extended the lag phase of all organisms including psychrotrophes (pseudomonads) and reduction of differential counts in sheep and goat meat were noted throughout the refrigerated storage. On sixth day (control) and seventh day (solution "A treated") meat samples developed off odour and discoloration with total viable count (TVC)>10(7) cfu/g. Solution B treated meat samples showed no spoilage at seventh or eighth day, indicating an extended shelf-life of 3 and 2 days when compared with control and solution A treated meat, respectively.     

添加抗氧化剂对冷藏(0℃)腊肉脂肪降解的影响

以传统腊肉为原料,将腊肉分为A组(直接真空包装)、B组(添加异抗坏血酸钠后真空包装)、C组(添加茶多酚后真空包装),于0℃条件下贮藏,并对贮藏过程中脂肪的降解情况进行了研究。实验结果显示,随贮藏时间延长,三组肥腊肉含水量下降;脂肪含量呈下降趋势;冷藏至120d时酸价分别上升了1.897、1.241、0.822mg/g;过氧化值分别上升了3.356、2.945、1.914meq/kg。本实验表明,在冷藏条件下抗氧化剂异抗坏血酸钠和茶多酚均有抑制腊肉酸价和过氧化值升高的作用,有利于抑制脂肪降解,延长腊肉贮藏时间;与异抗坏血酸钠相比,添加茶多酚对腊肉的抗氧化效果更好。