scholarly journals Assessment of Microbiological Safety and Physicochemical Changes of Grey Oyster Mushroom (Pleurotus sajor-caju) during Storage at 4 °C and 25 °C

2021 ◽  
Vol 50 (10) ◽  
pp. 2993-3002
Author(s):  
Suhaili M. ◽  
Nor-Khaizura M.A.R. ◽  
Nur Hanani Z.A. ◽  
Ismail-Fitry M.R. ◽  
Samsudin N.I.P. ◽  
...  
Keyword(s):  
Oyster Mushroom ◽  
Plate Count ◽  
Slight Reduction ◽  
Microbial Quality ◽  
Quality And Safety ◽  
Microbial Counts ◽  
Physicochemical Changes ◽  
Increasing Trend ◽  
Colour Changes ◽  
Aerobic Plate Count

This study aimed to evaluate the microbiological and physicochemical properties of grey oyster mushroom during storage (day 0, 3, 6, 9, 12) at 4 °C and 25 °C. The microbial quality and safety analyses were aerobic plate count (APC), yeast and mould count, Escherichia coli count, Bacillus cereus count, and Listeria monocytogenes count, while the physicochemical analyses were pH, water activity, colour, and firmness. Grey oyster mushroom stored at 4 °C showed increasing trend in all microbial counts. A similar trend was observed at 25 °C, but with higher microbial counts except for L. monocytogenes which had a slight reduction from 1.82 ± 1.16 at day 0 to 0.24 ± 0.34 log CFU/g at day 6. The pH of grey oyster mushroom was quite stable when stored at 4 °C (6.42 ± 0.03 at day 0 to 6.46 ± 0.21 at day 12). A decrease in pH was observed when the mushroom was stored at 25 °C (6.42 ± 0.03 at day 0 to 5.38 ± 0.93 at day 6). The Browning Index (BI) increased which indicated by the colour changes on the mushroom cap (front and back) especially at 25 °C. Firmness analysis carried out on mushroom cap and stalk showed a decreasing trend during storage, at which 25 °C displayed prominent loss of firmness in cap and stalk as compared to 4 °C. In conclusion, slower deterioration was observed in grey oyster mushroom stored at 4 °C as compared to 25 °C. This is based on lower microbial counts, and minimal changes in pH, BI, and firmness of grey oyster mushroom.

Microbial Quality of Hoummos (Chickpea Dip) Commercially Produced in Jordan

1994 ◽  
Vol 57 (5) ◽  
pp. 431-435 ◽  
Author(s):  
MOHAMMED I. YAMANI ◽  
BASIM A. AL-DABABSEH
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Low Ph ◽  
Plate Count ◽  
Microbial Quality ◽  
Aerobic Plate Count ◽  
And Staphylococcus Aureus ◽  
Reference Samples ◽  
Hygienic Conditions

Sixty samples of fresh hoummos (chickpea dip) from 15 restaurants were examined in winter and summer to find out numbers and types of microorganisms present. Five reference samples, produced by the investigators under hygienic conditions, were examined for comparison. The microbial load of commercial hoummos was high, and spherical lactic acid bacteria (LAB) belonging to Lactococcus, Enterococcus and Leuconostoc were the predominant microorganisms. The means of the aerobic plate count (APC) and the counts of LAB and coliforms (1.9 × 108, 1.6 × 108 and 2.9 × 105/g, respectively) in summer samples were significantly higher (p < 0.05) than the averages of the same counts in winter samples (2.7 × 107, 1.6 × 107 and 2.2 × 103/g). The average summer and winter yeast counts were 4.2 × 104 and 1.5 × 104g, respectively. In reference samples of hoummos, APC and LAB counts were < 103/g, while the coliform and yeast counts were < 10/g and 102/g, respectively, indicating lack of hygienic practices during the production of commercial hoummos. Salmonella was not detected in any sample, and Escherichia coli and Staphylococcus aureus counts of all samples were < 10/g. The relatively low pH of hoummos (the average pH of all samples was 5.1) and the rapid growth of LAB, possibly accompanied by production of inhibitory substances, may explain the predominance of these bacteria, and could have contributed to the absence of the pathogens examined.

