Evaluation of Photoshop software potential for food colorimetry

This paper presents a simple method that shows how digital imaging and software analysis can be combined for color measurement. The results showed that L^∗, a^∗ and b^∗ values from Hunter colorimeter and the digital imaging method had appropriate correlation with R² of greater than 0.98, however color values obtained from digital imaging method can be used only to monitor the trend of color changes and relative comparison and there is a noticeable difference between L^∗, a^∗ and b^∗ from digital imaging and values of Hunterlab colorimeter. By using equations presented in this paper, L^∗, a^∗ and b^∗ values obtained from digital imaging method can be successfully converted to Hunterlab color values. Changes in color of Mazafati date during ripening by hot acetic acid solution were monitored by use of this method. L^∗, a^∗, and b^∗ values of the samples decreased during ripening.     

Fishmeal-based diet decreases the redness of sunshine bass (Morone chrysops × Morone saxatilis) fillets

The objectives of the present study were to determine the effects of feeding a fishmeal-based diet on color attributes and lipid oxidation in sunshine bass (Morone chrysops × Morone saxatilis) fillets during retail display. A balanced diet containing 30 percent fishmeal (FM) or a diet containing poultry byproduct meal as a complete replacement of fishmeal (PB) was fed to sunshine bass for fifteen months. Harvested fish were filleted, overwrapped with polyvinyl chloride film and stored at 2 °C (REF) or over ice (ICE), under an illuminated retail display. Samples (n = 6) were analyzed after 0, 3, 6, or 9 d storage for color attributes (CIE L^∗, a^∗, b^∗, hue angle and chroma), thiobarbituric acid-reactive substances (TBARS), and pH. TBARS and pH increased (P < 0.05) during storage, indicating progress in lipid oxidation and protein changes. FM fillets demonstrated lower (P < 0.05) a^∗ (redness) value and greater (P < 0.05) hue angle than PB fillets. Since consumer acceptance of sunshine bass is dependant upon its white flesh, fishmeal supplementation could be used as a dietary strategy to improve fish marketability.     

Effect of low voltage electrical stimulation on biochemical and quality characteristics of Longissimus thoracis muscle from one-humped Camel (Camelus dromedaries)

The effects of electrical stimulation (90 V) 20 min post mortem on meat quality and muscle fibre types of four age group camels (1–3, 4–6, 7–9, 10–12 years) camels were assessed. Quality of the Longissimus thoracis at 1 and 7 days post mortem ageing was evaluated using shear force, pH, sarcomere length, myofibrillar fragmentation index, expressed juice, cooking loss and L^∗, a^∗, b^∗ colour values. Age of camel and electrical stimulation had a significant effect on meat quality of L. thoracis. Electrical stimulation resulted in a significantly (P < 0.05) more rapid pH fall in muscle during the first 24 h after slaughter. Muscles from electrically-stimulated carcasses had significantly (P < 0.05) lower pH values, longer sarcomeres, lower shear force value, higher expressed juice and myofibrillar fragmentation index than those from non-stimulated ones. Electrically-stimulated meat was significantly (P < 0.05) lighter in colour than non-stimulated based on L^∗ value. Muscles of 1–3 year camels had a significantly (P < 0.05) lower shear force value, and pH, but longer sarcomere, and higher myofibrillar fragmentation index, expressed juice, and lightness colour (L^∗) than those of the 10–12 years camels. The proportions of Type I, Type IIA and Type IIB were 25.0, 41.1 and 33.6%, respectively were found in camel meat. Muscle samples from 1–3 year camels had significantly (P < 0.05) higher Type I and lower Type IIB fibres compared to those from 10–12 year camel samples. These results indicated that age and ES had a significant effect on camel meat quality.     

Efficacy of bacteriophage LISTEXP100 combined with chemical antimicrobials in reducing Listeria monocytogenes in cooked turkey and roast beef

