Edible nano-encapsulated cinnamon essential oil hybrid wax coatings for enhancing apple safety against food borne pathogens.

Post-harvest losses of fruits due to decay and concerns regarding microbial food safety are significant within the produce processing industry. Additionally, maintaining the quality of exported commodities to distant countries continues to pose a challenge. To address these issues, the application of bioactive compounds, such as essential oils, has gained recognition as a means to extend shelf life by acting as antimicrobials. Herein, we have undertaken an innovative approach by nano-encapsulating cinnamon-bark essential oil using whey protein concentrate and imbibing nano-encapsulates into food-grade wax commonly applied on produce surfaces. We have comprehensively examined the physical, chemical, and antimicrobial properties of this hybrid wax to evaluate its efficacy in combatting the various foodborne pathogens that frequently trouble producers and handlers in the post-harvest processing industry. The coatings as applied demonstrated a static contact angle of 85 ± 1.6°, and advancing and receding contact angles of 90 ± 1.1° and 53.0 ± 1.6°, respectively, resembling the wetting properties of natural waxes on apples. Nanoencapsulation significantly delayed the release of essential oil, increasing the half-life by 61 h compared to its unencapsulated counterparts. This delay correlated with statistically significant reductions (p = 0.05) in bacterial populations providing both immediate and delayed (up to 72 h) antibacterial effects as well as expanded fungal growth inhibition zones compared to existing wax technologies, demonstrating promising applicability for high-quality fruit storage and export. The utilization of this advanced produce wax coating technology offers considerable potential for bolstering food safety and providing enhanced protection against bacteria and fungi for produce commodities.

Prevalence and genomic characterization of Salmonella isolates from commercial chicken eggs retailed in traditional markets in Ghana.

Salmonella enterica are important foodborne bacterial pathogens globally associated with poultry. Exposure to Salmonella-contaminated eggs and egg-related products is a major risk for human salmonellosis. Presently, there is a huge data gap regarding the prevalence and circulating serovars of Salmonella in chicken eggs sold in Ghana. In this study, 2,304 eggs (pools of six per sample unit) collected from informal markets in Accra, Kumasi and Tamale, representing the three ecological belts across Ghana, were tested for Salmonella. Antimicrobial susceptibility testing and Whole Genome Sequencing (WGS) of the isolates were performed using standard microdilution protocols and the Illumina NextSeq platform, respectively. The total prevalence of Salmonella was 5.5% with a higher rate of contamination in eggshell (4.9%) over egg content (1.8%). The serovars identified were S. Ajiobo (n = 1), S. Chester (n = 6), S. Hader (n = 7), S. enteritidis (n = 2); and S. I 4:b:- (n = 8). WGS analysis revealed varied sequence types (STs) that were serovar specific. The S. I 4:b:- isolates had a novel ST (ST8938), suggesting a local origin. The two S. enteritidis isolates belonged to ST11 and were identified with an invasive lineage of a global epidemic clade. All isolates were susceptible to ampicillin, azithromycin, cefotaxime, ceftazidime, gentamicin, meropenem, and tigecycline. The phenotypic resistance profiles to seven antimicrobials: chloramphenicol (13%), ciprofloxacin (94%), and nalidixic acid (94%), colistin (13%), trimethoprim (50%) sulfamethoxazole (50%) and tetracycline (50%) corresponded with the presence of antimicrobial resistance (AMR) determinants including quinolones (gyrA (D87N), qnrB81), aminoglycosides (aadA1), (aph(3")-Ib aph(6)-Id), tetracyclines (tet(A)), phenicols (catA1), trimethoprim (dfrA14 and dfrA1). The S. enteritidis and S. Chester isolates were multidrug resistant (MDR). Several virulence factors were identified, notably cytolethal distending toxin (cdtB gene), rck, pef and spv that may promote host invasion and disease progression in humans. The findings from this study indicate the presence of multidrug resistant and virulent strains of Salmonella serovars in Ghanaian chicken eggs, with the potential to cause human infections. This is a critical baseline information that could be used for Salmonella risk assessment in the egg food chain to mitigate potential future outbreaks.

Modelling the Survival of Acid-Adapted and Nonadapted Escherichia coli O157:H7 in Burkina: A Western African Traditional Fermented Milk Product.

