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1.
J Food Sci ; 2024 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-39323244

RESUMEN

In this study, microcapsules of Lactiplantibacillus plantarum 299V were prepared using an emulsification/internal gelation technique. Loads of the probiotics were condensed to 9.86 ± 0.13 log CFU/g after 24 h fermentation of the microcapsules. Physical characterization revealed that L. plantarum 299V cells were uniformly distributed within the core of the microcapsules, with a mean diameter of 109.81 ± 0.39 µm and a span value of 0.36 ± 0.00, which were comparable to those of the unfermented microcapsules (p > 0.05). The viability of L. plantarum 299V in the fermented microcapsules was 2.08 ± 0.15 log higher than that of free cells at the end of 5 h simulated gastrointestinal digestion (p < 0.05). Oysters were able to accumulate the fermented microcapsules through filter feeding, resulting in a load of probiotics exceeding 6.00 log CFU/g. The presence of L. plantarum 299V-carrying microcapsules in oyster tissues significantly suppressed spoilage-causing bacteria during 11 days refrigeration storage, suggested by the tested parameters, including total psychrotrophic bacteria, H2S-producing bacteria, and Pseudomonas spp. (p < 0.05). Pathogenic bacteria, including Vibrio parahaemolyticus and Salmonella enterica artificially introduced into oysters, were also significantly suppressed by over 1.00-log within 4 days compared to control samples (p < 0.05). In summary, oysters bioaccumulated with fermented L. plantarum 299V-carrying microcapsules, justified a novel probiotic-carrying product to exsert the health-promoting effect of probiotics. This solution could also enhance the microbial quality and safety of oysters during storage.

2.
Foods ; 13(7)2024 Mar 24.
Artículo en Inglés | MEDLINE | ID: mdl-38611294

RESUMEN

In commercially available honey, the application of a heat treatment to prevent spoilage can potentially compromise its beneficial properties and quality, and these effects worsen with extended storage. The high-pressure processing (HPP) of honey is being explored, but its long-term impact on honey quality has not been characterised yet. This study evaluated the effects of HPP and thermal processing on the microbial load, physicochemical quality (i.e., hydroxymethylfurfural content and diastase activity), and antioxidant capacity of honey after treatment and following extended storage (6, 12, and 24 months) at 20 °C. Pasteurization (78 °C/6 min) effectively eliminated the microorganisms in honey but compromised its physicochemical quality and antioxidant activity. HPP initially showed sublethal inactivation, but storage accelerated the decrease in yeasts/moulds and aerobic mesophiles in honey (being <1 log CFU/g after 24 months of storage) compared to unprocessed honey and honey thermally treated under mild conditions (55 °C/15 min). The physicochemical characteristics of the quality of HPP-treated honey and raw unprocessed honey did change after long-term storage (24 months) but remained within regulatory standards. In conclusion, HPP emerged as a more suitable and safe preservation method for Apis mellifera honey, with a minimal risk of a loss of antioxidant activity compared to traditional industrial honey pasteurization.

3.
Foods ; 13(5)2024 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-38472788

RESUMEN

In this study, the addition of mango seed extract (MSE) in goat meatballs was assessed. The efficacy of three different levels of MSE extract, namely T1 = (2.5 mL/100 g of meat emulsion v/w), T2 = (5.0 mL/100 g of meat emulsion v/w), T3 = (7.5 mL/100 g of meat emulsion v/w), and T0 (control without mango seed extract), was conducted for evaluation of changes in water activity (aW), pH, total phenolic compounds, DPPH, peroxide value, TBARS, microbial quality, and sensory attributes of the goat meatballs stored at refrigerated temperature (4 ± 1 °C). Incorporation of the mango seed extract T3 (7.5 mL/100 g) showed that it can potentially better maintain change in pH and water activity. Total phenolic and DPPH activity decreased significantly (P0.05) among all samples throughout storage; however, the highest value was noted for T3 among all samples. The MSE-added goat meatballs (T3) group had lower significant (p < 0.05) peroxide values than the other samples. The T3 sample added with MSE exhibited significant (p < 0.05) lower TBRAS values as compared to other treatments. Comparatively lower microbial proliferation and better sensory attributes were maintained among the treated groups during the entire storage time. The results show that the inclusion of MSE extract T3 (7.5 mL/100 g) is a promising natural antioxidant that can maintain a better quality of goat meatballs at refrigerated temperature (4 ± 1 °C) under aerobic packaging conditions.

