Plate Count Bacteria Research Articles

Microbiological quality, fungal diversity and aflatoxins contamination in carob flour (Prosopis flexuosa)

Carob flour is obtained from pods of some species of Prosopis, leguminous trees that abound in many desert habitats worldwide. Currently, this product is available in healthy food stores in several countries, including Argentina, as a nontraditional meal of growing interest with multiple applications for the preparation of puddings, biscuits and snacks, among others. The objective of the present study was to evaluate the microbial quality of carob flour on basis of the presence of deteriorative and pathogenic microorganisms. Fungal diversity of the mycobiota was also studied with a special interest in toxigenic fungi. Eighteen samples of carob flour (Prosopis flexuosa) were analysed. Standard plate count of aerobic mesophilic bacteria showed levels of contamination ranging from <102 (estimative) to 6.8 × 105 CFU/g; total coliforms from <102 (estimative) to 4.7 × 105 CFU/g; moulds and yeasts from 2.1 × 102 to 8.1 × 104. In all samples, the absence of Salmonella sp. was verified in 25 g and counts of Bacillus cereus less than 102 were observed. These results indicate that from the safety point of view the carob flour studied does not have a significant microbial load. Regarding to fungal contamination, Aspergillus and Penicillium were the genera more diverse in species and were present in all the samples. Some of the species identified were potential mycotoxins producers. Among the most frequently detected species in the studied mycobiota were the Aspergillus of the Flavi section, well recognized as potential aflatoxin producers. The A. flavus species was one of the most widely distributed, since it was detected in almost all samples. A. parasiticus and A. arachidicola were found more sporadically. Aflatoxins analysis demonstrated that a high proportion of the samples were contaminated with aflatoxins in concentrations relatively low, ranging from 1.26 to 20.33 μg/kg of total aflatoxins. Type G aflatoxins are much less frequent contaminants than type B aflatoxins, which is consistent with the fact that A. parasiticus and A. arachidicola (producers of type B and G aflatoxins) were detected sporadically, while A. flavus, which produces aflatoxins B1 and B2, was present in a high number of samples. Results of the present work indicate that carob flour is susceptible to Aspergillus section Flavi and aflatoxin contamination and should be subjected to aflatoxin monitoring prior to marketing as required for other traditional crops.

Antibiotic sensitivity of bacteria associated with selected waste dumpsites in Akure, Nigeria

A study was carried out to determine the antibiotic sensitivity pattern of bacteria isolates associated with selected waste dumpsites in Akure metropolis, Nigeria. Results revealed that the total plate count of bacteria ranged from 1.3×105 cfu/g to 3.0×106 cfu/g. Bacillus subtilis, Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhi, Streptococcus faecalis, Shigella dysenteriae, Escherichia coli, Micrococcus luteus, Serratia marcescens, Clostridium botulinum were the isolated bacterial species. The temperature and pH values ranged from 26˚C to 28˚C and 5.68 to 6.48 respectively. Pseudomonas aeruginosa and Serratia showed susceptibility to antibiotics while Micrococcus luteus exhibited resistance to the antibiotics. Some of these isolated bacteria are pathogenic and thus, poses potential threat to the local inhabitant of the area. Therefore, proper waste management practices must be put in place to avoid environmental health hazards.&#x0D; Keywords: bacteria, dumpsites, antibiotic, waste management, environmental health

Effect of nitrogen nanobubble preservation on the quality, microbial population, and storage life of fresh yellowfin tuna (Thunnus albacares)

The objectives of this study were to evaluate the effect of nitrogen nanobubble for storing fresh yellowfin tuna (Thunnus albacares). Yellowfin tuna were stored for 10 days in two types of treatment: nitrogen nanobubble (NNB) and conventional packaging process (CPC). Two methods including qualitative (organoleptic) and quantitative (histamine and mercury content, and total plate count of bacteria) were analyzed to determine the treatments effect on post-harvest quality, microbial population, and shelf-life of the fish. Results show that nitrogen nanobubble is proven to maintain dissolved oxygen levels remain in low conditions ( < 1 mg/L) during treatment. Although the organoleptic properties for both treatments do not show any significant differences, the lowest histamine and mercury contents are found in treatment NNB at 11.8 mg/kg and 0.14 mg/kg, respectively. The microbes in treatment NNB is achieved levels deemed safe (based on national standards) at 1.8 × 104 colonies/g, E. coli content <3 MPN/g, and the presence of Salmonella sp. are not detected. Our results suggest that treatment NNB is preferable for preservation process of fresh yellowfin tuna and might improve to extend the shelf-life.

