Dr. Ahmed Medhat Mohamed Al-Naggar
Professor of Plant Breeding,
Department  of Agronomy, Faculty of Agriculture, Cairo University, Egypt.

ISBN 978-93-90768-82-0 (Print)
ISBN 978-93-90768-90-5 (eBook)
DOI: 10.9734/bpi/crafs/v4

This book covers key areas of agricultural and food science research. The contribution by the author includes extended-spectrum beta-lactamase, bacterial resistance, foodborne pathogen, microbiological analyses, nutritional aspects, product survey, food security, shelf life, nutrition, organoleptic properties, preservation, inhibition, glycaemic index, traditional meals, macronutrients content, mycotoxins, contamination, mycotoxicity, mycotoxin metabolism, prevention, genotoxicity, aflatoxins, carcinogenicity, lipid oxidation, heavy metals, organic pollutants, vended street foods, pesticides, Mwea irrigation scheme, Fisher’s formula, sensory attributes, nutritional evaluation, malnutrition. This book contains various materials suitable for students, researchers and academicians in the field of agricultural and food sciences.


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Investigating the Incidence of Extended-Spectrum Beta-Lactamase (ESBL)-Producing Bacteria in Salad Vegetables in Ondo City, Nigeria

O. O. Bello, M. O. Oni, J. O. Bello, T. K. Bello

Current Research in Agricultural and Food Science Vol. 4, 18 February 2021, Page 1-15

Concerns about the safety of food, plants’ and animals’ welfares, as well as traceability are more preferred to the food products being supplied in plenitude. Vegetables are considered as the major reservoirs of opportunistic and emerging pathogens due to its diverse microbiome and they are also strongly influenced by biogeographic aspects of farming and food processing practices

Aim: This study was carried out to determine the occurrence of extended-spectrum beta-lactamase (ESBL) producing bacteria in salad vegetables in Ondo City, Nigeria. Study Design: An experimental study design with randomized sampling.

Place and Duration of the Study: The research was carried out in the Department of Biological Sciences of Wesley University, Ondo State, Nigeria.

Methodology: Samples of cucumber, carrot, green pea, green beans, sweet corn and cabbage were analysed on appropriate agar medium. Pure isolates were identified by biochemical tests and confirmation was done by the use of API 20 E and API 20 NE in accordance with standard procedures. ESBLs screening was carried out using the double disk synergy test. Data were statistically analyzed using MedCalc statistical software (version 17.2).

Results: Total viable bacterial counts (TVBCs) ranged from 1.1 × 103 to 7.1 x 105 cfu/ml; total coliform counts (TCC) ranged from 1.2 x 102 to 3.9 x 103 cfu/ml while total faecal counts (TFC) ranged from 0 to 2.9 × 102 cfu/ml. There were statistical differences in mean TVBCs of the samples (P < 0.05). The mean TCCs of cabbage, carrot and cucumber showed no statistical significance; green beans, green pea and sweet corn also showed no statistical significance (P > 0.05). One hundred and sixty (166) isolates obtained from the samples were identified as Bacillus cereus, Citrobacter freundii, Escherichia coli, Klebsiella pneumoniae, Morganella morganii, Pseudomonas aeruginosa, Proteus mirabilis, Staphylococcus aureus, Serratia marcesens and Staphylococcus saprophyticus. At least one member of all bacterial species, except S. saprophyticus, produced ESBL.

Conclusion: This study revealed that salad vegetables could be a vehicle for the spread of extended-spectrum beta-lactamase-producing bacteria which translates to a threat to public health around the world as salads are loved and consumed by all categories of people globally. There is need to educate the vendors and consumers on good sanitary practices during processing, display and sale of vegetables and also dangers associated with misuse of antibiotics.

Gundpak–A Khoa Based Traditional Milk Product of Nepal

Pushpa Prasad Acharya, Ganga Prasad Kharel, Ramakrishnna Chetana

Current Research in Agricultural and Food Science Vol. 4, 18 February 2021, Page 16-29

The main aim of this study is to investigate the present status of the traditionally produced gundpak, its technology, safety and quality attributes. 

