Total Aerobic Counts Research Articles

Antibiotics Susceptibility Pattern of Bacterial Isolates Obtained from Potable Water Sources in Okerenkoko Community, Delta State, Nigeria

Safety and purity of drinking and cooking water sources in rural and riverine communities like Okerenkoko have posed a challenge for scientific discuss in recent times. Water devoid of both chemical and microbiological contaminants have been identified as a major key to wellness of any populace. In this study, eight potable water sources were obtained and evaluated for the study; the potable water sources obtained were treated to a 10-fold serial dilution and plated for aerobic bacterial, fungal, Salmonella-Shigella and Escherichia coli count. The antibiotics sensitivity testing employed the modified Kirby- Bauer method using the Abtek biological multiple disc. The multiple drug resistance was mathematically deduced using the standards and breakpoints. The NMU and George borehole had 5.8 Log10CFU/ml and 5.4 Log10CFU/ml for the total aerobic bacterial count while the total fungal count were 3.1 Log10CFU/ml and 3.6 Log10CFU/ml respectively. The culturable flora observed during the study were Bacillus sp, Escherichia sp., Staphylococcus sp., Streptococcus sp., Shigella sp., Proteus sp., Pseudomonas sp., Klebsiella sp., Vibrio sp. Micrococcus sp. and Escherichia coli. The percentage resistance for the antibiotics revealed cefuroxime and ceftazidime had 64%, while nitrofurantoin had 71% and ofloxacin had 36%. Proteus sp. (1) had an MDR of 1.0, Klebsiella sp. (3) had 0.67 while Salmonella sp. and Escherichia coli had a MDR of 0.22 and 0.11. The findings of the study underscores the health challenges associated with the usage of the available potable water sources in Okerenkoko community. There is need for a community-wide campaign and sensitization on some basic water purification approaches as possible corrective actions to improve the quality of water; government must intervene and provide a routine and robust evaluation for both water safety and sanitary quality in rural communities.

Quality evaluation and microbial enumeration of plant based probiotic yoghurt from powdered milk and tiger nut milk

Some commercial yoghurt manufacturers have promoted the usage of artificial thickening and binding agents in the production of yoghurt. These substances, most of which are chemically synthesized could be dangerous. The purpose of this research is to assess the physicochemical characteristics of yogurt made from full cream milk, skimmed milk, and tiger nut milk. It also aimed to estimate the total aerobic plate count, total coliform count, and total mold count of the products for microbiological analyses. The powdered milk samples were reconstituted into liquid and the sorted-clean tiger nut was blended in order to extract the milk. Tiger nut milk proportion of 20 to 30 % was incorporated into the liquid milk before fermentation. The harvested yoghurt was assayed for sensory, physicochemical and microbial analyses. The result obtained showed a level of significant difference (p < 0.05). Among the samples produced, sample G has the least acceptable value 5.00 while sample C had the highest acceptable value 7.05 across the sensory scores. The values obtained from the physicochemical analysis showed that pH value ranged from 3.67 to 4.97. For TDS and titratable acidity (TA), the values ranged from 4.53 to 6.72 x 102 ppm and 0.62 to 0.87 respectively. None of the yoghurt samples had coliform growth on the medium after the incubation period while total viable count ranged from 78.67 to 227.33 cfu/ml and total mould count ranged from 16.67 to 56.67 sfu/ml at a dilution factor of 102. Tiger nut milk can be used in the production of yoghurt as a possible substitute because of its nutritional content and health advantages. Therefore, it is imperative to assert that the use of tiger nut milk in the manufacturing of yoghurt will improve the quality of yoghurt and ultimately result in a desired product.