Microbiological and Nutritional Analysis of Lettuce Crops Grown on the International Space Station.

The ability to grow safe, fresh food to supplement packaged foods of astronauts in space has been an important goal for NASA. Food crops grown in space experience different environmental conditions than plants grown on Earth (e.g., reduced gravity, elevated radiation levels). To study the effects of space conditions, red romaine lettuce, Lactuca sativa cv ‘Outredgeous,’ plants were grown in Veggie plant growth chambers on the International Space Station (ISS) and compared with ground-grown plants. Multiple plantings were grown on ISS and harvested using either a single, final harvest, or sequential harvests in which several mature leaves were removed from the plants at weekly intervals. Ground controls were grown simultaneously with a 24–72 h delay using ISS environmental data. Food safety of the plants was determined by heterotrophic plate counts for bacteria and fungi, as well as isolate identification using samples taken from the leaves and roots. Molecular characterization was conducted using Next Generation Sequencing (NGS) to provide taxonomic composition and phylogenetic structure of the community. Leaves were also analyzed for elemental composition, as well as levels of phenolics, anthocyanins, and Oxygen Radical Absorbance Capacity (ORAC). Comparison of flight and ground tissues showed some differences in total counts for bacteria and yeast/molds (2.14 – 4.86 log10 CFU/g), while screening for select human pathogens yielded negative results. Bacterial and fungal isolate identification and community characterization indicated variation in the diversity of genera between leaf and root tissue with diversity being higher in root tissue, and included differences in the dominant genera. The only difference between ground and flight experiments was seen in the third experiment, VEG-03A, with significant differences in the genera from leaf tissue. Flight and ground tissue showed differences in Fe, K, Na, P, S, and Zn content and total phenolic levels, but no differences in anthocyanin and ORAC levels. This study indicated that leafy vegetable crops can produce safe, edible, fresh food to supplement to the astronauts’ diet, and provide baseline data for continual operation of the Veggie plant growth units on ISS.

Response of the Bacterial Community and Antibiotic Resistance in Overnight Stagnant Water from a Municipal Pipeline.

Although drinking water safety has raised considerable concern, to date, the hidden health risks in newly released overnight water from a municipal pipeline have seldom received attention. In this study, bacterial community composition and the response of antibiotic-resistant bacteria (ARB) to ciprofloxacin, azithromycin, tetracycline, penicillin, and cephalosporin in overnight stagnant water were analyzed. With increases in heterotrophic bacteria plate count (HPC) during water stagnation, the numbers of ARB and the ARB/HPC ratios for the five antibiotics in resident water were observed to increase, which illustrated that the prevalence of ARB rose in the pipe network water during stagnation time (ST). Furthermore, during water stagnation for 12 h, an increase in bacteria related to fermentation was also observed. When the ST rose to 48 h, the fermentation bacteria become non-significant, and this was related to the exchange of pipe network water during daytime stagnation within the 48-h period. The antibiotic resistance index (ARI) showed that tetracycline had the highest resistance level in fresh water, and then decreased during water stagnation. When ST increased to 12 h, all ARI values of the five antibiotics were low, which was associated with changes in parameters during water retention and reduced resistance during short-term stagnation. When the ST increased to 24 and 48 h, the resistance to most antibiotics (except for tetracycline) increased, which showed that increasing antibiotic resistance is caused by the formation of biofilms in the pipeline during water stagnation.

