Total Mesophiles Research Articles

The bactericidal activity of acidic electrolyzed oxidizing water against Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes on raw fish, chicken and beef surfaces

The bactericidal efficacy of acidic electrolyzed oxidizing water (AC-EW) (pH = 2.30, free chlorine = 38 ppm) and sterile distilled water (DW) on three pathogens (Escherichia coli O157:H7 Salmonella Typhimurium, and Listeria monocytogenes) inoculated on raw trout skin, chicken legs and beef meat surfaces was evaluated. The decontaminating effect of AC-EW and DW was tested for 0 (control), 1, 3, 5 and 10 min at 22 °C. AC-EW significantly (P < 0.05) reduced the three pathogens in the inoculated samples compared to the control and DW. The level of reduction ranged between ca.1.5–1.6 logs for E. coli O157:H7 and S. Typhimurium in the inoculated foods. However, AC-EW exhibited less bactericidal effect against L. monocytogenes (1.1–1.3 logs reduction). AC-EW elicited about 1.6–2.0 log reduction in the total mesophilic count. Similar treatment with DW reduced pathogens load by ca. 0.2–1.0 log reduction and total mesophiles by ca. 0.5–0.7 logs. No complete elimination of the three pathogens was obtained using AC-EW possibly because of the level of organic matter and blood moving from food samples to the AC-EW solution. This study demonstrates that AC-EW could considerably reduce common foodborne pathogens in fish, chicken and beef products.

NOTA TÉCNICA: QUALIDADE MICROBIOLÓGICA DAS FARINHAS DE ORIGEM ANIMAL PROCESSADAS EM UNIDADES LOCALIZADAS NO ESTADO DE MINAS GERAIS, BRASIL

As farinhas de origem animal apresentam potencial de contaminação microbiológica, no entanto, são ainda muito utilizadas na formulação de dietas para animais. O objetivo deste estudo foi avaliar a qualidade microbiológica das farinhas de origem animal processados em oito unidades distribuídas no estado de Minas Gerais. As amostras de farinhas de vísceras (248), de carne e ossos (224), e farinhas de penas (216) foram coletadas para avaliação microbiológica no recebimento de uma fábrica de ração, localizada na cidade de Viconde do Rio Branco, MG. Os resultados demonstraram um elevado índice de contaminação bacteriana pelas espécies Salmonella sp. (5,3x102) e Staphylococcus sp. (4,5x105), coliformes totais (2,8x105), coliformes termotolerantes (3,3x105), mesófi los totais (4.7x105), e colônias de fungos (3,6x105). As farinhas de origem animal processadas na unidade “A” apresentaram os maiores níveis de contaminação microbiológica. Além disso, as farinhas de vísceras foram os subprodutos com qualidade inferior. As farinhas de origem animal obtidas nas unidades de processamento estão fora do padrão exigido pela legislação no que se refere a qualidade microbiológica e colocam em risco a qualidade fi nal da ração. Concluiuse que as farinhas de origem animal não atendem a qualidade mínima para serem comercializadas para as fábricas de rações.

Sunflower protein films incorporated with clove essential oil have potential application for the preservation of fish patties

The incorporation of sunflower protein films with clove essential oil and the application of the resulting materials on the preservation of sardine patties were studied. The addition of clove essential oil to formulations based on sunflower protein concentrates allowed to prepare biodegradable and edible films with increased antioxidant properties and important in vitro antimicrobial properties. The presence of clove essential oil modified protein interactions reducing water solubility and glass transition temperature of resulting films, but it did not modify markedly their moisture content, thickness, color, opacity, water vapor permeability and mechanical properties. When applied to the preservation of refrigerated sardine patties these films allowed to retard fish lipidic auto-oxidation and to slightly delay the growth of total mesophiles, proving once again the importance of checking the films functionality in real food systems.

