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1.
PLoS One ; 19(8): e0304692, 2024.
Article in English | MEDLINE | ID: mdl-39110654

ABSTRACT

During the last years, growing interest in the use of mare's milk in food production is observed. The subject of the study was to evaluate the feasibility of mare's milk for the production of yogurt ice cream and synbiotic ice cream. Four variants of mare's milk ice cream were developed: ice cream with yogurt bacteria without inulin (YO) and with 2% of inulin (YO+I), synbiotic ice cream with 2% inulin and Lacticaseibacillus rhamnosus (LCR+I) and with Lactiplantibacillus plantarum (LP+I). Ice creams were enriched with inulin in order to evaluate its influence on the viability of LAB and on the product quality. Physicochemical, textural and sensory analyses were performed. Count of viable bacteria cells was also evaluated. Obtained ice creams did not differ in terms of protein, fat and total solids content (1.85-1.91%, 7.33-7.58% and 24.66-26.96% respectively), but differed in acidity. Ice cream YO, the only one without inulin, had the highest acidity, what suggests that inulin decrease this parameter. Regardless the type of LAB starter culture and inulin addition, samples had the same range of overrun (35.20-44.03%) and melting rate (73.49-79.87%). However the variant of ice cream influenced textural properties and colour parameters. All obtained mare's milk ice creams had high overall sensory quality. It was noticed, that ice cream with inulin had higher count of LAB (>7logCFU/g), than sample without inulin (>6logCFU/g). In conclusion, mare's milk may be considered as feasible raw material for yogurt ice cream and synbiotic ice cream production.


Subject(s)
Ice Cream , Milk , Synbiotics , Yogurt , Ice Cream/analysis , Ice Cream/microbiology , Yogurt/analysis , Yogurt/microbiology , Animals , Synbiotics/analysis , Milk/chemistry , Horses , Female , Inulin , Lacticaseibacillus rhamnosus/metabolism , Humans , Food Microbiology
2.
Sci Rep ; 14(1): 15471, 2024 07 05.
Article in English | MEDLINE | ID: mdl-38969697

ABSTRACT

This study examines the effect of phycoerythrin (PE) from a cyanobacterial Nostoc strain encapsulated with alginate as a potential prebiotic to produce synbiotic ice cream products with Lactobacillus casei. It was found that the addition of the encapsulated PE affected, mostly favourably, the physicochemical properties, antioxidant activity, probiotic survival, volatile compound contents, and sensory acceptability of the synbiotic ice cream samples before and after aging at the freezing periods of one day to eight weeks. Thus, it confirms the prebiotic potential of PE for synbiotic ice creams with L. casei.


Subject(s)
Alginates , Ice Cream , Lacticaseibacillus casei , Phycoerythrin , Synbiotics , Lacticaseibacillus casei/metabolism , Ice Cream/microbiology , Alginates/chemistry , Phycoerythrin/chemistry , Synbiotics/administration & dosage , Antioxidants/chemistry , Nostoc/metabolism , Probiotics
3.
Molecules ; 29(13)2024 Jul 07.
Article in English | MEDLINE | ID: mdl-38999174

ABSTRACT

This study investigated a novel probiotic-enriched ice cream containing fermented white kidney bean homogenate to explore its potential health benefits in the future. We assessed the viability of various probiotic strains during ice cream production and storage, focusing on their potential to reach the gut, and evaluated overall antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), ferric reducing antioxidant power (FRAP), and total polyphenol content (TPC) assays. The incorporation of fermented white bean homogenate significantly increased antioxidant capacity compared to the control group. Notably, strains such as Lacticaseibacillus rhamnosus GG and Lactiplantibacillus plantarum 299v demonstrated the most pronounced effects on antioxidant activity, suggesting potential synergistic benefits between probiotics and bioactive compounds in fermented white beans. Although all probiotic strains experienced decreased viability during storage, certain strains, particularly L. plantarum 299v and Lacticaseibacillus casei DN-114001, showed promising survival rates even after 6 months. These results suggest the potential for developing probiotic ice cream containing viable bacteria capable of reaching the gut and contributing to a healthy gut microbiota. Overall, this study highlights the potential of probiotic-enriched ice cream with fermented white kidney bean homogenate to combine the established benefits of probiotics for gut health with the enjoyment of consuming ice cream.


Subject(s)
Antioxidants , Fermentation , Ice Cream , Probiotics , Antioxidants/pharmacology , Antioxidants/chemistry , Ice Cream/microbiology , Phaseolus/chemistry , Polyphenols/chemistry , Polyphenols/pharmacology , Microbial Viability/drug effects
4.
Food Chem ; 454: 139839, 2024 Oct 01.
Article in English | MEDLINE | ID: mdl-38810444

ABSTRACT

Probiotic lactic acid bacteria have been widely studied, but much less was focused on probiotic yeasts in food systems. In this study, probiotic Saccharomyces cerevisiae var. boulardii CNCM I-745 was employed to prepare ice cream added with and without inulin (1%, w/v). Metabolomics analysis on the effect of inulin showed 84 and 147 differentially expressed metabolites identified in the ice cream samples from day 1 and day 30 of storage (-18 °C), respectively. Various potential functional metabolites were found, including citric acid, ornithine, D-glucuronic acid, sennoside A, stachyose, maltotetraose, maltopentaose, maltohexaose, maltoheptaose, cis-aconitic acid, gamma-aminobutyric acid, L-threonine, L-glutamic acid, tryptophan, benzoic acid, and trehalose. Higher expression of these metabolites suggested their possible roles through relevant metabolic pathways in improving survivability of the probiotic yeast and functionality of ice cream. This study provides further understanding on the metabolic characteristics of probiotic yeast that potentially affect the functionality of ice cream.


