Glycogen and zinc-enriched ferritin as bioavailable nanoparticulate nutrients released from gastrointestinal digestion of pacific oyster (Crassostrea gigas).

Oyster is a low-carbon animal food enriched with protein, glycogen, and trace minerals. Nano-nutrients are increasingly perceived as an unignorable part of foods. Here, simulated gastrointestinal digestion released a considerable amount of nanoparticulate nutrients from raw and cooked oysters. They were identified as glycogen monomers with size of 20-40 nm and their aggregates, as well as 6 nm-sized bare cores of ferritin containing iron and zinc (4:1, w/w). FITC-labeling and flow cytometry unveiled the efficient uptake of oyster glycogen by polarized Caco-2 cells via macropinocytosis and receptor-mediated endocytosis. Calcein-fluorescence-quenching assay revealed divalent-metal-transporter-1- and macropinocytosis-mediated enterocyte iron absorption from oyster ferritin. Zinquin-fluorescence flow cytometry and ex-vivo mouse ileal loop experiments demonstrated the ready intestinal zinc absorption from oyster ferritin via macropinocytosis, as well as the good resistance of oyster ferritin to phytate's inhibition on zinc absorption. Overall, our results offer a new insight into the digestive and chemical properties of oysters.

How Worried Are You about Food Fraud? A Preliminary Multi-Country Study among Consumers in Selected Sub-Saharan African Countries.

Food fraud is an old, recurring, and global threat to public health. It poses a serious threat to food security in sub-Saharan Africa (SSA). Despite the prevalence of food fraud in SSA, little is known about how food fraud is viewed by consumers. This study aims to provide an overview of consumers' concerns about food fraud in SSA. A multi-country survey was conducted in October 2022-31 January 2023, and 838 valid responses were returned. To reduce the large and correlated dataset, Principal Component Analysis (PCA) was used. Five components were derived from PCA: (i) Staple foods; (ii) Premium food and drink products; (iii) Trust in reliable sources; (iv) Trust in less reliable sources; and (v) Trust in food vendors. The findings revealed Ghanaian (mean rank = 509.47) and Nigerian (mean rank = 454.82) consumers tended to score higher on the measure of food fraud concern suggesting that they were less confident in the safety and quality of the food they consume. Demographic characteristics including age, number of children, personal and family experience of food fraud and PCA components such as 'Staple foods', 'Trust in reliable sources', and 'Trust in food vendors' significantly predicted the model. This is the first preliminary study to provide empirical findings on consumers' concerns about food fraud in SSA. Practical and policy recommendations for the region are suggested. This includes (i) modelling the AfriFoodinTegrity in West Africa across other major regions such as Central, East, and Southern Africa; (ii) establish a regional sub-Saharan Africa Rapid Alert System for Food and Feed (SSA-RASFF) platform; and (iii) food safety and food fraud reports could be incorporated into SSA-RASFF portal for information sharing.

Effect of packaging materials and storage conditions on the microbial quality of pearl millet sourdough bread.

Sourdough is one of the oldest methods of cereal fermentation applied mainly for the sole purpose of baking and has been proven to enhance the production of microbiologically safe products. This study investigated the effect of packaging materials and storage conditions on the microbial quality and some intrinsic parameters of the sourdough bread. Pearl millet flour was naturally fermented for 72 h to obtain sourdough which was used with pearl millet flour to produce sourdough bread while the control bread was produced with pearl millet flour and yeast. The bread samples were packaged in low density polyethylene and aluminium foil and stored at -5, 4, 6, 28 and 37 °C. The total bacteria count (log cfu/g) and total fungal count (spore/g) increased with an increase in storage temperature and storage days. Fungi colonies isolated from stored bread samples include species of Rhizopus, Aspergillus, Penicillium and Mucor. A significant increase (p ≤ 0.05) in the pH and decrease in the moisture content of the bread samples were observed as storage period and storage temperature increased. Sourdough fermentation improved the microbial qualities and extended the shelf life of bread.