In this study the traditional production technology of ‘gundpak’ was examined by selecting the beneficiaries purposively from Kathmandu valley who involved directly to its production, sales and consumption.

The major ingredients used for gundpak production are khoa, sugar, ghee and gund and minor ingredients are different dried fruits, nuts, watermelon seeds, medicinal plants/herbs. Mostly, two varieties of gundpak found in the market i.e., normal and medicinal. According to the producers and sellers shelf life of gundpak at ambient condition in summer a week and in winter two weeks. Gundpak, is a popular khoa based traditional milk product of Nepal and commonly used as a sweet delicious food. Twelve market samples of gundpak were collected from the different areas of Kathmandu valley. The physico-chemical, sensory and microbiological analyses of the samples were investigated. The commercial samples were not found consistent in their chemical compositions, microbiological and physico-chemical parameters. This study embarks the beneficiaries to train about the ingredients, processing technology, health and safety aspects of the products. It is recommended that the concerned authorities should give emphasize to develop the mandatory standard of the product, trained the producers, encouraging the business people for the investment and production of gundpak. It will definitely help poverty alleviation.

Background: Food consumption has been changing during the past decade and need for instant formulation is being increased. The potential of growth of convenience foods in Kenya is vastly untapped.

Objective: The study aimed at developing a dehydrated instant ox tail soup mix Fortified with with Mushroom (Pleurotus ostreatus) and Moringa (Moringa oleifera) Leaves Powder and other vegetables to enhance its protein quality and reduce the difficulty in preparation of the soup in order to minimize the problem of protein-energy malnutrition in Kenya.

Methods: In this study After destalking of Moringa leaves they were washed with clean water. The leaves were then boiled with 0.1% (v/v) sodium metabi-sulphite for 10 minutes. The leaves were then spread out on the racks for 15 min o drip off water. They were then spread thinly on mesh and allowed to dry in the oven dryer for four 4 hours. The dried leaves were ground into powder and packaged in a plastic container and stored at room temperature. Fresh oyster mushrooms (Pleurotus ostearus (Jacq.) P. Kumm. were cleaned, chopped into small pieces of about 5-7 mm thickness, then pretreated by blanching in water at 60ºC for about 2 minutes, cooked and dried to a moisture content of 5-7%, then dried, sieved and stored in airtight containers. The oxtail was cut into small pieces and soaked in vinegar for 10 minutes this is because vinegar tends to kill salmonella, E. coli and other gram-negative bacteria. It was then taken to an oven to dry it further at 70ºC for 48 hours, then ground and packed in airtight container at room temperatures. Tomatoes were cut into slices, cooked, cooled, and the pulp was dried in an oven drier for 3 hours at 60ºC. The dried pulp was ground and packaged in airtight glass containers. Proximate analysis was done according to AOAC methods (2005).

Results: Proximate analysis were as follows: Oyster mushroom powder the fat, ash, protein, moisture and total carbohydrates were as follows 2.5%, 8.1%, 31.5% 3, 73% and 40.8% respectively on dry weight basis. In the case of Moringa powder the fat, ash, protein, and total carbohydrate results were as follows: 6.3%, 9.5%, 33.4%, and 57.63%. Ox tail powder the results were as follows fat was 14.6%, ash 5.1%, protein 23.7%, total carbohydrates 36.2% and moisture content 4.72%.

Conclusion: Instant oxtail soup fortified with mushroom (Pleurotus ostreatus) and Moringa Leaves powder can be developed using Oyster mushroom.

Background: Senna didymobotrya grows naturally in East Africa and is commonly used to treat microbial infections by African communities due to the presence of various phytochemicals such as alkaloids, terpenoid, anthraquinones, tannins, saponins, phenols and flavonoids. Extracts of the candle brush have been found to also contain antimicrobial properties against bacteria such as Staphylococcus aureus and Bacillus cereus

Objective: This study was conducted to evaluate the effectiveness of the crude extract of candle brush (Senna didymobotrya) leaves against Aspergillus niger in the reduction of post-harvest losses in tomatoes.