Subject(s)
Ice Cream , Inulin , Metabolomics , Prebiotics , Probiotics , Saccharomyces cerevisiae , Synbiotics , Inulin/metabolism , Probiotics/metabolism , Synbiotics/analysis , Prebiotics/analysis , Saccharomyces cerevisiae/metabolism , Ice Cream/analysis , Ice Cream/microbiology , Saccharomyces boulardii/metabolism , Saccharomyces boulardii/chemistry
5.
Braz J Microbiol ; 55(2): 1735-1744, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38727922

ABSTRACT

AIMS: To develop and characterize a functional lactose-free ice cream with added ginger and honey, evaluate the survival of Lacticaseibacillus casei CSL3 under frozen storage and the simulated gastrointestinal tract (GIT), as well as antioxidant activity and product acceptability. METHODS AND RESULTS: The survival of Lacticaseibacillus casei CSL3 was evaluated for 180 days, under frozen storage, and GIT at 60 days. At 15 days of storage, proximal composition, antioxidant activity, color, pH, acidity, fusion, density, overrun, and sensory analysis were performed. Ice cream was an effective food matrix for maintaining the viability of CSL3, with concentrations > 7 log CFU g- 1 during storage and GIT. In addition, the analysis showed overrun and prebiotic characteristics through high values of antioxidant activity and phenolic compounds, good acceptability, and purchase intention. CONCLUSIONS: The product has satisfactory market potential (acceptance rate of 95.19% and purchase intention rate > 96%), and it could become another means of inserting probiotics in food.


Subject(s)
Honey , Ice Cream , Lacticaseibacillus casei , Probiotics , Zingiber officinale , Honey/analysis , Zingiber officinale/chemistry , Ice Cream/microbiology , Ice Cream/analysis , Lacticaseibacillus casei/chemistry , Lacticaseibacillus casei/metabolism , Probiotics/chemistry , Humans , Antioxidants/chemistry , Lactose/metabolism , Gastrointestinal Tract/microbiology , Food Storage , Microbial Viability/drug effects
6.
Nutrients ; 15(14)2023 Jul 20.
Article in English | MEDLINE | ID: mdl-37513648

ABSTRACT

To determine the potential bioavailability of macroelements (Ca, Mg, P, K), probiotic ice cream samples (Lactaseibacillus paracasei L-26, Lactobacillus casei 431, Lactobacillus acidophilus LA-5, Lactaseibacillus rhamnosus and Bifidobacterium animalis ssp. lactis BB-12) from sheep's milk with inulin, apple fiber and inulin, or apple fiber and control samples were submitted to in vitro digestion in the mouth, stomach and small intestine. The bioavailability of calcium in the ice cream samples ranged from 40.63% to 54.40%, whereas that of magnesium was 55.64% to 44.42%. The highest bioavailability of calcium and magnesium was shown for the control samples. However, adding 4% inulin reduced the bioavailability of calcium by about 3-5% and magnesium only by about 5-6%. Adding 4% apple fiber reduced the bioavailability of calcium by as much as 6-12% and magnesium by 7-8%. The highest bioavailability of calcium was determined in ice cream with L. paracasei, and the highest bioavailability of magnesium was determined in ice cream with L. casei. The bioavailability of phosphorus in ice cream ranged from 47.82% to 50.94%. The highest bioavailability of phosphorus (>50%) was in sheep ice cream fermented by B. animalis. In the control ice cream, the bioavailability of potassium was about 60%. In ice cream with inulin, the bioavailability of potassium was lower by 3-4%, and in ice cream with apple fiber, the bioavailability of potassium was lower by up to 6-9%. The bioavailability of potassium was significantly influenced only by the addition of dietary fiber. The results of the study confirmed the beneficial effect of bacteria on the bioavailability of Ca, Mg and P.


Subject(s)
Bifidobacterium animalis , Ice Cream , Probiotics , Synbiotics , Animals , Sheep , Milk/metabolism , Inulin/metabolism , Biological Availability , Ice Cream/microbiology , Calcium , Magnesium , Lactobacillus acidophilus , Bifidobacterium animalis/metabolism
7.
Nutrients ; 14(21)2022 Oct 23.
Article in English | MEDLINE | ID: mdl-36364717