4.
Foods ; 13(5)2024 Mar 03.
Artículo en Inglés | MEDLINE | ID: mdl-38472901

RESUMEN

The present study aimed to evaluate the antioxidant capacity of ethanolic extracts from post-harvest sunflower and maize stalk residues, and their impact on the chemical composition, physicochemical parameters, lipid oxidative stability, microbiological properties, and sensory characteristics of pork liver pâtés over a 90-day storage period. Four formulations were prepared: a control group (CON), a batch with butylated hydroxytoluene as a synthetic antioxidant (BHT), 1% ethanolic extract from sunflower residues (SSRE), and 1% ethanolic extract from maize residues (MSRE). The MSRE had a higher total phenol content and showed better antioxidant activity relative to the SSRE (p < 0.01). The addition of SSRE decreased the lightness and increased the redness in the pork liver pâtés, with these pâtés showing the highest total color difference compared to the control (p < 0.01). The crop extracts increased the n-6 and total PUFA contents in pâtés and improved the PUFA/SFA ratio (p < 0.01). Formulations containing crop residue extracts showed higher TBARs and POV values than the control and BHT group (p < 0.01), indicating a pro-oxidant effect and accelerated lipid oxidation in pâtés during storage. As far as microbiological quality, the presence of crop residue extracts decreased the total viable count, lactic acid bacteria, and psychotropic aerobic bacteria (p < 0.01). The incorporation of crop extracts in the pork pâtés impaired their sensory quality, particularly color, odor, aroma, and flavor, and decreased their overall acceptability. These results indicated that, while the crop residue extracts were not as effective as synthetic antioxidants in preserving the lipid stability of pâtés, they demonstrated potential for enhancing the microbial quality of this type of meat product.

5.
Heliyon ; 10(6): e27878, 2024 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-38545174

RESUMEN

In Sri Lanka, several tea grades are produced in factories located in different agro-climatic regions within three geographical elevations. The study aimed to determine the microbial quality of different tea grades and composite tea samples obtained from factories situated at diverse locations. The average APC, yeast & mould counts and coliforms in different tea grades ranged from 3.4 × 103 to 2.0 × 104 cfu/g, 4.8 × 102 to 2.5 × 103 cfu/g and 0.005 to 3.9 × 101 Most Probable Number (MPN)/g respectively. The tea samples collected from different factories had mean values of APC and yeast & mould as 5.3 × 103±1.3 × 103 cfu/g and 9.7 × 102±1.9 × 102 cfu/g. Escherichia coli (E.coli) and Salmonella were not detected either in tea grades or in composite samples. The identified microorganisms in tea samples belong to phyla Firmicutes, Proteobacteria, Ascomycota, Basidiomycota and Zygomycota. The samples collected from the mid country elevation had the highest counts of APC and yeast & mould counts were high in the low country elevation. More than 70 % of the tested samples comply with the SLTB guidelines given for the microbiological quality of black tea. The distribution of bacterial, yeast and mould and coliform densities of tea were significantly variable with respect to geographic areas.

6.
J Microbiol Methods ; 220: 106909, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38432551

RESUMEN

Escherichia coli are widely used by water quality managers as Fecal Indicator Bacteria, but current quantification methods do not differentiate them from benign, environmental Escherichia species such as E. marmotae (formerly named cryptic clade V) or E. ruysiae (cryptic clades III and IV). Reliable and specific techniques for their identification are required to avoid confounding microbial water quality assessments. To address this, a multiplex droplet digital PCR (ddPCR) assay targeting lipB (E. coli and E. ruysiae) and bglC (E. marmotae) was designed. The ddPCR performance was assessed using in silico analysis; genomic DNA from 40 local, international, and reference strains of target and non-target coliforms; and spiked water samples in a range relevant to water quality managers (1 to 1000 cells/100 mL). Results were compared to an analogous quantitative PCR (qPCR) and the Colilert method. Both PCR assays showed excellent sensitivity with a limit of detection of 0.05 pg/µL and 0.005 pg/µl for ddPCR and qPCR respectively, and of quantification of 0.5 pg/µL of genomic DNA. The ddPCR allowed differentiation and quantification of three Escherichia species per run by amplitude multiplexing and showed a high concordance with concentrations measured by Colilert once proportional bias was accounted for. In silico specificity testing underlined the possibility to further detect and distinguish Escherichia cryptic clade VI. Finally, the applicability of the ddPCR was successfully tested on environmental water samples where E. marmotae and E. ruysiae potentially confound E. coli counts based on the Most Probable Number method, highlighting the utility of this novel ddPCR as an efficient and rapid discriminatory test to improve water quality assessments.


