Total Number Of Colonies Research Articles

Investigation on the Microbial Diversity of Fresh-Cut Lettuce during Processing and Storage Using High Throughput Sequencing and Their Relationship with Quality.

Microbial community distribution in vegetables can affect their quality. This study analyzed the distribution of the microbial community at various stages during processing and storage with the microbial diversity analysis, and evaluated the correlation between the dominant bacteria and sensory quality of lettuce using correspondence analysis with multiple regression analysis. Results showed that the process of washing, cutting, then disinfection and dewatering could change the community distribution and dominant bacteria in lettuce, and maintain better texture, morphology, aroma, color qualities of lettuce. The total number of colonies and relative abundance of Xanthomonas in fresh-cut lettuce decreased, while Afipia and Ralstonia increased during processing and pre-storage (storage for 6 h, 12 h and 1 d). After storage for 3 d, the total number of colonies in lettuce increased (more than 5 log CFU/g), especially the relative abundance of Pseudomonas, which led to the obvious deterioration of the sensory quality of lettuce. Throughout the process, the number of Bacillus cereus, Staphylococcus aureus, and E. coli was less than 100 CFU/g and 3 MPN/g. The number of typical pathogenic bacteria, Salmonella, Listeria monocytogenes and E. coli O157:H7, was below the detection limit. Overall, the prevention and control of psychrotrophic Pseudomonas in lettuce was still necessary. These results will provide useful information for the fresh-cut lettuce industry.

The Infection Control Route in the Operating Room Effectively Reduces the Wound Infection of Patients.

Surgical care is one of the significant aspects of global healthcare, with approximately 234 million operations being conducted annually. Surgical treatment has a substantial risk of complications and death. This study was conducted to explore the application effect of the infection control route in the operating room on the wound infection prevention care of patients. The clinical data of 136 patients receiving surgical treatment from October 2018 to October 2019 were retrospectively analyzed. The participants were assigned via random draw at a ratio of 1 : 1 to receive either routine care management (control group) or the infection control route (research group). The surgical wound infections of patients in the two groups were compared. The research group had higher scores in surgical materials management and disinfectant management than the control group (P < 0.01). In the research group, the total number of colonies within 5 minutes before surgery, 25 minutes after the start of surgery, and after surgery were all smaller than those in the control group (P < 0.01). There were no significant differences in the grade B healing rate between the two groups (P > 0.05), and the research group had a significantly higher healing rate in grade A than the control group, but its grade C healing rate and wound infection rate were significantly lower than those in the control group (P < 0.05). In the research group, the length of hospital stay, the time to get out of bed, the antibiotic use duration, and the stitch removal time was significantly shorter than those in the control group (P < 0.0001). The research group received a higher clinical nursing satisfaction than the control group (P < 0.05). The infection control route in the operating room for infection prevention care effectively reduces the wound infection rate of patients and accelerates their postoperative recovery.

Combination of Chitosan, Tea Polyphenols, and Nisin on the Bacterial Inhibition and Quality Maintenance of Plant-Based Meat.

Plant-based meat products have gained attention in the food industry and with consumers. Plant-based meat products primarily comprise plant proteins and are rich in nutrients. However, the products are highly susceptible to bacterial contamination during storage. Biological preservatives are easily degradable alternatives to chemical preservatives and can preserve different kinds of food. In order to investigate the preservation properties of chitosan (CS), tea polyphenols (TPs), and nisin treatments on plant-based meats, the sensory evaluation, color difference, pH, TBARS, and the total plate count of E. coli, S. aureus, and Salmonella, indicators of the biological preservative-treated plant-based meat, were determined in this study. The experiment involved blank control- and biological preservative-treated samples. We found that the total microbial count exceeded the national standard provisions in the control samples stored for 14 days. The colors, tissue structures, and flavors of plant-based meat have gradually deteriorated, with the sensory score dropping from 90 to 52. The sample had a loose tissue structure and an obvious sour taste. However, the shelf life of the plant-based meat samples treated with different combinations of the biological preservatives increased compared to the shelf life of the control samples. After 56 d of storage, 1% chitosan, 2.5% tea polyphenols, and 0.04% nisin sensory reduction to 56, the total number of colonies and S. aureus were 4.91 and 2.95 lg CFU/g, approaching the national standard threshold; E. coli was 2 lg CFU/g, reaching the national standard threshold. Thus, the samples treated with 1% chitosan, 2.5% tea polyphenols, and 0.04% nisin had the longest shelf life (56 days) among all experimental groups. Hence, this study reveals that a combination of biological preservatives may be a non-toxic alternative for the efficient preservation of plant-based meat products.