Single and combined effects of tea polyphenols and edible chitosan coating on the shelf life improvement of refrigerated dagger-tooth pike conger (Muraenesox cinereus)

ABSTRACT In China, the preservation of refrigerated daggertooth piker congers (Muraenesox cinereus) has received increasing attention in recent years due to the increased demand for fresh congers. In this study, the effect of tea polyphenols (0.1%, 0.2%, 0.4%) and chitosan (0.5%, 1%, 2%) on daggertooth piker conger preservation was evaluated based on major spoilage bacteria detected during cold storage. The preservation quality was assessed through sensory scores, TVB-N, and TBARS concentrations and plate counts of total bacteria, H2S-producing bacteria, and Pseudomonas. The results showed that all concentrations of tea polyphenols and chitosan successfully inhibited spoilage bacterial growth, suppressed TVB-N (total volatile basic nitrogen) and TBARS (thiobarbituric acid-reactive substances) generation, and improved the sensory score, although the results were not dose-dependent. The optimal concentrations of tea polyphenols and chitosan were 0.2% and 0.5%, respectively. A later assessment of the synergistic effect of tea polyphenols and chitosan coating conger samples with both preservatives at their optimal concentration. Possibly, due to their mechanic difference in bacteriostasis, the combined treatment significantly inhibited the growth of H2S-producing bacteria and Pseudomonas, indicating a better antibacterial effect than when using one of the preservatives alone. Finally, combined tea polyphenol and chitosan treatment prolonged the first- and second-grade freshness of refrigerated congers for 4–6 days.

Análise microbiológica da água de diferentes fontes da Escola Estadual Agrotécnica Afonso Queiroz

Water is essential for the survival of the human being and the balance of nature, though it can hold several microorganisms that can cause different pathologies what makes necessary its microbiological control. The aim of this study was to evaluate the microbiological quality of the water from different sources of the Afonso Queiroz State Agrotechnical School located in the city of Patos de Minas, Minas Gerais, Brasil. Two samples of the shallow well and the Canavial Stream were collected during the morning and afternoon periods. Using the Colilert method, it was possible to identify total coliforms, Escherichia coli and plate counts of heterotrophic bacteria. It was concluded that the water evaluated was not within the standards of the current legislation, due to the presence of at least one microorganism researched. Therefore, the water from the sources cannot be used for human consumption, becoming mandatory the adoption of preventive measures and adequate treatment to preserve the water sources.

An evaluation of alternative methods for sanitizing hatching eggs

Different sanitization methods were evaluated as alternatives to formaldehyde fumigation for the reduction of eggshell and yolk sac microbiological counts, improvement of eggshell quality, incubation parameters, and day-old chick quality. A total of 10,080 hatching eggs were collected from a 70-wk-old commercial broiler breeder flock and distributed in a completely randomized block design with seven treatments: fumigation with paraformaldehyde (5.03g/m3/30min), fumigation with ozone (5-15ppm/30min), ultraviolet light-C irradiation (8.09mW/cm2; 120 s; UV-C), hydrogen peroxide spraying (3%; 0.69mL/egg), peracetic acid spraying (0.3%; 0.69mL/egg; PAA), water spraying (0.69mL/egg; water control), and without disinfection (dry control-DC). Spraying eggs with PAA and UV-C significantly reduced aerobic bacteria plate counts compared to the DC group. In addition, eggs disinfected with PAA had lower Enterobacteriaceae counts than the DC and water control groups. Eggshell quality, incubation parameters, and microbiological counts for yolk sac did not differ (P > 0.05) among treatments. This study demonstrated the potential for the application of PAA and UV-C for eggshell disinfection instead of formaldehyde; however, an electronic microscopic evaluation of the eggshell is necessary to determine if these methods cause any damage to the cuticle.

