Mold Counts Research Articles

Impact of native spray‐dried lactic acid bacteria, packing density and wilting time on fermentation characteristics of experimental maize and lucerne silages

AbstractThis study aimed at investigating the effects of an autochthonous microbial inoculant microencapsulated by spray‐drying on fermentation parameters, microbiological composition, mycotoxin level and aerobic stability of maize and lucerne silages. Experiment 1, a completely randomized design with a 2 × 2 × 4 factorial arrangement of treatments, evaluated inoculation (control or Lactobacillus plantarum Hv75, Pediococcus acidilactici 3903 and Lactobacillus buchneri B463), packing density (148.5 kg dry matter (DM)/m3 or 181.5 kg DM/m3) and storage period (0, 1, 30 or 60 days) in maize silage. Lactic acid bacteria (LAB) supplementation produced higher DM and lower acetic acid and deoxynivalenol contents compared to the control (p < 0.05). However, these differences were small in terms of practical applications. Experiment 2 evaluated effects of microbial inoculation (similar as in experiment 1), wilting time (3 or 21 h) and storage period (0, 3, 30 or 60 days) in lucerne silage. LAB supplementation increased DM and lactic acid content, reduced pH and concentrations of acetic acid, ethanol and ammonia nitrogen/total nitrogen compared to the control (p < 0.05). In addition, inoculation increased total LAB population and decreased yeast and mould counts (p < 0.05). Although the strains displayed potential to be used as a bio‐inoculant at different lucerne moisture levels, prolonged wilting positively influenced DM, crude protein and fibre degradation (p < 0.05). Therefore, the addition of this spray‐dried inoculant to lucerne silages with longer wilting could be recommended for the attainment of silage quality.

Микробиологическая оценка процесса проращивания зерна пшеницы и гречихи

Introduction. Sprouted grain can cause food poisoning, since inappropriate conditions can promote the growth of pathogenic microorganisms on the grain surface. As a result, products of long-term storage use thermally-treated sprouted grain, the parameters of which depend on the initial bacteria content. There are different ways to reduce bacterial contamination of sprouted grain, each of which has its own advantages and disadvantages. Natural substances with antimicrobial properties, such as medicinal herbs, can serve as decontaminators. However, no scientific research has been performed so far to determine the exact temperature of grain sprouting to minimize its microbiological contamination. The research objective was to investigate the effect of antimicrobial agents and sprouting conditions on the microflora of wheat and buckwheat grain.
 Study objects and methods. The study featured wheat grain and green buckwheat grain. A set of experiments was performed to define the effect of antimicrobial agents and sprouting conditions on the quantity of mesophilic aerobic and facultative anaerobic microorganisms (QMAFAnM), molds, and yeasts. During sprouting at 10–30°C for 90 h, the grain was irrigated with distilled water, potassium permanganate solution (KMnO4), calendula infusion, and celandine i nfusion. QMAFAnM and the count of molds and yeasts were determined by standard methods; the qualitative analysis of the microflora was based on their morphological and cultural characteristics.
 Results and discussion. Microflora development during sprouting of wheat and buckwheat grains was controlled by selecting appropriate conditions and grain treatment methods. The herbal infusions for sprouting reduced the total microbial insemination of grain during sprouting by 52–68%; the calendula infusion reduced the contamination with molds by 47–51%, yeasts – by 100%.
 Conclusion. The research revealed the total microbial count and the count of mold and yeast colonies in dry sprouted grain. The optimal temperature of sprouting wheat and buckwheat was 20 ± 2°C in the infusion of medicinal herbs: it minimized the microflora of sprouted grain and reduced the sprouting time to 46 h. Calendula infusion could be recommended for commercial use in order reduce the microbiological contamination of sprouted grain. The initial microbial population of the product was found to affect the mode of heat treatment in long-term storage products.