ABSTRACT

We conducted a study to determine the survival of bacterial cells under in vitro digestion. For this purpose, ice cream mixes were prepared: control, with 4% inulin, 2.5% inulin and 1.5% apple fiber and 4% apple fiber. Each inoculum (pH = 4.60 ± 0.05), containing 9 log cfu g-1 bacteria, at 5% (w/w) was added to the ice cream mixes (Lacticaseibacilluscasei 431, Lactobacillus acidophilus LA-5, Lacticaseibacillus paracasei L-26, Lacticaseibacillusrhamnosus, Bifidobacterium animalis ssp. lactis BB-12) and fermentation was carried out to pH 4.60 ± 0.05. The in vitro digestion method simulated the stages of digestion that occur in the mouth, stomach and small intestine under optimal controlled conditions (pH value, time and temperature). At each stage of digestion, the survival rate of probiotic bacteria was determined using the plate-deep method. As expected, in the oral stage, there was no significant reduction in the viability of the probiotic bacteria in any ice cream group compared to their content before digestion. In the stomach stage, Bifidobacterium animalis ssp. lactis BB-12 strain had the highest viable counts (8.48 log cfu g-1) among the control samples. Furthermore, a 4% addition of inulin to ice cream with Bifidobacterium BB-12 increased gastric juice tolerance and limited strain reduction by only 16.7% compared to the number of bacterial cells before digestion. Regarding ice cream samples with Bifidobacterium BB-12, replacing part of the inulin with apple fiber resulted in increased survival at the stomach stage and a low reduction in the bacterial population of only 15.6% compared to samples before digestion. At the stomach stage, the positive effect of the addition of inulin and apple fiber was also demonstrated for ice cream samples with Lacticaseibacilluscasei 431 (9.47 log cfu g-1), Lactobacillus acidophilus LA-5 (8.06 log cfu g-1) and Lacticaseibacillus paracasei L-26 (5.79 log cfu g-1). This study showed the highest sensitivity to simulated gastric stress for ice cream samples with Lacticaseibacillusrhamnosus (4.54 log cfu g-1). Our study confirmed that the 4% addition of inulin to ice cream increases the survival rate of L. casei and Bifidobacterium BB-12 in simulated intestinal juice with bile by 0.87 and 2.26 log cfu g-1, respectively. The highest viable count in the small intestine stage was observed in ice cream with L. acidophilus. The addition of inulin increased the survival of L. rhamnosus by 10.8% and Bifidobacterium BB-12 by about 22% under conditions of simulated in vitro digestion compared to their control samples. The survival rates of L. casei and L. paracasei were also highly affected by the 4% addition of apple fiber, where the increase under gastrointestinal passage conditions was determined to range from 7.86-11.26% compared to their control counterparts. In comparison, the lowest survival rate was found in the control ice cream with L. rhamnosus (47.40%). In our study at the intestinal stage, only five ice cream groups: a sample with 4% inulin and L. acidophilus, a control sample with Bifidobacterium BB12, a sample with 2.5% inulin and 1.5% apple fiber with Bifidobacterium BB12, a control sample with L. rhamnosus, a sample with 4% fiber and L. rhamnosus reported bacterial cell counts below 6 log cfu g-1 but higher than 5 log cfu g-1. However, in the remaining ice cream groups, viable counts of bacterial cells ranged from 6.11 to 8.88 log cfu g-1, ensuring a therapeutic effect. Studies have clearly indicated that sheep milk ice cream could provide a suitable matrix for the delivery of probiotics and prebiotics and contribute to intestinal homeostasis. The obtained results have an applicative character and may play an essential role in developing new functional sheep milk ice cream.


Subject(s)
Bifidobacterium animalis , Ice Cream , Malus , Probiotics , Sheep , Animals , Ice Cream/microbiology , Inulin/pharmacology , Milk/microbiology , Lactobacillus acidophilus , Dietary Fiber , Digestion
8.
Food Microbiol ; 102: 103929, 2022 Apr.
Article in English | MEDLINE | ID: mdl-34809955

ABSTRACT

A mix base for ice cream (MBIC) is used to produce artisanal or industrial ice creams and desserts and consists of a mixture of different ingredients, including sugar, egg yolk, natural flavors, starch and milk proteins. MBICs, which have chemical-physical characteristics that include a pH of 5.61 and an activity water (Aw) less than or equal to 0.822, are packaged in tin boxes and stored at ambient temperature. Despite the low Aw, MBIC can support osmotolerant and osmophilic yeast growth. The aim of our work was to study the behavior of Zygosaccharomyces rouxii, the main microorganisms responsible of MBIC spoilage, either in the vivo or in a model system in order to inhibit its growth by the selection of antimicrobial agents. Different osmotolerant yeasts belonging to the genus Zygosaccharomyces were isolated and identified from spoiled and unspoiled lots of MBICs. In particular, Z. rouxii was the predominant species responsible for the spoilage, which depended on the high temperature of storage (>20 °C) and was highlighted by the presence of alcohol, esters, acids and gas (CO2), which blew open the tin boxes. To stop spoilage, different antimicrobial compounds were tested: sulfur dioxide, sorbic and benzoic acids and ethanol. However, only 2% v/v ethanol was required to achieve the total inhibition of the Z. rouxii cocktails tested in this work. The use of other antimicrobials cannot be recommended because they were not able to stop yeast spoilage and changed the color and flavor of the products. Conversely, the use of ethanol is suggested because of its extreme effectiveness against osmotolerant yeasts, and the added amount was less than or equal to the taste threshold limit. The MBICs, treated with ethanol, were stable till the end of their shelf-life (6 months).