The effect of edible coating contained Kecombrang leaves concentrate on gourami fish fillet quality

Gourami fillet is fishery product that perishable and has short shelf life. To prolongs its shelf life, the application of edible coating could be performed. Edible coating is a thin layer that covers food products and serves as a protector against mass transfer (such as moisture, oxygen, light, lipids, and solutes) and as an additive carrier. Kecombrang contains bioactive compounds that act as antimicrobials. This study was aimed to know the effect of concentration addition of Kecombrang leaves concentrate to gourami fillet quality during storage at ±4°C. The experimental design used was Randomized Complete Design. The treatments were concentration of added concentrate of Kecombrang leaves (K) at amount of 1% (K1), 2% (K2), 3% (K3), and 4% (K4). The results showed that the application of edible coating contained Kecombrang leaves concentrates at concentration of 4% on gourami fillets showed best results according to color intensity, pH, free fatty acid content, and the total plate count of bacteria.

USE OF DIFFERENT PROBIOTICS FOR PREVENTION OF VIBRIOSIS DISEASE ON TIGER SHRIMP LARVAE REARED IN FIBERGLASS TANKSUSE OF DIFFERENT PROBIOTICS FOR PREVENTION OF VIBRIOSIS DISEASE ON TIGER SHRIMP LARVAE REARED IN FIBERGLASS TANKS

To counter disease problems caused by vibriosis in shrimp hatchery, this recent study used three different probiotics to be tested on tiger shrimp (Penaeus monodon) postlarvae. The study arranged four treatments as follows: A: a combination of three liquid-form probiotics Brevibacillus laterosporus BT951, Bacillus subtilis BM12, and B. licheniformis BM58; B: a combination of three powder-form probiotics Brevibacillus laterosporus BT951, Bacillus subtilis BM12, and B. licheniformis BM58; C: a commercial powder probiotic containing Bacillus subtilis; and D: control (without probiotic), each treatment with three replications. This study was set up in a completely randomized design experiment using twelve fiberglass tanks filled with 750 L sterile sea water and stocked with 30,000 nauplii in the Awarange shrimp hatchery of the Research Institute for Brackishwater Aquaculture and Fisheries Extension Installation in Barru. Variables observed in this study were the survival rate of the shrimp postlarvae at the end of the experiment, total vibrio count (TBV) and total plate count of common bacteria (TPC) in the culture water. The results showed that the survival rate of tiger shrimp applied either in liquid (A: 61.5±4.7%) or powder form (B: 48.6±6.8%), and control (without probiotic) (D: 51.2±4.4%) were not significantly different (P&gt;0.05). However, survival rates in these three treatments differed (P&lt;0.05) with that of the commercial probiotic (C: 21.7±9.9%). TBV/TPC ratio in the tank waters treated with the commercial probiotic (2.26-37.52%) was much higher than that of the liquid form probiotic (0.86-1.98%), powder form probiotic (1.25-8.37%), and control (1.93-2.84%). Ammonia-nitrogen in treatment C (1.462-2.989 mg/L) was relatively higher than that of in treatment A (1.595-2.435 mg/L), treatment B (1.644-2.115 mg/L), and treatment D (1.051-1.858 mg/L).

Effects of Liquid Probiotics (Lactobacillus sp.) on Microflora Balance, Enzyme Activity, Number and Surface Area of the Intestinal Villi of Broiler

The aims of this study were to determine the effects of probiotic liquid as feed additive on productivity, microflora balance, enzym activity, number and surface of intestinal villi of broiler. This study was used experimental method with Completely Randomized Design (CRD) on 144 Day Old Chicks (DOC) Lohman strain, which divided into 4 treatment groups and 6 replications. The treatment was the basal feed without the addition of liquid probiotic (P0); basal feed with 0,2 v/w liquid probiotic (P1); basal feed with 0,4 v/w liquid probiotic (P2) and basal feed with 0,6 v/w liquid probiotic (P3). Liquid probiotic containing composition of Lactobacillus sp. 1,4x10 10 cfu/mLl. Data were analyzed using a CRD followed by the Duncan Multiple Range Test. The results showed that liquid probiotic ( Lactobacillus sp.) as food additive give the significant effect (P 0,05) to protease and lipase activity. It`s showed significant effect (P<0,01) to total plate count (TPC) of lactid acid bacteria, Salmonella sp., Eschericia coli , surface of intestinal villi.. The result were concluded that the higher concentration of liquid probiotics in feed the higher microflora balance, protease and lipase activity, number and surface of intestinal villi. Decreasement of Salmonella sp. and Eschericia coli TPC. As suggestion, a liquid probiotics ( Lactobacillus sp.) 0.6 v/w in feed can produce the higher performance. Keywords: broilers, intestinal characteristics, liquid probiotic