Propolis: a natural product as an alternative for disinfection of embryonated eggs for incubation

During the cooling process of embryonated eggs, there is a natural air flux from the surface to the inner part of the eggs, carrying contaminants such as bacteria and fungi through the shell's pores, infecting embryos and resulting in the inability to hatch or poor chick quality. Formaldehyde, a toxic product, is still the most used disinfectant for embryonated eggs in the aviculture industry. In order to evaluate the antimicrobial activity of the green propolis ethanolic extract as an alternative to formaldehyde, 140 hatching eggs from laying hens were collected and submitted to disinfection with five different treatments: T1 - without disinfection; T2 - formaldehyde fumigated eggs; T3, T4 and T5 disinfection by immersion in propolis solution in the concentrations of 2,400 µg, 240 µg and 24 µg, respectively. The contamination levels by total mesophiles and fungi of the egg shells (Aspergillus sp. and other moulds) after disinfection with propolis were lower than when compared to the control without disinfection. In comparison with formaldehyde, the 240 µg and 24 µg propolis concentrations did not differ regarding antibacterial activity, but for antifungal activity the 2,400 µg and 240 µg concentrations were more efficient. The 2,400 µg and 240 µg propolis treatments presented a hatching rate of 94.1%, compared to only 84.6% for the formaldehyde treatment. The green propolis ethanolic extract presented antibacterial and antifungal activities in embryonated eggs showing that it can be a new natural disinfectant product substituting formaldehyde.

Assessment of the impact of hydrogen peroxide solutions on microbial loads and quality factors of red bell peppers, strawberries and watercress

The impact of sodium hypochlorite and hydrogen peroxide (H2O2 at 1 and 5%) solutions on Listeria innocua in red bell peppers, total mesophiles in strawberries and total coliforms in watercress was studied. Quality attributes such as colour, firmness and pH were studied for all products; total anthocyanins content was determined for strawberries. Sensorial analyses were also carried out for all products. Results showed that H2O2 (5%) provided the highest reductions of microbial loads. Besides H2O2 (1%) had a lower impact, it was more effective than water-washings. Sodium hypochlorite solutions lead to microbial reductions comparable to water risings. In terms of quality, H2O2 (5%) was the solution with higher negative impact on products' colour. For strawberries, such colour alterations were also detected by sensorial analyses. The anthocyanins content decreased significantly. Overall it was found that H2O2 (1%) was a good sanitizer solution, since microbial reduction was attained while quality factors did not suffer considerable alterations.

Effect of protective atmospheres on physicochemical, microbiological and rheological characteristics of sliced Mozzarella cheese

Mozzarella cheese slices packaged in bags of polyvinylidene chloride under vacuum (V) and using a gas mixture of equal parts of CO2 and N2 (G) were stored at 4°C for 8 weeks and analysed at different storage times by physicochemical, microbiological and rheological characterization. Expected values of moisture, total nitrogen, soluble nitrogen at pH 4.6, and chloride contents and of pH were observed. The degradation of αs1-casein was greater than β-casein degradation, while no significant differences were observed due to the packaging methods. Coliform microorganisms were not detected, while levels of moulds and yeasts counts were acceptable. Expected values of total mesophile counts were obtained. The temperature at crossover moduli (Tc) was determined from temperature sweeps carried out by rheometry. Greater values of Tc were observed in samples G. The influence of temperature on complex viscosity was studied by an Arrhenius-type equation. Activation energy values were obtained from the solid-like region (20–40°C) and liquid-like region (40–60°C). A more rapid change in viscosity with temperature was observed when storage time increased and when storage method V was used.