Evaluation of microbiological quality and organoleptic properties of smoked dried fish sold in Wukari markets Taraba state, Nigeria

This study was conducted to investigate and assess the microbiological quality and organoleptic properties of smoked dried fish sold in Wukari markets, Nigeria. Eight samples of smoked dried fish (SA,CA,MB,SC,TP,CO,SA1,SA2) were analyzed for microbial quality and organoleptic properties using standard methods. The total bacteria aerobic plate count of bacterial cells ranged from 1.31 × 106 to 2.22 × 107, coliform count 1.00 × 105 to 7.40 × 106, Staphylococcal count 4.00 × 106 to 6.10 × 106 and fungi 1.50 × 106 to 8.3 × 106 cfu/g in the fish samples respectively. The microbial load of all samples was higher than the acceptable limit of 5.0 × 105 cfu/g. Identification of bacterial isolates revealed the presence of Staphylococcus aureus, Staphylococcus epidermidis, Bacillus spp, Pseudomonas spp, Escherichia coli, Salmonella typhi and Klebsiella spp. The mould isolates were Aspergillus niger, Aspergillus flavus, Penicillium and Clasporium. From the sensory evaluation of all samples, shawa was the most preferred in terms of appearance, colour, tenderness, aroma and general acceptability. Kulungu was the least preferred in terms of appearance, colour and texture, catfish and tilapia were the least preferred in terms of aroma and ragon ruwa was the least preferred in terms of tenderness and general acceptability. In conclusion, the presence of some pathogenic microorganisms isolated from this study is an indication that samples were contaminated and can potentially pose a health hazard to the consumers. Thus, there is need for smoked fish sellers and marketers to take hygienic measures during smoking and handling of smoked fish so as to avoid contamination.

Chitosan coating with grape peel extract: A promising coating to enhance the freeze–thaw stability of beef

This study investigated the effect of chitosan coating with grape peel extracts (CH + GPE) on the physiochemical properties, protein and lipid oxidation, microstructure, and bacterial community diversity of beef during freeze–thaw (F–T) cycles. The results indicated that the CH + GPE groups had lower pH values, total aerobic count, total volatile base nitrogen, and thiobarbituric acid reactive substance values and better protection against color, water holding capacity, and sensory quality after five F–T cycles. The CH + GPE coating effectively inhibited beef microstructure destruction during the F–T cycles. High-throughput sequencing analysis revealed that the CH + GPE coating contributed to a decline in the bacterial diversity of beef and inhibited the growth of pathogenic bacteria. Interestingly, the CH + GPE coating affected the correlation between quality parameters and bacteria in beef. Consequently, the CH + GPE coating can be used as a novel packaging for preventing the loss of frozen meat quality due to temperature fluctuations.

Microflora, Contents of Polyamines, Biogenic Amines, and TVB-N in Bovine Offal and Game Meat for the Raw-Feeding of Adult Dogs.

Microflora and contents of biogenic amines/polyamines and total volatile basic nitrogen (TVB-N) in 99 samples of bovine offal (red offal, n = 41 and other offal and mixes, n = 45) and wild game meat (n = 13) for raw meat-based diets (RMBD) for dogs were analyzed. Samples were bought in 11 local pet food shops and in one game-handling establishment in Austria (Lower Austria, Styria, and Vienna) in September and October 2022. Median contents (first and third quartiles in brackets) of cadaverine, histamine, tyramine, spermidine, and spermine were 20.7 [16.7; 28.6]; 25.4 [17.1; 47.2]; 18.9 [13.6; 38.9]; 15.2 [11.2; 21.2]; and 41.9 [<limit of detection; 64.5] mg/kg wet weight, respectively. The sum of putrescine + cadaverine + histamine + tyramine was >50 mg/kg in 85.9% of samples, indicating the use of low-quality ingredients or inappropriate storage conditions. However, only 10.1% of samples were determined to be not compliant with a maximum amine content proposed for pet food. Median contents of the total aerobic bacteria counts (TACs), Pseudomonas, and Enterobacteriaceae were 7.4 [6.4; 8.0]; 6.5 [5.5; 7.7]; and 4.8 [3.9; 5.6] log CFU/g, respectively, with significantly lower counts in red offal RMBD (p < 0.05). TVB-N exceeded 150 mg/kg in 87.9% of samples. The TACs and Enterobacteriaceae numbers in red offal RMBD were comparable to those in food-grade red offal after 6 days of aerobic storage at 7 °C, i.e., temperatures higher than required for food-grade offal, but acceptable for animal by-products intended for RMBD production. In 80.8% of samples, numbers of Enterobacteriaceae exceeded the EU legal limit. From 12 of these samples, Salmonellae was able to be isolated, with counts from 0.03 MPN/g to 110 MPN/g. Salmonella enterica ser. Montevideo (n = 3), and S. enterica ser. Give and S. enterica ssp. Diarizonae (n = 2 each) were the most frequently isolated, while Listeria monocytogenes was rarely recovered (2%). Whilst exposure of humans handling such pet food can be reduced by hygiene precautions, the risk remains that dogs can acquire a feed-borne salmonellosis and shed the pathogen.