Microbial diversities and potential hazards of Korean turbid rice wines (makgeolli): Multivariate analyses

A number of makgeolli (Korean traditional turbid rice wine) products are commercially available in various forms. To date, there has been no comprehensive investigation of these products. Here, we collected samples of almost all of the makgeolli products that are currently commercially available (n = 167), recorded their manufacturing variables, and examined physiochemical parameters and microbial communities, using quantitative and qualitative methods. The aerobic plate count (APC) and counts of lactic acid bacteria (LAB), acetic acid bacteria (AAB), fungi, total coliforms, and Bacillus cereus were obtained, and the presence of Escherichia coli and eight foodborne pathogens was also examined. The data obtained were segmented and analyzed based on multiple variables associated with the manufacturing characteristics. Despite high ethanol contents (up to 16.0%) and high acidities (pH 3.3–4.5), the rice wine products examined here had diverse and abundant microbiotas (mean values: APC, 5.3; LAB,4.4; AAB,1.5; fungi, 3.8 log CFU/ml). In particular, LAB and fungi, which are used as co-starter cultures during rice wine manufacturing, accounted for the majority of the microbiotas. Bivariate analyses revealed significant positive correlations between the individual micro-organism counts (Pearson correlation coefficient = 0.668–0.947). Among the manufacturing variables considered in this study, only the pasteurization status had a significant effect on the microbial communities of rice wine products (p < 0.05). When examining the presence of foodborne pathogens, B. cereus was isolated from some of the rice wine products (58.1%) at low levels (<100 CFU/ml), and its detection rate was not significantly lower in the pasteurized products than the raw products. Overall, the results presented here provide a comprehensive overview of the microbiotas of commercially available turbid rice wines and their relationships to manufacturing variables. These data will help to direct future studies focusing on rice wine quality and safety control measures.

PERHITUNGAN ANGKA LEMPENG TOTAL BAKTERI PADA TELUR AYAM RAS

Poultry farm chicken eggs is one of the favorite food for society besides meat and fish, because it is highly nutritious, versatile and cheaper than other eggs. The sample of this research uses 8 (eight) samples of poultry farm chicken eggs. This study aims to determine the quality of poultry farm chicken eggs microbiology based on the total plate count of bacteria. The results showed average the total plate count of bacteria on 8 chicken eggs is 104 CFU/ml. This shows that the results still qualified the standard defined by BPOM that is 107 CFU/ml and its mean poultry farm chicken eggs is safe for consumption.&#x0D; &#x0D; Keywords: Poultry farm chicken eggs, Total Plate Count of Bacteria

Cultivable anaerobic and aerobic bacterial communities in the fermentation chambers of Holotrichia parallela (coleoptera: scarabaeidae) larvae.