Sensory, physicochemical and microbiological quality of fermented milk supplemented with probiotic diet Jenipapo osmotically dehydrated

There is a concern for people to consume more healthy foods, among these foods has been highlighted in recent years the probiotic fermented milk as well as having the nutritional characteristics of the basic food groups, also promotes beneficial health effects due to consumer action of probiotic bacteria existing in its constitution. As a consequence of these facts the present study aimed to develop and evaluate the probiotic fermented milk added with skim genipap osmotically dehydrated in relation to physicochemical, microbiological and sensory. We made the following physical and chemical analyzes (pH, titratable acidity, fat, protein, total solids, ash, carbohydrates and calories), microbiological (determining the number of lactic bacteria, most probable number (MPN) of coliforms at 35 and 45oC and counting total mesophile bacteria). In sensory analysis was applying the acceptance test for the following attributes: sweetness, aroma, texture, taste and overall impression and the determination of purchase intent. The results showed that fermented milk produced, kept during storage in the required microbiological standards ANVISA, the number of bacteria which is the microflora was 6.0 X10 7 CFU / mL after 28 days storage, the results of physicochemical and sensory show that the product has a high nutritional value and good acceptance by consumers, becoming a great alternative to commercial products since.

Comparison of Different Washing and Disinfection Protocols Used by Food Services in Southern Brazil for Lettuce (&amp;lt;i&amp;gt;Lactuca sativa&amp;lt;/i&amp;gt;)

Different protocols have been used for washing and disinfecting leafy vegetables in Brazilian food services, however its effect on microbial reduction was barely studied. The aim of this study was to evaluate the effectiveness of lettuce washing and disinfecting protocols used by food services. The treatments evaluated were: washing in potable tap water (T1); washing and dipping in potable tap water (T2); washing with potable tap water and dipping in a solution of sodium hypochlorite (200 ppm of free chlorine) for 15 min (T3); and 30 min (T4); washing with potable tap water and dipping in 2% vinegar solution (T5); and 20% vinegar solution (T6). After the treatments, the samples were microbiologically evaluated to measure bacterial reductions. The microbial counts showed that the mean total mesophile reductions were: 0.64 log for T1, 0.75 log for T2, 2.06 log for T3, 2.46 log for T4, 1.68 log for T5 and 1.72 log for T6, and the mean total coliform reductions were: 1.11 log for T1, 1.09 log for T2, 2.29 log for T3, 2.35 log for T4, 1.6 log for T5 and 2.09 log for T6. Based on these results it can be concluded that protocols which used 200 ppm sodium hypochlorite for 15 to 30 min (T3 e T4), were the most effective, followed by treatment with 20% vinegar solution (T6). The latter method, however, turned the lettuce dark during the distribution period.

Efficacy of non-thermal technologies and sanitizer solutions on microbial load reduction and quality retention of strawberries

The effect of non-thermal technologies (ozone in aqueous solution, ultrasound and ultraviolet C radiation) and washings with chemical solutions (sodium hypochlorite and hydrogen peroxide) on safety and quality features of strawberries was studied. These treatments were applied before fruit storage at two different temperatures (4 and 15°C). The overall impact on microbial loads (total mesophiles, and yeasts and moulds) and selected quality attributes (colour, firmness, pH, total anthocyanins and ascorbic acid content) was assessed.During storage under refrigerated temperature, washing with hydrogen peroxide solutions resulted in strawberries with lower microbial loads, when compared to the other treatments. However, it produced significant key quality attributes losses, such as colour and total anthocyanins content.The results presented show that ozone and ultrasound are promising alternatives to thermal treatments. The application of such technologies, before refrigerated storage of strawberries, allowed a satisfactory retention of all quality characteristics analysed, while being efficient in controlling microbial contamination.

Study of changes in physicochemical and microbiological characteristics of shrimps ( Melicertus kerathurus) stored under modified atmosphere packaging

Fresh minimally processed shrimps were stored under modified atmosphere packaging (60% CO 2:40% N 2 for MAP A and 92.9% N 2:5.1% CO 2:2% O 2 for MAP B) for 5 days at 3 °C. Total mesophiles, H 2S forming bacteria, Pseudomonas spp., Brochothrix thermosphacta, firmness, color and sensory parameters were investigated throughout the whole time of the experiment. During storage period samples stored under MAP B managed to retain firmness values close to the initial values. All microbial populations growth was suppressed by the presence of MAP A. Samples stored under MAP B managed to maintain their firmness values close to the initial ones while MAP A samples were significantly less firm ( p < 0.05).