Subject(s)
Ethanol/pharmacology , Food Contamination , Ice Cream , Saccharomycetales , Food Microbiology , Ice Cream/microbiology
9.
Arq. Ciênc. Vet. Zool. UNIPAR (Online) ; 24(1, cont.): e2404, jan-jun. 2021. graf
Article in English | LILACS, VETINDEX | ID: biblio-1252766

ABSTRACT

Ice cream is susceptible to contamination by handling and bad hygiene conditions during both the storage process and the fractioning for sale, and once contaminated, it can cause diseases. The purpose of this survey was to evaluate the microbiological quality of ice cream sold in bulk, of pasty and soft types, offered for consuming. Thirty samples of pasty ice cream sold in bulk, and thirty samples of soft ice cream were analyzed through the counting of thermotolerant coliforms, coagulase-positive Staphylococcus spp., and searching for the presence of Salmonella spp. During the study, a total of ten (33%) samples of pasty ice cream and five (16%) samples of soft ice cream were found to be beyond the limits established by the Brazilian law. Salmonella spp. was found in four samples (6.7%). These results are an alert for the need of greater attention to the microbiological quality of ice cream in order to ensure the safety of its consumers.(AU)


Os sorvetes são suscetíveis à contaminação pela manipulação e más condições higiênicas durante o processamento, armazenamento e do fracionamento para venda, uma vez contaminados podem causar doenças. O objetivo deste estudo foi avaliar a qualidade microbiológica de sorvetes, vendidos a granel, pastosos e expressos, oferecidos para consumo. Trinta amostras de sorvete pastoso, vendido a granel, e trinta amostras de sorvete expresso foram analisadas realizando-se contagem de coliformes termotolerantes, Staphylococcus spp. coagulase-positiva e pesquisando-se a presença de Salmonella spp. Foram detectadas dez (33%) amostras de sorvete pastoso e cinco (16%) amostras de sorvete expresso fora dos limites estabelecidos pela legislação brasileira. Salmonella spp. foi encontrado em quatro amostras (6,7%). Esses resultados alertam para a necessidade de uma maior atenção à qualidade microbiológica dos sorvetes, a fim de garantir a segurança do consumidor.(AU)


Los helados son susceptibles a la contaminación por manipulación y malas condiciones higiénicas durante el procesamiento, almacenamiento y fraccionamiento para venta, una vez contaminados pueden causar enfermedades. El objetivo de este estudio ha sido evaluar la calidad microbiológica de helados vendidos a granel, pastosos y suaves, ofrecidos para el consumo. Se analizaron treinta muestras de helados pastosos vendidos a granel, y treinta muestras de helados suaves, realizándose el conteo de coliformes termotolerantes, Staphylococcus spp. coagulase positiva e investigándose la presencia de Salmonella spp. Se detectaron diez (33%) muestras de helado pastoso y cinco (16%) muestras de helado blando fuera de los límites establecidos por la legislación brasileña. Salmonella spp. se encontró en cuatro muestras (6,7%). Esos resultados destacan la necesidad de una mayor atención a la calidad microbiológica de los helados, con el fin de garantizar la seguridad del consumidor.(AU)


Subject(s)
Salmonella , Staphylococcus , Coliforms , Ice Cream/microbiology , Hygiene , Coagulase/analysis
10.
Br J Nutr ; 126(12): 1794-1808, 2021 12 28.
Article in English | MEDLINE | ID: mdl-33593462

ABSTRACT

Strenuous physical activity, sleep deprivation and psychological stress are common features of military field training. The present study aimed to evaluate the effects of supplementation with a synbiotic ice cream on salivary IgA, gastrointestinal symptoms, well-being indicators and gut microbiota in young military participants undergoing field training. Sixty-five military completed the study: one group was supplemented for 30 d with synbiotic ice cream containing: 2·1 × 108 CFU/g for Lactobacillus acidophilus LA-5 and 2·7 × 109 CFU/g for Bifidobacterium animalis BB-12 and 2·3 g of inulin in the 60 g of ice cream at manufacture, and the other with a placebo ice cream. Volunteers were evaluated at pre-supplementation (baseline), post-supplementation and after a 5-d military training. Bifidobacterium and Lactobacillus genera were measured in stool samples and both showed a higher differential abundance post-supplementation and training. Salivary IgA and gastrointestinal symptoms decreased at post-training in both groups (P < 0·05; main effect of time); however, supplementation with synbiotic did not mitigate this effect. Tenseness and sleepiness were decreased in the synbiotic-treated group, but not in the placebo group at post-military training (P = 0·01 and 0·009, respectively; group × time effect). The other well-being indicators were not affected by the synbiotic supplementation. In conclusion, 30 d of synbiotic ice cream supplementation containing inulin, L. acidophilus LA-5 and B. animalis BB-12 favourably modulated gut microbiota and improved tenseness and sleepiness in healthy young military undergoing a 5-d field training. These improvements may be relevant to this population as they may influence the decision-making process in an environment of high physical and psychological stress.