Radio frequency pasteurization and heating uniformity of canned pineapple.

This research investigated heating uniformity and pasteurization of canned pineapple using radio frequency (RF) energy. Experiments were conducted in a 6kW, 27.12MHz pilot-scale RF system. Results showed that the temperature difference was more than 16°C, and the standard deviation was 4.38°C at the end of heating when using RF heating alone. Water bath-assisted RF (WRF) heating effectively improved the heating uniformity, the temperature difference was less than 7°C and the standard deviation was 2.52°C at the end of heating in the condition of electrode gap (210mm), chord length of the fruit block (26mm),and the initial temperature of sugar solution (80°C). When the total number of colonies reached 4-log reduction, water bath (WB) heating alone needed 660 s, and WRF heating needed 180 s. Vitamin C, hardness, and color of fruit blocks were well preserved using WRF heating compared with WB alone. PRACTICAL APPLICATION: This study shows that the pasteurization of canned food by radio frequency heating can achieve better food quality than the traditional pasteurization methods. Therefore, this research can promote the application of radio frequency heating technology in canned food pasteurization.

Evaluation of Microbial Contamination in Cold Dishes and Prevalence of Foodborne Pathogens in Jilin Province

This study evaluated the microbial contamination status of cold dishes consumed by residents of Jilin Province and investigated to determine the incidence of four pathogenic bacteria in cold dishes. A total of 300 samples of cold dishes, including meat, vegetable, and mixed products, were collected from three purchasing places: supermarkets, farmers' markets, and mobile vendors. Viable bacteria were isolated using conventional culture methods. After separation, a quick and easy PCR was used to detect Listeria monocytogenes, Staphylococcus aureus, enterotoxigenic Escherichia coli, and Salmonella. The results showed that the total number of microbial colonies in the vegetable samples exceeded the standard rate of 8% and the total number of microbial colonies in the meat and mixed samples did not exceed the standard. The total microbial colony count exceeded the standard in all three procurement sites, with the highest exceedance of 7.4% in the mobile vendor sites. The detection rates of enterotoxigenic E. coli, S. aureus, L. monocytogenes, and Salmonella, among the four pathogenic bacteria detected in all samples, were 4.3, 3.3, 3.0, and 1.0%, respectively. This study can be used to qualitatively assess the microbiological quality associated with cold dishes. It provides data to support the detection of possible food safety problems.

Karakteristik Kimiawi dan Total Bakteri Asam Laktat (BAL) Kecap Ikan Tandipang (Dussumieria sp.) dengan Penambahan Ekstrak Buah Nanas

The purpose of this study was to obtain a formula of rainbow fish sauce with pineapple extract and to determine the effect of adding pineapple extract on the fermentation process and total lactic acid bacteria. With the addition of 0%, 5%, 10%, 15%, and pineapple extract treatment and fermented for 7, 14, 21 days in an incubator with a temperature of 40-50 ℃. The test parameters are Sensory Analysis which includes appearance, aroma, and viscosity (SNI 01-2346-2006), pH (AOAC, 2005), total lactic acid bacteria. The results of the sensory test research for the appearance of the 5% sample, 15% aroma, 10% viscosity with a fermentation time of 21 days were the most preferred by panelists with an average value of 6.8, 6.4, 7. The average pH value on day 7 ranged from 6.77 to 6.67, day 14 ranges from 6.67 to 6.59, day 21 ranges from 6.40 to 6.35. The test results of the highest colony Lactic Acid Bacteria in the sample with the addition of pineapple extract as much as 15% fermentation on the 21st day with a total colony number of 1.46 × 10³ CFU / ml.

