Meat quality,microbiological status and consumer preference of beef gluteus medius aged in a dry ageing bag or vacuum

This study investigated meat quality and consumer preference after ageing beef gluteus medius in a water vapour-permeable dry-ageing bag or in vacuum for 14 days. Higher ageing and trim losses but lower thawing loss, cooking loss and water content were found in samples aged in dry ageing bags compared to those aged in vacuum. Samples aged in dry ageing bags had higher total bacteria and yeast counts but lower lactic acid bacteria counts than those aged in vacuum, both before and after trimming. Meat aged in dry ageing bag was more tender and juicier and overall preferred by consumers compared with samples aged in vacuum. Female participants outperformed the males in detecting differences in palatability. No differences were found in pH, smell, shear force, colour, Enterobacteriaceae, and mould counts. Thus, by using a dry ageing bag, it is possible to produce dry-aged meat in a more controlled condition without negative effects on sensory or other quality attributes.     

Extension of the display life of lamb with an antioxidant active packaging

Fresh lamb steaks were treated with three different preparations of natural antioxidants: one group was packaged with a rosemary active film, the second group was packaged with an oregano active film, and the third group was sprayed on the meat surface with a rosemary extract before packaging in a high-oxygen atmosphere. Samples were stored under illumination at 1 ± 1 °C for 13 days. Metmyoglobin formation, lipid oxidation (TBARS), instrumental colour (CIE a¹), psychrotrophic bacterial counts (PCA), sensory discolouration and off-odour were determined. The use of a rosemary extract, a rosemary active film or an oregano active film resulted in enhanced oxidative stability of lamb steaks. Active films with oregano were significantly more efficient than those with rosemary, exerting an effect similar to that of direct addition of the rosemary extract; in fact, they extended fresh odour and colour from 8 to 13 days compared to the control.     

Fresh meat color evaluation using a structured light imaging system

The objective of this study was to investigate the efficacy of a computer vision system (CVS) with structured light for meat color assessment. Three muscles (longissimus dorsi (LD), semimembranosus (SM), and psoas major (PM)) from eight beef carcasses were obtained at 1 day postmortem, vacuum packaged and assigned to three aging periods (9, 16, and 23 days). After aging, steaks were cut and displayed for 7 days at 3 °C under light. The surface colors were evaluated by using a Minolta, the CVS and trained color panel. In general, the CVS was highly correlated to the sensory scores, and showed an equivalent meat color assessment compared to the colorimeter. The CVS had a significantly higher correlation with the panel scores for the lighter and more color stable samples compared to the colorimeter. These results indicate that the CVS with structured light could be an appropriate alternative to the traditional colorimeter by offering improved precision and accuracy over the colorimeter.     

Effects of dry aging of bone-in and boneless strip loins using two aging processes for two aging times

This experiment investigated the combined effects of two dry-aging methods (unpackaged and in a bag), two loin-cut styles (bone-in shell loins and boneless strip loins), and two aging times (21 and 28 days) on the physical, chemical, sensory, and microbial properties of dry-aged beef. Sections from shell and strip loin were assigned randomly to be aged unpackaged or aged packaged in a bag with high moisture permeability. Weight losses increased with aging time. Shell loins lost more (P < 0.05) weight during aging compared with strip loins; dry aging in a bag had less (P < 0.05) weight loss than unpackaged aging. There were no differences (P > 0.05) in any of the sensory traits between shell and strip loins or dry aging using a traditional method or in a bag. Dry aging in a bag creates positive effects on yields, no negative effects on product quality, and adds flexibility and control of the aging environment.     

Effects of teeth maturity and fatness of Nellore (Bos indicus) steer carcasses on instrumental and sensory tenderness

This study sought to evaluate the effects of teeth maturity and carcass fatness on physical and sensory traits of the beef ribeye (M. longissimus thoracis). Carcass sides (n = 60) of Nellore steers were grouped into six categories, according to teeth maturity (2, 4 and 6 permanent incisors), and fatness (2 – slight and 3 – average). The boneless ribeye cuts (6th – 9th ribs) were vacuum packed and aged for 14 days. Steaks, 2.5 cm thick, were evaluated as to sarcomere length, shear force and sensory attributes. Sarcomere length was not affected (P > 0.05) by maturity or fatness. Teeth maturity did not influence (P > 0.05) tenderness measured by instrumental or sensory analysis, however rib steaks from fatter carcasses displayed better tenderness (P < 0.01) and lower cooking losses (P < 0.01). In the Nellore steer carcasses produced in Brazil, fatness may be more important than teeth maturity to improve meat tenderness.     