Subject(s)
Bifidobacterium animalis , Gastrointestinal Microbiome , Ice Cream , Military Personnel , Probiotics , Synbiotics , Double-Blind Method , Humans , Ice Cream/microbiology
11.
BMC Infect Dis ; 20(1): 83, 2020 Jan 29.
Article in English | MEDLINE | ID: mdl-31996135

ABSTRACT

BACKGROUND: The more quickly bacterial pathogens responsible for foodborne illness outbreaks can be linked to a vehicle of transmission or a source, the more illnesses can be prevented. Whole genome sequencing (WGS) based approaches to source tracking have greatly increased the speed and resolution with which public health response can pinpoint the vehicle and source of outbreaks. Traditionally, WGS approaches have focused on the culture of an individual isolate before proceeding to DNA extraction and sequencing. For Listeria monocytogenes (Lm), generation of an individual isolate for sequencing typically takes about 6 days. Here we demonstrate that a hybrid, "quasimetagenomic" approach ie; direct sequencing of microbiological enrichments (first step in pathogen detection and recovery) can provide high resolution source tracking sequence data, 5 days earlier than response that focuses on culture and sequencing of an individual isolate. This expedited approach could save lives, prevent illnesses and potentially minimize unnecessary destruction of food. METHODS: Naturally contaminated ice cream (from a 2015 outbreak) was enriched to recover Listeria monocytogenes following protocols outlined in the Bacteriological Analytic Manual (BAM). DNA from enriching microbiota was extracted and sequenced at incremental time-points during the first 48 h of pre-enrichment using the Illumina MiSeq platform (2 by 250), to evaluate genomic coverage of target pathogen, Listeria monocytogenes. RESULTS: Quasimetagenomic sequence data acquired from hour 20 were sufficient to discern whether or not Lm strain/s were part of the ongoing outbreak or not. Genomic data from hours 24, 28, 32, 36, 40, 44, and 48 of pre-enrichments all provided identical phylogenetic source tracking utility to the WGS of individual isolates (which require an additional 5 days to culture). CONCLUSIONS: The speed of this approach (more than twice as fast as current methods) has the potential to reduce the number of illnesses associated with any given outbreak by as many as 75% percent of total cases and potentially with continued optimization of the entire chain of response, contribute to minimized food waste.


Subject(s)
Food Microbiology , Foodborne Diseases/microbiology , Ice Cream/microbiology , Listeria monocytogenes/genetics , Listeriosis/microbiology , Metagenomics , Disease Outbreaks , Foodborne Diseases/epidemiology , Humans , Listeria monocytogenes/classification , Listeriosis/epidemiology , Phylogeny , Time Factors , Whole Genome Sequencing
12.
J Dairy Sci ; 103(1): 172-175, 2020 Jan.
Article in English | MEDLINE | ID: mdl-31704018

ABSTRACT

Listeria monocytogenes was linked to an outbreak of foodborne illness associated with in-process contaminated ice cream in the United States from 2010 to 2015 that sickened 10 individuals and led to 3 deaths. Ice cream obtained from the outbreak was used in this study to examine the population dynamics of L. monocytogenes as in-process contaminants compared with artificially inoculated cells. Because challenge studies of food products generally use artificial contamination, it is necessary to understand the differences in survival, if any, between these 2 types of contaminants. We hypothesized that laboratory-grown cultures of the pathogen that were not exposed to the environmental stresses of the manufacturing facility would show different population dynamics in an ice cream challenge study compared with in-process contaminants. In this study, half of the outbreak-associated ice cream samples were artificially inoculated with a 10 cfu/g cocktail of L. monocytogenes; the other half contained only the in-process contaminants. All samples were stored at -20°C and tested for pathogen levels (n = 10 for each contaminant type at each time point) by the most probable number method at 3-mo intervals for 36 mo. Generally, population levels between the 2 contamination states in the ice cream were not significantly different and L. monocytogenes survived for at least 36 mo, regardless of contamination state. Overall, our results suggest that the use of L. monocytogenes as an artificial contaminant in challenge studies and risk assessment of ice cream during frozen storage give results similar to those shown by in-process contaminants.


Subject(s)
Disease Outbreaks , Food Contamination/analysis , Food Microbiology , Foodborne Diseases/microbiology , Ice Cream/microbiology , Listeria monocytogenes/physiology , Listeriosis/microbiology , Animals , Colony Count, Microbial , Freezing , Humans , Listeriosis/epidemiology , United States/epidemiology
13.
J Environ Sci Health B ; 55(3): 265-272, 2020.
Article in English | MEDLINE | ID: mdl-31762384

ABSTRACT

Food contaminated with Shiga toxin-producing Escherichia coli (STEC) represents a hazardous public health problem worldwide. Therefore, the present study was performed to elucidate the virulent and antimicrobial resistance characteristics of STEC isolated from milk and dairy products marketed in Egypt. A total of 125 samples (raw market milk, bulk tank milk, Kareish cheese, white soft cheese, and small scale-produced ice cream, 25 each) were collected for determination the prevalence and antimicrobial resistance profiling of STEC. Thirty-six STEC isolates were recovered from milk and dairy products. Serological analysis illustrated that three isolates were E. coli O157:H7 and 33 isolates belonged to different serotypes. Molecular examination indicated that all isolates harboured stx1 and/or stx2 genes, 14 isolates expressed eaeA gene and 3 isolates possessed rfbE gene. Antimicrobial resistance profiling of the isolates was both phenotypically and genetically examined. Interestingly, 31 out of 36 (86.11%) isolates were multidrug-resistant and harboured the extended-spectrum ß-lactamase encoding genes, namely, blaCTX-M-15, blaSHV-12 and blaCTX-M-14. Moreover, 12 isolates (33.33%) harboured plasmid-mediated quinolone resistant gene, qnrS. The overall conclusion of the current investigation indicated insufficient hygienic measures adopted during milking, handling, and processing leading to development of pathogenic and multidrug-resistant STEC.