Asunto(s)
Bacterias , Escherichia coli , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Calidad del Agua , ADN
7.
Food Sci Nutr ; 12(1): 564-573, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38268890

RESUMEN

Butter is a perishable food, and its microbial deterioration occurs in refrigeration conditions, leading to a reduction in shelf life and a loss of sensory properties. This study aimed to investigate the effect of chia seed extract (CSE) on the microbial and sensory properties of pasteurized sweet cream butter at 2°C. Ethanolic extract of chia seeds was prepared and added to the butter samples in concentrations of 0.05%, 0.1%, 0.25%, and 0.5% (v/w), and its effects on microbiological and sensory quality were evaluated at 15-day intervals during 60-day refrigerated storage. The results indicated that the addition of 0.25% and 0.5% CSE to butter treatments decreased total viable counts by 0.25-0.6 log CFU/g, total psychrotrophic counts by 1-1.5 log CFU/g, and coliform counts by 3-4 log CFU/g compared to the control sample on days 45 and 60 of storage. Moreover, concentrations of 0.1%-0.5% CSE reduced mold and yeast counts by 1.5-2.6 log CFU/g on days 30-60 of storage compared to the control sample. Escherichia coli and Staphylococcus aureus were not detected in any samples during storage. CSE had a significant effect on the sensory properties (except for aroma) of the butter samples during the 60-day storage. The best color, flavor, and overall acceptance scores were assigned to the treatments containing 0.1%-0.5% CSE compared to the control sample. It could be concluded that adding 0.1% and 0.25% CSE to refrigerated and pasteurized butter can retard microbial spoilage and improve its sensory properties at the same time.

8.
J Food Prot ; 87(1): 100194, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-37977504

RESUMEN

This study aimed to evaluate the quality of honey in the supply chain from the Gera district to Jimma town in southwest Ethiopia and develop a predictive model to detect adulteration. A preliminary survey revealed that poor handling practices and adulteration negatively impacted honey's physicochemical and microbial quality. For laboratory analysis, 268 honey samples were collected from households, cooperatives, chira markets, Agaro markets, and Jimma markets. They were mixed separately to create composite samples representing different value chain actors. Laboratory results indicated that honey samples from supply chain actors confirmed significant differences (p < 0.05) in physicochemical and microbial quality. The study found that the extent of adulteration and physicochemical quality loss increased from producers to Jimma retailers, indicating multiple-stage adulteration along the supply chain that could pose a risk to the safety and quality of the product. The physicochemical quality parameters of the honey samples in the study varied within the following ranges: moisture (18.35-19.42%), water activity (0.48-0.61), viscosity (7.45-10.28 Pas), pH (3.41-4.0), titratable acidity (34.01-36.03 meq/kg), ash (0.1-0.23%), electrical conductivity (0.25-0.39 mS/cm), Total Soluble Solid (75.9-77.5 °Brix), Water insoluble Solid (0.16-2.48 g/100 g), Diastase Activity (6-14 DN), and Hydroxymethylfurfural (0.2-27.7 mg/kg). Microbiological analyses showed that total aerobic bacterial and fungal load ranged from 2.7 × 101-2.29 × 102 and 3.2 × 101-4.57 × 102, respectively. A predictive model was developed using adulteration indicator parameters, showing good linearity (R2>90%) and predictive capacity for detecting adulteration with sugar syrup.