Nutritional, Texture, and Sensory Properties of composite biscuits produced from breadfruit and wheat flours enriched with edible fish meal.

This study aimed to develop biscuits with improved nutritional contents using edible fish meal from catfish as the source of macro- and micronutrient enrichment while trying to reduce the input of wheat flour in biscuit-making process. The biscuit was produced using edible fish meal (EFM: 0%-40%) from catfish, improved quality breadfruit (IQBF: 0%-60%), and wheat flours (WF: 0%-40%). Macro (crude protein, fat, fiber, ash, and carbohydrate)- and micro (calcium, magnesium, potassium, phosphorus, sodium, and iron)-nutrient contents of the biscuit were determined. The color (lightness-L*, redness-a*, and yellowness-b*), texture (hardness, springiness, and adhesiveness), and sensory (taste, texture, and overall acceptability) attributes of the biscuits were assessed using standard methods. Model characteristics of the responses were profiled, and numerical optimization technique was used to predict combination/blends that produce biscuits with desired nutritional contents. Moisture, crude protein, fat, fiber, and ash values were in the range of 3.50%-5.57%, 3.06%-15.52%, 13.62%-26.00%, 0.31%-1.40%, and 1.98%-5.32%, respectively. The iron, calcium, and phosphorus contents of the biscuit ranged from 103.85 to 201.30 mg/100 g, 100 to 754 mg/100 g, and 8 mg/100 g to 304 mg/100 g, respectively. Interaction between the models for WF and EFM was significant and this significantly affected the L* (36.37-51.90) and adhesiveness (0.01-0.29) values for color and texture, respectively. Similar observations were also noticed for most of the nutrients. The quadratic models selected for the nutrients were all significant (p < .05) and the adjusted R 2 ranged from 0.61 to 0.84 and 0.59 to 0.97 for the macro- and micronutrients, respectively. In conclusion, a biscuit from IQBF, WF, and EFM of 61.33, 0.07, and 38.60 with protein, fat, ash, iron, and calcium contents of 10.41%, 17.59%, 2.05%, 120.52 mg/100 g, and 500.00 mg/100 g, respectively, was produced.

Occurrence of bacteria and endotoxins in fermented foods and beverages from Nigeria and South Africa.

In Africa, fermented foods and beverages play significant roles in contributing to food security. Endotoxins are ubiquitous heat stable lipopolysaccharide (LPS) complexes situated in the outer cell membranes of Gram-negative bacteria. This study evaluated the microbiological quality of fermented foods (ogiri, ugba, iru, ogi and ogi baba) and beverages (mahewu and umqombothi) from selected Nigerian and South African markets. The bacterial diversity of the fermented foods was also investigated and the identity of the isolates confirmed by biochemical and molecular methods. Isolate grouping was established through hierarchal clustering and the samples were further investigated for endotoxin production with the chromogenic Limulus Amoebocyte Lysate assay. The total aerobic count of the samples ranged from 5.7 to 10.8 Log CFU/g. Fourteen bacteria genera were detected with most of the isolates being members of the Enterobacteriaceae family. Sphingomonas paucimobilis and Escherichia coli were the dominant Gram-negative bacterial species detected. There were considerable variations in the concentrations of endotoxins produced and the lowest endotoxin concentration was found in ogi (4.3 × 10 EU/g) and the highest in iru (5.5 × 104 EU/g) while, 44% of umqombothi samples had endotoxins. Ogi baba samples had better microbial quality than other samples due to its reduced bacterial load and endotoxin levels. There was a strong positive (r = 0.714, r = 0.996) and significant (p < 0.01) correlation between the endotoxin levels and bacterial loads of the samples. Some previously unreported species of bacteria found in the fermented foods included Aeromonas haemolyticus and Rhizobium radiobacter. This is the first comprehensive report on endotoxins in fermented foods and beverages in Africa. Furthermore, the occurrence of pathogenic bacteria and toxins in the foods and beverages is of serious concern that calls for immediate action.