Subject(s)
Dairy Products/microbiology , Drug Resistance, Bacterial/drug effects , Shiga-Toxigenic Escherichia coli/drug effects , Shiga-Toxigenic Escherichia coli/pathogenicity , Adhesins, Bacterial/genetics , Animals , Carbohydrate Epimerases/genetics , Cheese/microbiology , Drug Resistance, Bacterial/genetics , Egypt , Escherichia coli O157/drug effects , Escherichia coli O157/isolation & purification , Escherichia coli O157/pathogenicity , Escherichia coli Proteins/genetics , Food Microbiology , Ice Cream/microbiology , Microbial Sensitivity Tests , Milk/microbiology , Plasmids/drug effects , Plasmids/genetics , Prevalence , Shiga-Toxigenic Escherichia coli/isolation & purification , Transaminases/genetics , Virulence/genetics , beta-Lactamases/genetics
14.
J Dairy Sci ; 102(11): 9721-9726, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31447156

ABSTRACT

In our previous study, we observed the sporadic presence of potentially heat-injured cells of Listeria innocua in ice cream mix following a selective enrichment protocol. Although injured cells have not yet been reported to cause any disease outbreaks, it is important to understand their presence in heat-treated food matrices. In this study, we propose a possible protective role of air pockets that may help explain the sporadic presence of potentially heat-injured cells following heat treatment. Challenge studies were conducted by inoculating ice cream mix samples (42% total solids, 16.3% fat, 22.2% total sugar, and 3.4% protein) with Listeria innocua (an established surrogate) at a mean spiking level of 4.0 log cfu/g. The inoculated samples were heat-treated at 69°C for 30 min and potentially heat-injured cells were detected using buffered Listeria enrichment broth, followed by plating on modified Oxford and Rapid'LMono agars. Scanning electron microscopy and atomic force microscopy were conducted on the air-dried, spiked ice cream mix samples, before and after the thermal treatment stages. Although direct plating did not reveal any intact cells in the heat-treated ice cream mix, a more sensitive enrichment protocol was able to identify cells that were potentially heat-injured. The scanning electron micrographs showed air pockets of different sizes in the ice cream mix samples. The spiked mix samples before heat treatment showed some Listeria cells unevenly distributed in the mix matrix and some entrapped within the larger air pockets. After heat treatment, scanning electron and atomic force micrographs showed cells entrapped only within the larger air pockets. The mix matrix, however, did not show any Listeria cells. Confirmation of Listeria at all stages of analysis was done using MALDI-TOF. These observations suggest that the Listeria cells could be entrapped within the larger air pockets and thus may undergo inadequate thermal effect. This could have resulted in their detection as potentially heat-injured cells, as evident under the conditions of the experiment. These results are preliminary observations and further studies are necessary to draw conclusions and understand the true implications of these findings.


Subject(s)
Food Microbiology , Hot Temperature/adverse effects , Ice Cream/microbiology , Listeria/isolation & purification , Animals , Listeria/ultrastructure , Microscopy, Atomic Force , Microscopy, Electron, Scanning
15.
Infect Genet Evol ; 73: 214-220, 2019 09.
Article in English | MEDLINE | ID: mdl-31039448

ABSTRACT

We review how FDA surveillance identifies several ways that whole genome sequencing (WGS) improves actionable outcomes for public health and compliance in a case involving Listeria monocytogenes contamination in an ice cream facility. In late August 2017 FDA conducted environmental sampling inside an ice cream facility. These isolates were sequenced and deposited into the GenomeTrakr databases. In September 2018 the Centers for Disease Control and Prevention contacted the Florida Department of Health after finding that the pathogen analyses of three clinical cases of listeriosis (two in 2013, one in 2018) were highly related to the aforementioned L. monocytogenes isolates collected from the ice cream facility. in 2017. FDA returned to the ice cream facility in late September 2018 and conducted further environmental sampling and again recovered L. monocytogenes from environmental subsamples that were genetically related to the clinical cases. A voluntary recall was issued to include all ice cream manufactured from August 2017 to October 2018. Subsequently, FDA suspended this food facility's registration. WGS results for L. monocytogenes found in the facility and from clinical samples clustered together by 0-31 single nucleotide polymorphisms (SNPs). The FDA worked together with the Centers for Disease Control and Prevention, as well as the Florida Department of Health, and the Florida Department of Agriculture and Consumer Services to recall all ice cream products produced by this facility. Our data suggests that when available isolates from food facility inspections are subject to whole genome sequencing and the subsequent sequence data point to linkages between these strains and recent clinical isolates (i.e., <20 nucleotide differences), compliance officials should take regulatory actions early to prevent further potential illness. The utility of WGS for applications related to enforcement of FDA compliance programs in the context of foodborne pathogens is reviewed.