Investigating the Effect of Probiotics as Natural Preservatives on the Microbial and Physicochemical Properties of Yogurt-Marinated Chicken Fillets

Microbial flora of probiotic yogurt can have nutraceutical properties and improve beneficial health effects of food products. In this study, microbial and physicochemical properties of raw chicken fillets dipped in regular yogurt and probiotic yogurt containing Lactobacillus casei, preserved at 4°C for 9 days, were studied. In this regard, microbial analysis (Staphylococcus aureus, fecal coliform, yeasts, and molds) and physicochemical analysis (pH, water holding capacity, cooking loss percentage, Thiobarbituric acid reactive substances, and texture profile analysis) were performed during the storage time. In comparison with control samples, the amount of Staphylococcus aureus, fecal coliforms, yeast and mold counts, pH index, malondialdehyde value, and cooking loss percentage reduced significantly ( P < 0.05 ) in the chicken fillets treated with regular and probiotic yogurt, while the water holding capacity increased in six days. It was concluded that probiotic and regular yogurts reduced microbial growth and improved the physicochemical quality of chicken fillets during storage and cooking time.

Fermentation of liquid feed with lactic acid bacteria reduces dry matter losses, lysine breakdown, formation of biogenic amines, and phytate-phosphorus.

This study investigated the fermentation of liquid feed for pigs and the effect of lactic acid bacteria (LAB) supplementation on fermentation rate, dry matter losses (DML), formation of biogenic amines, and degradation of phytate-P. The basal substrate in all three in vitro batch experiments consisted of 50% canola meal, 25% wheat, and 25% barley. The mixed substrates were adjusted to a dry matter (DM) content of 28.4% and fermented in 1-liter vessels at 37 °C for 24 h. Experiment 1 focused on changes in pH profiles over time. Treatments were as follows: 1) liquid feed without additive (control) and 2) liquid feed supplemented with a mixture of Lactobacillus plantarum, Pediococcus pentosaceus, and Lactobacillus lactis (adLAB) at 2.0 × 105 CFU/g liquid feed (wet wt.; n = 8). Substrate pH was measured every 2 h. Experiment 2 focused on DML and the impact of fermentation on phytate-P. Treatments were identical to experiment 1 (control and adLAB; n = 8). Measured parameters included concentration of lactic acid, acetic acid, ethanol, and phytate-P, and DML after 24 h of fermentation. Counts of molds, Enterobobacteriaceae, yeasts, and LAB were determined in one combined sample of all replicates. Dry matter losses were lower in LAB-supplemented fermentations (5.89%) compared to the control (11.8%; P < 0.001). Supplementation with LAB reduced the phytate-P content (2.66 g/kg DM) compared to the control (3.07 g/kg DM; P = 0.002). Experiment 3 evaluated DML and the impact of fermentation on formation of biogenic amines. Treatments were as follows: 1) control, 2) adLAB (2.0 × 105 CFU LAB/g liquid feed), 3) adLys (0.60% DM supplemented lysine), and 4) adLAB+Lys (combination of adLAB and adLys; n = 8). The fermentation of adLys resulted in a nearly complete breakdown of supplemented lysine, whereas only 10% of supplemented lysine was lost in adLAB+Lys. Furthermore, all adLys samples tested positive for cadaverine (mean concentration 0.89% DM), whereas no adLAB samples contained cadaverine above the detection limit (P < 0.001). Results indicate that DML is reduced in fermentations supplemented with homofermentative LAB. Fermentation of liquid feed with homofermentative LAB can effectively reduce the degradation of supplemental lysine and has the potential to further improve P availability.