“Chilled” pork—Part I: Sensory and physico-chemical quality

Chilled meat exportation comprises chilling within 48 h post-mortem to temperatures < 0 °C without freezing and holding under these conditions for several weeks. The effects of this ageing on sensory quality of pork are unknown and hence the objective of this study was to compare the sensory quality of Canadian pork as found in an export (Japan) market and locally. Regardless that the Japanese market's quality criteria were met, pork sorted on-line differed (P < 0.05) from that for the domestic market only for lightness, exudate and cooking loss; no differences in intramuscular fat content were observed. Overall, a trained panel scored weaker pork and meat flavours and odours in the export than the domestic pork as a result of either the quality by selection if roasted or the ageing (− 1.7 °C, 43 days exported chilled or 3.1 °C, 5 days domestic) if grilled or shabu shabu. Grilled pork was also more tender, sweeter and had stronger caramel flavour with the chilled ageing.     

“Chilled” pork — Part II. Consumer perception of sensory quality

The objective of this study was to compare consumer perception of the sensory quality of grilled Canadian pork destined for Japanese and domestic markets, with particular reference to export selection criteria imposed by Japanese importers and transportation conditions. Consumers from Quebec, Canada tasted local and export quality pork subjected to “chilled” (aged 43 days at − 1.7 °C) or conventional ageing (5 days at 3.1 °C). Consumers' scores (out of 10) were higher (P < 0.05) in the “chilled” than conventionally aged pork for tenderness (6.8 vs 5.7), juiciness (6.6 vs 6.0), taste liking (6.4 vs 5.9) and overall acceptability (6.7 vs 6.1). When informed that the conventionally aged, domestic quality pork was destined for the domestic market, consumer scores increased significantly (P < 0.05). No effect of information was observed on the perception of the ‘chilled’ export quality meat, perhaps a consequence of the high sensory quality observed prior to labelling.     

Influence of vacuum skin packaging on color stability of beef longissimus lumborum compared with vacuum and high-oxygen modified atmosphere packaging

The objective of this study was to investigate how color stability of beef is affected by vacuum skin packaging (VSP) compared with vacuum packaging (VP) and high-oxygen modified atmosphere packaging (MAP; 80% O₂ and 20% CO₂). Longissimus lumborum muscles were aged in vacuum for 7 days and then cut into 2-cm-thick slices and repacked using VSP, VP and MAP for another 7 days. Color stability was measured during the next 5 days in air and samples for α-tocopherol and NADH analyses were obtained at the beginning and end of aerobic storage. Color stability, α-tocopherol and NADH of steaks were affected by packaging methods and storage time in air (P < 0.05). Higher a* value was obtained in VSP on day 5 compared with VP. Steaks packed in VSP had better color stability than in VP and their color was similar to MAP at the end (day 5) of storage.     

Effects of an enriched housing environment on sensory aspects and fatty-acid composition of the longissimus muscle of light-weight finished lambs

We analysed the effect of enriched housing on the sensory meat quality and fatty acid composition of longissimus muscle in 60 entire Rasa Aragonesa lambs, housed indoors for 5 weeks in six pens (10 lambs/pen, 0.95 m²/lamb, initial weight 17.13 ± 0.18 kg and carcass mean 12.23 ± 0.23 kg); three control pens (barren) and three enriched pens (straw, platform with ramps and a small ramp). The final weight, carcass weight, fatness scores and cooking losses of meat from enriched lambs (EG) were higher and pH 24 was lower (P ≤ 0.05). The EG lambs had more C18:0 and total SFA (P ≤ 0.05). Lamb odour and grass odour were more intense in EG (P ≤ 0.05). Overall liking was higher for EG (P ≤ 0.05) and associated with tenderness (P ≤ 0.0001). The results suggest that environmental enrichment can have effects on fatty acid composition and sensory meat quality.     

Investigation of the effects of commercial carcass suspension (24 and 48 h) on meat quality in high oxygen modified atmosphere packed beef steaks during chill storage

Hanging for 24 or 48 hours (h) of intact carcasses in the chill store cooler prior to further processing occurs periodically at processor level due to demand for product. The aim of the study was to investigate the effects of commercial carcass suspension (24 and 48 h) on meat tenderness attributes in modified atmosphere packed beef steaks during chill storage. A secondary objective was to investigate protein oxidation reactions occurring and the subsequent meat tenderness consequences. Carcasses were hung for 24 or 48 h in order to reproduce commercial short term storage of meat at processor level. Experimental gas atmospheres used in packs consisted of; 40%, 50%, 60%, 70% and 80% oxygen, with all packs containing 20% CO₂ and the remainder being provided by the filler gas N₂. Steaks from the 24 h suspended carcasses were tougher than those from 48 h suspended muscle. Additionally, packaging systems with high oxygen had a negative influence on tenderness (instrumental) and consumer determined juiciness in cooked beef steaks. The carbonyl content and TBARS numbers increased to the greatest extent in high oxygen packed samples. Protein oxidation was directionally and significantly correlated (P < 0.01) to the higher O₂ treatments. Protein and lipid oxidation also occurred to a greater extent in the samples from the 48 h treatment, possibly due to physical matrix differences in the meat compared to the 24 h treatment. Meat from the 48 h treatment appeared less red than meat from the 24 h treatment.     