scholarly journals Sensory, Physicochemical and Microbiological Characteristics of Venison Jerky Cured with NaCl and KCl

2016 ◽  
Vol 5 (4) ◽  
pp. 36 ◽  
Author(s):  
Wannee Tangkham ◽  
Frederick LeMieux
Keyword(s):  
Moisture Content ◽  
Physicochemical Characteristics ◽  
Plate Count ◽  
Purchase Intent ◽  
High Sodium ◽  
Microbial Counts ◽  
Microbiological Characteristics ◽  
Nacl Concentration ◽  
Aerobic Plate Count ◽  
Hedonic Scale

<p>Traditionally, jerky is produced from sliced whole muscle marinated in a high sodium chloride (NaCl) concentration and dried. Because a high salt diet has been linked to hypertension, salt substitutes are often recommended as a healthier alternative. However, potassium chloride (KCl), a popular salt substitute may impart an undesired bitterness and metallic aftertaste. The objective of this study was to evaluate specific attributes of venison jerky prepared in three different (NaCl/KCl) salt solutions. Through sensory testing, each preparation was evaluated for consumer product acceptance and purchase intent. Additionally, the venison jerky was assayed for physicochemical characteristics and microbial counts. Using a 9-point hedonic scale, sixty-eight consumers evaluated the jerky for acceptability of flavor, texture, taste, saltiness, bitterness and overall liking. Physicochemical characteristics were evaluated for moisture content, pH, color and TBAR. Jerky was assayed for microbial counts via aerobic plate count, <em>Escherichia coli</em>, <em>Staphylococcus aureus</em> and<em> Campylobacter</em> spp. Results show that jerky prepared with 100% KCl received the most desirable score (8.75), compared to jerky prepared with 100% NaCl (6.28), and jerky prepared with 50% NaCl + 50% KCl (6.13). Acceptability and purchase intent questionnaires indicate jerky prepared with 100% KCl ranked the highest at 86.8% and 70.6%, respectively. Jerky prepared with 100% KCl had the lowest moisture content, TBAR, and a* values (P&lt;0.05). No <em>E. coli</em>, <em>S. aureus </em>and<em> Campylobacter </em>spp.<em> </em>were detected over the 28 day period. Our study suggests that jerky prepared with KCl represents a low sodium alternative to traditional jerky.</p>

scholarly journals Comparative assessment of dried fish quality collected from market and drying centre at Kuakata in Patuakhali, Bangladesh

2021 ◽  
Vol 33 (1) ◽  
pp. 137-146
Author(s):  
MST. NILOY JAMAN ◽  
MD. SAZEDUL HOQUE ◽  
FARJANA YEASMIN ◽  
MD. MAHMUDUL HASAN ◽  
MD. ABU SAYED RIPON ◽  
...  
Keyword(s):  
Quality Characteristics ◽  
Plate Count ◽  
Microbial Quality ◽  
E Coli ◽  
Significant Difference ◽  
Dried Fish ◽  
Aerobic Plate Count ◽  
Bombay Duck ◽  
And Storage

The study identified the quality differences of dried Chinese pomfret (Stromateus chinensis), Bombay duck (Harpodon nehereus) and ribbon fish (Trichiurus haumela) from market and drying center at Kuakata, Patuakhali. The sensory, nutritional and microbial quality of collected dried samples were evaluated following organoleptic quality index, standard AOAC and aerobic plate count methods, respectively. Organoleptically no significant difference found between the samples from market and drying center. The highest moisture content value was obtained in Bombay duck (29.78%) from the market and lowest value in Chinese pomfret (20.06%) from drying center. The highest and lowest protein content was in Chinese pomfret (60.73%) and Bombay duck (47.9%) from drying center and market, respectively. The lipid and ash content varied from 2.85% to 7.20% and 13.98% to 19.57% for all the dried fish species collected from both sites. Microbiologically, higher aerobic plate count (APC), total E. coli count (TEC) and total Salmonella count (TSC) were found in Chinese pomfret at 1.96×106 CFU/g, 3.98×105 CFU/g and 1.62×105 CFU/g from market and lowest count found in Bombay duck at 5.05×105, 2.22×105 and 0.81×105 from drying center, respectively. In ribbon fish no Salmonella sp. was found. Based on the sensory and nutritional quality the study conclude that among three species and two sites studied, the dried Bombay duck from the fish drying center had better quality characteristics than the counter parts. However, higher microbial load especially pathogenic TSC and TEC suggests to improve hygiene and sanitary practices, better market distribution and storage facilities need to be followed by the producers for safe and quality dried fishery products.