Biogenic Amine Content Analysis of Three Chicken-Based Dry Pet Food Formulations.

The pet food market is constantly expanding, and more and more attention is paid to the feeding of pets. Dry foods stand out and are often preferred due to their long shelf life, ease of administration, and low cost. In this context, dry foods are formulated from fresh meats, meat meals, or a mix of the two. These raw materials are often meat not fit for human consumption; they might be subject to contamination and proliferation of microorganisms which, by degrading the organic component, can lead to the formation of undesirable by-products such as biogenic amines. These nitrogenous compounds obtained by decarboxylation of amino acids can therefore be found in high-protein foods, and their ingestion in large quantities can cause intoxication and be harmful. This study aims at analyzing the possible presence of biogenic amines in three different formulations of chicken-based kibbles for pets: one obtained from fresh meat, one from meat meal, and one from a mix of the two. This study is also focused on the presence of free amino acids as they represent the key substrate for decarboxylating enzymes. Mass spectrometry (Q-TOF LC/MS) was used to analyze the presence of biogenic amines and free amino acids. The results show that fresh-meat-based products have a lower content of biogenic amines, and at the same time a higher quantity of free amino acids; on the contrary, meat-meal- and mix-based products have a greater quantity of biogenic amines and a lower concentration of free amino acids, suggesting that there has been a higher microbial proliferation as proved by the total aerobic mesophilic bacteria counts. It is therefore clear that fresh-meat-based kibbles are to be preferred when they are used for preparing dry pet food due to the lowest concentration of biogenic amines.

Evaluation of vacuum packaging for extending the shelf life of Sardinian fermented sausage

Salsiccia sarda or Sardinian fermented sausage is a traditional dry-fermented sausage included in the list of traditional food products of Sardinia (Italy). At the request of some producing plants, the possibility of extending the shelf life of the vacuum-packed product up to 120 days was evaluated. Manufacturing of 90 samples, representing 3 different batches of Sardinian fermented sausage was carried out in two producing plants (A and B). In the packaged product and subsequently every 30 days for four months (T0, T30, T60, T120), the following analyses were conducted on all samples: physicochemical characteristics, total aerobic mesophilic count, Enterobacteriaceae count, detection of Listeria monocytogenes, Salmonella spp., mesophilic lactic acid bacteria, and coagulase-positive Staphylococci. Moreover, surfaces in contact and surfaces not in contact with food were sampled in both producing plants. Sensory profile analysis was also performed for every analysis time. At the end of the extended shelf life, pH values were equal to 5.90±0.11 (producing plant A) and 5.61±0.29 (producing plant B). Water activity mean values at T120 were 0.894±0.02 (producing plant A) and 0.875±0.01 (producing plant B). L. monocytogenes was detected in 73.3% (33/45) of the samples from producing plant A, with mean levels of 1.12±0.76 log10 CFU/g. In producing plant B, L. monocytogenes was never detected. Enterobacteriaceae were detected in 91.1% (41/45) of samples in producing plant A with mean values of 3.15±1.21 log10 CFU/g, and in 35.5% (16/45) samples in producing plant B samples with mean values of 0.72±0.86 log10 CFU/g. Salmonella and Staphylococcus aureus were never detected. Regarding environmental samples, the sites that were most contaminated by L. monocytogenes were the bagging table (contact surface) and processing room floor drains (non-contact surface) with a prevalence of 50% each (8/16 positive samples for both sampling sites). Sensory analysis results showed that at T30 the overall sensory quality was at its highest; moreover, the visual-tactile aspect, the olfactory characteristics, the gustatory aspects, and the texture showed significant differences in samples throughout the shelf life, with a decreased intensity at 120 days of storage. Overall, the quality and sensory acceptance of the vacuum-packed Sardinian fermented sausage were not affected until 120 days of shelf-life. However, the possible contamination by L. monocytogenes calls attention to the hygienic management of the entire technological process. The environmental sampling was confirmed as a useful verification tool during control.