High pressure carbon dioxide combined with high power ultrasound processing of dry cured ham spiked with Listeria monocytogenes

Traditionally, thermal treatments for the inactivation of Listeria monocytogenes in meat products involve undesirable changes of the product quality. In recent years, efforts have been carried out to develop alternative methods to inactivate L. monocytogenes without affecting the product quality attributes. In this context, the feasibility of combined high pressure carbon dioxide and high power ultrasound (HPCO₂ + HPU) treatment to inactivate L. monocytogenes inoculated on the surface of dry cured ham was investigated. Inactivation data were determined at 6, 8 and 12 MPa, as a function of temperature (22, 35, 45 °C) and treatment time (0.5 to 30 min), and compared to those obtained after thermal and HPCO₂ treatments.Color, pH and acidity changes of the samples after both thermal and HPCO₂ + HPU treatments were measured and compared, sensorial profile of the treated samples was evaluated by a sensory panel and shelf-life was determined by a storage study for 4 weeks at 4 °C.The results clearly revealed that HPU alone was not able to induce any microbial inactivation while HPCO₂ + HPU treatment always assured a certain level of inactivation, variable with the process temperature used: the inactivation efficiency was demonstrated higher at 35 °C rather than 22 °C and no enhancement was observed at 45 °C compared to 35 °C. Process conditions of 12 MPa, 35 °C, at 10 W for 5 min assured inactivation to undetectable level of L. monocytogenes spiked on the surface of the product with an initial concentration of about 10⁹ CFU/g. No differences were detected between acidity, pH, color and sensory attributes of the untreated and HPCO₂ + HPU treated dry cured ham surface, while slight differences were measured between the values obtained for the untreated and thermally treated samples. Additionally, the storage study demonstrated that a full microbial and quality shelf-life was assured for 4 weeks at 4 °C. The results obtained may open the doors to the application of such an innovative process at industrial level, in particular to treat ham-type or meat products.     

Sensory and Microbiological Parameters of Stored Wild Boar Meat

The influence of temperature on microbiological and sensory parameters of wild boar meat kept for 21 days was studied. Total viable count was higher in meat stored at 15 °C than at lower temperatures on day 21. Colour saturation and hue did not differ at any temperature, but odor differences occurred in meat at 15 °C. Redness (a*) in meat at 0 °C was higher than at 15 °C. Meat stored at 0 or 15 °C differed in b* after 21 days, and in L* after 7 days. Observance of National and European legislation concerning handling of wild game is important in providing health-friendly meat.     

Nucleotide breakdown products of seer fish (Scomberomorus commerson) steaks stored in O2 scavenger packs during chilled storage

Freshness of seer fish (Scomberomorus commerson) steaks packed with and without O₂ scavenger was assessed by sensory and chemical methods. O₂ scavenger used in the present study reduced the O₂ level in the pack to less than 0.01% within 24 h. Samples in air packs were sensorily acceptable only up to 12 days compared to 20 days in O₂ scavenger packs. TVB-N levels were 37 and 34 mg N₂/100 g and TMA-N levels were 16.4 and 15.2 mg N₂/100 g on the day of sensory rejection for air and O₂ scavenger packs, respectively. IMP decrease and Hx increase was significantly (P < 0.05) faster in air packed samples compared to O₂ scavenger packs. On sensory rejection day, the average K, Ki, P and H values were 63–65%, Fr value was 34% and G value was 178% for O₂ scavenger packed samples compared to 81%, 18% and 443% for air packed samples, respectively.Industrial relevanceThe O₂ scavenger is an innovative active packaging technique, which is highly effective in reducing the O₂ present inside the pack. This can be used in place of traditional vacuum packaging for extending the shelf life of fish products, which reduces the use of vacuum packaging equipments thereby making the process cost effective.     

Breed, slaughter weight and ageing time effects on physico-chemical characteristics of lamb meat

The effects of breed, slaughter weight and ageing time on the meat quality of the three most important Spanish breeds were considered. Two hundred and twenty-five lambs of Rasa Aragonesa-local meat breed-, Churra-local dairy breed- and Spanish Merino were used. Animals (75 of each breed) were slaughtered at three different live weights (10–12, 20–22 or 30–32 kg), and the meat was aged for 1, 2, 4, 8 or 16 days. The meat pH, colour, amount of haem pigments, intramuscular fat, moisture, hydroxyproline content and sarcomere length were measured at 24 h post-mortem. Meat texture was measured by compression after each ageing time. The pH of the samples ranged from 5.50 to 5.58. Meat colour varied with breed and slaughter weight (P ⩽ 0.01), the M. longissimus thoracis was lighter in the youngest animals and in the Churra breed and redder in Merinos. Intramuscular fat increased and moisture decreased for heavier lambs. Differences in collagen were associated with breed (P ⩽ 0.01); total and insoluble collagen contents were higher in the Churra breed. Sarcomere length was only slightly affected by slaughter weight. Meat from the Churra breed had the highest values at high levels of compression. Suckling lambs (10–12 kg) had greater myofibrillar toughness than heavier lambs and ageing strongly influenced myofibrillar tenderness.     