Asunto(s)
Miel , Miel/análisis , Etiopía , Carbohidratos/análisis , Agua/análisis , Ciudades
10.
Foods ; 12(22)2023 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-38002143

RESUMEN

Artisanal salami is produced in small-scale production plants, where the lack of full automation might result in higher variability in food intrinsic properties. The aim of the present study was to evaluate the inter- and intra-batch variability in physicochemical parameters and its impact on microbial quality and occurrence of foodborne pathogens on 480 samples collected from six batches of an artisanal Italian production of organic salami. Relatively high total bacterial counts (TBC) were found on the surface of the table in the stuffing room (4.29 ± 0.40 log cfu/cm2). High loads of Enterobacteriaceae in the meat mixture of batch 2 and TBC in batch 5 were associated with a higher occurrence of bacterial pathogens. During ripening, water activity (aw) and pH failed to reach values lower than 0.86 and 5.3, respectively. Six Staphylococcus aureus and four Listeria monocytogenes isolates were collected from the salami meat mixture during ripening and the processing environment. A total of 126 isolates of Enterobacteriaceae were characterized at a species level, with Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, and Citrobacter freundii isolated from the final products. Results suggest the relevance of first steps of production in terms of the hygiene of raw materials and handling during stuffing procedures, especially when the physicochemical parameters of the final products do not reach values that represent hurdles for foodborne pathogens.

11.
Foods ; 12(22)2023 Nov 19.
Artículo en Inglés | MEDLINE | ID: mdl-38002227

RESUMEN

Meat discoloration, lipid oxidation, and undesirable texture are inevitable phenomena in basa fish fillets during storage, which in turn limits their exportation as well as decreases consumer acceptability. In addition, increasing consumers' requirements for high-quality, minimally processed, and ready-to-cook fish fillets with an extended shelf-life is a great challenge, particularly with lifestyle changes. Accordingly, this study aimed to improve the quality, lipid stability, fatty acid profile, and lipid nutritional quality indices (LNQI) of basa fish fillets during chilling storage at 4 °C for 15 days using pepsin enzyme (E, 0.1%), rosemary oil (R, 0.5%), citric acid (CA, 0.5%), and their combination (0.1% E + 0.5% R; 0.1% E + 0.5% CA; and 0.1% E + 0.5% R + 0.5% CA). Our results revealed that all treated samples exhibited a significant increase in protein content, a significant decrease in fat content, and a marked reduction in pH, total volatile base nitrogen (TVBN), thiobarbituric acid (TBA), free fatty acids, and shear force (SF) values in comparison to control ones. Moreover, significant improvements in sensory scores, color stability, fatty acid profile, LNQI, and microbial quality of all treated samples were observed. Such findings were more pronounced in samples treated with a mixture of pepsin, rosemary, and citric acid (TVBN: 2.04 vs. 6.52 mg%; TBA: 0.40 vs. 2.68 mg malonaldehyde/Kg; and SF: 8.58 vs. 19.51 Kgf). Based on the obtained results, there was an extension for the shelf life of all treated basa fish fillet samples, especially in samples treated with a mixture of pepsin, rosemary, and citric acids when compared with the control samples (˃15 days versus 10 days). Additionally, eucalyptol, camphor, isoborneol, and α-pinene are the main components of rosemary, with great antioxidant and antimicrobial activity. In conclusion, the mixture of pepsin, rosemary, and citric acid can be applied easily in the seafood industry and at the household level to provide ready-to-cook fish fillets of high quality with great health benefits.