Microbiological Quality and Safety of Pizza Held Out of Temperature Control in University Dining Halls

Pizza is a popular food consumed around the world every day. Hot food temperatures were obtained from 19,754 nonpizza samples and 1,336 pizza temperatures were taken from dining facilities operated by Rutgers University between 2001 and 2020. These data showed that pizza was more frequently out of temperature control than many other foods. A total of 57 pizza samples that were out of temperature control were collected for further study. Pizza was tested for total aerobic plate count (TPC), Staphylococcus aureus, Bacillus cereus, Lactic acid bacteria, coliforms, and Escherichia coli. Water activity of pizza and surface pH of each individual pizza component (topping, cheese, bread) were measured. Predictions for the growth of four relevant pathogens were made for select pH and water activity values using ComBase. Rutgers University dining hall data show only about 60% of all foods that are pizza are held at the appropriate temperature. When pizza contained detectable microorganisms (∼70% of samples), average TPC ranged from 2.72 log CFU/g to 3.34 log CFU/g. Two pizza samples contained detectable S. aureus (∼50 CFU/g). Two other samples contained B. cereus (∼50 and 100 CFU/g). Five pizza samples contained coliforms (4–9 MPN/g), and no E. coli were detected. Correlation coefficients (R2 values) for TPC and pickup temperature are quite low (<0.06). Based on the pH and water activity measurements, most (but not all) of the pizza samples would be considered to potentially require time temperature control for safety. The modeling analysis shows that the organism most likely to pose a risk would be S. aureus, and the largest magnitude increase predicted is 0.89 log CFU at 30°C, pH 5.52, and water activity 0.963. The overall conclusion from this study is that while pizza represents a theoretical risk, the actual risk would likely only manifest for pizza samples that are held out of temperature control for time periods of more than eight hours.

Rapid detection of bacterial load in food samples using disposable respirometric sensor sachets

We describe a new sensor platform for simple on-site analysis of total aerobic viable counts (TVCs) in food samples, which uses disposable sealable plastic sachets with phosphorescent oxygen sensor inserts and liquid growth media. Food samples are collected, placed directly in the sachets, which are then sealed and incubated at 30 °C while monitoring (hourly or endpoint) sensor signals non-invasively with a commercial handheld reader FirestingO2. The growth of microbiota produces characteristic respiration profiles, from which sample initial TVC load is quantified: the Threshold Time (TT, in hours), when the sensor signal reaches the set signal threshold, is determined and calibration equation is applied to it to calculate sample TVC load. The initial calibration equation, which provides the conversion of measured TT values (hours) into TVC, was generated with pure Escherichia coli culture: log(CFU/g) = 8.30–0.60 *TT25 ° for signal threshold of 25 degrees phase. Another calibration equation, which provides a better representation of whole food microbiota, was generated with a panel of 90 different food samples: log(CFU/g) = 8.53–0.60 *TT25°. This simple sensor system shows good correlation with traditional plate counting TVC method (ISO 4833) and suitability for autonomous on-site or in-field operation. Time to result of 1–6 h provided by the sensor sachet system is more than seven time faster than for the standard method.

Oxygen Sensor-Based Respirometry and the Landscape of Microbial Testing Methods as Applicable to Food and Beverage Matrices.

