Bioavailability of Macroelements from Synbiotic Sheep's Milk Ice Cream.

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.

Sheep Milk Symbiotic Ice Cream: Effect of Inulin and Apple Fiber on the Survival of Five Probiotic Bacterial Strains during Simulated In Vitro Digestion Conditions.

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.

Zygosaccharomyces rouxii is the predominant species responsible for the spoilage of the mix base for ice cream and ethanol is the best inhibitor tested.

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).

Microbiological evaluation of pasty and soft ice cream / Avaliação microbiológica de sorvetes pastosos e expressos / Evaluación microbiológica de helados pastosos y suaves

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)

Immune status, well-being and gut microbiota in military supplemented with synbiotic ice cream and submitted to field training: a randomised clinical trial.

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.

Quasimetagenomic source tracking of Listeria monocytogenes from naturally contaminated ice cream.

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.

Prevalence and antimicrobial resistance of Shiga toxin-producing Escherichia coli in milk and dairy products in Egypt.

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.

Short communication: Long-term -20°C survival of Listeria monocytogenes in artificially and process-contaminated ice cream involved in an outbreak of listeriosis.

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.

Short communication: Entrapment of Listeria cells within air pockets of ice cream mix matrix may lead to potentially heat-injured cells.

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.

Whole genome sequencing uses for foodborne contamination and compliance: Discovery of an emerging contamination event in an ice cream facility using whole genome sequencing.

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.

Caracterização físico-química e microbiológica de gelado comestível com a polpa de jaca liofilizada / Physicochemical and microbiological characterization of edible ice cream with jack fruit lyophilized pulp

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.

Application of an Environmental Phage-Based Assay (Sample6 Detect HT/L) for the Detection of Listeria spp. in Ice Cream.

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.

The Effect of Encapsulation on The Stability of Probiotic Bacteria in Ice Cream and Simulated Gastrointestinal Conditions.

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.

The effects of the addition of starter cultures and stevioside on technological low-fat fermented sherbet ice-cream without sugar.

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.

Microbial assessment of pathogenic bacterial growth in ice cream and kulfa.

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.

Listeria cross contamination levels in raw ice cream mix can serve as a predictor of their potential presence as heat-injured cells.

Listeriosis is a life-threatening infection caused by foods contaminated with Listeria monocytogenes. Some of the major ice cream recalls in recent years reaffirm the ability of this food-borne pathogen to survive in diverse dairy processing environments and cause cross contamination. Inspection reports revealed certain lapses in implementing adequate hygienic practices for Listeria persistence in the processing environment, leading to cross contamination of ice cream. The higher levels of cross contamination of raw ice cream mix might result in random heat-injured cells when exposed to minimum heat treatment (69°C for 30 min). These heat-injured cells could later recover under abusive storage and handling conditions and pose a health risk. Evidence about the presence of injured cells in ice cream mix may thus prove useful to establish the overall Listeria risk, which was the aim of this study. Challenge studies were conducted to evaluate the dose-dependent presence of heat-injured cells of Listeria. Ice cream mix formulations of 4 different types (36, 40, 42, and 45% total solids) were inoculated at 2.0, 3.0, and 4.0 log cfu/g levels of Listeria innocua (an established surrogate). The dose levels were selected based on a likely cross contamination on the raw side from environmental Listeria, especially due to their resident nature and growth in harborage sites. The samples were exposed to minimum heat treatment (69°C for 30 min) and the survivors, including heat-injured cells, were enumerated using standard protocols. A binary logistic regression model was fitted for evaluating the severity of risk. The influence of total solids, water activity, and pH variability were also studied on Listeria survival. The enrichment protocol, using buffered Listeria enrichment broth, followed by plating on modified oxford agar and Rapid L'mono medium, revealed the random presence of heat-injured cells in buffered Listeria enrichment broth, only at the highest dose level of 4+ logs. Any potential risk from heat-injured cells was thus limited only to the highest levels of cross contamination, irrespective of the type of the mix. Significantly, none of the pasteurized ice cream mix samples supported the recovery of any heat-injured cells of Listeria during 72 h holding at 7°C, even at the highest dose level of 4+ logs, under the conditions of experimentation. The level of cross contamination (dose) emerged as a predictor of the potential presence of heat-injured cells of Listeria exposed to minimum pasteurization treatment.

Rapid Detection of Listeria in Ice Cream in 13 Hours Using the Roka Listeria Detection Assay.