The occurrence and co-occurrence of aflatoxin and fumonisin along the maize value chain in southwest Nigeria.

Aflatoxin and fumonisin are two major foodborne mycotoxins: toxic chemicals produced by fungi that contaminate food commodities including maize, a staple food in sub-Saharan Africa. Aflatoxin causes liver cancer, and is associated with acute liver toxicity and immunotoxicity; while fumonisin is associated with neural tube defects in infants and esophageal cancer. Both mycotoxins have been associated with child growth impairment. Previous studies suggest that co-occurrence of these mycotoxins may have potentially synergistic toxicological effects. Despite health risks associated with co-occurrence of these mycotoxins, no study has examined their co-occurrence along key food supply chains in Africa. This study is the first report that examines the occurrence and co-occurrence of aflatoxins and fumonisins along the maize value chain in Nigeria. All samples were analyzed using LC-MS/MS. About 52% and 21% of the samples had aflatoxin levels above the Nigerian and US standards for human food, respectively. Though no regulatory limits exist for fumonisin in Nigeria, 13% of the samples contained fumonisin levels higher than the US regulatory limit. Aflatoxin levels can become dangerously high in maize stored four months or longer. Adequately addressing mycotoxin risk requires consideration of the entire maize value chain and associated value chains for food production.

Food safety knowledge, attitudes and practices among consumers in developing countries: An international survey.

An international survey among consumers in developing countries from Asia and Africa on food safety knowledge, attitudes and practices (KAP) was carried out using structured questionnaires. Data were collected from 453 consumers comprising 265 from Africa and 188 from Asia. Significant difference (p < 0.05) on food safety knowledge attitude and practice between consumers from Africa and Asia was observed. In Africa, consumers in Cameroon had the least food safety knowledge (73.15 ±â€¯16.43) compared to Ghana (78.19 ±â€¯15.84) and Nigeria (88.16 ±â€¯8.88). Similarly, consumers in Iran had the least food safety knowledge (73.33 ±â€¯19.84) in Asia compared to Malaysia (88.36 ±â€¯11.64) and Pakistan (89.42 ±â€¯9.89). Among the respondents, 89% were aware of food poisoning while 304 (67.1%) consume food kept for long at room temperature. There was significant difference (p < 0.05) in food safety knowledge, attitudes and practices of consumers between Africa and Asia. Overall, respondents from Asia have better food safety knowledge than respondents from Africa.

Investigation of the Metabolic Profile and Toxigenic Variability of Fungal Species Occurring in Fermented Foods and Beverage from Nigeria and South Africa Using UPLC-MS/MS.

Fungal species recovered from fermented foods and beverage from Nigeria and South Africa were studied to establish their toxigenic potential in producing an array of secondary metabolites including mycotoxins (n = 49) that could compromise human and animal safety. In total, 385 fungal isolates were grown on solidified yeast extract sucrose agar. Their metabolites were extracted and analyzed via ultra-performance liquid chromatography tandem mass spectrometry. To examine the grouping of isolates and co-occurrence of metabolites, hierarchal clustering and pairwise association analysis was performed. Of the 385 fungal strains tested, over 41% were toxigenic producing different mycotoxins. A. flavus and A. parasiticus strains were the principal producers of aflatoxin B1 (27⁻7406 µg/kg). Aflatoxin B1 and cyclopiazonic acid had a positive association. Ochratoxin A was produced by 67% of the A. niger strains in the range of 28⁻1302 µg/kg. The sterigmatocystin producers found were A. versicolor (n = 12), A. amstelodami (n = 4), and A. sydowii (n = 6). Apart from P. chrysogenum, none of the Penicillium spp. produced roquefortine C. Amongst the Fusarium strains tested, F. verticillioides produced fumonisin B1 (range: 77⁻218 µg/kg) meanwhile low levels of deoxynivalenol were observed. The production of multiple metabolites by single fungal species was also evident.