The current status of microbiological testing methods for the determination of viable bacteria in complex sample matrices, such as food samples, is the focus of this review. Established methods for the enumeration of microorganisms, particularly, the 'gold standard' agar plating method for the determination of total aerobic viable counts (TVC), bioluminescent detection of total ATP, selective molecular methods (immunoassays, DNA/RNA amplification, sequencing) and instrumental methods (flow cytometry, Raman spectroscopy, mass spectrometry, calorimetry), are analyzed and compared with emerging oxygen sensor-based respirometry techniques. The basic principles of optical O2 sensing and respirometry and the primary materials, detection modes and assay formats employed are described. The existing platforms for bacterial cell respirometry are then described, and examples of particular assays are provided, including the use of rapid TVC tests of food samples and swabs, the toxicological screening and profiling of cells and antimicrobial sterility testing. Overall, O2 sensor-based respirometry and TVC assays have high application potential in the food industry and related areas. They detect viable bacteria via their growth and respiration; the assay is fast (time to result is 2-8 h and dependent on TVC load), operates with complex samples (crude homogenates of food samples) in a simple mix-and-measure format, has low set-up and instrumentation costs and is inexpensive and portable.

Bacteriological Quality and Antimicrobial Resistant Patterns of Foodborne Pathogens Isolated from Commonly Vended Street Foods in Arba Minch Town, Southern Ethiopia.

Ready-to-eat foods sold by street vendors act as potential sources for the spread of various foodborne infectious diseases. Thus, local determination of the level of foodborne bacterial pathogens and their antimicrobial resistance pattern is essential. A community-based cross-sectional study was conducted from September 5th, 2022 to December 31th, 2022. The required data were collected by a structured questionnaire and observation checklist. Randomly selected street-vended foods were aseptically collected, and the bacteriological quality was assessed by using culture techniques. Different biochemical tests were used to identify and characterize bacterial isolates. The antimicrobial-resistant test for isolated foodborne bacterial pathogens was carried out by using the Kirby-Bauer disc diffusion method. The data were analyzed using SPSS version 22. A total of 34.2% (113/330) with a 95% CI of 29.1-39.4 of commonly consumed street-vended foods were identified as having unsatisfactory total mean aerobic bacterial counts (>105 CFU/g; 4.3 × 105 CFU/g). The mean total Enterobacteriaceae, coliform, and staphylococcal counts were found to be 1.4 × 105 CFU/g, 2.4 × 104 CFU/g, and 3.4 × 104 CFU/g, respectively. A total of 12.7% (42/330) of foodborne pathogens were recovered attributed to Staphylococcus aureus (31, 9.4%), Salmonella species (6, 1.8%), and E. coli O157:H7 (5, 1.5%). 6.5% and 16.1% of isolated S. aureus were found to be methicillin-resistant and multidrug-resistant (MDR), respectively. Additionally, 33.3% of Salmonella isolates and 40% of E. coli O157:H7 isolates were found to be MDR. Street-vended foods in this setting have a considerable number of unsatisfactory bacterial qualities, along with drug-resistant foodborne pathogens. Thus, more effective health education and training for vendors, regular inspections of vending sites, and regular surveillance of drug resistance patterns of foodborne pathogens are all essential.

Sterilize Methods Comparison for Soils: Cost, Time, and Efficiency

Soil sterilization is generally used to eliminate or reduce microbial activity in studies involving microbial inoculations, soil enzymes, among others. Achieving an adequate sterility condition is not straightforward due to the variety of resistance structures that are generated in soil microbial ecosystems and the reservoirs that can form between soil aggregates. This is why finding an effective method to achieve good sterilization is important in methodological terms, so the present work aims to compare the effectiveness of three widely used methodologies to sterilize soil and to evaluate their cost/benefit in terms of time and inputs invested. Four treatments were tested: gamma irradiation, sterilization cycles at different times: three cycles of 1 h each and four cycles of 15 min each, and chloroform vapors. The evaluation and comparison of all samples sterilized by the different methodologies were based on the total aerobic heterotrophic bacterial count. The results of this study suggest that it is more efficient to use autoclaving methods because the process is more accessible in terms of equipment and methodologies, and the final results are the same. In the case of this work, sterilization with chloroform vapors had to be rejected. While the use of gamma radiation may be more efficient in terms of time, it can be a costly and inaccessible service for some laboratories that do not have the equipment. Therefore, the most viable options in terms of time, cost, and benefit are those using autoclaves. Among these, shorter treatment times mean a reduction in the cost of using the equipment, so the option of 15-minute cycles is desirable.

Longitudinal Study for the Detection and Quantification of Campylobacter spp. in Dairy Cows during Milking and in the Dairy Farm Environment.