As important pests, scarab beetle larvae survive on plant biomass and the microbiota of the fermentation chamber play an important role in the digestion of lignocellulose-rich diets. However, the cultivable microbes, especially the anaerobic cultivable microbes, are still largely unknown. Here, both cultivable anaerobic and aerobic bacterial communities associated with the fermentation chamber of Holotrichia parallela larvae were investigated. In total bacteria cells directly enumerated by the 4’, 6-diamidino-2-phenylindole (DAPI) staining method, the viable plate counts of cultivable bacteria in the fermentation chamber accounted for 0.92% of proportion. These cultivable bacteria were prone to attach to the fermentation chamber wall (88.41%) compared to the chamber contents. Anaerobic bacteria were dominant in the cultivable bacteria attaching to the fermentation chamber wall (70.20%), while the quantities of anaerobes and aerobes were similar in the chamber contents. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE), fingerprinting and sequence analysis of isolated colonies revealed that the cultivable bacteria are affiliated with class γ-Proteobacteria, Bacteroidia, Actinobacteria, Clostridia and β-Proteobacteria. γ-Proteobacteria was the major type of anaerobic cultivable bacteria and even the only one type of aerobic cultivable bacteria. Taken together, our results suggest, for the first time, that anaerobic microbiota are dominant in cultivable bacteria in the special anoxia niche of the fermentation chamber from H. parallela larvae. These bacterial isolates could be a treasure trove for screening lignocellulytic microbes which are essential for the plant biomass digestion of this scarab species.

Isolation and Characterization of Stream Water Bacteria from ESA-OKE Metropolis

Water is essential to life, but many people do not have access to clean and safe drinking water and many die of waterborne bacterial infections. The study accessed the bacteria mean count of the three selected reputable streams in Esa-Oke metropolis and identified the bacteria isolated from the streams. The viable bacterial count was determined by the water samples up to 100.1 from 10 and 10 dilutions. Pour plate and streak plate methods were used for bacteria plate count and sub culturing respectively. Selective and differential media were also used for bacteria characterization. The result obtained from plate count shows that Afon Oke had higher count than other and also revealed that there is more Staphylococcus aureus in Ekoro than other while that from Arubu had more Pseudomonas aeruginosa than others. The study concluded that the stream should be monitor from the source since they are very close to residential areas and outbreak of water borne disease in imminent as well as the water inspection from the source should be consider very important.

Effects of Different Dietary Levels of Whey Lactose as a Prebiotic Disaccharide on the Productive Performances and Selected Indices of the Caecal Micro-Environment in Broiler Chickens

Abstract The primary aim of this study was to investigate the impact of three dietary levels of lactose (LAC) originating from conventional dried whey (DW) and the duration of these treatments (from 8 to 21 or to 42 days of age) on growth performance, basic post-slaughter traits and excreta quality of broiler chickens kept in cages. A secondary purpose was to investigate the effect of LAC level on some parameters of the caecal micro-environment and gross morphology in these birds. A total of 560 Ross 308 chickens (sex ratio 1:1) were assigned to 7 dietary combinations with 10 replicate cages of 8 birds per cage. The control group was fed basal diets consisting of maize, wheat and soybean meal. The other 6 groups received the same basal diets with DW added in amounts equivalent to a LAC dietary levels of 1, 2 or 3%. Only continuous feeding (day 8 to 42) with 1% and 2% levels of LAC was found to yield the overall body weight gain (BWG) during the whole 42-day rearing period, which was significantly higher than that on the control diet, with a larger share of breast meat in carcass at a 2% LAC. However, these effects were associated with greater faecal score values indicating more watery excreta compared with the control. Increasing levels of LAC augmented the relative caecal weight and length. A reduction in the caecal pH was confirmed at day 21 for birds fed 1% and 2% of dietary LAC. The lower pH values were correlated to an increased sum of total volatile fatty acids (VFA), causing large increases in the concentration of undissociated forms of individual VFA. The decline in plate counts of coliform bacteria was observed with 2% and 3% LAC, whereas the counts of lactic acid-producing bacteria (LAB) were higher at these two LAC levels. The present findings lead to the conclusion that the dietary level of 2% LAC originated from DW is the most effective in enhancing the productivity of broilers, with moderate occurrence of undesirable side effects.