Microbiological Quality of Raw Camel Milk in Degahbour District of Jarar Zone, Somali Regional State, Ethiopia

A cross-sectional study was carried out to evaluate microbiological quality of raw camel milk in Degahbour district. A total of 40 pooled raw camel milk samples (each with a volume of 450 mL) were collected from the udders and milk handling equipment of producers in Degahbour district. The raw milk samples were subjected to laboratory analyses to evaluate standard plate counts (SPC), total coliform count (TCC) yeast and mold count (YMC) to determine the microbiological quality of the raw camel milk in the study area. The overall mean SPC, CC and YMC for raw camel milk samples collected from the udder was 5.35 ± 0.19, 2.59 ± 0.16 and 1.71 ± 0.12, respectively. The overall mean counts for samples collected from the equipment of producers were 6.72 ± 0.17, 4.71 ± 0.23 and 1.61 ± 0.21 for SPC, CC and YMC, respectively. Significant difference (P 0.05) in mean SPC, TCC and YMC was observed between milk samples collected from pastoral and agro-pastoral production systems as well as collected from udders and milk equipment. In general, it was concluded that raw camel milk samples collected from the udder as well as from the equipment of producers were contaminated with SPC, CC and YMC, with loads exceeding the respective acceptable limits. Therefore, hygienic production and postharvest handling practices need to be followed to improve the quality and suitability of camel milk for its intended use in the study area.

Evaluation of Aerobically Packaged Fibre Enriched Low Fat Kadaknath Chicken Patties under Refrigeration Storage

The fibre enriched low fat kadaknath chicken patties were packaged aerobically and evaluated for storage stability under refrigeration. The pH, TBA and FFA values of treated patties were lower as compared to control throughout the storage. A progressive and significant (P<0.05) increment in the pH, TBA and FFA values of control as well as fibre enriched low fat kadaknath chicken patties were observed with the advancement of storage in aerobically kadaknath chicken patties. The total plate count (TPC) followed a significantly (P<0.05) increasing pattern from 0 to 12 day in aerobic packaging in control as well as fibre enriched low fat kadaknath chicken patties. The psychotropic counts as well as Yeast and Mold count under aerobic packaging were not detected up to 9 day of storage either in control or in fibre enriched low fat kadaknath chicken patties and these were detected on 12 day of storage. The coliform were not detected during the entire period of storage in aerobic packaging. Sensory attributes under storage study did not have any significant (P>0.05) difference between control and fibre enriched low fat kadaknath chicken patties on all storage days of aerobic packaging. The mean scores for all the sensory attributes for both control as well as fibre enriched low fat kadaknath chicken patties decreased gradually with increasing storage period. From the study it was concluded that the fibre enriched low fat kadaknath chicken patties may be considered as health full product which was very well stable and accepted up to 12 day in aerobic packaging under refrigeration.

Microbiological quality of panipuri sold in and around Greater Hyderabad municipal corporation, Telangana

The microbiological quality of panipuri sold at street vended panipuri, moderately hygienic food courts, and hygienically maintained restaurants in and around Greater Hyderabad Municipal Corporation, Telangana State was studied. Twenty-five samples from each source were collected and analyzed. The total viable count, Total coliform count, Fecal coliform count, and Yeast and mold counts in the samples collected from street vended panipuri were 3.6×10⁹ cfu/gm, 5.2× 10⁷ cfu/gm, 3.8×10⁶ cfu/gm, and 3.2×10³ cfu/gm respectively, 1.7×10⁷cfu/gm, 4.3×10⁵ cfu/gm, 1.2×10⁵ cfu/gm, 7.2×10² cfu/gm respectively in the samples collected from the moderately hygienic food courts and 2.8×10⁵cfu/gm, 3.6×10⁴cfu/gm, 4.7×10³ cfu/gm, and 1.2×10²cfu/gm respectively from hygienically maintained restaurants. The incidence of staphylococcus aureus was 100%, 100% and 72%, Bacillus cereus of 44%, 28% and 16%, Salmonella of 16%, 8% and 0% (Nil), Shigella of 24% 12%, and 4%, Escherichia coli of 88%, 72% and 48%, Streptococcus fecalis of 64%, 44%, and 24% respectively from the street vended panipuri, moderately hygienic food courts and hygienically maintained restaurants. The counts of staphylococcus aureus were 2.6×10⁶, 5.2×10⁵, and 2.3×10³, Bacillus cereus of (3.8×10³), (4.9×10²), 2.5×10², Salmonella of 3.9×10², 9.5×10¹, Nil, Shigella of 8.6×10³, 3.9×10², 5.8×10¹, Escherichia coli of 3.6×10², 2.9×10³, 4.2×10⁴ and Streptococcus fecalis of 8.6×10¹, 8.7×10², 2.6×10³ cfu/gm respectively from the samples collected from street vended panipuri, moderately hygienic food courts and hygienically maintained restaurants.