Campylobacteriosis outbreaks have repeatedly been associated with the consumption of raw milk. This study aimed to explore the variation in the prevalence and concentration of Campylobacter spp. in cows' milk and feces, the farm environment and on the teat skin over an entire year at a small German dairy farm. Bi-weekly samples were collected from the environment (boot socks), teats, raw milk, milk filters, milking clusters and feces collected from the recta of dairy cows. Samples were analyzed for Campylobacter spp., E. coli, the total aerobic plate count and for Pseudomonas spp. The prevalence of Campylobacter spp. was found to be the highest in feces (77.1%), completely absent in milking equipment and low in raw milk (0.4%). The mean concentration of Campylobacter spp. was 2.43 log10 colony-forming units (CFU)/g in feces and 1.26 log10 CFU/teat swab. Only a single milk filter at the end of the milk pipeline and one individual cow's raw milk sample were positive on the same day, with a concentration of 2.74 log10 CFU/filter and 2.37 log10 CFU/mL for the raw milk. On the same day, nine teat swab samples tested positive for Campylobacter spp. This study highlights the persistence of Campylobacter spp. for at least one year in the intestine of individual cows and within the general farm environment and demonstrates that fecal cross-contamination of the teats can occur even when the contamination of raw milk is a rare event.

Microbial Assessment of Food Contact Surfaces in Restaurants/Food Canteens at Ahmadu Bello University Main Campus, Samaru, Zaria, Kaduna State, Nigeria

Food contact surface is any surface with which food; especially unpackaged food normally comes in contact. These surfaces can harbour harmful micro-organisms and other substances which can contaminate food. This study was aimed at assessing the microbial quality of food contact surfaces from restaurants/food canteens in Ahmadu Bello University Main Campus, Samaru, Zaria, Kaduna State, Nigeria. Ninety nine swab samples were collected from hands, plates, pots, spoons and tables, and analyzed for total aerobic plate count (TAPC), total coliform counts (TCC), Escherichia coli and Staphylococcus aureus. The overall results showed that the mean TAPC obtained from pots (2.3 × 107 cfu/cm2 ) was significantly higher (P &lt; 0.05) than those obtained from plates, hands, spoons and tables, while the mean TCC obtained from hands (4.5 × 106 cfu/cm2 ) was higher than those obtained from tables, plates, spoons and pots respectively. The prevalence of E. coli was significantly higher than that of S. aureus (36.6% vs 27.3%), but all occurred at a significant rate (P &lt; 0.05). E. coli isolates showed resistance to ampicillin (30.6%), amoxicillin (27.8%) and tetracycline (25.0%), while that of S. aureus isolates showed high resistance to penicillin (100%), amoxicillin (88.9%), ampicillin (88.9%) and tetracycline (85.5%).Both E. coli and S. aureus isolates showed multidrug resistance nature with greater percentage (38.9%) of the E. coli and S. aureus (29.6%) isolates having MARI of 0.3 and 0.4 respectively. The high value of both TACP and TCC coupled with the isolation of E. coli and S. aureus may indicate faecal and sewage contaminations associated with unhygienic and unsanitary practices. The study recommends proper personal hygiene especially of the hands, washing and rinsing the food contact surfaces with warm soapy water and sanitizers; and proper disposal of sewage and garbage materials to reduce or eliminate hazards.

Effect of different concentrations of gellan gum with/without 0.50% basil essential oil on the physicochemical properties of gellan gum-rice bran oil coating emulsions and their application in egg preservation

This work investigated the effects of different concentrations (0.10 %, 0.15 % or 0.20 %, w/v) of gellan gum (GG) with/without 0.50 % (v/v) basil essential oil (BEO) on physicochemical properties of gellan gum-rice bran oil (GG-RBO) emulsions. The results showed that GG-RBO emulsions with 0.15 % or 0.20 % GG were more stable than GG-RBO emulsion with 0.10 % GG (as evidenced by higher apparent viscosity and absolute zeta potential, but smaller average particle size and lower turbidity), thus displaying better coating performances (as evidenced by bigger contact angle but lower moisture content). The presence of BEO further improved their stability and coating performances. Coating with GG-BRO or GG-RBO-BEO emulsion with 0.15 % GG significantly delayed the increase in weight loss, and the decrease in haugh unit, yolk index and albumen pH of eggs during 42 days storage; moreover, GG-RBO-BEO emulsion caused lower total aerobic plate count. Therefore, GG-RBO, especially GG-RBO-BEO emulsion has potential in egg preservation.