The antinutritional and vitamin composition of high-quality yam flour as affected by yam specie, pretreatment, and drying method.

Fresh yams are not shelf stable due to its high susceptibility to physiological deterioration; hence, its conversion into a more stable product like flour can stimulate its industrial application as a substitute to wheat flour. The influence of yam species, pretreatment, and drying method on the antinutritional factor and vitamin composition of high-quality yam flour (HQYF) was determined. Four different yam species were pretreated with 0.28% potassium metabisulphite for 15 min and blanching at 70°C for 15 min. The differently pretreated slices were thereafter dried with cabinet dryer at 60°C for 48 h and open sun for 3 days, then milled into flour. The flour samples were analyzed for antinutritional and vitamin contents using standard laboratory procedures. The antinutritional factors in the high-quality yam flour were significantly (p < .05) affected by yam specie, pretreatment, and drying methods. The low level of alkaloids (0.02 mg/100 g) and phytates (13.43 mg/100 g) in the flour samples from D. rotundata in this study underscores its safety for absorption in the body when consumed/used as food formulations. The main and interactive effect of specie of specie, pretreatment, and drying methods influenced the vitamin content of the high-quality yam flour significantly (p < 0.05). The appreciable level of vitamin C (20.87-30.91 mg/100 g) recorded in all the HQYF could indicate the product of good nutritional quality for the consumers.

Microbiological assessment of maize ogi cofermented with pigeon pea.

Maize was cofermented with pigeon pea for ogi production and evaluated for microbiological qualities. White maize and pigeon pea were mixed at ratios of 90:10, 80:20, 70:30, 60:40, and 50:50, respectively, with 100:0 serving as the control. Mixtures were cofermented for 96 h at 27 ± 2°C, and microbiological and sensory qualities analyzed were carried out using analysis of variance. Values were significant at p ≤ .05. Results showed that there was a gradual decrease in the pH and increase in total titratable acidity (TTA), respectively, during fermentation in all the samples. At the end of fermentation, pH ranged from 3.47 to 4.27 and TTA ranged from 0.47% to 0.54%, respectively. Total heterotrophic count (THPC) ranged from 5.76 to 5.90 log cfu/g; lactic acid bacteria (LAB) from 6.15 to 5.98 log cfu/g; and yeasts from 5.51 to 5.79 log cfu/g. Microorganisms isolated were lactic acid bacteria (Lactobacillus buchneri, L. casei, L. pentosus, Pediococcus pentosaceus), yeasts (Saccharomyces cerevisiae, Candida kefyr, C. krusei, C. tropicalis), molds (Aspergillus niger, A. flavus, Penicillium oxalicum, Mucor racemosus and Rhizopus stolonifer) and other aerobic bacteria (Klebsiella oxytoca, Enterobacter amnigenus, Staphylococcus xylosus, Bacillus subtilis, B. firmus, Corynebacterium kutscheri, C. striatum, and C. afermentans). In conclusion, the total heterotrophic plate count (THPC) in fortified maize: pigeon pea products was very high. This could constitute health hazards to infants as weaning foods. However, the microbial loads could be reduced through heat treatment as ogi is usually boiled or treated with boiled water before consumption and it can therefore be concluded that the fortified maize: pigeon pea products could be used as weaning foods.

Influence of drying temperature and storage period on the quality of cherry and plum tomato powder.

The quality changes of cherry and plum tomatoes dried at different temperatures (60, 65 and 70°C) milled into powder and stored for 8 weeks were assessed in this study. The ascorbic acid and lycopene content of the tomato powders were significantly different with values that ranged from 5.10 to 7.70 mg/100 g and 211.53 to 246.02 mg/kg, respectively. Color parameters redness (a*) and chroma decreased, while lightness (L*), yellowness (b*), and hue increased as the drying temperature increased. In addition, increase was observed in the total fungal load and lightness of the two tomato varieties at all temperatures, while the titratable acidity, pH, ascorbic acid, lycopene, redness, and yellowness increased as the storage period increased to 8 weeks. The 60°C dried plum tomato powder had the best result in terms of quality retention at the end of the storage period. Some quality parameters increased and decreased with drying and storage of plum and cherry tomato powders.