Burkina, a traditional fermented dairy product, is consumed in most parts of West Africa, including Ghana. Studies on the microflora of Burkina have indicated the presence of Escherichia coli and other pathogenic organisms. Thus, predicting the survival of E. coli in the product will inform the best manufacturing and handling practices. This study investigated the combined effect of storage temperature and time on the survival of acid-adapted and acid-non-adapted E. coli O157:H7 in Burkina. Samples were pasteurised and inoculated with acid-adapted or acid-non-adapted E. coli O157:H7. They were stored at 5, 15, and 30°C for 0, 2, 4, 6, 8, 10, 12, 14, 18, and 48 h, and the bacteria colonies were enumerated. Growth rate (survival versus time) models were developed using MATLAB software. Observed data were fitted to the Baranyi model using the DMFit curve fitting software. The E. coli O157:H7 strain appeared inherently tolerant to acid, with storage time having the most significant effect on the response parameter, survival (log CFU/mL). A negative correlation was observed for the primary models (survival versus time), which accounted for 79-97% of the relationship (p < 0.05). Although E. coli survived, its growth was inhibited over time regardless of acid adaptation.

Prevalence and antimicrobial susceptibility pattern of Campylobacter jejuni in raw retail chicken meat in Metropolitan Accra, Ghana.

Although, Campylobacter spp. are a major cause of foodborne gastroenteritis, its occurrence and antimicrobial resistance traits have not been well defined in low income countries, particularly in Africa. In this study, retail chicken was sampled (n = 400) between February 2019 to January 2020 in Metropolitan Accra, Ghana, to determine the prevalence and antimicrobial susceptibility pattern of Campylobacter jejuni. Raw chicken samples were obtained in wet markets (n = 315) and supermarkets (n = 85) and each subjected to direct plating and broth enrichment according to standard culture methods for Campylobacter spp. with the identity of presumptive positive colonies confirmed by MALDI-TOF. The susceptibility of isolates to antibiotics commonly used for campylobacteriosis in humans (in order to reflect the One Health significance of Campylobacter at the human-food interface) were then assessed by disc diffusion. A prevalence of 38.3% was recorded and all isolates were confirmed as Campylobacter jejuni. Enrichment yielded 127 positives while direct plating yielded 55 positives with low level of agreement in detection between these assays (Kappa = 0.15). Among samples positive by direct plating, the mean Campylobacter count was 1.9 log10 CFU/g (sd ±0.8). About 13% (7/55) of the samples positive by direct plating contained counts of 3log and above. Samples from the wet market yielded more positives than those from the supermarket with the rate of isolation from wet markets being 1.6 times that of the supermarket. Among 182 isolates characterized for their antimicrobial susceptibility, resistance to fluoroquinolones was 99.5%, tetracyclines 100% and macrolides 26.9%. Multi-drug resistance was also observed in 26.9% of the screened isolates. The findings point to a potential high level of exposure of humans to Campylobacter jejuni through chicken meat and thus the need for education on hygienic preparation and handling of raw chicken. High rates of resistance to classes of antimicrobials critically important for treating Campylobacter infections in humans; fluroquinolones and macrolides, affirm the need for stronger regulatory control of antimicrobials and enhanced antimicrobial stewardship in chicken production.

Microbial Diversity and Metabolite Profile of Fermenting Millet in the Production of Hausa koko, a Ghanaian Fermented Cereal Porridge.