EFFECT OF SODIUM ACETATE AND NISIN ON MICROBIOLOGICAL AND CHEMICAL CHANGES OF CULTURED GRASS CARP (CTENOPHARYNGODON IDELLA) DURING REFRIGERATED STORAGE

ABSTRACTMicrobiological quality, lipid oxidation and fatty acid composition of grass carp Ctenopharyngodon idella slices dipped in sodium acetate (0, 1 and 3%), nisin (0, 0.1 and 0.2%) or their combination during refrigerated storage of 8 days were monitored. Both nisin and sodium acetate inhibited the proliferation of total mesophile and lactic acid bacteria in dose dependent manner, but the combination treatments exhibited the higher efficacy in retardation of microbial growth. Higher concentrations of sodium acetate (3%) were more effective in preventing lipid oxidation. By the end of the storage period, higher n3 fatty acids, EPA (C20:5n‐3) and DHA (C22:6n‐3) content and lower n6/n3 ratio were found in the samples treated with 3% sodium acetate + 0.1 and 0.2% nisin. Nisin in combination with sodium acetate can therefore be used as the effective preservatives to maintain the quality of slices during refrigerated storage.PRACTICAL APLICATIONSAntimicrobial agents such as sodium acetate and nisin are found to be effective in preventing microbial growth and improving quality of food under storage condition. Treatment of slices using 3% sodium acetate in combination with 0.2% nisin was recommended as the best condition for maintaining the quality of grass carp slices stored under the refrigerated condition.

Study on Thermosonication and Ultraviolet Radiation Processes as an Alternative to Blanching for Some Fruits and Vegetables

The impacts of ultraviolet-C radiation, blanching by heat, and combination of heat/ultrasounds (thermosonication) were studied for Listeria innocua (inoculated) in red bell peppers, total mesophiles in strawberries and total coliforms in watercress, in the temperature range 50–65 °C. Quality attributes such as colour and firmness were studied for all products, and total anthocyanins content was additionally determined for strawberries. Results showed that ultraviolet-C radiation was the least effective treatment in terms of microbial load reduction and was equivalent to a simple water washing. Log reductions were 1.05 ± 0.52 for L. innocua, 0.53 ± 0.25 for total coliforms and 0.26 ± 0.18 for total mesophiles. This treatment had the lowest impact on the quality parameters analysed. Thermosonication treatment was similar to heat blanching for all microorganism/product tested, excepted for total coliforms in watercress at 65 °C, in which thermosonication had a higher effect (p < 0.05). Heat blanching at 65 °C allowed 7.43 ± 0.12 log-cycles reduction, while loads were diminished by 8.24 ± 0.13 log-cycles if thermosonication at the same temperature was applied. Thermosonication also allowed better quality retention, when compared to heat blanching at the same temperatures. The impact of thermosonication on microbial load reductions was statistically significant and thermosonicated samples retained quality attributes better than heat blanched ones at the same temperatures (p < 0.05). Hence, it can be concluded that thermosonication is a promising process and may be a favourable alternative to the conventional thermal treatments.

Modelling Microbial Load Reduction in Foods Due to Ozone Impact

Ozone is a strong sanitizer that can be applied as a convenient washing-treatment to foods. The main objective was to study the ozone impact on Listeria innocua in red bell peppers, total mesophiles in strawberries and total coliforms in watercress. Modelling microbial load reduction throughout treatment time and due to ozone effect were also targets. The microbiological reductions observed for ozonated samples were higher than the ones obtained for water dipping. However, total coliforms/watercress were less sensitive to both deionized-water and ozonated-water washings. A Weibull-based model was adequate in describing microbiological reductions and may contribute to design more effective sanitizing processes.

MODIFIED ATMOSPHERE PACKAGING OF NOPAL (PRICKLY PEAR CACTUS STEMS, OPUNTIA SPP.)