Nutritional composition and antinutritional properties of maize ogi cofermented with pigeon pea.

Maize was cofermented with pigeon pea for ogi production and evaluated for nutritional (proximate composition, minerals, vitamins, and amino acid profile analyses) and antinutritional (phytate, tannin, and trypsin inhibitor activity analyses) qualities. White maize and pigeon pea were mixed at ratios of 90:10, 80:20, 70:30, 60:40, and 50:50, respectively, with 100:0 serving as the control. Mixtures were cofermented for 96 hr at 27°C ± 2°C and nutritional, mineral, and antinutritional qualities were analyzed using analysis of variance. Results of proximate analysis showed that the values were significantly difference at p ≤ .05. Maize cofermented with pigeon pea at a ratio of 60:40 had the highest protein (22.79 mg/100 g), fat (19.27 mg/100 g), ash (2.98 mg/100 g), crude fiber (0.73 mg/100 g), and lowest moisture (1.98 mg/100 g) content, and was significantly (p ≤ .05) different from the other ratios. Of all the mixtures analyzed, 60:40 was significantly (p ≤ .05) different and had the highest Vitamin B1, B2, and B3 contents. Amino acid profile results showed that maize cofermented with pigeon pea at a ratio of 60:40 showed the highest contents of lysine (93.95 mg/g), tryptophan (20.38 mg/g), isoleucine (54.78 mg/g), phenylalanine (86.23 mg/g), leucine (109.55 mg/g), and valine (68.29 mg/g), respectively, and was significantly (p ≤ .05) different from the other ratios. Results of antinutritional analysis showed low phytate, tannin, and trypsin inhibitor values in maize cofermented with pigeon pea at a ratio of 60:40 when compared with other ratios. The cofermented maize-pigeon pea product 60:40 had high amino acid profile than the others.

Mycobiota and co-occurrence of mycotoxins in South African maize-based opaque beer.

Beer, a beverage consumed throughout the world, is mainly derived from cereals. In this study, fungal and mycotoxin contamination, as well as the physicochemical properties of maize-based opaque beer (umqombothi) obtained from the Gauteng province of South Africa, was investigated. The mean water activity, pH and total titratable acidity of the analysed beer samples were 0.91, 3.76 and 1.20% lactic acid, respectively. The investigation revealed Aspergillus, Penicillium, Phoma and Saccharomyces as the predominant fungal genera with a mean fungal load of 3.66 × 105 CFU/mL. Among the mycotoxigenic fungal species recovered, Aspergillus flavus had the highest incidence of 26%. Previously unreported strains such as P. chrysogenum strain AD25, A. sydowii strain AD 22 and A. tritici strain AD 11 were found. Furthermore, mycotoxin quantitative analysis via liquid chromatography-tandem mass spectrophotometry showed that deoxynivalenol was the dominant mycotoxin occurring in 84% of the samples. This was followed by enniatin B that occurred in 75% of samples ranging from 12 to 44 µg/L and fumonisin B1 (FB1) (incidence of 53% at a maximum level of 182 µg/L). Generally, there was low occurrence aflatoxins, whereas T-2, HT-2, nivalenol, zearalenone, 3- and 15-acetyl-deoxynivalenol were not detected. All the samples analysed had safe levels of mycotoxins tested but were contaminated by at least two mycotoxins that could pose some additive or synergistic health effects among consumers. On average: a 60 kg adult consuming 1-6 L/day of the beer was exposed to FB1 + FB2 at an estimated 2.20-13.20 µg/kg body weight/day. These values were far above the maximum tolerable daily intake of 2 µg/kg bw/day established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA). The study demonstrates that consumption of umqombothi can significantly enhance dietary exposure to multiple mycotoxins among consumers, and therefore accentuates the need for strategies aimed at reducing toxigenic fungal colonization and mycotoxin contamination in the beer processing chain.