Subject(s)
Food Microbiology , Ice Cream/microbiology , Listeria/genetics , Listeria/isolation & purification , Whole Genome Sequencing , Food Industry , Humans , Manufacturing and Industrial Facilities
16.
Hig. Aliment. (Online) ; 33(288/289): 1357-1361, abr.-maio 2019. tab
Article in Portuguese | LILACS, VETINDEX | ID: biblio-1482161

ABSTRACT

A liofilização é um método utilizado para a conservação das características nutricionais, protegendo a estrutura primária e contribuindo para preservar componentes como vitaminas e minerais, com redução mínima de volume, bem como manter o sabor e aroma semelhantes ao fruto in natura, como por exemplo a jaca. Diante deste contexto, este estudo almejou aplicar o processo de liofilização nos frutículos de jaca, e desenvolver formulações de sorvete com a polpa. Observou-se que os resultados das análises microbiológicas das formulações de sorvete estavam de acordo com a legislação vigente, e os teores de proteína obtiveram valores de 1,34%, 1,44% e 1,74% respectivamente para as formulações 0%, 7,40% e 19,35% de polpa liofilizada, observando-se que todas as formulações apresentaram resultados fora dos padrões permitidos pela legislação vigente que determina um mínimo de 2,5%. Conclui-se que o processo de elaboração do sorvete atendeu às boas práticas de fabricação, devido à sua inocuidade.


Subject(s)
Artocarpus , Food Preservation , Chemical Phenomena , Ice Cream/analysis , Ice Cream/microbiology , Ice Cream/standards , Food Composition , Freeze Drying
17.
J AOAC Int ; 102(4): 1132-1137, 2019 Jul 01.
Article in English | MEDLINE | ID: mdl-30691546

ABSTRACT

Background: Dairy products are common sources of Listeria outbreaks, and early detection of the pathogen is critical to prevent outbreaks of illnesses and financial losses for dairy producers. Objective: This study aimed to evaluate Sample6 Detect HT/L for effective detection of Listeria monocytogenes and L. innocua in ice cream. Methods: Performance of the Sample6 DETECT HT/L was compared with U.S. Food and Drug Administration (FDA) Bacteriological Analytical Manual (BAM) Chapter 10 method for detection of Listeria spp. in ice cream using an unpaired study design. Results: R2-enriched samples tested with Sample6 Detect HT/L performed as well as the reference method at all time points tested from 15 to 24 h. R2 is a proprietary blend for use with the test kit that helps with early detection. All the dPODC values (Sample6 Detect HT/L presumptive and confirmed results) equaled zero, indicating 100% concordance between the methods. Both Sample6 Detect HT/L and FDA BAM results showed low dPODC values, with confidence intervals indicating no significant differences between Sample6 Detect HT/L and reference method results. Conclusions: Sample6 Detect HT/L is suitable to detect Listeria spp. in ice cream, even with a 12 h enrichment. Sample6 Detect HT/L demonstrated equivalent detection of L. monocytogenes and L. innocua from R2-enriched samples as expected with 15 and 18 h enrichment when compared with the 24 h FDA BAM method for L. monocytogenes. Highlights: These results indicate that Sample6 Detect HT/L, primarily developed for environmental samples, can be used to detect Listeria spp. in ice cream with less incubation time, resulting in faster detection.


Subject(s)
Food Contamination/analysis , Ice Cream/microbiology , Listeria monocytogenes/isolation & purification , Bacteriophage Typing/methods , Food Microbiology/methods
18.
Acta Sci Pol Technol Aliment ; 18(4): 361-371, 2019.
Article in English | MEDLINE | ID: mdl-31930788

ABSTRACT

BACKGROUND: The maintenance and strengthening of public health and the prevention of diseases associated with the malnutrition of children and adults is an urgent and acute problem facing the population of the whole world. Diabetes type 2 has become a serious problem for modern medicine. This disease is widespread throughout the world among children and adolescents. There are substantial grounds to believe that this global incidence is related to obesity and physical inactivity. There is a diverse assortment of ice-creams and frozen desserts available all around the world. Even with the development of the ice-cream industry, frozen desserts for people suffering from diabetes type I and II have not been sufficiently developed. Therefore, this study aims to select low-calorie components for use in the manufacture of sherbet ice-cream without sucrose in their composition, with a low glycemic index and with a high content of protein and vitamins. METHODS: Tо develop the technology and formulation of the product, a combination of appropriate starter cultures and their ratios were determined. The most suitable fruit mix with a low glycemic index was chosen to maintain the product with properties desirable to consumers. RESULTS: Combined starter cultures, consisting of CHN-22 and St-Body 1 at a ratio of 7:3 were selected experimentally. The best thixotropic properties were shown by the test samples with a titratable acidity of 60–65°Ð¢ at a fermentation temperature of 33 ±1°C. The fruit mixture for the sherbet ice-cream was made from fruits and berries recommended for people with diabetes, including cherries, blueberries and lingonberries at a ratio of 3:4:3, respectively. The part of the mixture that was inserted into the sherbet ice-cream was evaluated as 25% of the weight of the final mixture. Stevioside and syrup of Jerusalem artichoke were selected at amounts of 0.05% and 7.5% by weight of the mixture respectively. The resulting sherbet was not inferior in sweetness to the control sample with 21% sucrose. The shelf life of the low-fat fermented sherbet ice-cream without sugar was obtained according to the results of research on organoleptic, physicochemical and microbiological properties and was substantiated as 3 months at 18°Ð¡. CONCLUSIONS: The presented production procedure enables the manufacture of a low-fat, sugar-free product with preventive and therapeutic properties for people who suffer from diabetes and obesity. Studies were conducted on the influence of the introduced starter cultures and sweeteners on the organoleptic, physicochemical and rheological parameters of the developed low-fat frozen sherbet. Starter cultures and doses of stevioside which had a favorable effect on the indicators of the finished product were selected.