The aim of this study was to verify the effectiveness of the commercially available anti-Listeria phage preparation LISTEX^™P100 in reducing Listeria monocytogenes on ready-to-eat (RTE) roast beef and cooked turkey in the presence or absence of the chemical antimicrobials potassium lactate (PL) and sodium diacetate (SD). Sliced RTE meat cores at 4 and 10 °C were inoculated with cold-adapted L. monocytogenes to result in a surface contamination level of 10³ CFU/cm². LISTEX^TMP100 was applied at 10⁷ PFU/cm² and samples taken at regular time intervals during the RTE product's shelf life to enumerate viable L. monocytogenes. LISTEX^™P100 was effective during incubation at 4 °C with initial reductions of L. monocytogenes of 2.1 log₁₀ CFU/cm² and 1.7 log₁₀ CFU/cm², respectively, for cooked turkey and roast beef without chemical antimicrobials (there was no significant difference to the initial L. monocytogenes reductions in the presence of LISTEX^TMP100 for cooked turkey containing PL and roast beef containing SD-PL). In the samples containing no chemical antimicrobials, the presence of phage resulted in lower L. monocytogenes numbers, relative to the untreated control, of about 2 log CFU/cm² over a 28-day storage period at 4 °C. An initial L. monocytogenes cell reduction of 1.5 log₁₀ CFU/cm² and 1.7 log₁₀ CFU/cm², respectively, for cooked turkey and roast beef containing no chemical antimicrobials was achieved by the phage at 10 °C (abusive temperature). At this temperature, the L. monocytogenes cell numbers of samples treated with LISTEX™ P100 remained below those of the untreated control only during the first 14 days of the experiment for roast beef samples with and without antimicrobials. On day 28, the L. monocytogenes numbers on samples containing chemical antimicrobials and treated with LISTEX^TMP100 stored at 4 and 10 °C were 4.5 log₁₀ CFU/cm² and 7.5 log₁₀ CFU/cm², respectively, for cooked turkey, and 1.2 log₁₀ CFU/cm² and 7.2 log₁₀ CFU/cm², respectively, for roast beef. In both cooked turkey samples with and without chemical antimicrobials stored at 10 °C, the phage-treated samples had significantly lower numbers of L. monocytogenes when compared to the untreated controls throughout the 28-day storage period (P < 0.0001). For roast beef and cooked turkey containing chemical antimicrobials treated with LISTEX^TMP100 and stored at 4 °C, no more than a 2 log CFU/cm² increase of L. monocytogenes was observed throughout the stated shelf life of the product. This study shows that LISTEX^™P100 causes an initial reduction of L. monocytogenes numbers and can serve as an additional hurdle to enhance the safety of RTE meats when used in combination with chemical antimicrobials.     

The antioxidative properties of mustard leaf (Brassica juncea) kimchi extracts on refrigerated raw ground pork meat against lipid oxidation

The efficacy of varying concentration of mustard leaf kimchi ethanolic extracts (MK) in retarding oxidative rancidity was tested with raw ground pork. Freshly ground pork meat was assigned to one of the following five treatments: control (no antioxidants); AC-0.02 (0.02% ascorbic acid); MK-0.05, 0.1, and 0.2 (0.05%, 0.1% and 0.2% MK, respectively). The pH of the samples decreased and the TBARS values and free fatty acids (%) increased considerably (P < 0.05) during storage. The total bacterial count was lower in MK-0.1 and MK-0.2 than the control during storage. The internal L∗ value and a∗ value decreased (P < 0.05) with the addition of MK. The internal b∗ value of MK treatments were higher (P < 0.05) than that for the control and increased incrementally with MK concentration. The TBARS values and free fatty acids (%) of MK-0.02 was lowest among the treatments. The peroxide value of the control increased until 7 days and reached the maximum value at a certain storage time and decreased thereafter. In the other treatments it increased. All treatments had lower concentration of conjugated dienes (P < 0.05) compared to the control sample, after the first day. Mustard leaf kimchi ethanolic extracts exhibited a protective effect against lipid oxidation in raw ground pork.     

The effect of thawing methods on the quality of eels (Anguilla anguilla)

Physical (colour), chemical (pH, total volatile basic nitrogen (TVB-N), thiobarbituric acid values (TBA)) and microbiological (total aerobic mesophylic bacteria, salmonella, coliform, yeast and mould counts) analyses were carried out on thawed European eel (Anguilla anguilla). Different thawing treatments were used (in a refrigerator, in water, in air at ambient temperature and in a microwave oven). The results obtained were compared statistically with those of fresh fish. pH, TBA and a^∗ values of thawed samples usually decreased significantly (P < 0.05) when compared to the fresh control. Salmonella was not detected in any of the samples. Coliform and mould counts of fresh control and thawed samples were <1 CFU/g. Total aerobic mesophylic bacteria count of all thawed fish decreased. However, the yeast count of the refrigerator–thawed samples increased. The lowest total aerobic mesophylic bacteria and yeast counts were determined in water–thawed samples. Water thawing is therefore suitable for frozen eel.     