Combination effect of phosphate and vacuum packaging on quality parameters of Rutilus frisii kutum fillets in ice

Improving food quality among consumers is of high importance. This case in fish meat due to its quick spoilage is the more obvious. Therefore in this study in order to maintain and improve the quality of fish meat, effect of pretreatment with three different phosphate compounds including sodium tripolyphosphate (STPP), sodium pyrophosphate (PP) and mixture of them (STPP + PP) in combination with vacuum packaging (VP) on Rutilus frisii kutum fillets stored in ice was investigated. Phosphate pretreatment showed the synergistic effect with VP on reduction of psycrophilic bacteria, chemical and sensory deterioration of Rutilus frisii kutum fillets as evidenced by the lowered microbial counts, thiobarbituoric acid and total volatile base, compared with samples stored in air and those kept under VP. Pretreatment with PP resulted in the retarded protein denaturation as evidenced by the reduced changes in sulfhydryl content during the extended storage. Increase in water holding capacity accompanied by the decrease in pH was observed in samples pretreated with phosphates, especially tripolyphosphate. No marked autolytic degradation in samples kept under VP with and without phosphate pretreatment was observed throughout the storage as indicated by no changes in electrophoresis patterns. Determined shelf life based on psychrophilic bacteria counts for Rutilus frisii kutum fillets pretreated with STPP and stored under VP, until 15 days and according to sensory analysis until 12 days compared with samples stored in air. Therefore, the effective retardation of psycrophilic bacteria, chemical and sensory deterioration of Rutilus frisii kutum fillets stored under VP could be achieved by pretreatment with tripolyphosphate.     

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.     

Influence of storage period and packaging method on sliced dry cured beef “Cecina de Leon”: Effects on microbiological,physicochemical and sensory quality

Quality aspects of sliced dry-cured beef “Cecina de León” preserved in vacuum and gas mixtures (20%/80% CO₂/N₂ and 80%/20% CO₂/N₂) were studied. The evolution of microbiological, physicochemical and sensory parameters were analysed during storage (210 days) at 6 °C. Although microbial counts at 60 days of the gas-packaged samples were lower than the vacuum-packed ones, they were never higher than the spoilage limit (7 log ufc/g). A slight increase (p < 0.05) in pH was observed throughout storage of “Cecina de León” packaged under vacuum and in gas mixtures. However, a decrease (p < 0.05) in a_w was observed during storage of “Cecina de León” packaged under vacuum but a_w did not vary (p > 0.05) during storage in the gas-packaged samples. No changes were observed (p > 0.05) in lightness (L¹), redness (a¹) and yellowness (b¹) in vacuum and gas packaged samples during storage. However, sensorially evaluated colour showed lower values in gas packaged samples during 30 days storage. This difference was decisive in establishing the shelf-life of “Cecina de León” slices preserved in gas mixtures (20%/80% CO₂/N₂ and 80%/20% CO₂/N₂). Therefore, from a microbiological point of view, gas mixtures are more effective in extending the shelf-life of “Cecina de León” slices. It is concluded that vacuum packaging allows longer storage than gas-packaging as it maintains a good visual appearance of “Cecina de León”, the main parameter in consumers’ perception of meat quality.     

Preparation and use of freshwater fish,rohu (Labeo rohita) protein dispersion in shelf-life extension of the fish steaks

A process to enhance shelf-life of freshwater fish, rohu, on ice using combination treatment of coating the fish steaks with gel dispersion from the same fish and low-dose gamma irradiation is described. Washed pieces of freshwater fish, rohu were converted into gel by dilute acetic acid treatment. The gel was homogenized in water to a dispersion having 29 g/L protein, apparent viscosity of 1.0 Pa s and pH 3.5. Coating of fresh rohu steaks by dipping in the dispersion for 1 h or gamma irradiation at 1 kGy gave a shelf-life of 32 days in ice, in comparison to 20 days for the untreated steaks. Irradiation at 1 kGy of the dispersion-coated steaks enhanced their shelf-life to 42 days. Bleaching of the pink colour of the steaks by the treatment was prevented when one of either butylated hydroxy anisole or ascorbic acid was incorporated at 5 g/kg (w/v) in the dispersion.