12.
J Insects Food Feed ; 9(9): 1187-1197, 2023 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-37997599

RESUMEN

Mopane worms (Gonimbrasia belina) is an important source of food and contribute to the nutrition of people who consume them. However, the traditional processing methods may have detrimental effects on the nutritional value and should also guarantee microbial quality. In this study, the nutritional composition and microbial quality of mopane worms processed under different boiling time (0-20 min) and drying temperature (40-60 °C) conditions were investigated and optimised using response surface methodology. An increase in the boiling time at the lowest drying temperature resulted in an increase in protein content and reduction in coliform counts. The optimum conditions of boiling for 20 min and drying at 40 °C resulted in mopane worms with a protein content of 49.4% DW and coliform counts <1.5 log cfu/g. In addition, high concentrations of crude fibre (13.6% DW) and fat (20.2% DW), as well as Fe (19.0 mg/100 g) and Zn (17.9 mg/100 g) were also recorded. A decrease in the total bacterial count, Escherichia coli and yeasts and moulds at the boiling time ≥20 min irrespective of the drying temperature suggested that exposure to heat reduced the microbial growth and contamination. Reduction of the mopane worms' moisture content (<7%) due to drying further slowed down the rate of microbial growth. The optimal processing conditions (boiling for 20 min and drying at 40 °C) are recommended for pretreatment of mopane worms prior to further processing into various products.

14.
Heliyon ; 9(9): e19273, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37662740

RESUMEN

Fresh produce continues to be the main source of foodborne illness outbreaks, particularly in developing countries where water stress results in the use of surface wastewater all year round for irrigation of vegetables. The objective of the current study was to evaluate the microbial quality of lettuce irrigated with wastewater from Onyasia river. Lettuce and soil were sampled from selected vegetable farms on the Eastern gate of the Ghana Atomic Energy Commission land alongside surface wastewater from the Onyasia river, which is used as the main source for irrigation. Samples were analyzed for aerobic mesophilic plate counts, total coliforms count, fecal coliforms count, Salmonella counts and intestinal parasites using standard methods. Surface wastewater was found to be contaminated with mean fecal coliform counts of log 3.50 cfu/100 mL. Enterobacter cloacae, Acinetobacter baumannii, and Klebsiella pneumonia were also isolated from the wastewater samples. No intestinal parasite egg was detected in wastewater samples. While fecal coliforms and Salmonella spp were not detected, mean aerobic mesophilic plate counts (log 4.82 cfu/g) and total coliforms count (log 3.50 cfu/g) were recorded in the lettuce samples. Enterobacter asburiae, Acinetobacter baumannii, Klebsiella variicola and Citrobacter freundii were isolated from lettuce. Infective larvae of helminths were observed on lettuce samples at a density of 36/g-648/g with a mean of 342/g. Soil samples recorded a mean aerobic mesophilic plate counts of log 6.14 cfu/g, total coliforms count of log 4.90 cfu/g while fecal coliforms and Salmonella spp were not detected (<1 cfu/g) Soil samples yielded a mean infective larval count of 1941.5 larvae/g and a Strongyle count of 12 eggs/g. Even though less than 1 cfu/g of Salmonella spp were found, the study found lettuce to be contaminated with other foodborne bacteria pathogens, opportunistic bacteria pathogens, eggs and infective larvae of intestinal parasites of health importance. As a consequence, the microbial food safety risk associated with wastewater irrigated vegetables was observed to be high with possible public health implications. It is recommended that wastewater from the Onyasia River should be treated before use for irrigation of lettuce.

15.
Molecules ; 28(17)2023 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-37687126

RESUMEN

Short shelf-life and poor microbial quality of minimally processed foods of plant origin pose a serious problem for the food industry. Novel techniques of minimal treatment combined with disinfection are being researched, and, for fresh juice, the addition of antimicrobial agents appears to be a promising route. In this research, fresh, nonfiltered, unpasteurized carrot juice was mixed with four potential antimicrobials (bourbon vanilla extract, peppermint extract, cannabidiol oil, and grapefruit extract). All four variants and the reference pure carrot juice were analyzed for metapopulational changes, microbial changes, and physicochemical changes. The potential antimicrobials used in the research have improved the overall microbial quality of carrot juice across 4 days of storage. However, it is important to notice that each of the four agents had a different spectrum of effectiveness towards the groups identified in the microflora of carrot juice. Additionally, the antimicrobials have increased the diversity of the carrot juice microbiome but did not prevent the occurrence of pathogenic bacteria. In conclusion, the use of antimicrobial agents such as essential oils or their derivatives may be a promising way of improving the microbial quality and prolonging the shelf-life of minimally processed foods, such as fresh juices, but the technique requires further research.