Methods: A completely randomised design with two treatments, each replicated six times was used. In this study. Dried leaves were ground into a fine powder and extracted using the Soxhlet apparatus with 100% methanol. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of the extract were determined against Aspergillus niger. The shelf life of tomatoes was determined by spraying the extract reconstituted in water at 0.4 g/ml and further analysed the total viable counts at three-day intervals and checking for the growth of mould, colour changes and odours as indicators of spoilage.

Results: After extraction 22 g of the crude extract was obtained from the dried leaves The MIC and MFC of the methanol crude extract against Aspergillus niger were 0.04 g/ml. The shelf life of the treated tomatoes was 14 days while for the untreated was 9 days. T-test results at (P?0.05) Showed a significant difference between the treated and untreated samples based on the total viable counts.

Conclusion: The crude extract of the candle brush inhibited the growth of Aspergillus niger in fresh tomatoes and also prolonged the shelf life of tomatoes for 14 days. Further studies should be done to evaluate the market acceptability of the tomatoes.

Background: During processing of banana, peels are discarded which are valuable source of potassium, dietary fiber with percentages up to 40-50% protein, 8-11% lipids, and 2.2- 10.9% fatty acids. Therefore, a high value nutrition baking flour can be made using dried ripe banana peels and reduce disposal of the banana peel.

Objective: This study was conducted to develop a high value nutritious baking flour from dried banana peels.

Methods: Ripe banana peels were treated with steam blanching at 57°C for 12 hours to prevent enzymetic discoloration. The peels were then cut into small pieces of 1cm in thickness for easier drying and placed on trays. They were then placed in a preheated dehydrator. The initial temperature set was a 62ºC for 12 hours. The temperature was reduced to 57°C after 12 hours making it a total of 24 hours for drying banana peels completely. The dried banana peels were crushed into fine flour using sterile mortar and pestle. Banana peel flour obtained was incorporated in whole meal flour formulation at four different levels as 0, 10, 20, and 30%.

Sensory evaluation was done by assessing the organoleptic properties on over all acceptability using a nine- point Hedonic scale. Proximate analysis in percentage was carried out on the following parameters; moisture content, carbohydrate, protein, lipid, Ash crude fibre, ntioxidant (Vitamin C) and total dietary fibre.

Results: Whole meal cake with 20% banana peel flour was found to be the most accepted formulation. It had good physical characteristics. Proximate composition results of 20% ripe banana peel flour were as follows: Moisture-17.2±0.05%, Crude protein- 5.5±0.01%, Crude fibre-19.2±0.01%, Ash 8.8±0.02% and Carbohydrates- 14.6±0.01%., Lipids 1.5±0.01, Vitamin C91.30±0.01 and total dietary fibre 20.14±0.01 for 20% banana peels flour.

Conclusion: Ripe banana peel flour has potentials to be added in to patent baking flour to make healthy food products.

Background: A lot of health hazards have been associated with artificial preservatives including: hyperactivity in children, breathing problems such as asthma and bronchitis, weakening of heart tissues, obesity since some contain fatty acids especially in processed foods and gastrointestinal disorders. Food borne diseases caused by lack of food preservation measures have continuously been a menace to human health and have led to the use of preservatives. Sulfite is a common preservative in fruits and was found to have the following side effects: headaches, allergies, palpitations and cancer. Another down side of artificial preservative is that a lot of time is used in developing and acquiring it thus making it expensive. There is therefore need for a natural preservative.

Objectives: This study was conducted to develop a natural preservative from guava leaves extract that would help increase the shelf-life of strawberries.

Methods: Crude extract was obtained by crushing dry guava leaves into 100 g powder and adding 600 ml of boiled water. The mixture was allowed to stand for 1 hr to allow extraction. The extract was then filtered and used to determine its inhibition against fungi. The extract was also serially diluted to obtain 5 different concentrations which were used to determine their effectiveness in increasing the shelf life of the strawberries.