Effect of gamma irradiation and calcium carbonate on the overall quality of pumpkin jam during storage

This study was to investigate the effects of combination of calcium carbonate with irradiation technique on quality characteristics, nutritional values, bioactive components, microbiological loading, and sensory evaluation of pumpkin jam during storage period for 12 months. Pumpkin jam samples were treated with calcium carbonate 1% (CCS), irradiation (2 kGy) and the combination of CCS + 2 kGy. The results indicated that the CCS + 2 kGy treatment significantly helped in retaining ascorbic acid content, which established a little decrease. CCS and CCS + 2 kGy treatments reported similar values for carotenoid contents. Whereas, CCS + 2 kGy treatment showed the highest total flavonoid content. The application of CCS + 2 kGy treatment also reduced the microbial growth for total aerobic plate, yeast and mold counts. The degree of color was higher recorded for CCS treatment, while CCS + 2 kGy treatment gained the highest scores for texture, flavor, taste, and overall acceptability at the end of the storage period. Overall the results pertained that the use of Gamma irradiation combined with calcium carbonate prolonged the shelf life of the pumpkin jam by reduced the microbial load, maintained the quality characterizes, nutritional values, bioactive components, and consumer acceptability of pumpkin jam during storage.

Microbiological Evaluation of Some Fermented Milk Products Retailed for Sale at Local Markets

The consumption of fermented milks by man dates from the beginning of civilization. Fermented milk products are dairy foods that have been fermented with lactic acid bacteria such as Lactobacillus, Lactococcus and Leuconostoc. One hundred random samples of some locally manufactured fermented dairy products including; plain yoghurt, stirred yoghurt, flavored yoghurt, homemade rayeb, and sterilized rayeb (20 of each) were collected from local markets to be examined for their microbiological fitness. The obtained results clarified that the mean value of Coliforms count was 4.10×102 ± 2.0×10, 1.72×102 ± 2.1×10 and 1.65×103 ± 2.69×102 6.10×102 ± 6.4×10 for plain yoghurt, flavored yoghurt and homemade rayeb, respectively. The mean value of S. aureus count was 2.0×10 ± 1.0×10, 6.4×10 ± 4.5×10, 7.23×102 ± 5.4×10 and 1.32×102 ± 2.1×10 stirred yoghurt, flavored yoghurt, homemade rayeb and sterilized rayeb, respectively. Moreover, yeast and molds counts were performed. It could be concluded that the majority of investigated fermented dairy products were contaminated, at different degrees, with Coliforms, S. aureus, yeasts and molds giving an indication of poor sanitary measures adopted during manufacturing, storage, handling, and distribution of these products. In addition, it was observed that homemade rayeb had lower quality than other fermented dairy products.