Removal of microorganisms and antibiotic resistance genes from swine wastewater: a comparison between polyaluminum chloride (PAC), polyaluminum sulfate (LST), and aluminum hydroxide iron (LT)

The presence of antibiotic-resistant bacteria (ARB) and antibiotic-resistance genes (ARGs) in swine wastewater may present a threat to the environment and public health. Conventional swine wastewater treatment processes generally fail to effectively reduce the content of ARGs. Therefore, it is necessary to develop a highly efficient and low-cost treatment method to solve this environmental problem. In doing so, we evaluated the application of three common coagulants in the treatment of swine wastewater. Using metagenomics, we evaluated the removal efficiency of ARG loads, as well as the effect of coagulation on the structure and diversity of swine wastewater, and on the bacterial community. The results showed that the three coagulants could effectively reduce the physicochemical pollution indexes of swine wastewater (e.g., TP, NTU, COD). After treatment, the loads of a variety of antibiotics in the swine wastewater were significantly reduced, with the exception of NFX and SMD, which were all close to 100%. At the same time, in evaluating the total number of microbial colonies and the total number of fecal Escherichia coli bacteria under the three conditions, Polyaluminum Chloride (PAC) ranked first among the three coagulants with 89.18%, 93.07%, 89.92%, 98.76%, 99.60%, and 98.68%. Metagenomic analysis revealed that the abundance of cfcC, tetX, mphE, msrE, tet36, and other ARGs in the water sample after the LST treatment was significantly lower than that of the original swine wastewater sample. These findings demonstrate the feasibility of using coagulants to treat swine wastewater, which is of great significance for improving water quality and reducing the potential impacts of ARGs.

Shelf-life prediction model of fresh-cut potato at different storage temperatures

The fresh-cut potato is popular in many foods, but its shelf-time is difficult to predict. Through orthogonal test, the fresh-cut potato was dipped in chlorine dioxide solution (100 mg/L), citric acid solution (1.5%) and potassium sorbate solution (0.1%) in order, and then packaged with polyvinylidene chloride plastic film for the best preservation effect. Then, the processed potatoes were stored in 0 °C, 4 °C, 7 °C and 10 °C. The quality-change relationship between samples over time and temperature are mainly studied by weight loss, PPO activity and total number of colonies. The results show that the weight loss, the PPO activity and the total number of colonies increased with the increase of the time and the temperature, and the temperature of 0 °C is optimum for the storage of fresh-cut potato. The kinetic models of the weight loss, the PPO activity and the total number of colonies are established based on experimental data. By comparing the predicted values with the experimental values, it is shown that the shelf-life prediction model of PPO activity can offer a more accurate prediction of the shelf life of fresh-cut potato at different temperatures. We anticipate that our results might be used to forecast and evaluate the quality of vegetables in the process of logistics. • Three different shelf-life prediction models of fresh-cut potato are provided. • The PPO activity prediction model can predict the shelf life of fresh-cut potato at different temperatures. • Effect of temperature is a key factor in the storage and transportation processes of fresh-cut potato.

Performance of eugenol emulsion/chitosan edible coating and application in fresh meat preservation

A green chitosan-based coating was prepared by incorporating chitosan-stabilized eugenol emulsions into chitosan solution. The physical, mechanical, rheological, and stability property of chitosan coatings were characterized and then the effect of chitosan coatings on the shelf-life of fresh meat was investigated. Emulsion incorporation greatly improved the performance of chitosan coating, including stronger anti-corrosion against pH and UV-light resistance and lower water vapor permeability. Emulsion incorporation greatly increased the inhibition zone for Escherichia coli and Staphylococcus aureus by 6.9 and 8.7 mm, respectively. After the application of coating, meat kept a bright red appearance within 14 days and its spoilage was prevented. After 14-day storage, pH value, the total number of colonies, and TVB-N of meat still met the quality standard, demonstrating that the shelf-life of meat was prolonged from 6 to 14 days. The knowledge provides a green coating to extend the shelf-life of fresh meat. Novelty impact statement Chitosan-stabilized emulsions were added into chitosan-coating materials. Eugenol-loaded chitosan coating had a good protection effect on the color of meat. Shelf-life of fresh meat was prolonged to 14 days by eugenol/chitosan coating.