Results: The plates with the highest concentration of guava leaves extract had the lowest number of microbial colonies while the one with the lowest concentration on had the highest number of microbial colonies. The control samples had by far a higher number of microbial colonies than all the different concentrations of the extract.

Conclusion: The crude extracts of guava leaves showed inhibition against fungi and increased the shelf life of strawberries. Further studies need to be conducted in order to obtain a purified preservative from the extract.

Evaluating the Glycaemic Index and Macronutrients Content of Three Traditional Cameroonian Meals

Etoundi Omgba Cunégonde Blanche, Mbock Émilie Danielle, Djopnang Djimbie Justin, Moussambe Abanga Agathe, Ngom Ngom Trésor

Current Research in Agricultural and Food Science Vol. 4, 18 February 2021, Page 68-76

Glycaemic index (GI), is an adequate tool not only for diet schedule, but also for the management of metabolic pathologies. It’s a parameter used to classified carbohydrates containing food according to their ability to raised blood glucose. We aimed to determine the GI and macronutrients content (Mc) of three Cameroonian meals commonly consumed. The studied sauces, commonly called “Bongo’ô Tchobi” (BT), “Kwem’’ with groundnut (KG) and “Flutted pumkin with pistachio” (FP) were mainly constituted of seeds of Aframomum aulacocarpos and citratum, Manihot esculenta leaves with Arachis hypogaea seeds and Telfairia occidentalis leaves with Citrullus colocynthis, seeds respectively. These sauces were all associated to Manihot esculenta tuber called  “Cassava”  (CA).  We  included  30  healthy  male’s  volunteers  who  were invited to participate in the study on four visits. After a 10-14 hours overnight fasting, the Oral Glucose Tolerance Test was carried out on day one of the visits. For the three meals, the experiment was repeated three times. Their capillary finger-prick blood samples were collected. The GI values were computed from the area under the glycemic-response curve of each food with glucose as reference. The macronutrients content (Mc) of each sauce and that of CA were determined separately. Results show that, the mean GI was respectively 96.85 ± 2.04; 91.22 ± 5.20; and 88.68 ± 3.47 for BT, KG, and FP. The total fiber content was high (p<0.05) for FP. A positive correlation was observed between the carbohydrates content of the tests meals and their GI (r=0.5; p<0.667) which means that, GI increases with the level of the available carbohydrates in the meal. The carbohydrates content value of CA was high (p<0.05) compared to all the sauces. As the sauces presented a poor carbohydrates content than Cassava, they can be proposed to people with carbohydrates metabolism disorders. These data are intended to serve as nutritional guidelines for the population and will also help nutritionists in diet schedule and formulation of foods proper for specific groups or for people in need to control their diet behavior. However, they should be associated with less carbohydrates accompaniment to prevent a high and/or chronic postprandial glycaemia.

A Critical Overview of Mycotoxin Contamination of Foods and Feeds

M. U. Ukwuru, C. G. Ohaegbu, A. Muritala

Current Research in Agricultural and Food Science Vol. 4, 18 February 2021, Page 77-98

Mycotoxins contamination of foods and feeds remain a great challenge to food safety and of public health and economic significance. Mycotoxins occur in various foodstuffs, from raw agricultural commodities to processed foods with varying impacts on food processing. The major group of mycotoxins that contaminate foods and feeds include aflatoxins, fumonisins and patulin. Several studies conducted to reveal the metabolism of mycotoxins in the body are reviewed. Health implications of mycotoxins upon consumption of adequate doses are diverse. They include sub- acute mycotoxicosis, immune suppression, carcinogenicity, genotoxicity, morbidity and mortality in animals and humans as well as interaction with nutrient assimilation. Mycotoxicity of foods have tremendous effect on international trade, resulting in huge losses. There are regulations, though not in all countries, aimed at preventing and controlling Mycotoxins which operate only on industrially processed foods and those meant for exports but not locally processed ones. A number of strategies for preventing mycotoxins have been proposed but the awareness for implementation is very low. The use of media to create awareness is a viable option.