Microbiological and Color Aspects of Cooked Sausages Made from a Standardized Porcine Blood Cell Concentrate

2007 ◽  
Vol 70 (5) ◽  
pp. 1181-1186 ◽  
Author(s):  
BERNHARD NOWAK ◽  
ADOLF HEISE ◽  
NIKOLAI TARNOWSKI ◽  
THEDA von MUEFFLING
Keyword(s):  
Blood Cell ◽  
Whole Blood ◽  
Anaerobic Bacteria ◽  
The Other ◽  
Plate Count ◽  
Table Salt ◽  
Microbial Counts ◽  
Aerobic Plate Count ◽  
The Impact ◽  
Coagulase Positive Staphylococci

The objective of this study was to determine the potential for blood cell concentrates (BCCs) from pigs as an ingredient in food. Sausages were made for this study according to a basic recipe for a type of blood sausage that is common in Germany. First, sausages were produced with rind and kettle broth only, and different amounts (2.5 to 31%) of standardized blood cell concentrate (s-BCC) were added (15% table salt [NaCl] and 25% protein content). Then, sausages were made with whole blood and compared with s-BCC sausages; both the BCC and blood had been pretreated either with NaCl or curing salt (nitrite). The impact of BCC and blood on the color (La*b*) of these rind sausages was determined. Finally, blood sausages were made with 12% s-BCC and either natural spices or spice extracts. These sausages were investigated microbiologically and compared to customary commercial blood sausage products (with whole blood) in terms of aerobic plate count (APC), Enterobacteriaceae, sulfite-reducing anaerobic bacteria, coagulase-positive staphylococci, and spore-forming bacilli. The desired color parameters (L, 34.5; a*, 17.8; and b*, 10.6) were obtained with the addition of about 12% s-BCC. Curing the blood or BCC beforehand had no significant (P &gt; 0.05) influence on the color. The microbial counts of both the blood (APC, 4.4 log CFU/g) and the natural spices (APC, 6.6 log CFU/g) were relatively high. The spices were responsible for the relatively high microbial counts in the sausages, particularly the bacilli (6.4 log CFU/g). However, these counts were comparable to those found in commercial blood sausages. The bacteria introduced into the sausage by the blood had no significant impact on the bacterial counts of the end product. The bacterial loads of the sausages produced with 12% s-BCC and spice extracts were significantly lower (APC and bacilli, 2.0 log CFU/g) than those of the other blood sausages (APC, ∼4.4 log CFU/g; bacilli, 3.2 to 4.0 log CFU/g).

Adenosine Triphosphate Bioluminescent Assay to Enumerate Bacterial Numbers on Fresh Fish

1986 ◽  
Vol 49 (8) ◽  
pp. 647-650 ◽  
Author(s):  
DONN R. WARD ◽  
KATHLEEN A. LaROCCO ◽  
DEBRA J. HOPSON
Keyword(s):  
Adenosine Triphosphate ◽  
Enzymatic Degradation ◽  
Plate Count ◽  
Microbial Quality ◽  
Bioluminescent Assay ◽  
Fresh Fish ◽  
Microbial Counts ◽  
Conventional Plate ◽  
Differential Filtration

The microbial quality of fresh fish was determined by using a bacterial ATP bioluminescent assay. Assay procedures included differential filtration followed by enzymatic degradation of somatic ATP. This technique limited interference from non-bacterial ATP sources and thus bacterial ATP was quantitated by using the luciferin-luciferase reaction in an automated luminometer. Good correlation (r = .96) was obtained from four species of finfish when microbial counts, determined from ATP analyses, were compared to counts determined by using conventional plate count procedures.