Optimization and shelf-life evaluation of mayonnaise like paste prepared using avocado pulp

The purpose of this study was to analyze the use of avocado pulp in place of egg yolk in the preparation of a mayonnaise-like paste. Eight formulations of mayonnaise were obtained with avocado pulp ranging from 51.2 to 70% and sunflower oil ranging from 30 to 48.68%, with all other constituents remaining constant. Sensory evaluation revealed that the mayonnaise made from 55% avocado pulp and 45% sunflower oil was the best when compared to marketed products in terms of sensory evaluation, proximate analysis, microbiological analysis, acid value, and peroxide value. The optimized product was superior in terms of color and overall acceptability than the control sample (P &lt; 0.05). The chemical analysis, i.e., the moisture, fat, protein, ash and carbohydrate contents were found to be 40.54%, 51.1%, 1.22%, 1.71% and 6.23%, respectively, for the optimized product and 26.41%, 66.22%, 0.34%, 1.11% and 6.33%, respectively, for the control sample. Total plate count and yeast and mold count (cfu/g) were found to be 170.3 and 89.33, respectively, for the optimized product and 160.67 and 84, respectively, for the control product. There was an increase in both acid value and peroxide value at all temperatures during storage but a lower increase was found in the sample stored at 25°C. Using the accelerated shelf life technique, the shelf life of optimized mayonnaise like paste based on acid value was found to be 61 days, 41 days and 13 days at 25°C, 40°C and 50°C, respectively. Similarly, the shelf life based on peroxide value was found to be 35 days, 20 days and 12 days at 25°C, 40°C and 50 °C, respectively. Avocado incorporated mayonnaise with acceptable sensory quality and good spreadability can be prepared. Determinations of acid and peroxide values were carried out at regular intervals, ranging from 5 days to 30 days during the storage of mayonnaise. No chemical analysis was done for longer than 30 days, and also no microbiological analysis was performed for the entire storage period; these analyses would be necessary in further research to confirm the shelf life of mayonnaise.

Determination of Deoxynivalenol and Total Aflatoxin Levels in Commonly Traded Grains in The Commercial City of Katsina-Ala North-Central Nigeria

This study determined the total aflatoxin and deoxynivalenol levels in grains traded in the commercial city of Katsina-Ala, North-Central Nigeria, from 300 samples obtained from 30 composites, of 10 different locations, using the direct competitive Enzyme Linked Immunosorbent Assay (ELISA). Moisture content, total aerobic microbial count, mould count, coliform and Escherichia coli were determined using standard analytical methods. Mycotoxins were detected in all samples across the study locations; total aflatoxin ranged from 2.30 to 8.4 ppb, which were within the maximum limits for aflatoxins, deoxynivalenol (DON) concentration ranged from 2,900.00 to 8,400.00 ppb that was above the maximum limits. Moisture was high in all samples with content ranging from 9.0279 to 12.3851 %, microbial contamination was observed on the grains. It was also observed that, these grains were more predisposed to DON than aflatoxin, thus vulnerability of the grains to DON was in the order: sorghum &gt; maize &gt; millet, whereas total aflatoxin level was in the order: sorghum &gt; millet &gt; maize respectively. Pearson’s 2-tailed correlation at 0.05 level of significance revealed strong correlation of deoxynivalenol with moisture content across locations, while ANOVA at 5 % level of significance established the presence of mycotoxins and their precursors across the locations. This fundamentally, showed microbial tainting of these cereals in the study location indicating that farmers and marketers handle these grains in an unhygienic manner.

Identification of microflora and lactic acid bacteria in pado, a fermented fish product prepared with dried Pangium edule seed and grated coconut

Pado is a unique fermented fish product of West Sumatera Indonesia, prepared using dried Pangium edule Reinw seed in combination with grated coconut, with or without salt. Changing of microflora during fermentation has not been extensively reported. This study observed the changes of microflora, especially lactic acid bacteria, during fermentation for 7 days at room temperature (25-30 °C) of pado without the addition of salt. No microorganisms were found on dried P. edule seed. Enterobacteriaceae and spore-forming bacteria decreased and were not found at the end of the fermentation, while the yeast and mold counts were relatively constant at a low level. Instead, lactic acid bacteria increased along with the fermentation process, in line with the decreasing of pH, water contents, and water activity of the fish product. Apparently, few species of lactic acid bacteria are involved during fermentation, most likely due to the use of P. edule seed (as no salt was used). Partial sequencing based on the 16S rRNA gene showed that Lactobacillus plantarum and Lactobacillus pentosus were consistently identified at the various fermentation steps. This study reports that although lactic acid bacteria predominate, only a few species are involved in pado fermentation.