Monitoring the Effects of Processing, Storage Days and Storage Temperatures on Lipid Oxidation and Palatability of Processed Snail Meat Products

I. Iwanegbe, J. O. Igene, G. U. Emelue, J. U. Obaroakpo

Current Research in Agricultural and Food Science Vol. 4, 18 February 2021, Page 99-111

The effect of processing methods, storage days (d) and storage temperatures on the lipid oxidation and palatability of processed snail meat products was carried out in this study. Oxidation of lipids can occur in foods containing substantial amounts of fat, like milk and meat products, oils, nuts and also those that contain only minor amounts of lipids, such as vegetable products. Samples of snail meat products were subjected to 2-thiobarbituric acid (TBA) test for Malonaldehyde(MA) with water-TBA reagent as blank periodically at 0, 5, 10, 15, 20, 25 and 30 d. Meat samples were served to trained panellists who evaluated the products based on colour, flavour, tenderness, juiciness and overall acceptance. The results showed that the unseasoned-fried product had the lowest lipid oxidation values 0.04, 0.13 and 0.19 mg malonaldehyde/kg meat in all the storage periods at 0-5, 10-20 and 25-30 d respectively. Lipid oxidation values of products stored for 10-20d were 0.2565, 0.3040 and 0.3548. Lipid oxidation values were lower in freezer stored product than refrigerated product at 0-20d. Lipid oxidation values increased with increasing storage days for all the products. The seasoned smoke-dried product had lower lipid values throughout the storage period than the seasoned fried product. The regression curve for colour was a = 5.282 and b = - 5.342 while acceptability was a = 4.455, b = -3.438. This relationship implies that TBA values give a strong estimate of colour and acceptability.

Practical Applications: Four different treatments were considered for evaluation; unseasoned fried (USF), seasoned fried (SF), seasoned oven- dried (SOD) and seasoned smoke-dried (SSD) and the products were kept under three storage conditions (room, fridge and freezer). The regression relationships between TBA values and the sensory attributes (colour and overall acceptance) of the products were evaluated. Our results suggest that cold storage and proper packaging retard the development of lipid oxidation in snail meat products. Smoke-drying with seasonings had lower lipid oxidation values than the seasoned fried product throughout the storage period. The shelf life of processed meat could be extended by smoke-drying and curing without adverse effect on the quality and overall acceptance of meat.

This study was aimed at investigating the presence of heavy metals and volatile organic pollutants in street-vended foods sourced from three selected locations in Lagos State, Nigeria, to ascertain their safety level. Food toxicity results from contamination of foods with heavy metals, its bioaccumulation and biomagnifications in the food chain. The study was carried out using complete randomization design and Cluster sampling technique to source vended street foods from three locations (Marina, Yaba and Apapa). The eight Food products studied were roasted (plantain, fish, yam, corn), suya meat, meat pie, egg roll and doughnuts. Lead, Cadmium, Copper, Mercury, Iron, Zinc and organic pollutants in Foods and particulate matter in Environment were examined. Heavy metals detected in vended street foods from Marina, Yaba and Apapa Lagos were; iron, copper, lead and zinc, at level ranging from 0.14 mg/kg–2.80 mg/kg, 0.08 mg/kg – 0.27 mg/kg, 0.01 mg/kg – 0.18 mg/kg, and 0.01 mg/kg – 0.04 mg/kg, respectively. Mercury and Cadmium were below detectable limit. Significantly (P<0.05) higher iron presence of 2.80 mg/kg and 1.99mg/kg were respectively, noticed in suya from Apapa and roasted fish also from Apapa. Significantly (P<0.05) higher lead (Pb) content of 0.18 mg/kg was observed in dough nut from Yaba, however, roasted plantain, roasted fish and meat pie all sourced from Yaba gave significantly (P<0.05) lower lead content of 0.01 mg/kg. The Zinc content of roasted fish, suya and egg roll sourced from Marina, Yaba and Apapa were all significantly (P<0.05) difference, with particular respect to food type. Higher iron content of 2.80 mg/kg was noticed in suya from Apapa. Volatile organic compounds (TPH, PAHs, Phenol) were observed to be below detectable limit (<0.001 mg/kg) in all the vended street food samples. Particulate matter in air; SPM, PM1, PM2.5, PM10 and VOCs ranged from 0.34 – 0.84 mg/m3, 0.32 – 0.56 mg/m3, 0.32 – 0.68 mg/m3, 0.33 – 0.79 mg/m3 and <0.001 – 0.24 mg/m3, respectively. PM1 and PM25 from the three locations were not statistically significant (P>0.05). One major source of pollution for most vended street foods is vehicular emission. All the vended food samples had lead (Pb) content above the CODEX permissible limit of 0.01 mg/kg. The presence of high lead content in Vended Street food is a major source of occupational health hazards. Further work on the comprehensive outdoor air quality and street food quality in Lagos State to serve as a protection to public health and consumer interest is highly recommended.