Asunto(s)
Antiinfecciosos , Daucus carota , Alimentos , Antiinfecciosos/farmacología , Desinfección , Extractos Vegetales/farmacología
16.
Front Nutr ; 10: 1184005, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37533575

RESUMEN

A survey was conducted in Hisar, located in Haryana, India, to assess the quality of raw chicken meat. To ensure comprehensive coverage, healthy broiler chickens were obtained from various meat retail outlets in Hisar city, encompassing the majority of such establishments. Additionally, a sample of control chickens was obtained from the Livestock Farm, College of Veterinary Sciences, Lala Lajpat Rai University of Veterinary and Animal Sciences (LUVAS), Hisar, Haryana, India. The raw chicken meat was grouped into two categories, breast cut and thigh cut. The breast muscles, which include pectoralis major and pectoralis minor, and the thigh muscles, which include the abductor muscles, were chosen as the samples for proximate analysis, which included physico-chemical, sensory, and microbiological analyses of raw chicken meat. The analysis of the raw meat in the laboratory revealed inconsistent variations between the control and retail samples in terms of parameters, such as proximate composition, pH, the water-holding capacity (WHC), thiobarbituric acid (TBA), instrumental color analysis, and sensory evaluation. The moisture content of the control breast sample was significantly higher (p < 0.05) than that of the samples from shops 2, 3, and 5. However, it was statistically similar to that of the samples from shops 1, 4, and 6. The total plate and psychrotrophic counts of the control thigh sample were significantly lower than those of the samples from shops 3, 4, 5, and 6. Among the thigh pH values, the samples from shops 1, 2, 5, and 6 had significantly higher pH values than the control sample. The variations in the various parameters were multifactorial and established the superiority of birds slaughtered under laboratory conditions and grown in university farms compared to the raw chicken meat available in retail outlets in Hisar city.

17.
Ultrason Sonochem ; 98: 106517, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37454538

RESUMEN

In this study, a decontamination technology combining ultrasound (US) and plasma-activated water (PAW) was developed to better preserve crayfish. First, the decontamination efficacy of US, PAW and their combinations (UP) on crayfish was quantified after 0, 20, 40, or 60 min of treatments. The total viable count (TVC) was reduced by 0.27-0.77 Log CFU/g after individual US or PAW treatments, while a TVC reduction of 1.17 Log CFU/g was achieved after 40 min of UP treatment. Besides, the changes in psychrotrophic bacteria, lactic acid bacteria, yeasts and molds followed a similar trend to TVC. UP treatments normally resulted in more significant reductions in the natural microbiota of crayfish than US or PAW treatments. Furthermore, the microbial quality, physicochemical properties and sensory properties of crayfish after different treatments were assessed during storage at 4 °C for 12 days. According to TVC and total volatile basic nitrogen (TVB-N) values, the control group became unacceptable from 4 days, US or PAW groups became unacceptable from 6 days, while UP group extended the storage time to 8-10 days. During storage, thiobarbituric acid reactive substances (TBARS) values of all the groups were maintained below 0.5 mg/kg, among which the control group exhibited the highest value (0.39 mg/kg). Moreover, UP treatment effectively retarded the deterioration in color and texture properties of crayfish. Fourier transform infrared (FTIR) spectroscopy analysis indicated that UP treatment decreased the α-helix contents and increased the ß-sheet contents of crayfish proteins, while the structural changes were not evident at the end of storage. Low-field nuclear magnetic resonance (LF-NMR) analysis revealed that UP treatment reduced the water migration and enhanced the stability of bond water in crayfish. In addition, E-nose analysis revealed the protection of UP treatment on the sensory properties of crayfish during storage. This study demonstrated that the combinations of US and PAW treatments effectively accelerated the decontamination of crayfish and contributed to better storage quality.