Changes in nutritional and physico-chemical properties of pearl millet (Pennisetum glaucum) Ex-Borno variety flour as a result of malting.

The effect of malting periods on the nutritional composition and physico-chemical properties of flour from pearl millet (Ex-Borno) variety was evaluated. Grains were steeped at 25 °C for 24 h and germinated for different durations (12, 24, 36, 48, 60, 72, 84 and 96 h) before kilning at 55 °C for 18 h. The kilned seeds were devegetated, milled, sieved and analysed for their proximate composition, amino acid composition, total phenolic content, functional and pasting properties. The carbohydrate, fat and total phenolic contents of the pearl millet flour samples decreased while protein content increased with increased malting periods. Leucine was the dominant amino acid in the flour and 48 h-malted flour had the highest total amino acid (6.72). Peak viscosity significantly decreased as the malting period increased. Solubility index, pasting temperature and phenolic content of the flours ranged from 5.13 to 17.24%, 69.05 to 89.5 °C and 130.20 to 169.90 mg/100 g, respectively. Malting offers a means of improving the nutritional profile of Ex-Borno pearl millet flour with an increased protein and fibre and reduced fat content. Malting also enhanced the functional and pasting properties of the flour.

Awareness and Prevalence of Mycotoxin Contamination in Selected Nigerian Fermented Foods.

Fermented food samples (n = 191) including maize gruel (ogi), sorghum gruel (ogi-baba), melon seed (ogiri), locust bean (iru) and African oil bean seed (ugba) from Southwest Nigeria were quantified for 23 mycotoxins, including aflatoxin B1 (AFB1), fumonisin B1 (FB1), and sterigmatocystin (STE) using liquid chromatography-tandem mass spectrometry. The practices, perceived understanding and health risks related to fungal and mycotoxin contamination amongst fermented food sellers was also established. Data obtained revealed that 82% of the samples had mycotoxins occurring singly or in combination. FB1 was present in 83% of ogi-baba samples, whereas 20% of ugba samples contained AFB1 (range: 3 to 36 µg/kg) and STE was present in 29% of the ogi samples. In terms of multi-mycotoxin contamination, FB1 + FB2 + FB3 + STE + AFB1 + alternariol + HT-2 co-occurred within one sample. The awareness study revealed that 98% of respondents were unaware of mycotoxin contamination, and their education level slightly correlated with their level of awareness (p < 0.01, r = 0.308). The extent to which the analyzed mycotoxins contaminated these food commodities, coupled with the poor perception of the population under study on fungi and mycotoxins, justifies the need to enact fungal and mycotoxin mitigation strategies along the food chain.

Bacterial species and mycotoxin contamination associated with locust bean, melon and their fermented products in south-western Nigeria.

The microbiological safety of spontaneously fermented foods is not always guaranteed due to the undefined fermenting microbial consortium and processing materials. In this study, two commonly consumed traditional condiments (iru and ogiri) and their respective raw seeds (locust bean and melon) purchased from markets in south-western Nigeria were assessed for bacterial diversity and mycotoxin contamination using 16S rRNA gene sequencing and liquid chromatography tandem mass spectrometry (LC-MS/MS), respectively. Two hundred isolates obtained from the raw seeds and condiments clustered into 10 operational taxonomic units (OTUs) and spanned 3 phyla, 10 genera, 14 species and 2 sub-species. Bacillus (25%) and Staphylococcus (23.5%) dominated other genera. Potentially pathogenic species such as Alcaligenes faecalis, Bacillus anthracis, Proteus mirabilis and Staphylococcus sciuri subsp. sciuri occurred in the samples, suggesting poor hygienic practice during production and/or handling of the condiments. A total of 48 microbial metabolites including 7 mycotoxins [3-nitropropionic acid, aflatoxin B1 (AFB1), AFB2, beauvericin, citrinin, ochratoxin A and sterigmatocystin] were quantified in the food samples. Melon and ogiri had detectable aflatoxin levels whereas locust bean and iru did not; the overall mycotoxin levels in the food samples were low. There is a need to educate processors/vendors of these condiments on good hygienic and processing practices.