Critical Evaluation of Types and Classification of Pesticides Used on Tomatoes Grown in Mwea Irrigation Scheme, Kirinyaga County, Kenya

Momanyi, Violet Nakhungu, N. Keraka, Margaret, A. Abong’o, Deborah, N. Warutere, Peterson

Current Research in Agricultural and Food Science Vol. 4, 18 February 2021, Page 125-141

This study evaluated 403 farmers from the open fields and greenhouses in Mwea Irrigation Scheme on the types and classification of pesticides farmers use to control pests and diseases on tomatoes, in July 2017 to June 2018. Production of enough food to meet consumer demand on quality and quantity are almost impossible without the use of pesticides in developed and developing countries. Five greenhouse tomato farmers were purposively selected while sample size of 196 open field farmers was calculated using Fisher’s formula. Cross-Sectional design that used a structured questionnaire and focus group discussions was used to collect data from 201 farmers in Gathingiri, Tebere, Kangai, Wamumu, Murinduko, Nyangati, Mutithi and Thiba wards. Accuracy of data was ensured by pre-testing the questionnaire on tomato farmers from a neighbouring Maragua sub-county. Errors were corrected and omissions added to the questionnaire. Descriptive statistics was carried out for frequencies, percentages, means, standard errors, variance and data subjected to T-test at 95% Confidence Interval to determine significant differences between variables. Results from interviews revealed that farmers applied 57 and 12 pesticides under different trade names on tomatoes in the open fields and greenhouses respectively. Pyrethroids, carbamates, nicotinoids, organophosphates, and organochlorines were applied on tomatoes among others. The 20 and 12 pesticides mainly used in open fields and greenhouses were WHO Class II (60%) and WHO Class III (42%), respectively. Farmers heavily relied on different types of pesticides to control a wide range of major pests and diseases such as Tuta absoluta and blight respectively. Chlorantraniliprole and mancozeb are the main pesticides used on tomatoes. Most pesticides, WHO toxic class II including pyrethroids and carbamates should be used following the manufacturers’ recommendations to prevent human health risks. Compliance with pesticide use standards will prevent occurrence of residues on tomatoes and other vegetables and thus minimize their effects on human health.  Training and awareness by the Ministry of agriculture, Kirinyanga County government are needed on use of less toxic pesticides equally effective in controlling pests and diseases, such as WHO  classes III and IV and bio-pesticides that have minimal negative effects on human  health.

Unleavened bread or Chapathis were made with partial replacement of wheat flour with date paste and soy flour with different variations. The dates and soy flour were added to the wheat flour at levels of 30%, 50%, 60% and 35%, 25%, 20% respectively. Mineral, and vitamin content of dates incorporated chapathis increased remarkably and energy decreased from 341 kcal in control to 241 kcal in incorporated chapathis. They were nutritionally superior in iron by more than 2 mg and protein by more than 5 g than control in the different variants. The incorporated chapathis were subjected to sensory analysis by a panel of 100 members using the 9 point hedonic scale. With a few exceptions of soy flour incorporated chapathis acceptability in terms of sensory attributes and nutritional quality suggests the suitability of the dates incorporated chapathis. The addition of date paste and soy flour resulted in significant improvement in protein, and mineral contents in wheat-date paste, soy flour blends.