Chemical composition characteristics of the longissimus and semimembranosus muscles for pigs from New Zealand and Singapore

A range of composition characteristics of the longissimus (LL) and semimembranosus (SM) muscles were compared between pigs raised in intensive and extensive production systems in New Zealand (NZ), and pigs raised in an intensive system in Indonesia for supply to the Singapore market (n = 8/group). Ultimate pH was slightly higher for the Singaporean LL muscles (P < 0.05), while LL muscle of the NZ extensive group was redder (higher a^∗ values) and contained more fat (P < 0.05). Muscle iron levels were highest for the NZ extensive group and lowest for a lighter group within the Singapore pigs (P < 0.05). Differences in fatty acid concentrations, which were also measured in a sample of the belly cut, could largely be attributed to the effects of diet, with higher levels of alpha linolenic acid for the NZ extensive group (P < 0.05) due to linseed in the diet, and much higher levels of linoleic acid and the P:S ratio for the Singapore group (P < 0.05). Some statistically significant differences in amino acid concentrations were shown between muscles and groups, but they were not large. With respect to compounds with potential bioactive properties, coenzyme Q_10, and taurine levels were higher in pork from NZ pigs, and carnosine levels were highest for the NZ intensive group (P < 0.05). The LL muscle contained more coenzyme Q₁₀ and taurine, but less carnosine than the SM muscle (P < 0.001). It is concluded that some of these composition differences in the pork from the muscles and groups compared may be of commercial importance, but several are likely to have been due to dietary or weight differences.     

Chemical and biochemical changes of hybrid catfish fillet stored at 4 °C and its gel properties

Chemical and biochemical changes of aquacultured hybrid catfish fillet (Clarias macrocephalus × Clarias gariepinus) and its gel-forming ability as affected by age and sex of fish along with storage time were investigated. Fillets were stored at 4 °C for 0, 3, 6, 9, 12 and 15 days. There was no significant effect of sex and age of fish as well as storage time on fat, moisture and ash contents (P > 0.05). The total protein, water soluble protein, and salt soluble protein contents of the fillets significantly decreased with storage time (P < 0.05). On the other hand, pH, total volatile base nitrogen (TVB-N) and autolytic degradation products (ADP) increased as storage time continued (P < 0.05). Decreases in Ca²⁺-ATPase activity and gel properties were observed as storage time increased. However, there was no significant effect of either sex or age of fish on textural properties of gel (P > 0.05). Hybrid catfish fillet stored at 4 °C should be processed within 6 days.     

Quality assessment of wild European eel (Anguilla anguilla) stored in ice

The quality assessment of wild European eel (Anguilla anguilla) stored in ice and in boxes without ice (3 ± 1 °C) was investigated by the sensory analysis, levels of nucleotide breakdown products and biogenic amines for up to 19 days. Sensory analysis was assessed using the Tasmanian Food Research Unit Scheme. K and related values (K_i, G, P, H and F_r) were used as freshness indicators. Linear regressions (r²) obtained from K, K_i, G, P, H and F_r were 0.95, 0.96, 0.83, 0.96, 0.99 and 0.96, respectively, for eel stored in ice whereas, for eel kept in boxes without ice, the values were 0.86, 0.86, 0.96, 0.91, 0.98 and 0.86, respectively. When eel stored in ice and in boxes without ice were considered at the limit of acceptability by assessors at ∼12–14 days and ∼5–7 days, respectively, the average K, K_i and P values were ∼70–85%, H values were ∼60% and F_r values were ∼10% for both storage conditions. The level of histamine exceeded the legal limit (5 mg/100 g fish) in eel stored without ice after 6–7 days and, in ice, after 13–14 days of storage, at which time eels were rejected by the sensory panel. The concentrations of biogenic amines were higher in eel stored in boxes without ice than in eel kept in ice. The levels of histamine in the muscle of eel kept in boxes without ice and in ice increased to the maximum levels of 17.9 mg/100 g on day 12 and 12.6 mg/100 g on day 19, respectively.     

The effects of gamma-irradiation on the nucleotide degradation compounds in sea bass (Dicentrarchus labrax) stored in ice

The effects of two irradiation doses (2.5 and 5 kGy) on nucleotide breakdown compounds in sea bass stored in ice were investigated. Nucleotide degradation was slower in sea bass irradiated at 2.5 and 5 kGy than untreated samples. Irradiated samples had lower hypoxanthine and inosine content than the control group. Significant differences (p < 0.05) in K and related values were found between control groups and irradiated samples (2.5 and 5 kGy). H and G values showed a good correlation with storage time (r² ? 0.98) while linear regressions of K and Ki ranged from 0.95 and 0.93 to 0.98 and 0.97, respectively. A dose of 5 kGy seemed to be more effective than that of 2.5 kGy to reduce nucleotide breakdown in sea bass. The best linear correlation was obtained from G and H values; thus, they might be used as freshness indicators for non-irradiated and irradiated sea bass.     