Microbial Quality of Ground and Comminuted, Raw and Cooked Turkey Meat1

1981 ◽  
Vol 44 (2) ◽  
pp. 139-143 ◽  
Author(s):  
G. A. MCKINLEY ◽  
J. S. AVENS
Keyword(s):  
Plate Count ◽  
Most Probable Number ◽  
Processing Plant ◽  
Microbial Quality ◽  
Probable Number ◽  
E Coli ◽  
Turkey Meat ◽  
Aerobic Plate Count ◽  
Meat Samples

The microbial quality of ground and comminuted turkey meat was examined using raw meat and meat after two cooking times. Eight triplicate samples were obtained from a commercial processing plant over an 8-month period and analyzed for aerobic plate count (APC), coliforms, Escherichia coli, Staphylococcus aureus, Clostridium perfringens and Salmonella. The APC for 29%of the raw ground and 0% of the raw comminuted turkey meat samples was greater than 5.0 × 106/g. Raw ground and comminuted meat yielded a mean coliform most probable number (MPN) of 2.2 × 102 and 6.2 × 102/g respectively. Mean E. coli MPNs per gram were 12 for raw ground and 49 for raw comminuted meat. Twenty-five percent of the 24 raw ground samples, and 46% of the comminuted samples exceeded 50 E. coli MPN/g. S aureus was isolated from 25% of the raw ground and 54% of raw comminuted samples. Salmonellae were isolated from 8% of the raw ground samples and 12% of raw comminuted samples. C. perfringens was isolated from 50 and 55% of 40 ground and 40 comminuted meat samples, respectively. Cooking reduced the microbial numbers and isolation frequency from all samples.

scholarly journals Nutritional Content and Microbial Quality of Complementary Foods Produced from Blends of Orange-Fleshed Sweet Potato and Edible Insects

2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 732-732
Author(s):  
Isaac Agbemafle ◽  
Doris Hadzi ◽  
Francis Amagloh ◽  
Francis Zotor ◽  
Manju Reddy
Keyword(s):  
Sweet Potato ◽  
Infant Nutrition ◽  
Energy Content ◽  
Plate Count ◽  
Microbial Quality ◽  
Edible Insects ◽  
Nutritional Content ◽  
Complementary Foods ◽  
Steam Cooking ◽  
Orange Fleshed Sweet Potato

Abstract Objectives Improved formulations of complementary foods (CFs) with animal-source foods (ASFs) is an eminent strategy to improve infant nutrition, but they are expensive and not readily available in many food insecure settings which are a haven of edible insects. Hence, we developed orange-fleshed sweet potato (OFSP) based CFs supplemented with Cricket or palm weevil larvae (PWL), examined its nutritional content and microbial quality for infant feeding. Methods OFSP roots were sourced from local farmers, peeled, sliced, steam cooked and mechanically dried into OFSP flour. Cricket powder and PWL paste were obtained from commercial producers, steam cooked, and mechanically dried into Cricket/PWL flours. OFSP flour was mixed with either Cricket/PWL flours in the ratios of 100:0 (control), 85:15, 70:30, and 50:50 and used to produce ready-to-eat CFs. The CFs were evaluated for nutrient composition and microbial contamination using standard methods. ANOVA followed by Dunnett's test was used to compare all the formulations to the control. Results There were increase in protein (4.80 to 36.75%), iron (1.26 to 4.38 mg/100 g), zinc (0.69 to 10.65 mg/100 g) and calcium (45.54 to 152.77 mg/100 g) contents of the OFSP-based CFs with increased supplementation with Cricket/PWL flour. The carbohydrate and β-carotene content decreased but the energy content increased with increased supplementation with cricket/PWL flour from 344.52 Kcal/100 g in 100% OFSP CF to 541.09 Kcal/100 g in 50:50 CFs (OFSP: PWL) (P = 0.001). Aerobic mesophilic count (AMC) of the OFSP: Cricket CFs was 60 cfu/g as compared to 1300 cfu/g for the OFSP: PWL CFs. Comparing the OFSP-based Cricket/PWL CFs to the commercial Cricket or PWL, there was 35–331-fold reduction in AMC. Bacillus cereus (BC), aerobic (APC) and anaerobic plate count (NPC) was 0 cfu/g for the OFSP: Cricket CFs. BC, APC and NPC were 100, 260 and 130 cfu/g respectively for the OFSP: PWL CFs. Conclusions Steam cooking, then mechanical drying significantly reduced microbial concentrations in commercial Cricket and PWL to below minimum limits set by the Ghana Standards Authority for CFs requiring heating to boiling before consumption. OFSP-based Cricket/PWL composite flours could be safe viable alternatives as nutritious CFs in countries where they are culturally accepted as food. Funding Sources Nutritional Sciences Council at Iowa State University.