Effect of buckwheat flour on quality characteristics of chevon sausages

A study was conducted to evaluate the efficacy of different levels (0, 2, 4 and 6%) of buckwheat flour (Fagopyrum esculentum) on quality characteristics and storage stability of chevon sausages. Shelf life of chevon sausages incorporated with 0% (control) and 6% extended buckwheat flour was studied during refrigerated storage (4±1ºC) at 5 days interval up to 20 days. Significant (p<0.05) higher cooking yield, emulsion stability and water holding capacity was observed in chevon sausages incorporated with 6% buckwheat flour. Moisture and total ash contents increased (p<0.05); however protein content decreased (p<0.05) with the increased level of buckwheat flour in chevon sausages. Chevon sausages incorporated with 6% buckwheat flour recorded (p<0.05) superior sensory scores compared to control and other formulations. TBRS (2-thiobarbuteric acid reactive substance) values, free fatty acid values, total plate counts, total psychrophilic counts, coliform and yeast and mould counts were significantly (p<0.05) reduced in buckwheat flour treated sausages. Addition of buckwheat flour in chevon sausages resulted in superior (p<0.05) sensory scores compared to control during 20 days of refrigerated storage. It can be concluded that addition of 6% buckwheat flour isoptimalin formulation of chevon sausagesfor better quality characteristics.

Assessment of aflatoxin M1 and B1 in some dairy products with referring to the analytical performances of enzyme-linked immunosorbent assay in comparison to high-performance liquid chromatography.

Background and Aim:Aflatoxin M1 (AFM1) is a major fungal metabolite found in milk coming from aflatoxin B1 (AFB1) contaminated rations and is subsequently present in milk-based products demonstrating a serious public health hazard. This study aimed to investigate the levels of AFM1 and AFB1 in milk and some dairy products consumed widely by infants and children.Materials and Methods:This study investigated the incidence of AFM1 in 105 samples of processed cheese, Ras cheese, and raw milk (35 of each) retailed in the Egyptian markets. The degree of sensitivity and accuracy was evaluated using the enzyme-linked immunosorbent assay (ELISA) method followed by the estimation of the positive samples using the high-performance liquid chromatography (HPLC) with fluorescence detection. Mold count was determined in the examined samples by investigating AFB1 content using HPLC.Results:AFM1 was found in all investigated Ras cheese, raw milk, and 82.86% of the processed cheese samples with mean values of 51.05±6.19, 40.27±3.996, and 10.77±1.39 ng/kg, respectively. Moreover, there was statistically no significant difference between AFM1 levels in the core and crust parts of the tested Ras cheese. AFM1 contaminated Ras cheese and raw milk samples were 48.57% and 25.71%, which exceeded the European and Egyptian tolerance levels. Results showed an acceptable correlation between ELISA and HPLC methods with no significant difference (p>0.05). Alternatively, none of the examined samples proved to be contaminated with AFB1 despite the presence of mold with mean counts of 3.79±3.29, 4.39±4.34, and 4.84±4.29 log CFU/g in the examined processed cheese, Ras cheese, and raw milk samples, respectively.Conclusion:Therefore, it is urgent to regularly inspect the contamination of animal feeds with AFB1 and apply special measures and novel techniques to protect the feed and food from public health hazards.

