Acrylamide is a carcinogenic, neurotoxic, and genotoxic compound formed from free asparagine and reducing sugars during frying or baking of food products. The potato products French fries and chips are substantial contributors to acrylamide intake. The aim of the present work was to study effects of lactic acid and other α -hydroxy acids on acrylamide formation in French fries. Effective inhibition of acrylamide formation in French fries was obtained by short-time dipping in 0.4% solution of lactic acid before par-frying. It is suggested that the inhibitory effect on acrylamide formation is due to formation of a 6-ring ester-acid amine between the protonated α -hydroxy acid and free asparagine. The highest efficiency was achieved by applying lactic acid solution in a two-step procedure with dipping before and after par-frying. This process can be adopted to industrial conditions by lactic acid dipping after blanching and thereafter by submerging the par-fried French fries in lactic acid solution directly after the fryer. Use of this technology will contribute to lower acrylamide levels and reduced consumer exposure from French fries.

The effect of apple phenolics on the oxidative damage caused to myofibrillar proteins by an in vitro metal-catalyzed oxidation system was investigated. Three pure phenolic compounds (chlorogenic acid, (−)-epicatechin and phloridzin) and an apple peel extract were added to myofibrillar proteins in three concentrations (50, 100 and 200 μM), and a blank treatment was included as a control. All suspensions were subjected to Fe3+/H2O2 oxidation at 37 °C during 10 days, and protein oxidation was evaluated as carbonylation (α-amino adipic and γ-glutamic semialdehydes) and Schiff base cross-links. Significant inhibition by apple phenolics was found as compared to the control treatment, with (−)-epicatechin being the most efficient antioxidant and phloridzin showing the weakest antioxidant effect. The higher concentrations of apple extract showed effective antioxidant activity against protein oxidation in myofibrillar proteins, emphasizing the potential of apple by-products as natural inhibitors of protein oxidation in meat products.

Various direct (citrate, malate and succinate) and indirect (pyruvate and glutamate) Krebs cycle substrates were added to ground beef in order to investigate their effect on the inter-conversion of Mb redox forms in aerobic and anaerobic packaging. Glutamate, malate, succinate, pyruvate, and citrate added (up to totally 0.1 mol/kg) to ground bovine M. semimembranosus mixed with either ground porcine or bovine fat, altered the myoglobin redox forms in aerobic and anaerobic packaging systems. In anaerobic packaging, a mixture of succinate and glutamate formed deoxymyoglobin rapidly and it remained in this state for 13 days. In aerobic packaging (75% O2), the highest oxymyoglobin level occurred with a molar ratio of (glutamate–malate) to citrate of 3:1. In this case, oxymyoglobin was more prevalent after 6–8 days of storage in aerobic condition than without addition of these compounds. Pyruvate induced metmyoglobin formation, acting as a pro-oxidant. Succinate presumed leading to FADH2; was most effective at converting metmyoglobin to deoxymyoglobin in anaerobic packaging. In aerobic packaging, NADH presumed formed by the oxidation of glutamate may maintain oxymyoglobin levels, but adding citrate as well is recommended. Overall, a combination of substrates relevant to mitochondrial oxygen consumption, improved meat color stability.

Krebs cycle substrates (KCS) can stabilise the colour of packaged meat by oxygen reduction. This study tested whether this reduction releases reactive oxygen species that may lead to lipid oxidation in minced meat under two different storage conditions.KCS combinations of succinate and glutamate increased peroxide forming potential (PFP, 1.18–1.32mmolperoxides/kg mince) and thiobarbituric acid reactive substances (TBARS, 0.30–0.38mgmalondialdehyde (MDA) equivalents/kg mince) under low oxygen storage conditions. Both succinate and glutamate were metabolised. Moreover, under high oxygen (75%) storage conditions, KCS combinations of glutamate, citrate and malate increased PFP (from 1.22 to 1.29mmolperoxides/kg) and TBARS (from 0.37 to 0.40mgMDA equivalents/kg mince). Only glutamate was metabolised.The KCS combinations that were added to stabilise colour were metabolised during storage, and acted as pro-oxidants that promoted lipid oxidation in both high and low oxygen conditions.