Research Note: Preservative effect of compound spices extracts on marinated chicken

The antimicrobial effect of 21 nature spices essential oils (EOs) on marinated chicken was investigated and response surface analysis was applied to obtain the optimal combination. Cassia bark EO, cinnamon EO, tea tree EO, and angelica EO had the best antibacterial effect. Their inhibition zone diameters (IZD) were 23 mm, 21 mm, 15 mm, and 12 mm, and their minimal bactericidal concentrations (MBC) were 1.25 μL/mL, 1.25 μL/mL, 10.00 μL/mL, 20.00 μL/mL. Using the Box-Behnken Design model, with the minimum total number of spoilage bacteria as the evaluation index, the optimal mixture was cassia bark EO 2.40 μL/mL, cinnamon EO 1.00 μL/mL, tea tree EO 3.50 μL/mL, and angelica EO 9.00 μL/mL. Compared with the control group, the total number of colonies was reduced by 1.3 log unites at the 12th sampling day, and the protein degradation process was slowed down owing to the preservative addition. These results indicate the potential application of nature extracts in chicken and other meat preservation.

Effects of Ilisha elongata proteins on proliferation and adhesion of Lactobacillus plantarum

The effects of aquatic proteins on the proliferation and adhesion of intestinal probiotic bacteria were investigated by in vitro fermentation and mouse in vitrointestinal tissue models. Compared with the control group, the Illisha elongata protein reduced the growth time of Lactobacillus plantarum (LP45) by 34.25% and increased the total number of colonies by 6.61%. The Ilisha elongata salt-solubale protein performed better than water-soluble protein in vitro proliferation of LP45. Ilisha elongata salt-soluble protein significantly increased the number of viable bacteria adhering to intestinal, and caused changes in the amount of polysaccharides, proteins and biofilms in the intestinal tissue model. These results indicate that the Ilisha elongata protein is beneficial to the proliferation and adhesion of probiotics in the intestinal, and can be used as an active protein beneficial to intestinal health.

Impact of salt concentration on bacterial diversity and changes in biogenic amines during fermentation of farmhouse soybean paste in Northeast China

Farmhouse soybean paste in Northeast China is a traditional fermented product made from soybean, and more than 11% (w/w) salt is usually added during production to control the fermentation process. In this study, the variations in bacterial diversity, biogenic amines(BAs) and physicochemical properties during the natural fermentation of soybean paste with different salt concentrations (8%, 9%, 10%, 11%, and 12%) were studied. The results show that at 0 days (0 d) of fermentation in soybean paste, the dominant genera included Staphylococcus, unidentified Clostridiales, and Sporolactobacillus. During fermentation from 30 d to 90 d, the dominant genera were Tetragenococcus and Staphylococcus. However, the proportions of the dominant genera were different depending on the salt concentration. Putrescine(Put), tryptamine(Try), β-phenethylamine(Phe), cadaverine(Cad), histamine(His), and tyramine(Tyr) showed negative correlations with salt concentration. The amino type nitrogen(ANN), titratable acidity(TTA) and total number of colonies were also negatively correlated with salt concentration. Analysis of the correlation between genera and BAs showed that 12 genera were positively correlated with BAs, and 4 genera were negatively correlated with BAs. The results of this study indicated that salt has a significant impact on bacterial diversity during the fermentation of soybean paste, which in turn affects the changes in bacterial metabolites. From the perspective of food safety, the amount of salt added in the soybean paste can be reduced to 10% under the existing fermentation conditions.

Optimization of superheated steam treatment conditions for wheat aleurone layer flour

Although, wheat aleurone layer flour (WALF) is a good source of nutrients, it has certain disadvantages due relatively high levels of lipids and various of microorganisms and enzymes. Therefore, in the current study, the effect of superheated steam (SS) treatment on stabilization of WALF was investigated. This study aims to explore the effects of SS treatment on the degradation of free fatty acids of WALF under different conditions. The optimal process was obtained by an orthogonal optimization experiment, including optimized SS temperature, material moisture and treatment time. Results showed that the free fatty acids content of WALF significantly were decreased with SS treatment as the increase of treatment temperature, material moisture content and treatment times (p<0.05). Therefore, the optimum treatment conditions were selected during SS treatment. Compared with raw WALF, the activity of enzymes, total number of microbial colonies and phytate content in WALF were notably reduced after the SS of optimal condition. Nevertheless, its total dietary fiber content, insoluble dietary fiber content, pentosan content, total phenol content and total antioxidant capacity presented a remarkable increase (p<0.05).

Efficacy of Dental Barriers in Aerosols and Splatters Reduction During an Ultrasonic Scaling: An In-vitro Study.