Involvement of Clostridium gasigenes and C. algidicarnis in 'blown pack' spoilage of Brazilian vacuum-packed beef

The objectives of this study were to isolate psychrotrophic clostridia from Brazilian vacuum-packed beef cuts (spoiled or not) and to identify the isolates by using 16S rRNA gene sequencing. Anaerobic psychrotrophic microorganisms were also enumerated and samples were collected to verify the incidence of psychrotrophic clostridia in the abattoir environment. Vacuum-packed beef cuts (n = 8 grossly distended and n = 5 non-spoiled) and environmental samples were obtained from a beef packing plant located in the state of São Paulo, Brazil. Each sample was divided in three subsamples (exudate, beef surface and beef core) that were analyzed for vegetative forms, total spore-forming, and sulfide reducing spore-forming, both activated by alcohol and heat. Biochemical profiles of the isolates were obtained using API20A, with further identification using 16S rRNA gene sequencing. The growth temperature and the pH range were also assessed. Populations of psychrotrophic anaerobic vegetative microorganisms of up to 10¹⁰ CFU/(g, mL or 100 cm²) were found in ‘blown pack’ samples, while in non-spoiled samples populations of 10⁵ CFU/(g, CFU/mL or CFU/100cm²) was found. Overall, a higher population of total spores and sulfide reducing spores activated by heat in spoiled samples was found. Clostridium gasigenes (n = 10) and C. algidicarnis (n = 2) were identified using 16S rRNA gene sequencing. Among the ten C. gasigenes isolates, six were from spoiled samples (C1, C2 and C9), two were isolated from non-spoiled samples (C4 and C5) and two were isolated from the hide and the abattoir corridor/beef cut conveyor belt. C. algidicarnis was recovered from spoiled beef packs (C2). Although some samples (C3, C7, C10 and C14) presented signs of ‘blown pack’ spoilage, Clostridium was not recovered. C. algidicarnis (n = 1) and C. gasigenes (n = 9) isolates have shown a psychrotrophic behavior, grew in the range 6.2-8.2. This is the first report on the isolation of psychrotrophic Clostridium (C. gasigenes and C. algidicarnis) in Brazil. This study shows that psychrotrophic Clostridium may pose a risk for the stability of vacuum-packed beef produced in tropical countries during shelf-life and highlights the need of adopting control measures to reduce their incidence in abattoir and the occurrence of ‘blown pack’ spoilage.     

Influence of fermentation on some quality characteristics of trifoliate yam (Dioscorea dumetorum) hardened tubers

Processing of Dioscorea dumetorum tubers into flour could be a means of adding a longer-term value to this tropical plant with a high nutritional potential but which possesses a post-harvest hardening problem, characterised by a hard-to-cook defect. In an attempt to investigate the changes leading to fermentation of hardened tubers, CIE L^∗a^∗b^∗ parameters and some physicochemical properties of the yams were monitored. Four fermentation periods (0, 2, 4, 7 and 14 days) under ambient temperature (23 ± 5 °C) in the presence and absence of oxygen were studied. The results showed that fermentation significantly (p ? 0.05) increased a^∗ and b^∗ parameters, and decreased L^∗ parameter. However, browning affected more tubers fermented in the presence of oxygen. All the anti-nutrients evaluated (total phenols, phytic acid, oxalates, trypsin inhibitors and α-amylase inhibitors) decreased by significant levels (p ? 0.05) within 14 days of fermentation. However, the rates of anti-nutrient losses varied for each constituent and followed first-order reaction kinetics.     

Assessment of the sensory quality and shelf stability of selected Horro beef muscles in Ethiopia

The objective of this work was to assess sensory quality and retail life of Horro beef muscles in Ethiopia. Six muscles: M. rhomboideus (RM), M. infraspinatus (IS), M. longissimus lumborum (LL), M. semimembranosus (SM), M. biceps femoris (BF) and M. rectus femoris (RF) were considered. Sensory quality of the muscles was rated by a 9-member trained panel for palatability, tenderness, juiciness, amount of connective tissue (ACT), lean color and surface discoloration and measured by Warner-Bratzler Shear Force (WBSF). Retail life of the six muscles were evaluated for CIE 1976 L^∗a^∗b^∗ color values across 6 days. Significant differences (p < 0.05) between muscles for all sensory attributes and WBSF were found. Significant L^∗a^∗b^∗ color values of muscles and USDA quality grades by retail life were found (p < 0.05). Significant correlations (p < 0.05 or p < 0.01) of key parameters were also identified.     