Asunto(s)
Astacoidea , Agua , Animales , Viabilidad Microbiana , Recuento de Colonia Microbiana , Alimentos Marinos
18.
Environ Pollut ; 334: 122140, 2023 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-37414126

RESUMEN

Faecal pollution in aquatic environments is a worldwide public health concern, yet the reliability and comprehensiveness of the methods used to assess faecal contamination are still debated. We compared three approaches, namely a culture-based method to enumerate Faecal Indicator Bacteria (FIB), a FIB-targeting qPCR assay, and High-Throughput Sequencing (HTS) to detect faeces- and sewage-associated taxa in water and sediment samples of an impacted model lagoon and its adjacent sea across one year. Despite at different levels, all approaches agreed in showing a higher contamination in the lagoon than in the sea, and higher in sediments than water. FIB significantly correlated when considering separately sediment and water, and when using both cultivation and qPCR. Similarly, FIB correlated between cultivation and qPCR, but qPCR provided consistently higher estimates of FIB. Faeces-associated bacteria positively correlated with cultivated FIB in both compartments, whereas sewage-associated bacteria did only in water. Considering their benefits and limitations, we conclude that, in our study site, improved quali-quantitative information on contamination is provided when at least two approaches are combined (e.g., cultivation and qPCR or HTS data). Our results provide insights to move beyond the use of FIB to improve faecal pollution management in aquatic environments and to incorporate HTS analysis into routine monitoring.


Asunto(s)
Monitoreo del Ambiente , Aguas del Alcantarillado , Aguas del Alcantarillado/microbiología , Monitoreo del Ambiente/métodos , Reproducibilidad de los Resultados , Microbiología del Agua , Bacterias/genética , Heces/microbiología , Agua
19.
Heliyon ; 9(6): e16911, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37332921

RESUMEN

Tej is an Ethiopian traditional alcoholic beverage with significant social and economic importance. Due to the spontaneous fermentation process of Tej, several issues such as safety, quality, and physicochemical properties of the final products is rquired to be assessed. Thus, this study was aimed to assess the microbial quality, physicochemical, and proximate properties of Tej associated with different maturity time. The microbial, physicochemical and proximate analyses were carried out by standard protocol. Lactic acid bacteria (6.30 log CFU/mL) and yeast (6.22 log CFU/mL) were the dominat microorganisms of all Tej samples at different maturity time, with significant differences (p = 0.001) in mean microbial count among samples. The mean pH, titratable acidity and ethanol content of Tej samples were 3.51, 0.79 and 11.04% (v/v), respectively. There were significant differences (p = 0.001) among the mean pH and titratable acidity values. The mean proximate compositions (%) of Tej samples were as follows: moisture (91.88), ash (0.65), protein (1.38), fat (0.47) and carbohydrate (3.91). Statistically significant differences (p = 0.001) were observed in proximate compositions of Tej samples from different maturity time. Generally, Tej maturity time has a great impact on the improvement of nutrient composition and the increment of the acidic contents which in turn suppress the growth of unwanted microorganisms. Further evaluation of the biological, and chemical safety and development of yeast-LAB starter culture are strongly recommended to improve Tej fermentation in Ethiopia.

20.
Foods ; 12(9)2023 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-37174463

RESUMEN

The efficiency of natural olive pomace extracts for enhancing the quality of fresh-cut apples was compared with commercial ascorbic acid and two different packaging films (biodegradable polylactic acid (PLA) and oriented polypropylene (OPP)) were tested. The composition of atmosphere inside the packages, the physicochemical parameters (firmness, weight loss and color), the microbial load, total phenolic content and antioxidant activity of fresh-cut apples were evaluated throughout 12 days of storage at 4 °C. After 12 days of refrigerated storage, a significant decrease in O2 was promoted in PLA films, and the weight loss of the whole packaging was higher in PLA films (5.4%) than in OPP films (0.2%). Natural olive pomace extracts reduced the load of mesophilic bacteria (3.4 ± 0.1 log CFU/g and 2.4 ± 0.1 log CFU/g for OPP and PLA films, respectively) and filamentous fungi (3.3 ± 0.1 log CFU/g and 2.44 ± 0.05 log CFU/g for OPP and PLA films, respectively) growth in fresh-cut apples after five days of storage at 4 °C, and no detection of coliforms was verified throughout the 12 days of storage. In general, the olive pomace extract preserved or improved the total phenolic index and antioxidant potential of the fruit, without significant changes in their firmness. Moreover, this extract seemed to be more effective when combined with the biodegradable PLA film packaging. This work can contribute to the availability of effective natural food additives, the sustainability of the olive oil industries and the reduction of environmental impact. It can also be useful in meeting the food industries requirements to develop new functional food products.

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