ABSTRACTBackground:Barrier enclosure systems were suggested as the protective equipment for aerosol-generating procedures.Objective:The aim of this study was to investigate the efficiency of dental barriers in aerosols and splatters reduction during an ultrasonic scaling.Materials and Methods:Two types of dental barriers: (1) metal frame with plastic wrap (MFPW) and (2) plastic shield chamber (PSC) were investigated. Ultrasonic scaling was performed on dental phantom head with and without the use of dental barriers. To detect the splatter contamination, the water system of the scaler was circulated with 0.1% fluorescein dye and filter papers were set at several parts of dental chair, body of an operator, and assistance. For bioaerosol production, water containing 107 colony-forming unit (CFU)/mL of Lactobacillus acidophilus was used as a water coolant system of the scaler.Results:The total surface contamination found on the body of the operator was significantly decreased when using both MFPW and PSC barriers (P < 0.05). A significant reduction on the assistant’s body and the dental chair was only observed when PSC was used (P < 0.05). For bacterial aerosols, both barriers significantly reduced the number of bacterial colonies when compared with no barrier used (P < 0.05). The percentages of total colonies reduction for MFPW and PSC were 78.13 (±1.69) and 69.24 (±2.49), respectively. However, no difference in the total number of bacterial colonies was observed between the two types of barriers.Conclusion:A dental barrier system was effective in aerosols and splatters reduction during an ultrasonic scaling.

Effects of Ilisha elongata protein, soy protein and whey protein on growth characteristics and adhesion of probiotics

The effects of different food source proteins on the growth characteristics and intestinal adhesion of Lactobacillus plantarum 45 (LP45) were investigated by adding Ilisha elongata protein, soy protein and whey protein to the probiotic bacteria in vitro and using a probiotic adhesion model based on mouse intestinal tissues. Ilisha elongata protein and soy protein significantly reduced the growth time of LP45 and increased the total number of colonies fermented by LP45; whey protein only reduced the growth time of LP45; the effect of the three food source proteins on the acid production capacity of LP45 was small. These showed that the three food-derived proteins promoted the proliferation and adhesion of probiotics in the intestine, which were beneficial to the active role of intestinal probiotics and improved the intestinal microenvironment.

Combined effects of ultrasound and antioxidants on the quality maintenance of bay scallop (Argopecten irradians) adductor muscles during cold storage

The combined effects of ultrasound and the antioxidants of bamboo leaves (AOB) on the quality maintenance of the adductor muscle of scallops (AMSs) during cold storage was investigated. Ultrasound power at 350 W coupled with AOB solution (2% w/v) (UAOB-350) was applied to treat the AMSs according to Taylor diagram analysis. The microstructure, oxidative changes (lipid and protein oxidation), total numbers of colonies, total volatile basic nitrogen, and texture of the AMSs during 6 days of cold storage were analysed. The results indicated that UAOB-350 treatment could effectively retard protein and lipid oxidation and bacterial growth and maintain better microstructure and texture characteristics than AOB solution treatment alone, prolonging the shelf life of the AMSs by 2 days during storage at 4 °C. These results indicate that the UAOB-350 combination method has promising potential to maintain the quality and extend the shelf life of AMSs during cold storage.

Identification of mouldy rice using an electronic nose combined with SPME-GC/MS

Early warning of mildew in grain storage is extremely important to ensure the security of reserves. Japonica rice (Oryza sativa subspecies. Japonica) was used as an example in this study to develop a strategy for the establishment of an early warning and analysis system for grain mildew, that is, an electronic nose (E-nose) is used to analyse the volatile substances produced during the mildewing of japonica rice. The main volatile components of mildewed japonica rice were determined to be alcohol, aldehyde and ketone, to which the W2S sensor of the E-nose is sensitive. A gas chromatography-mass spectrometry (GC-MS) analysis showed that the content of mouldy markers (1-octen-3-ol and 3-octanone) and the response of the W2S sensor were highly correlated with the total colony number. Principal component analysis (PCA) and cluster analysis further verified the excellent performance of the E-nose in identifying japonica rice mildewing. Thus, it is feasible to use the E-nose in combination with GC/MS for the early detection of mould contamination of japonica rice.