Preliminary health risk assessment of two exudate gums as pharmaceutical excipients

Some exudate gums such as acacia and tragacanth gums have been certified to be used in pharmacy as excipients. In this study exudate gums, obtained from two local trees in Ghana: Cussonia arborea and Cordia mellinii, were assessed for their safety for use as pharmaceutical excipients. The crude gums were purified using water and 96% ethanol and digested by di-acid procedure using 65% HNO3 and 37% HCl (2:3) at 95 °C for elemental analysis. Quantification of Ca, Fe, Mg, Cu, Zn, Mn, Ni, Hg, Cd, Pb and As ions was done using AAS 400; Na and K using the single channel flame photometer; and P using Spectronic 20 spectrophotometer. Microbial quality of the purified gums was also determined by the British Pharmacopoeia method. Toxicity of the purified gums was evaluated using acute and sub chronic murine toxicity models. Quantities of elemental ions detected in both purified gums were not significantly high to affect the utilization of these gums as pharmaceutical excipients even in large dose and high dosing frequency drugs. Total aerobic viable counts of the gums were within the acceptable Pharmacopoeial specification and no harmful microorganisms were detected. Acute and sub-chronic toxicity tests of the gums showed that they are safe for use even in long term dosage regimen medications. Thus, when these gums are included in even long term use medicines as excipients, may not cause any harm to the patient. The gums are therefore safe and qualified for use as pharmaceutical excipients when purified.

Effect of UV-C Irradiation and High Hydrostatic Pressure on Microbiological, Chemical, Physical and Sensory Properties of Fresh-Cut Potatoes

UV-C irradiation and high hydrostatic pressure (HHP) successfully reduce the number of bacteria and their growth but can also affect phenolic and sugar content, as well as other physicochemical properties. Therefore, in this work, the effect of UV-C irradiation, HHP, and their combination, UV-C/HHP, on total aerobic mesophilic bacteria count (TAMBC), chlorogenic acid and sugar content, and other physicochemical properties of raw FCP were examined. Acrylamide and polycyclic aromatic hydrocarbons (PAH) were also monitored in treated FCP after frying. Vacuum-packed potato slices pretreated with an antibrowning agent were irradiated with UV-C (2.70 kJ m−2), treated with HHP (400 MPa/3 min) and combined UV-C/HHP, and stored for 15 days. The greatest reduction in TAMBC was achieved in the UV-C/HHP-treated samples, followed by the HHP treatment, and they both resulted in the slowest bacterial growth during storage. All treatments decreased the contents of chlorogenic acid, but the greatest reduction was observed in the HHP-treated samples. All treatments increased the content of reducing sugars, and UV-C/HHP did so significantly, which also led to an increase in acrylamide content in the fried FCP. PAH levels were below the established limits. Acceptable sensory attributes of all samples (raw, boiled, and fried) remained relatively stable during storage.

Effect of Two-Step Sous Vide Cooking and Storage on Microbiological and Oxidative Stability of Chicken Breast