Comparison of nutritional quality and sensory acceptability of biscuits obtained from native, fermented, and malted pearl millet (Pennisetum glaucum) flour.

The effects of fermentation and malting on the proximate composition, mineral content, amino acids and total phenolic content of pearl millet flour and biscuits were studied. Consumer tests of the biscuits samples were also done using two sets of panelists. The results showed that fermentation and malting improved the crude fiber, crude protein, carbohydrate and energy values of the pearl millet flour. For the biscuit samples, the fermented and malted biscuits had higher moisture, crude protein, crude fiber and energy value with lower fat and ash content as compared to the biscuits obtained from native flour. Fermentation and malting were further observed to increase majority of the essential and non-essential amino acids. Consumer tests among the different set of panelists showed differences in the loading patterns as observed through principal component analysis. In conclusion, this study shows that fermentation and malting improves nutritional, health composition of pearl millet flour as well as the sensorial acceptability of subsequent biscuits.

Prevention of microbial hazard on fresh-cut lettuce through adoption of food safety and hygienic practices by lettuce farmers.

Lettuce is consumed raw in salads and is susceptible to microbial contamination through environment, agricultural practices, and its morphology, thus, a potential vehicle for food-borne illness. This study investigated the effect of adoption of food safety and hygienic practices by lettuce farmers on the microbial safety of field sourced lettuce in Lagos State, Nigeria. Ten structured questionnaires were administered randomly to 10 lettuce farmers to assess food safety and hygienic practices (FSH). Two farmers who practice FSH and two farmers who do not practice NFSH were finally used for this study. Samples of ready-to-harvest lettuce, manure applied, and irrigation water were obtained for a period of five months (August - December 2013) and analyzed for total plate count (TPC), total coliform count (TCC), Escherichia coli, Listeria spp., Salmonella spp., and Shigella spp. counts. Result of microbial analyses of lettuce samples was compared with international microbiological specification for ready-to-eat foods. Results showed that the range of TPC on lettuce was 6.00 to 8.11 LogCFU/g from FSH farms and TPC of lettuce samples from NFSH farms ranged from 6.66 to 13.64 LogCFU/g. 1.49 to 4.85LogCFU/g were TCC ranges from lettuce samples obtained from FSH farms while NFSH farms had TCC ranging between 3.95 and 10.86 LogCFU/g, respectively. The range of isolated pathogen count on lettuce from FSH and NFSH farms exceeded the international safety standard; there was a significant difference in the microbial count of lettuce from FSH farms and NFSH farms. This study concludes that the lettuce samples obtained did not pass the international microbial safety standards. FSH compliance is a major determinant of the microbial safety of lettuce. Hence, the institution of FSH on farm to improve microbial safety of lettuce produced for public consumption is emphasized.

Quality changes in cocoyam flours during storage.

Cocoyam tubers were subjected to two processing methods (fermentation and parboiling) and milled into flour. The samples were stored at 25°C, 35°C, and 45°C and analyzed at 2 weeks interval for 8 weeks for their nutritional, functional, and pasting properties. Data obtained were subjected to multiple analysis of variance. Storage period and its interactive effect with the processing methods had significant (P < 0.05) effects on all the nutritional composition of the flour except for the fat content. Water absorption index, wettability, and bulk density ranged from 1.94-2.72%, 25.30-135.50 sec, and 0.48-0.71 g/cm3, respectively. The entire pasting properties were significantly affected by the storage period while the interaction between storage temperature, processing methods, and storage period affected all the pasting properties except the peak time, peak, and breakdown viscosity. This study showed that processing methods storage periods and storage temperatures produced cocoyam flour with different quality characteristics.