Modelling starch digestion in sweetpotato with biphasic digestograms

The kinetics of starch digestion in 20 sweetpotato samples obtained from Papua New Guinea were investigated using an in vitro procedure based on glucometry. Irrespective of the cultivars (3-mun, Carot kaukau, Wahgi besta, Nillgai, Baiyer kaukau, and 1-mun), provinces, farmers and locations, the samples exhibited biphasic digestograms, possibly due to initial impediments to amylolysis and/or transport of digestion products by non-starch components (e.g. plant cell walls). The biphasic digestograms were segmented into two monophasic digestograms using a second-order polynomial (average r² = 0.723; p < 0.001), and a modified first-order kinetic model adequately described the digestograms (average r² = 0.984, p < 0.001; mean relative deviation modulus, MRDM, =8). Generally, the digestion rate constants (initial, K_i = 3.2-5.2 × 10⁻³ min⁻¹; final, K_f = 3.8-18.4 × 10⁻³ min⁻¹) indicated faster digestion during the final segment after the initial impediments to digestion had possibly been overcome. K_i was significantly (p < 0.05) different among the samples, which did not significantly (p < 0.05) differ in K_f. A logistic model, which treated each digestogram as a single process, also adequately described the biphasic behaviours (average r² = 0.994, p < 0.001; mean relative deviation modulus, MRDM, =15). The digestion parameters from the segment and logistic approaches significantly (p < 0.05) differed among the sweetpotato samples. The rate of digestion from the logistic model was significantly (p < 0.05) related to the initial and final rates of digestion from the segment approach (K = 3.99 K_i + 0.65 K_f; r² = 0.456; p < 0.001). Irrespective of the approach, maximum starch digestion was less than 100% in some samples to indicate the presence of resistant starch type 1, 2 or both. The present study is the first to model biphasic starch digestograms.     

Microbiological and organoleptic characteristics of beef trim and ground beef treated with acetic acid, lactic acid, acidified sodium chlorite, or sterile water in a simulated commercial processing environment to reduce Escherichia coli O157:H7 and Salmonella

The objective of this study was to validate the effectiveness of acetic and lactic acids (2% and 5%), acidified sodium chlorite (1000 ppm), and sterile water in reducing Escherichia coli O157:H7 and Salmonella Typhimurium in inoculated beef trim in a simulated processing environment. Samples were collected to assess microbial characteristics at three processing points. Results from this study indicate that all treatments, including sterile water, reduced pathogen concentrations (P < 0.05) of both E. coli O157:H7 and Salmonella Typhimurium in ground beef up to 0.5 and 0.6 log by 24 h, respectively. In some cases, there were no significant differences between the antimicrobial treatments and the sterile water using this application method. Triangle sensory test results of non-inoculated beef indicated there were no differences (P < 0.05) in the means of correct responses between controls or antimicrobial treatments at 6 or 24 h. While interventions are important for beef trim, use of the interventions must be validated under industry conditions to ensure proper effectiveness.     

Prediction of beef quality attributes using VIS/NIR hyperspectral scattering imaging technique

Hyperspectral imaging images were used to predict fresh beef tenderness (WBSF: Warner-Bratzler Shear Force) and color parameters (L^∗, a^∗, b^∗). Sixty-five fresh strip loin cuts were collected from 33 carcass after 2 days postmortem. After acquiring hyperspectral images, the samples were vacuum packaged and aged for 7 days, and then the color parameters and WBSF of the samples were measured as references. The optical scattering profiles were extracted from the images and fitted to the Lorentzian distribution (LD) function with three parameters. LD parameters, such as the scattering asymptotic vale, the peak height, and full scattering width were determined at each wavelength. Stepwise discrimination was used to identify optimal wavelengths. The LD parameters’ combinations with optimal wavelengths were used to establish multi-linear regression (MLR) models to predict the beef attributes. The models were able to predict beef WBSF with R_cv = 0.91, and color parameters (L^∗, a^∗, b^∗) with R_cv of 0.96, 0.96 and 0.97, respectively.     