PERFORMANCE OF CULTURED White-leg Shrimp IN RICA Probiotic Application METHOD in PONDS AERATED WITH SUPERCHARGE BLOWER

Several ways have been done to encounter shrimp disease affecting cultured shrimp in Indonesian ponds in the last two decades. This research was aimed to find out the effect of different application of probiotic RICA4, RICA5, and RICA3 method on survival rate and production of white-leg shrimp (Litopenaeus vannamei) cultured in ponds aerated with supercharge blower. RICA probiotics are bacteria probiotics produced by the Research and Development Institute for Coastal Aquaculture, originally isolated from seaweed and sea sediment. This experiment was carried out in completely randomized design using nine 250-m2 experimental ponds stocked with 15 shrimp fries/m2. There were three treatments namely: A=alternate use of three probiotics RICA4, RICA5, and RICA3; B=combination use of three probiotics RICA4, RICA5, and RICA3; and C=control (without probiotic), each treatment with three replications and cultured with supercharge blower. Variables observed in this study were survival rate and production of the shrimp calculated at the end of experiment, total vibrio count (TBV) and total plate count of common bacteria (TPC) of the pond waters and sediments monitored every two weeks. The results showed that application of probiotic RICA4, RICA5, and RICA3 applied either in alteration or in combination significantly increased survival rate (P&lt;0.05) but not on production (P&gt;0.05) of the white-leg shrimp. TBV/TPC ratio in the control pond waters after 10-weeks culture (over than 10%) was relatively dangerous for the cultured white-leg shrimp. This shows that application of probiotic could prevent the growth of Vibrio spp in the cultured shrimp pond water.

Effect of UV-irradiation on plate counts of bacteria from paddy field soil

Effect of UV-irradiation on plate counts of bacteria from paddy field soil

Microbiological quality of Argentinian paprika

The aim of this study was to evaluate the microbiological quality of paprika produced in Catamarca, Argentina. Microbiological analyses were carried out for the enumeration of total aerobic mesophilic bacteria, coliforms, yeasts and molds, and the detection of Salmonella in samples obtained from different local producers during three consecutive years. The mycobiota was identified paying special attention to the mycotoxigenic molds. Standard plate counts of aerobic mesophilic bacteria ranged from 2.7×105 to 3.7×107CFU/g. Coliform counts ranged from <10 to 8.1×104CFU/g. Salmonella was not detected in any of the samples tested. Fungal counts (including yeasts and molds) ranged between 2×102 and 1.9×105CFU/g. These results showed a high level of microbial contamination, exceeding in several samples the maximum limits set in international food regulations. The study of the mycobiota demonstrated that Aspergillus was the predominant genus and Aspergillus niger (potential producer of ochratoxin A) the most frequently isolated species, followed by Aspergillus flavus (potential producer of aflatoxins). Other species of potential toxigenic fungi such as Aspergillus ochraceus, Aspergillus westerdijkiae, Penicillium chrysogenum, Penicillium crustosum, Penicillium commune, Penicillium expansum and Alternaria tenuissima species group were encountered as part of the mycobiota of the paprika samples indicating a risk of mycotoxin contamination. A. westerdijkiae was isolated for the first time in Argentina.

Biochemical and microbiological quality of fermented silage prepared from dressing waste of Indian major carps using different concentrations of jaggery

Present study investigated the shelf life of fermented silage prepared from dressing waste (gut and gills) of Indian major carps and the effect of different concentrations of jaggery as carbohydrate source, on the biochemical and microbiological changes in the silage. Fermented silage was prepared using jaggery at 10% w/w (F1) and 20% w/w (F2) concentrations. F2 had a lower crude fat and ash content. The lowest pH attained was 4.11 and 4.02 in F1 and F2 respectively by the end of 15 days. Significantly higher (p&lt;0.05) concentration of total volatile base nitrogen (TVB-N) was observed in F2 from the 30th day of storage. The rate of auto-oxidation was also significantly higher in F2 throughout the storage period of 60 days. Total plate count (TPC) of bacteria in F1 and F2 reduced significantly till the 15th day of storage. At the end of 60 days of storage, pH reached 5.55 and 5.67 in F1 and F2 respectively, thereafter the silage was considered spoiled. The study indicated that fermented fish silage prepared from viscera and gills of Indian major caps remained shelf worthy for a period of 60 days and the use of jaggery at concentrations higher than 20% (w/w) would not be viable as it led to faster spoilage rate and increased cost of production