Effect of garlic (Allium sativum) and Ginger (Zingiber officinale) on the microbial and sensorial quality of smoked mackerel fish (Scomber scombrus)

This study examined the effect of garlic (Allium sativum) and ginger (Zingiber officinale) on the microbial and sensorial quality of smoked mackerel fish (Scomber scombrus). Thirty six (36) pieces of fresh frozen Mackerel fish of 1.09kg average weight were purchased, dressed, dipped in a solution of 0% garlic or ginger (T0), 10% garlic (T1), 10% Ginger (T2) and 5% garlic and 5% ginger (T3) solution for 30 min, smoked dried and stored at 28±2 °C over the period of 60 days. Microbiological and sensory analyses were performed on the smoked fish samples. The result revealed that the garlic and ginger treatment of the smoked preserved fish sample were found very influential. The values of the total bacterial count and moulds and yeast count shows that there were significant variations (p≤ 0.05) among the samples. Samples treated with ginger and garlic had lower total bacterial count, yeast and mould count than the control. The organoleptic results showed that samples treated with garlic/ginger (T3) had the best acceptance than the other treatments.

Application Of Some GMP Steps in One Recent Slaughterhouse

This study is a trial aimed to improve the hygienic status of beef carcasses through the application of GMP on some steps of the slaughterhouse line in an abattoir in Alexandria Province. The trial was evaluated through the determination of aerobic mesophilic counts, coliforms count, enterobacteriaceae count, and mould and yeast count of swab samples which performed before and after application of the GMP. The samples used in this work have been obtained through Swabbing technique. Swabs were taken from the side surface of 160 random samples (80 samples before application of the GMP and 80 samples after application of the GMP) collected from the different parts of the slaughtering box, skin, evisceration station, and meat. Our results could show presence of high microbial counts on the meat contact surfaces during slaughtering, skinning and evisceration station before application of GMP which have a clear influence on the microbial load of carcasses surfaces. We could conclude that the application of GMP could significantly reduce all studied microbial counts and could improve the safety of beef meat. Moreover, we could recommend that all slaughterhouses must apply GMP along all steps of slaughter processing line as well as continuous personal hygiene and sanitation training to all workers and staff should be done to improve the hygienic status of such slaughterhouses to can produce high quality and safe meat and safe-guard consumer’s health.

Detection of artificial colors added to cooked faba beans (Ful medames) and microbial examination for samples obtained from street vendors in Egypt

BackgroundCooked dried beans are commonly consumed in many countries and are known in Egypt as Ful medames. Adding synthetic colors to keep the dishes more attractive may have toxic effects on the human body, as it may be unsafe to consume potentially microbial contaminated foods, especially when obtained from street vendors.AimThe aim of this study was to detect the types of artificial colors added to cooked faba bean (Ful medames) by street vendors in Egypt and highlight their health hazards and microbial hazards.Materials and methodsA total of 100 convincing samples were collected from street vendors from four large Egyptian cities. The coloring agents were extracted and purified from samples using the hydrochloric acid extraction method followed by separation using ascending paper chromatography. Total bacterial counts, coliforms, Bacillus cereus, Staphylococcus aureus, and mold and yeast counts were used for microbial tests on 24 samples obtained from Cairo and Giza cities.FindingsArtificial colors were detected in 46% of samples. From the total positive samples, sunset yellow, tartrazine, or both combined were identified in 26.1, 30.4, and 41.3%, respectively. Carmoisine was detected combined with tartrazine in only one sample. Giza and Cairo cities recorded the highest positive samples (64.3 and 42.9%, respectively), followed by Mansoura (10%). No added colors were detected in Mahala samples. Coliforms, mold, yeast, and bacillus were detected in most of the samples that were subjected to microbiological examination, whereas S. aureus was not found in any of the examined samples.ConclusionOverall, 46% of the examined samples from street vendors contained artificial colors, mainly tartrazine and sunset yellow, although the authorities of Egyptian standards do not allow any artificial additives to these types of food. Most positive samples were from more urban cities. Microbial contaminants found in the examined samples may be due to unhygienic approaches in such areas and lack of sanitary practices of street vendors. This also predisposes consumers to the risk of severe public health challenges.RecommendationsThe society should be made aware about the health hazards of the incessant usage of synthetic food colors. The public should be encouraged to add natural food coloring, such as carrots, through home cooking instead. Moreover, strict monitoring of street vendors for food safety regulation should be done by competent authorities.