Oxygen consumption rate (OCR) of muscle fibers from bovine semimembranosus muscle of 41 animals was investigated 3 to 4 h and 3 wk postmortem. Significant relations (P < 0.05) were found between OCR measurements and Warner-Bratzler shear force measurement. Muscles with high mitochondrial OCR after 3 to 4 h and low nonmitochondrial oxygen consumption gave more tender meat. Tender (22.92 ± 2.2 N/cm2) and tough (72.98 ± 7.2 N/cm2) meat samples (4 samples each), separated based on their OCR measurements, were selected for proteomic studies using mitochondria isolated approximately 2.5 h postmortem. Twenty-six differently expressed proteins (P < 0.05) were identified in tender meat and 19 in tough meat. In tender meat, the more prevalent antioxidant and chaperon enzymes may reduce reactive oxygen species and prolong oxygen removal by the electron transport system (ETS). Glycolytic, Krebs cycle, and ETS enzymes were also more abundant in tender meat

Animal and muscle characteristics were recorded for 41 cattle. The oxygen consumption rate (OCR) of M. semimembranosus was measured between 3.0-6.4 h post mortem (PM3-6) and after 3 weeks in a vacuum pack at 4 degrees C. Colour change measurements were performed following the 3 weeks using reflectance spectra (400-1100 nm) and the colour coordinates L*, a* and b*, with the samples being packaged in oxygen permeable film and stored at 4 degrees C for 167 h.Significant individual animal differences in OCR at PM3-6 were found for mitochondrial complexes land II. OCR of complex I declined with increased temperature and time PM, while residual oxygen-consuming side-reactions (ROX) did not. OCR of stored muscles was dominated by complex II respiration. A three-way regression between samples, colour variables collected upon air exposure and OCR of 3 weeks old fibres revealed a positive relationship between OCR and complex II activity and also between OCR and OCRROX. The presence of complex I and beta-oxidation activities increased metmyoglobin formation. (C) 2012 Elsevier Ltd. All rights reserved.

As part of the project “Religious slaughter (DIALREL): improving knowledge and expertise through dialogue and debate on issues of welfare, legislation and socio-economic aspects”, this paper discusses an evaluation of current practices during Halal and Shechita slaughter in cattle, sheep, goats and poultry. During religious slaughter, animals are killed with and without stunning by a transverse incision across the neck that is cutting the skin, muscles (brachiocephalic, sternocephalic, sternohyoid, and sternothyroid), trachea, esophagus, carotid arteries, jugular veins and the major, superficial and deep nerves of the cervical plexus. In this report, the restraint methods, stunning, neck cutting, exsanguination, slaughter techniques and postcut handling in the abattoir were assessed for religious slaughter. Information about the procedures used during religious slaughter in Belgium, Germany, Italy, the Netherlands, Spain, the UK, Turkey and Australia was collected by means of spot visits to abattoirs. To standardize the information gathered during the spot visits three guidelines were designed, one for each species, and translated into the national languages of the countries involved. The document included questions on the handling and restraint methods (stunning, neck cutting/exsanguination/slaughter techniques and postcut handling performed under religious practices) and for pain and distress of the animal during the restraint, neck cutting and induction to death in each abattoir. Results showed differences in the time from restraining to stun and to cut in the neck cutting procedures and in the time from cut to death.

Ground beef added Krebs cycle ingredients was packed in low and high oxygen for 13 and 8 days, respectively. Percentages of deoxymyoglobin, oxymyoglobin and metmyoglobin were determined. In low oxygen, the additives succinate and glutamate rapidly increased deoxymyoglobin levels and maintained the level at 100% dexoymyoglobin for 13 days. In high oxygen glutamate/malate supported stabilization of oxymyoglobin, but now citrate addition was important to stabilize oxymyoglobin for longer storage times. Optimal ratios of Krebs cycle ingredients were time dependent in high oxygen packing. Correct additions of Krebs cycle ingredients were superior to adding only water.

An optimum setting for electrical stunning of Atlantic salmon under commercial conditions was tested and compared against percussive stunning before and after pumping and at increasing durations of crowding (0.5 and 3h). For electrical stunning the fish were exposed to 60V, 100HzAC+DC for 6s after pumping. The results show that there were no significant differences in muscle pH or rigor index between fish exposed to electricity or a percussive force. Pumping and crowding did have a significant effect. Pumping alone halved the time until maximum rigor from 24 to 12h post mortem. Increasing crowding for 3h caused a significant drop in muscle pH and the time until onset of maximum rigor tension was reduced to 6h post mortem. We conclude that optimum electrical stunning performs equally well as percussive stunning and that future challenges for improving the pre rigor times for Atlantic salmon lays in the pumping and crowding conditions, and not in the selected stunning technique.