Prickly pear cactus stems (nopal or nopalito) are widely consumed in Mexico for their nutritional and health benefits, and also exported to some other countries. The effect of passive or semi-active modified atmosphere packaging (MAP) on the physico-chemical and microbiological characteristics of nopalitos was determined during storage at 5°C and 85% RH for up to 35 days. In semi-active MAP we have injected elevated pressures of CO 2 (20, 40 or 80 kPa) in the packages immediately after sealing. Passive atmospheres (where no CO 2 was added) were created with respiration gases and film permeability. Semi-active MAP with initial pressures of 40 or 80 kPa CO 2 increased the losses in texture, weight, chlorophyll content, dietary fiber content and color. Passive MAP, which developed an atmosphere of up to 8.9 kPa O 2 and up to 7 kPa CO 2 , and semi-active MAP with an initial 20 kPa CO 2 significantly decreased losses in all the quality parameters analyzed and in microbial population (total aerobic mesophiles, moulds and yeast counts), but slightly increased the total anaerobic mesophiles counts. The microorganisms identified were not pathogenic. Therefore, fresh prickly pear cactus stems can be stored for up to 32 days in MAP with CO 2 pressures ≤20 kPa without significant losses in quality, nor any significant increases in microbial population.

Contaminação microbiológica de alimentos comercializados em restaurantes de auto-serviço de Itumbiara-GO

The purpose of this study was to evaluate the microbiological conditions of food served in self-service restaurants in Itumbiara-GO. In total, we studied 23 restaurants and the foods collected were: pasta, tomato and cucumber salad, mayonnaise and meat from the pan. The samples were acquired with the support of the municipality's sanitary inspectors. Our research was focused on total mesophiles, coagulase positive taphylococci and heat tolerant coliforms. The sample preparations and their dilutions were performed according to the technique recommended by the Compendium of Methods for the Microbiological Examination of Foods. Non-contamination of food was confi rmed in only one restaurant. In 16 restaurants (69.6%), there were at least three types of food contaminated with scores above the standard allowed by law. All the pathogens studies were detected in at least one type of food. The most commonpathogen was coagulase positive Staphylococcus (86.5%). These results are alarming. The presence of potentially pathogenic microorganisms in the food demonstrates the poor sanitary conditions under which it was prepared.

The potential use of irradiation to extend the shelf‐life of clams (Ruditapes decussatus) during live storage: effect on bacterial and biochemical profiles

SummaryChanges in microbiological and biochemical quality of clams (Ruditapes decussatus) subjected to low doses of gamma irradiation (0.5 and 1 kGy) were investigated during alive storage, at 5 °C. The mortality rate was significantly lower for irradiated clams compared with the control. In the same way, ammonia content was lower for irradiated clams (especially 1 kGy irradiated group). Considerable levels of total mesophiles, coliforms, staphylococcus, faecal streptococcus and Escherichia coli were detected in the control and irradiation had immediately reduced these charges; all bacteria studied experienced a 1‐ to 3‐log reduction following 1 kGy irradiation. At the last day of storage, irradiated groups showed a noticeable reduction in the bacterial counts, whereas the mesophiles, staphylococcus and coliform germs were abundant in the control group (6.3, 2 and 1.7 log CFU g−1, respectively). Irradiation doses up to 1 kGy had not an immediate effect on fatty acids composition (P &gt; 0.05) and lipid profile was better in irradiated samples, where polyunsaturated fatty acid fraction was maintained throughout storage using irradiation. Also, sodium dodecyl sulphate‐polyacrylamide gel electrophoresis revealed minor changes in proteins bands between different samples. These results demonstrated that 1 kGy irradiation appeared to be the optimum dose for treating alive clams (R. decussatus), through improving the microbial quality and alleviating biochemical changes during refrigerated storage.