Color-stabilizing effect of lactate on ground beef is packaging-dependent

Previous research on lactate-induced color stability in ground beef did not address the potential influence of packaging. The objective of the present study was to examine the effects of lactate on the color stability of ground beef patties stored in different modified atmosphere packaging (MAP) systems. Ground beef patties with either 2.5% potassium lactate or no lactate were packaged in vacuum (VP), high-oxygen MAP (HIOX; 80% O₂ + 20% CO₂), carbon monoxide MAP (CO; 0.4% CO + 19.6% CO₂ + 80% N₂), or aerobic packaging (PVC) and stored for 0, 2, or 4 days at 2 °C. Lactate-treated patties were darker (P < 0.05; lower L∗ values) than control patties. Surface redness (a∗ values) was greater (P < 0.05) for lactate patties than the controls when stored in PVC, HIOX, and VP. However, lactate’s effects on a∗ values were not evident when packaged in CO (P > 0.05). The color-stabilizing effect of CO could have masked lactate’s effect on surface redness. While lactate patties in PVC and VP demonstrated lower (P < 0.05) discoloration than controls, no differences (P > 0.05) existed between controls and lactate samples in CO and HIOX. Our results indicated that the effects of lactate on ground beef color are dependent on packaging.     

Effects of buffered vinegar and sodium dodecyl sulfate plus levulinic acid on Salmonella Typhimurium survival,shelf-life,and sensory characteristics of ground beef patties

The inclusion of two sources of buffered vinegar and sodium dodecyl sulfate plus levulinic acid were studied as interventions for Salmonella Typhimurium and for their effect on shelf-life and sensory characteristics of ground beef. For the Salmonella challenge, beef trimmings (80/20) were inoculated then treated with 2% (w/v) liquid buffered vinegar (LVIN), 2.5% (w/w) powdered buffered vinegar (PVIN), a solution containing 1.0% levulinic acid plus 0.1% sodium dodecyl sulfate (SDLA) at 10% (w/v), or had no intervention applied (CNT). The same trim source and production methods were followed during production of patties for shelf-life and sensory testing without inoculation. SDLA patties had the largest reduction (P < 0.05; 0.70 log CFU/g) of Salmonella. However, LVIN and PVIN had the least (P < 0.05) psychrotrophic growth. SDLA patties had more purge (P < 0.05) and lower (P < 0.05) subjective color scores. There were not large differences in sensory characteristics, except PVIN exhibited stronger off-flavor (P < 0.05).     

Effects of carbon monoxide-modified atmosphere packaging and irradiation on E. coli K12 survival and raw beef quality

The objective of this study was to evaluate the combined effects of irradiation and carbon monoxide in modified atmosphere packaging (CO-MAP) on total plate counts, Escherichia coli K12, color, and odor of fresh beef during refrigerated storage. Beef was packaged aerobically or in CO-MAP, and irradiated at 0, 0.5, 1.0, 1.5 or 2.0 kGy then held at 4 °C for 28 days. Raw beef odor decreased and acid/sour, rancid and grassy odors increased starting on day 14. Initially, no difference existed for visual green color scores due to gas atmosphere. After 14 days of storage, aerobically packaged beef was greener and less red than CO-MAP packaged beef. The a∗ value of CO-MAP packaged beef was higher than that of aerobically packaged beef. Red color of CO-MAP packaged samples decreased slightly in some irradiated samples after 14 days of storage. On day 0 and thereafter, no coliforms were detect after irradiation at 1.5 or 2.0 kGy regardless of packaging format. These findings suggest that CO-MAP could be used to preserve beef color irradiated at doses sufficient to reduce microbial loads to safe levels during 28 days of storage.     

Postmortem changes in cazon fish muscle stored on ice

The biochemical, chemical and physical postmortem changes and their relation to the cazon muscle eating quality were studied during an 18 day storage period at 0 °C (ice). Content of ATP and breakdown products, K value, pH, trimethylamine (TMA-N), total volatile bases (TVB-N), water-holding capacity (WHC), colour and texture changes were examined. At the beginning of the study, the cazon muscle showed a low concentration of ATP and a high value of IMP. Regarding to the signs of freshness and deterioration, K value presented a linear increase (r² = 0.97) with an initial value of 1.05% and a final value of 58.9%. The TBV-N and TMA-N significantly increased (P < 0.05). As for the physical analysis whereas the pH and the WHC changed (P < 0.05); texture was not affected (P < 0.05). The overall results of this study indicated that the edible quality of cazon fish muscle was maintained during at least 18 days of ice storage.