A two-step sous vide method, which included a low temperature initial stage, was shown to improve texture parameters, increase the solubility of proteins, and decrease the cook loss in chicken breasts. The current work was designed to determine the effect of two-step sous vide and subsequent storage on the microbiological and oxidative stability of chicken breasts. Inoculated chicken breasts were vacuum packaged and cooked at two temperatures, 50 °C and 60 °C, combined in different ratios of the same total cooking time (120 min), and then stored for 21 days at 4 °C, 10 °C, and -20 °C, and compared with the one-step temperature treatment (60 °C for 120 min). One-step sous vide treatment resulted in the total inactivation of Enterococcus faecalis NCAIM B. 01312. Meanwhile, the two-step sous vide treatments resulted in a higher than 3 log reduction in Enterococcus faecalis NCAIM B. 01312, reaching the target pasteurization performance criterion of sous vide for poultry meat. Lipid oxidation and the odor of all chicken breasts remained acceptable for 21 days of storage at 4 °C and -20 °C. Conversely, all chicken breasts had higher lipid oxidation rates and odor after 21 days of storage at 10 °C. Two-step-sous-vide-treated chicken breasts were found to be microbiologically stable regarding Enterococcus faecalis NCAIM B. 01312 and total mesophilic aerobic counts during 21 days of storage at 4 °C and -20 °C, in contrast with those stored at 10 °C. It can be concluded that two-step-sous-vide-cooked chicken breasts had acceptable oxidative and microbiological stability during chilled and frozen storage, similar to one-step sous vide ones. These outcomes highlight that two-step heat treatment can be used as an alternative cooking method to improve the quality properties without compromising the storage life of chicken breasts.

Properties of cheese and ground beef in the presence of staghorn sumac

AbstractCost‐effective and under‐exploited plant species as functional food ingredients represent alternatives to chemicals with safety concerns and potent toxicity. Staghorn sumac (Rhus typhina) is considered a good source of natural polyphenols, which can be introduced into food products to carry out some specific technological functions (e.g., antioxidation and preservation). However, sumac fruit as a spice is under‐explored for its diversified uses in various food products as a novel functional ingredient. This study explored the technological feasibility and sensory acceptability of two representative sumac‐fortified food systems, namely Cheddar cheese and ground beef. Extracts of sumac (0.5%−5%) dose‐dependently increased the total phenolic and anthocyanin contents, while reducing thiobarbituric acid reactive substance (up to 46%), total plate counts of bacteria (up to 4.5 log colony‐forming units [CFU]/g) and pH of the cheese. In fresh ground beef, sumac extract at concentrations of 1%−5% was effective in reducing the total aerobic counts of Escherichia coli inoculated fresh ground beef by 0.16−1.14 log CFU/g, while improving meat color and oxidative stability during a storage period of 7 days at 4°C. Phytochemical profiling by high‐performance liquid chromatography showed the presence of gallic acid, caffeic acid, ellagic acid, quercetin and anthocyanins in the sumac extracts. These compounds were possibly responsible for the antimicrobial and antioxidant activities in the evaluated food systems. Sensory acceptability of Cheddar cheese or cooked beef meatballs with sumac extract addition (0.5%−3%) were similar to their respective controls. This study provides a feasible approach to satisfy health‐conscious consumers who favor a natural multifunctional ingredient to preserve food products.

Use of instant controlled pressure drop technology for the preservation of edible insects' (yellow mealworm) quality: assessment of microbial inactivation.

The world population is expanding, and with it, so is the need for proteins for the food and feed sectors. Conventional livestock production is correlated with negative environmental repercussions such as global warming, land degradation, and biodiversity loss. The nutritional content of edible insects is comparable to that of conventional meat, and insect farming offers various environmental advantages over livestock production, making it a favorable sustainable protein resource. However, to be placed on the market, insects should be processed, and their microbial load should be within the accepted range of the European Commission regulation (EU) 2021/882. The purpose of this research is to investigate the use of instant controlled pressure drop (DIC) technology for the microbial inactivation of yellow mealworm larvae. This innovative decontamination treatment was compared to blanching in hot water, the conventional processing method. We also investigated the impacts on enzymatic browning. Results showed that the application of rapid (20s) DIC treatment at 0.3MPa allowed reducing the total aerobic count and the total yeast and mold count of larvae below the thresholds authorized by the commission regulation. Pressure, temperature, and number of cycle factors were found to have significant effects on the decontamination, while the treatment time had no effect for most treatments. In regard to blanching, we were able to get the authorized load at 90°C for 360s. Decimal reduction times for DIC and blanching treatments were found to be 3.8s and 67.8s for total aerobic count, and 3s and 57s for total yeast and mold count, respectively. Furthermore, DIC-treated larvae showed a significant increase in juice color brightness, which could be traced back to the oxidative enzymatic inactivation of larvae, whereas there was a slight difference between blanched and untreated larvae juice colors.