Microbiological Quality of Commercial Tofu

1984 ◽  
Vol 47 (3) ◽  
pp. 177-181 ◽  
Author(s):  
T. G. REHBERGER ◽  
L. A. WILSON ◽  
B. A. GLATZ
Keyword(s):  
Microbiological Quality ◽  
Plate Count ◽  
Microbial Counts ◽  
Colony Forming Units ◽  
Low Levels ◽  
Microbial Groups ◽  
Yeasts And Molds ◽  
Processing Techniques

A study was done to investigate the microbiological quality of commercial tofu available in local retail outlets. A sampling method was first developed to obtain accurate and representative microbial counts of individual pieces of tofu. Plate count determination of total aerobic organisms, psychrotrophs, coliforms, sporeformers, yeasts and molds, and staphylococci were made on 60 tofu samples (representing three lots each of four different brands) obtained within 24 h after delivery to the retail store. In addition, for two brands that provided manufacturer's pull dates, the same microbial counts were obtained for samples stored in the laboratory at 10°C until the pull date. Of the tofu sampled immediately after purchase, 83% of the lots tested had total counts greater than 106 colony-forming units (CFU)/g and psychrotrophic counts greater than 104 CFU/g. In addition, 67% of the lots tested had confirmed coliform counts greater than 103 CFU/g. Very low levels (less than 10 CFU/g) of all other microbial groups tested for were found in the majority of lots. Samples held until the manufacturer's pull date contained higher total and psychrotrophic counts but lower or stable counts of other organisms compared with samples tested immediately after purchase. To improve the microbiological quality of tofu, processors need to reduce initial loads by improving sanitation and processing techniques, and retailers should provide more consistent and colder refrigerated storage.

Study of the Microbial Ecology of Wild and Aquacultured Tunisian Fresh Fish

2011 ◽  
Vol 74 (10) ◽  
pp. 1762-1768 ◽  
Author(s):  
MOUNA BOULARES ◽  
LOBNA MEJRI ◽  
MNASSER HASSOUNA
Keyword(s):  
Aeromonas Hydrophila ◽  
Microbiological Quality ◽  
Common Species ◽  
Microbial Populations ◽  
Plate Count ◽  
Gram Negative Bacteria ◽  
Fresh Fish ◽  
Psychrotrophic Bacteria ◽  
Aerobic Plate Count

Eighty samples of fresh fish were collected in Tunisia and analyzed for microbial load. Quality and hygienic safety of the meat and intestines of wild and aquacultured fresh fish were determined. The mesophilic aerobic plate count and populations of psychrotrophic lactic acid bacteria (LAB) and other psychrotrophic bacteria ranged from 5.67 to 7.29, 4.51 to 6, and 5.07 to 6.21 log CFU/g, respectively. For all microbiological determinations, bacterial counts were lower in meat than in the intestines of fresh fish. For all samples lower microbial populations were found in most of the wild fish than in the aquacultured fish. No isolates of the pathogenic genera Salmonella and Listeria were detected in any sample. Among the 160 strains of biopreservative psychrotrophic LAB and the 150 strains of spoilage psychrotrophic gram-negative bacteria identified by biochemical and molecular methods, Lactobacillus (six species) and Pseudomonas (six species) predominated. Lactococcus, Leuconostoc, Carnobacterium (C. piscicola and C. divergens), Aeromonas, and Photobacterium were the most common genera, and Lactococcus lactis, Lactobacillus plantarum, Pseudomonas fluorescens, and Aeromonas hydrophila were the most common species. These findings indicate that the microbiological quality of fresh fish in Tunisia can be preserved by controlling pathogenic and psychrotrophic bacteria.

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