KUALITAS SE’I SAPI YANG DITAMBAHKAN BUAH BELIMBING WULUH (Averrhoa bilimbi L) DENGAN LEVEL BERBEDA (Quality of se'i beef added bilimbi fruits (Averrhoa bilimbi l) with different levels)

The aims of this study was to evaluate the total bacterial colonies, antioxidant activity, lipid oxidation and organoleptic quality of se'i beef with the addition of bilimbi fruits (Averrhoa bilimbi L). The design used in this study was a completely randomized design (CRD) which consisted of 4 treatments and 3 replications. The treatments consisted of R0 = control (without the addition of Averrhoa bilimbi L), R1 = 2% addition of Averrhoa bilimbi L, R2 = 4% addition of Averrhoa bilimbi L and R3 = 6% addition of Averrhoa bilimbi L. The parameters observed included total bacterial colonies, antioxidant activity, lipid oxidation, aroma, color, taste and tenderness. The results showed that the administration of Averrhoa bilimbi L affected total bacterial colonies, antioxidant activity and lipid oxidation of se'i beef (P &lt;0.01) where the higher the level of addition of Averrhoa bilimbi L, the higher the antioxidant activity value, the total number of bacterial colonies decreased The value of lipid oxidation decreased while the addition of Averrhoa bilimbi L 2%, 4%, 6% resulted in relatively the same aroma, color, taste and tenderness of se'i. It is concluded that processing se'i sapiwith the addition of Averrhoa bilimbi L at a level of 6% have a good effect on total bacterial colonies, antioxidant activity and lipid oxidation of se'i sapi.

Dynamic Anlysis of Microbial Community Diversity in Chilled Chicken during Pre-cooling

In order to conduct a dynamic analysis of the microbial community structure of the pre-chilled water and chicken carcass during the pre-chilling process of broiler slaughter, and study the growth and decline of the two dominant floras. The TVC in the first-order, second-order pre-chilled water and chicken carcasses were detected, when the first batch of slaughtered chicken passed pre-cooled water for 0, 2, 4, 6 and 8 h. Subsequently, a high-through put sequencing method was used to dynamically analyze the community structure of them. The result of the determination of the total number of colonies showed that during the pre-cooling process, the TVC in the first-stage, pre-cooled water increased from 103 CFU/mL to 105 CFU/mL, and the TVC in the second-stage pre-cooled water increased from 102 CFU/mL to 104 CFU/mL. Before pre-cooling, the total number of colonies in chicken carcass was 4.53 lg CFU/g, after pre-cooling, the total number of colonies on the surface of the chicken carcass was higher than that before the pre-cooling within 4 to 8 hours, indicating that the pre-cooling water had lost the effect of cleaning and reducing bacteria, and might also cause cross-contamination of the chicken carcass. High-throughput sequencing found that during the pre-cooling process, the genus of Aeromonas in the first-stage pre-cooling water decreased, while the genus of Pseudomonas and Streptococcus increased; the genus of Acinetobacter in the second-stage pre-cooling water decreased, Pseudomonas increased; compared with before pre-cooling, Vagococcus and Weissella of the chicken carcass decreased, and the Chrysobacterium and Pseudomonas increased during the pre-cooling process. This study showed that the pre-cooling process had a better bacteria-reduced effect on Aeromonas, Vagococcus and Weissella, but had a poor reduction effect on Chrysobacterium and Pseudomonas. This provided a reference for the optimization of the chicken carcass pre-cooling process after slaughter, and at the same time provided a guarantee for the quality and safety of chilled chicken products.

Blowing on the Hot Food Increasing Bacteria Contamination

Blowing hot food and drinks is a culture in society that can cause food contamination with microorganisms. This study aims to determine the difference between the level of microorganism contamination in hot blown and unblown food. This study used a completely randomized design experimental method with blown and non-blown treatments. Each treatment was made twice. The calculation of the level of contamination is calculated by calculating the total number of colonies using the Coloni counter. The results showed that there was a significant difference (p = 0.001) between the samples that were blown (130 colonies 12 hours, 134 colonies 24 hours) and not blown (13 colonies 12 hours &amp; 21 colonies 24 hours), the number of bacterial contamination in the blown samples was more larger than the unblown sample. Conclusion: there is a significant difference in the number of microorganisms between blown and non-blown