Background: Listeria contamination is a major concern in the ice cream industry; therefore, early and accurate detection is vital. Current detection methods require about a 24 h enrichment period for detection. Objective: Enhance the early detection of Listeria in ice cream using the highly sensitive isothermal ribosomal RNA-based Roka/Atlas Listeria Detection Assay. Methods: The R2 Medium was developed for Listeria enrichment by Molecular Epidemiology, Inc. (Seattle, WA). Comparative growth curve studies were performed on the new R2 Medium for Listeria and the currently validated media for the Roka Listeria Detection Assay. Subsequently, a method comparison between the Roka Listeria Detection Assay and the U.S. Food and Drug Administration's (FDA) Bacteriological Analytical Manual (BAM) Chapter 10 reference method on ice cream was carried out. Results: The R2 Medium supports the growth of L. monocytogenes better than Buffered Listeria Enrichment Broth, Demi-Fraser broth, and Modified University of Vermont Broth, as indicated by the faster growth rate of the organism. When used as an enrichment medium in a method comparison study of ice cream, the results showed that R2 Medium-enriched samples tested with the Roka Listeria Detection Assay gave an equivalent performance compared with the 24 h FDA-BAM reference method at 10 and 18 h post-enrichment for Listeria. Conclusions: The results from this study indicate that the new R2 Medium and the highly sensitive Roka Listeria Detection Assay allowed for the rapid detection of Listeria species in ice cream in 13 h. Highlights: The Roka Listeria Detection Assay, in conjunction with a new media formulation (R2 Medium), allowed for the early detection of Listeria in ice cream and may be applied in other food matrixes and environmental samples.

Sensory Profile, Drivers of Liking, and Influence of Information on the Acceptance of Low-Calorie Synbiotic and Probiotic Chocolate Ice Cream.

The objective of this study was to evaluate the sensory profile and the influence of the information on the acceptance of the symbiotic chocolate ice cream made with sucrose and different sweeteners (aspartame, sucralose, neotame, Stevia with 60%, 85%, 95%, and 97% of rebaudioside A) through analysis of variance (ANOVA), Tukey's test, and partial least of square (PLS) regression. Quantitative descriptive analysis (QDA) was carried out by 18 assessors, who evaluated the samples in relation to the raised descriptors. Additionally, two acceptance tests (blind/informed) were performed with 120 consumers. The samples sweetened with sucralose and rebaudioside 97% presented similar profile to the control sample, thus having a better potential to replace sucrose in chocolate ice cream. The acceptance test carried out with information had higher scores for the attributes appearance, aroma, flavor, texture, and overall impression. The correlation between data from the acceptance tests and QDA showed that the descriptors "low-energy" and "natural sweetener" claims interfered negatively in the drivers of liking of chocolate ice cream. Therefore, we can conclude that some characteristics unnoticed by consumers were highlighted after providing the information about the product's characteristics. PRACTICAL APPLICATION: This research is important and contributes to the manufacture and development of low-calorie chocolate ice cream with functional properties, guiding, through suitable sensory and statistical tools, the application of stevia and other artificial sweeteners in products with reduction or total absence of sucrose and highlighting the impact of the labeling of these products on consumer perception.

The addition of inulin and Lactobacillus casei 01 in sheep milk ice cream.

The effect of the Lactobacillus casei 01 and inulin addition on sheep milk ice cream during storage (-18 °C, 150 days) was investigated. Control, probiotic and synbiotic ice cream (10% w/w sheep milk cream; 10% w/w sheep milk cream, L. casei 01, 6 log CFU/mL; 10% w/w inulin, L. casei 01, 6 log CFU/mL, respectively) were manufactured. Microbiological counts (probiotic count, survival after in vitro gastrointestinal resistance, Caco-2 cell adhesion), bioactivity and microstructure were analysed. Physical and textural characteristics, colour parameters, thermal analysis and organic acids/volatile compounds were also evaluated. All formulations supported L. casei 01 viability and maintained above the minimum therapeutic level (>6 log CFU/mL) during storage. Inulin did not affect L. casei 01 survival after the passage through simulated gastrointestinal tract and adhesion to Caco-2 cells while improved the ACE-inhibitory and antioxidant activity. L. casei 01 addition produced several volatile compounds, such as carboxylic acids, alcohols, aldehydes and ketones. Also, scanning electron microscopy showed an interaction between probiotic bacteria and inulin fibre on synbiotic ice cream and the adhesion of L. casei to Caco-2 cells was observed.

Enrichment of probiotic ice cream with different dietary fibers: Structural characteristics and culture viability.

This study evaluated the effect of 5 dietary fibers (apple, orange, oat, bamboo, and wheat) on the physicochemical, rheological, and textural characteristics; sensory properties; and culture viability of probiotic ice cream stored at -18°C for 180 d. The presence of orange and apple fibers increased the titratable acidity, decreased the lightness (color) value of the ice creams, and enhanced the red and yellow coloration. Compared with the control sample, the consistency indices and apparent viscosities of the experimental samples increased with the addition of all dietary fibers except oat fiber. The highest viscosity was obtained in the sample fortified with apple fiber, whereas the ice cream containing orange fiber showed the highest hardness after d 60 of storage. The addition of orange and apple fibers significantly increased melting resistance; however, panelists did not generally like these samples in terms of taste-flavor. All ice creams had viable counts of Lactobacillus acidophilus of ≥7 log cfu/g during storage except the samples with orange and bamboo fiber. Bifidobacterium lactis counts were also found to be >6 log cfu/g in those samples until d 150 of storage.