Subject(s)
Diterpenes, Kaurane/administration & dosage , Fermentation , Food Handling/methods , Fruit , Glucosides/administration & dosage , Ice Cream/analysis , Lactobacillales/metabolism , Chemical Phenomena , Diabetes Mellitus, Type 2/diet therapy , Dietary Fats/analysis , Dietary Sugars/analysis , Energy Intake , Glycemic Index , Humans , Ice Cream/microbiology , Rheology , Sensation
19.
Probiotics Antimicrob Proteins ; 11(4): 1348-1354, 2019 12.
Article in English | MEDLINE | ID: mdl-30426464

ABSTRACT

The objective of this work was to explore the effect of two encapsulating polysaccharides (sodium alginate and carrageenan) on the viability of probiotic bacteria (L. acidophilus) in ice cream and under simulated gastrointestinal (GIT) conditions. For the purpose, probiotic cells were encapsulated in sodium alginate and carrageenan by an encapsulator using standard operating conditions. Ice cream was manufactured by adding free and microencapsulated probiotics. The survival of free and encapsulated probiotics was monitored over a period of 120 days at - 20 °C. Furthermore, the survival of free and encapsulated probiotic bacteria under the simulated GIT conditions was investigated. The results of the study showed that encapsulation significantly (p < 0.05) improved the cell survival of probiotics in ice cream compared to free cells (non-encapsulated). The viable cell count of probiotic bacteria in the free-state in ice cream was 9.97 log cfu/ml at 0 day that decreased to 6.12 log cfu/ml after 120 days. However, encapsulation improved the viability of the probiotics in the prepared ice cream and GIT. The cell count of probiotics encapsulated with sodium alginate and carrageenan was 9.91 log cfu/ml and 9.89 log cfu/ml respectively at 0 day that decreased to 8.74 log cfu/ml and 8.39 log cfu/ml respectively after 120 days. Similarly, during simulated gastrointestinal assay, the survival rate of encapsulated probiotic bacteria in simulated gastric solution and intestinal solutions was higher than that of free cells. In the case of encapsulated bacteria, only three log while for free cells seven log reduction was recorded. Sodium alginate microcapsules exhibited better release profile than carrageenan. Conclusively, the incorporation of encapsulated probiotics had a significant effect on quality parameters and sensorial characteristics of ice cream.


Subject(s)
Bifidobacterium/chemistry , Drug Compounding/methods , Ice Cream/microbiology , Lactobacillus acidophilus/chemistry , Probiotics/chemistry , Alginates/chemistry , Bifidobacterium/growth & development , Carrageenan/chemistry , Drug Compounding/instrumentation , Food Additives/chemistry , Gastrointestinal Tract/microbiology , Humans , Ice Cream/analysis , Lactobacillus acidophilus/growth & development , Microbial Viability , Probiotics/metabolism
20.
Microsc Res Tech ; 81(12): 1501-1505, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30351509

ABSTRACT

Current study was focused to examine the total bacterial count in packed and unpacked ice cream and kulfa collected from 12 different localities of Lahore. The bacterial colonies were isolated and grown on agar-broth media under sterilized conditions. Serial dilution technique was used to compose the replicates to get total viable count of bacteria. Results in case of packed ice cream samples indicated maximum (618 × 10-6 CFU/g) and minimum (79 × 10-6 CFU/g) bacterial count while in case of unpacked ice cream samples maximum and minimum bacterial count was 163 × 10-6 CFU/g and 71 × 10-6 CFU/g, respectively. Whereas in case of packed kulfa samples, maximum and minimum recorded bacterial count was 163 × 10-6 CFU/g and 72 × 10-6 CFU/g, respectively. The LM and SEM of the isolated bacteria were also performed for correct identification. Results indicated that the total bacterial count recorded in the samples exceeded the standard tolerable range which can lead to serious health damage of consumers.


Subject(s)
Bacteria/growth & development , Frozen Foods/microbiology , Ice Cream/microbiology , Bacteria/isolation & purification , Bacteria/ultrastructure , Colony Count, Microbial , Food Contamination/analysis
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