Técnicas de pulverização e imersão com distintos desinfetantes sobre ovos incubáveis

Foram conduzidos dois experimentos com o objetivo de avaliar a eficiência de diferentes princípios ativos desinfetantes e dois métodos de desinfecção de ovos. No primeiro experimento, as desinfecções foram realizadas por pulverização, enquanto que no segundo foram feitas por imersão, em granja de reprodutoras pesadas imediatamente após a postura. Os experimentos foram constituídos por um tratamento sem desinfecção e outros seis utilizando soluções desinfetantes: fenol sintético (1040ppm), digluconato de clorexidina (200ppm), amônia quaternária (800ppm), amônia quaternária (400ppm) + uréia (600ppm), amônia quaternária (130ppm) + glutaraldeído (370ppm) e formaldeído (7,7g m-3). Em cada experimento houve tratamentos-controle com fumigação (formaldeído) e sem desinfecção alguma. Após a desinfecção, 40 ovos por tratamento foram avaliados para presença de mesófilos totais, bolores e leveduras, coliformes totais, Pseudomonas sp e Aspergillus sp. Foi conduzido embriodiagnóstico nos ovos não eclodidos para determinação do período da mortalidade embrionária, da contaminação interior dos ovos, tendo sido determinado o nascimento de pintos impróprios para a criação e a eclodibilidade. No experimento em que os ovos foram desinfetados por pulverização, a associação entre amônia e glutaraldeído apresentou maior contaminação para mesófilos totais em relação aos demais tratamentos, à exceção do tratamento com fenol sintético, que apresentou contaminação semelhante a todos. Não foram detectadas diferenças entre os tratamentos para bolores e leveduras, coliformes totais, Pseudomonas sp e Aspergillus sp e, tampouco, entre os resultados de embriodiagnóstico. No experimento em que os ovos foram desinfetados por meio de imersão, foi verificada maior contaminação por mesófilos totais nos ovos não-desinfetados em relação aos desinfetados com os diferentes princípios ativos. Os ovos sem desinfecção também apresentaram maior contaminação por coliformes totais em relação aos tratados com amônia e uréia, sendo os demais tratamentos similares a todos. A análise de contaminação por bolores e leveduras, Pseudomonas sp e Aspergillus sp mostrou resultados similares entre os tratamentos. Os ovos desinfetados com formaldeído tiveram maior mortalidade embrionária, no período de quatro a sete dias, em relação àqueles desinfetados com amônia quaternária, sendo os outros tratamentos similares a todos. De modo geral, os desinfetantes estudados apresentaram capacidade de ação na redução da contaminação microbiana da casca de ovos incubáveis. Todos os desinfetantes também demonstraram ser seguros sob o ponto de vista de sobrevivência dos embriões, sem grandes restrições.

Monitoring and Identification of Bacteria Associated with Safety Concerns in the Manufacture of São Jorge, a Portuguese Traditional Cheese from Raw Cow's Milk

The aim of this study was to assess the hygienic quality of raw milk used in the manufacture of São Jorge, a Protected Denomination of Origin Portuguese semihard cheese, as well as to ascertain the sanitary conditions prevailing during its processing. Viable counts of Enterobacteriaceae and Micrococcaceae were accordingly obtained, pertaining to 21 independent batches (including samples of raw milk, curd, and cheeses after 1, 3, and 4 months of ripening), from 7 dairy farms. Standard plate counts (log CFU per milliliter or per gram) ranged from 6.1 to 8.6 in raw milk, whereas they ranged from 7.0 to 8.0 in 4-month-old cheeses. Viable counts of Enterobacteriaceae ranged between 5.9 and 7.0 in raw milk and between 0.0 and 1.3 in 4-month-old cheeses. Species identified within this family encompassed Klebsiella oxytoca, Klebsiella cloacae, Klebsiella pneumoniae, Enterobacter sakazakii, and Escherichia coli; Klebsiella ornithinolytica, Klebsiella terrigena, and Serratia odorifera were detected only in raw milk. No Salmonella whatsoever could be detected in any of the samples. Viable counts of Micrococcaceae ranged between 4.7 and 5.9 and between 1.3 and 3.3 in raw milk and 4-month-old cheeses, respectively. Species identified within this family encompassed Staphylococcus sciuri, Staphylococcus epidermidis, Staphylococcus saprophyticus (which was found mainly in ripened cheeses), and Staphylococcus aureus (which was not detected in 4-month-old cheeses). Accompanying physicochemical analyses included determination of moisture, salt, and pH. Statistical analyses revealed a negative correlation between salt content and viable numbers of Enterobacteriaceae in cheese, whereas in the case of Micrococcaceae, a more negative correlation was found between viable numbers and moisture content than between viable numbers and pH. The results of our study indicate, in general, poor milk handling conditions in all farms, given that the indicators total mesophile and Enterobacteriaceae counts were high, between 100- and 1,000-fold those enforced by international standards pertaining to the matrices in question. However, by the time of regular consumption (i.e., after 4 months of ripening), São Jorge cheeses exhibit low levels of contamination by Enterobacteriaceae and S. aureus, as well as absence of Salmonella.