Hausa koko is an indigenous porridge processed from millet in Ghana. The process involves fermentation stages, giving the characteristic organoleptic properties of the product that is produced largely at a small-scale household level and sold as a street food. Like many other indigenous foods, quality control is problematic and depends on the skills of the processor. In order to improve the quality of the product and standardize the process for large-scale production, we need a deeper understanding of the microbial processes. The aim of this study is to investigate the microbial community involved in the production of this traditional millet porridge and the metabolites produced during processing. High-throughput amplicon sequencing was used to identify the bacterial (16S rRNA V4 hypervariable region) and fungal [Intergenic Transcribed Spacer (ITS)] communities associated with the fermentation, while nuclear magnetic resonance (NMR) was used for metabolite profiling. The bacterial community diversity was reduced during the fermentation processes with an increase and predominance of lactobacilli. Other dominant bacteria in the fermentation included Pediococcus, Weissella, Lactococcus, Streptococcus, Leuconostoc, and Acetobacter. The species Limosilactobacillus fermentum and Ligilactobacillus salivarius accounted for some of the diversities within and between fermentation time points and processors. The fungal community was dominated by the genus Saccharomyces. Other genera such as Pichia, Candida, Kluyveromyces, Nakaseomyces, Torulaspora, and Cyberlindnera were also classified. The species Saccharomyces cerevisiae, Stachybotrys sansevieriae, Malassezia restricta, Cyberlindnera fabianii, and Kluyveromyces marxianus accounted for some of the diversities within some fermentation time points. The species S. sansevieria and M. restricta may have been reported for the first time in cereal fermentation. This is the most diverse microbial community reported in Hausa koko. In this study, we could identify and quantify 33 key different metabolites produced by the interactions of the microbial communities with the millet, composed of organic compounds, sugars, amino acids and intermediary compounds, and other key fermentation compounds. An increase in the concentration of organic acids in parallel with the reduction of sugars occurred during the fermentation process while an initial increase of amino acids followed by a decrease in later fermentation steps was observed.

Low Consumption of Indigenous Fresh Dairy Products in Ghana Attributed to Poor Hygienic Quality.

This cross-sectional study was aimed at assessing consumer perceptions and microbiological quality of the fresh cow's milk products available in selected dairying communities in Ghana. Twenty-six focus groups (FGs) were conducted to understand the perceptions on barriers and facilitators to dairy consumption. These included six FGs for lactating mothers and five FGs for each of the following categories: pregnant women, women of reproductive age with children younger than 5 years, not pregnant and nonlactating women, and males. A separate quantitative survey followed and included 176 women of reproductive age (18 to 49 years) and 90 males (18 to 59 years) from 15 dairying communities in the Greater Accra, Eastern, and Central regions of Ghana. Also, 120 locally sourced fresh milk products were assessed for counts of total coliforms, fecal coliforms, and Enterococcus spp., and presence of pathogenic Streptococcus spp. , Escherichia coli, and Klebsiella pneumoniae by using standard microbiological methods. Fecal coliforms in dairy products, such as brukina, wagashi, and yogurt exceeded the specified limit of 10 CFU/mL, while the prevalence of E. coli and K. pneumoniae were 70 and 65%, respectively. Generally, respondents perceived indigenous dairy as unsafe. These perceptions were formed on the basis of visual cues of environmental and personal hygiene. Of the indigenous milk products consumed, brukina, a fermented milk and millet gruel (33%) and wagashie, a soft unfermented cheese (29%), were the most popular. However, only 19% of wagashie and 21% of brukina consumers believed these products were safe. Consistently, the odds of consuming a particular milk product was significantly higher if the consumer believed it was safe. Poor sanitation and unhygienic processing of otherwise healthy but perishable indigenous milk products has justifiably fueled the mistrust of consumers and may hinder potential intervention efforts to increase milk production and consumption in Ghana.

Drivers-of-Liking (DOL) for Boiled Milk among Women of Reproductive Age and Children Aged between One and Five Years in Peri-Urban Communities in Ghana.

Raw milk is heat treated in different ways to improve the safety of the milk for consumption. The heat treatment imparts different sensory properties to the milk that may influence its acceptance by consumers. In Ghana, fresh milk is boiled and sold locally to consumers. Generally, consumption amongst women of reproductive age and children under five is low. In this study, the sensory properties that drive liking for local boiled milk and other heat-treated milks in women of reproductive age and children between 1 and 5 years of age was studied. External preference mapping was used to understand the sensory properties of the milks that were liked by the two consumer groups. The sensory properties of boiled milk that made women of reproductive age like a particular product was its sweet and salty taste, smooth mouthfeel and artificial flavour. For children between 1 and 5 years, the oily aftertaste, boiled egg aroma as well as its sweet taste made them like the same product as the adults. This product also had a cooked aroma and flavour which could have influenced liking in the consumer groups. A small minority of adult consumers liked products that had a smooth and runny appearance with a raw/uncooked note.