Basil, marjoram, nutmeg and oregano essential oils as natural preservatives of Quark-type cheese

This study aims to evaluate the in vitro antimicrobial activity of basil, marjoram, nutmeg, and oregano essential oils to use the essential oil with better results for Quark-type cheese preservation. To verify the shelf life of Quark-type cheese without essential oil (CTL) and Quark-type cheese added with 0.05% essential oil (OE), microbiological and physicochemical analyses were performed for 35 days (4 °C). The acceptability of the product was also evaluated. The oregano essential oil showed strong antimicrobial activity in the disk-diffusion test (34.0 to 51.0 mm), and lower values of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against all species of bacteria tested. A lower mold and yeast count (p < 0.05) was observed during storage in OE denoting a positive effect in delaying its deterioration. On the other hand, there was no difference (p > 0.05) between the CTL and OE count of total mesophiles and Enterobacteriaceae. For the physicochemical parameters evaluated, there were no significant differences between the CTL and OE, thus denoting that the typical characteristics of this cheese were maintained. The Quark-type cheese added with oregano essential oil also showed good acceptability (> 7), which is a way to preserve the product with a natural additive.

Whole-plant soybean ensiling with chitosan and homolactic microbial inoculant: fermentative profile, aerobic stability, and sheep intake and digestibility

ABSTRACT This study aimed to evaluate the effects of chitosan and homolactic microbial inoculant on fermentative losses, chemical composition, fermentative profile, and aerobic stability of whole-plant soybean silage (WPSS). Additionally, it was evaluated nutrients intake and digestibility of sheep fed increasing levels of WPSS. Thirty experimental silos were randomly allocated to one of the following treatments: 1) CON: control, WPSS without additives; 2) LPPA: WPSS with Lactobacillus plantarum and Pediococcus acidilactici; and 3) CHI: chitosan, WPSS with 5 g/kg of chitosan. Ten male sheep were used to evaluate increasing dietary levels of WPSS: 0, 200, 400, 600, and 800 g/kg of diet dry matter (DM). Additives increased silage lactic acid bacteria and decreased the count of mold and yeast, gas, and total losses. Silages treated with additives had lower pH, NH3-N, and ethanol concentrations and higher lactic and propionic acids relative to CON. LPPA-treated silos showed higher organic matter and non-fiber carbohydrates content than CHI-ones. Additives increased the aerobic stability of WPSS. The addition of WPSS in sheep diets linearly increased nutrients intake and digestibility. Chitosan and LPPA improve WPSS fermentation, aerobic stability, and nutritional value. The WPSS in substitution to Cynodon hay increases sheep feed intake and nutrients digestibility.

Proximate, microbiology and nutritive properties of wheat-mango flakes

In this study, the proximate composition, microbiological, and nutrition evaluation of wheat-mango flakes was studied. A preliminary research work was done to ascertain the optimum acceptable levels of mango pulp addition to wheat flake production using 0 to 80 % (w/v) of wheat and mango pulp. Sensory evaluation was done and the most accepted flake samples were selected. Consequently, in the main research, the level of mango pulp was varied in a ratio of 0 to 50 giving rise to a total of five (5) samples. Proximate composition and microbiological analyses were done using standard analytical methods; furthermore, nutritive composition of the resultant flakes was also done using standard analytical procedures. The Flakes from 50:50 W: M had the highest protein content 14.4±0.02 %. The feed conversion efficiency (FCE), protein efficiency ratio (PER), net protein ratio (NPR), and apparent digestibility (AD) increased with the incorporation of mango pulp, yeast and mould counts ranged from 4 to 23 Cfu/g with 50:50 W: M having the highest count of 23 Cfu/g.