Effect of lyophilisation, refrigerated storage and frozen storage on the coagulant activity and microbiological quality of Cynara cardunculus L. extracts

AbstractBACKGROUND:Cheese‐makers have traditionally kept vegetable coagulants refrigerated until use, even though little was known of their microbiological quality or coagulant activity during storage. This study aimed to assess the efficacy of lyophilisation, refrigerated storage and frozen storage of fresh vegetable extract as a means of standardising coagulant activity in terms of coagulation times, pH and microbiological quality.RESULTS:Neither the pH nor the coagulation time of lyophilised extracts was significantly modified during 1 year; however, changes were observed following frozen storage, and more notable following refrigerated storage. Lyophilisation of aqueous extracts prompted the destruction of most micro‐organisms; low counts initially noted for total mesophiles, lactic acid bacteria and yeasts disappeared during the first few days of storage, due to low water activity. There was a generalised decrease in micro‐organism counts during frozen storage. Refrigeration was found to be unsuitable for storing of cardoon extract; an increase of roughly 2 log unit counts was recorded in total mesophile, lactic acid bacteria, yeast and mould counts after 1 year of refrigerated storage.CONCLUSION:Refrigerated storage cannot be considered a suitable method for prolonged conservation of aqueous cardoon extract. Both lyophilisation and frozen storage of aqueous extracts proved ideal for prolonged storage of vegetable coagulant. Lyophilisation additionally had certain advantages over frozen storage. Copyright © 2008 Society of Chemical Industry

A Comparative Study on the Effects of Glucose Monohydrate, Hot Water, and Sodium Pyrophosphate on Quality Parameters and Microbial Flora of Deboned and Matured Brisket

Organic acids, hot water (HW), and chlorine have been commonly used in carcass decontamination for years. However, it has been observed that organic acids have adverse effects on color and are corrosive, while HW is discoloring. On the other hand, glucose fermentation by lactic acid bacteria in meat during the rigor period might be effective in microbial inhibition, without producing an adverse effect on the organoleptic quality of meat. Therefore, this study has aimed at finding an alternative meat decontamination procedure without any adverse effects. In this study, briskets were treated with 6 different applications: D (+) glucose monohydrate (GM) (16.51 g/100 mL, 15%) dip, HW dip, sodium pyrophosphate (SPP) and HW dip, GM + SPP + HW, and GM + HW combined dip. Then, the results of these applications were compared. First, GM + HW and GM + SPP + HW applications indicated more inhibition on Pseudomonas spp., Coliform and total Mesophile Aerob Bacteria growth, resulting in lower acidity loss (P < 0.01). Second, additional use of SPP with GM and HW did not enhance microbial inhibition (P < 0.01). Finally and most importantly, GM, 15%, improved a and b Hunter values significantly (P < 0.01), producing a very intense red meat color that can be very attractive for meat producers and consumers.