Investigation of the physiological effects of live chilling in Atlantic salmon, Salmo salar, has been performed in two experiments. In the first, fish (mean weight 840 g) acclimatized to either 16, 8, or 4°C were directly transferred horizontally or vertically (9 combinations) to water temperatures of 16, 8, 4, or 0°C using a dip net. Blood samples were collected at 1 and 6 h (h) post-transfer. In the second experiment, fish (mean weight 916 g) acclimatized to 16°C were exposed to four temperature-drop regimes (no physical handling): 16–4°C (over 5 h), 16–4°C (over 1 h), 16–0°C (over 5 h), and 16–0°C (over 1 h). Blood samples were collected 1 h post-temperature drop. Physical transfers in the first trial, i.e., temperature drops, resulted in immediate (1 h) increases in blood lactate concentrations at all three temperatures, but levels were significantly reduced and close to pre-transfer levels after 6 h. Horizontal transfers, i.e., 16–16°C, 8–8°C, and 4–4°C, resulted in similar increases and were not significantly different from the groups exposed to temperature drops. The most severe vertical transfer (16-0) resulted in a swift loss of equilibrium and eventually death. In experiment 2, temperature drops from 16 to 4°C and from 16 to 0°C over a period of one or 5 h, without physically handling the fish, resulted in no significant increases in any of the measured parameters 1 h post-transfer, except in the 16–0 (1 h) group. The latter experienced a significant increase in blood sodium, glucose, lactate, and cortisol levels compared to all other groups. The results suggest that salmon are capable of tolerating relatively steep temperature drops without any significant negative effects on blood stress parameters and that physical stress from handling overrides the effect of thermal insults.

Lactobacillus plantarum 423, producer of bacteriocin 423, Lactobacillus curvatus DF38, producer of curvacin DF38, and a bacteriocin-negative mutant of L. plantarum 423 (423m) were evaluated as starter cultures in the production of salami from beef, horse, mutton, Blesbok (Damaliscus dorcas phillipsi) and Springbok (Antidorcas marsupialis). Growth of L. plantarum 423 and L. curvatus DF38 was best supported in Blesbok salami, as revealed by the highest growth rate during sweating, cold smoking and maturation, and final cell numbers after 70 days (1×10(8) and 5×10(7)cfu/g, respectively). Growth of Listeria innocua was the best suppressed in Blesbok salami fermented with L. plantarum 423 and L. curvatus DF38. Growth of L. innocua in horse salami was best suppressed when fermented with L. curvatus DF38. The final pH of salami fermented with L. plantarum 423 and L. plantarum 423m was slightly lower (4.4) compared to the pH of salami produced with L. curvatus DF38 (pH 4.7). No significant differences (P>0.05) were recorded by a trained sensory taste panel amongst the three starter cultures regarding colour and venison like aroma. Horse, Blesbok and Springbok salami were rated significantly higher (P⩽0.05) in salami flavour than mutton salami, which was rated the lowest for this attribute. Blesbok salami was rated the highest for sour meat aroma, while beef salami was rated the lowest. Springbok salami was rated the highest in terms of oily mouth feel. Beef salami had the most compact structure and horse salami the softest structure of all meat types fermented. In general, salami produced with L. plantarum 423 yielded the best sour meat aroma, colour, texture, venison like flavour, sour meat flavour and oily mouthfeel and is considered superior to the L. plantarum mutant (strain 423m) and L. curvatus DF38.

The northern European production technique for dry-cured meat sausages was used to produce a sliceable, fermented, and dried fish product rich in omega-3 polyunsaturated fatty acids (PUFA). The fatty fish Atlantic salmon (Salmo salar), the lean fish saithe (Pollachius virens) (1:1, w/w), Lactobacillus sakei, and 4 different milk protein-based ingredients were used in the recipes. The changes in the volatile compounds during cold storage (+4 degrees C) of vacuum-packed dried sausages were studied by dynamic headspace gas chromatography-mass spectrometer (GC-MS). Of the 117 volatile compounds identified, alcohols, alkanes, esters, aldehydes, ketones, and compounds derived from amino acids were the most prevalent groups of volatiles. Thirty volatiles decreased and 17 increased significantly (P < 0.1) during storage for 15 wk. Despite the high content of PUFA, amino acid catabolism and ester synthesis led to larger changes in the composition of volatiles in the fish product than did lipid oxidation reactions. The milk-protein-based powders that were used to physically stabilize the fish oil did not affect the lipid oxidation compounds.

Atlantic halibut (Hippoglossus hippoglossus), 1630 +/- 510 g at the start of the experiment were reared in tanks for 1 year and subjected to three different environmental regimes; Continuous light and Constant temperature (CC), Natural light and Constant temperature (NC) or Natural light and Ambient temperature (NA). Two diets were fed, where 50% of the dietary lipids were either herring oil or soybean oil supplemented. The fish were sampled in May, August and November the first year, and February and May the following year. The CC groups grew better than the NC and NA groups from May to November, and as a result had a significantly (p < 0.05) higher weight by the end of the experiment. This difference did however not affect muscle fibre size distribution, or the chosen muscle quality attributes texture, fat content, water or fat loss of the fillet. These quality attributes were influenced by season and body weight, whereas diet had no significant effect. The NA group had lower fat content of the fillet than the other environmental regimes in August, November and May(end), and fat content increased with increasing fish weight. Water and fat losses were lowest in November and February. The diet influenced the fatty acid profile of the musculature; the triacylglycerol fraction reflecting the dietary treatment while the polar fraction was less influenced by diet. The hardness of the fillet was not influenced by the environmental regimes, but by season, and hardness was at its lowest in August, and increased towards the following spring. The muscle fibre distribution varied only with season, and neither treatment nor diet had any effect on the muscle growth dynamics. Recruitment of new fibres seemed mainly to occur during winter, signified by maximum occurrence of fibres < 500 mu m(2) by the end of the experiment in May. (c) 2006 Elsevier B.V. All rights reserved.

ABSTRACT: The study aimed at substituting nitrite with carbon monoxide (CO) in cooked or fermented meat batter products by investigating color and color stability in myoglobin solutions, model meat systems, and full‐scale hotdog and salami sausages of pork and beef. For cooked model meat systems and hotdogs at 75 to 80 °C core temperatures, direct flushing with a 1% CO gas mixture during the last stage of the batter chopping produced an initial red color equal to nitrite or more intense than with nitrite. For fermented model meat systems and salami sausages with a final pH of 4.7, pretreatment and storage of ground raw meat in a 1% CO mixture, and later use of the pretreated meat in batters, also formed an initial red color in the final products. The color stability during air and light display of cooked and fermented meat products with CO was inadequate compared to products with nitrite, although the red color of CO products was largely maintained by anaerobic packaging and storage. Spectra of carboxy‐ and nitrosomyoglobin at pH 4.7 demonstrated higher absorbance for carboxymyoglobin.

ABSTRACT Blanched and nonblanched potato rods (var. Beate) were fermented with Lactobacillus plantarum strain NC8 (109 colony‐forming units [CFU]/mL) at 37 °C for 45 and 120 min. Potato rods were pre‐fried at 170 °C for 3 min, cooled, and subsequently deep‐fried for 2 min 15 s. Potato juice (var. Beate) was fermented with the same strain (108 CFU/mL) at 30 °C for 1 to 5 h. Lactic acid fermentation of nonblanched potato rods for 45 min reduced acrylamide level in French fries with 48%, and with 71% after 120 min. By blanching potato rods before fermentation, reductions in acrylamide after 45 min and 120 min were 79% and 94%, respectively. Blanching, and especially fermentation, reduced visually judged browning of the French fries. Fermentation of potato juice reduced pH from 5.70 to 4.05 after 3 h. Simultaneously, glucose declined from 610.8 mg/100 mL to 7.9 mg/100 mL, fructose from 457.8 mg/100 mL to 0.0 mg/100 mL, and sucrose from 132.0 mg/100 mL to 29.2 mg/100 mL. Asparagine content remained largely unaffected between 0 h (1217.5 μmol/100 mL) and 4 h (1175.6 μmol/100 mL) and increased slightly (1470.3 μmol/100 mL) after 5 h fermentation. Levels of several other amino acids involved in Maillard reactions, that is, alanine, arginine, phenylalanine, and serine, decreased during fermentation. It is concluded that acrylamide formation during production of French fries can be effectively lowered by lactic acid fermentation of potato rods before deep‐frying. The reduction is due to reduced levels of reducing sugars rather than reduction of available asparagine.

Although the Cape fur seal is harvested commercially in southern Africa, no data exist to indicate whether its meat composition is such that it can be consumed by humans. Presently, these animals are harvested mainly for their hides. Little is known about the chemical composition of the meat and blubber and whether it could be processed into food or animal feed. This is the first report on the chemical composition of the Pectoralis muscle and fat of seal pups and bulls. The fat content in the muscle of pups was higher (4.2g/100g) than recorded in bulls (2.4g/100g). The protein content in muscle, on the other hand, was similar (23.2g/100g) for animals of both age groups. The blubber of bulls had a higher protein level (26.6g/100g) compared to that of pups (14.6g/100g), but a lower fat content (67.1g/100g vs 77.2g/100g). Muscle of bulls contained 33% saturated fatty acids (SFA), 29% monounsaturated fatty acids (MUFA) and 38% polyunsaturated fatty acids (PUFA). Muscle of pups contained 39% SFA, 30% MUFA and 31% PUFA. The toxin content in Cape fur seal blubber was lower than that reported for the blubber of Canadian seals. The organochlorine content in the blubber of Cape fur seals was lower than 13.7ng/g oil, whereas levels as high as 87.2ng/g have been reported in Canadian seal oil. The chemical composition of the Cape fur seal is such that it could be classified as a healthy meat source.