2023

The present study was conducted to determine the pre harvest interval of chlorpyrifos and quinalphos in hyacinth bean in the agro-climatic condition of Bangladesh to ensure safe food for the consumers. A supervised field trial was undertaken in the experimental field of Entomology Division of BARI, Gazipur and the selected pesticides (chlorpyrifos and quinalphos) were sprayed with the recommended dose (1.5 ml/L of water). The samples were collected at 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 and 12 days after spray (DAS). The collected samples were extracted and cleaned up using modified Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) extraction technique and the residues were determined by Gas Chromatography (GC) coupled with Flame Thermionic Detector (FTD). The residue of chlorpyrifos was detected upto 8 DAS (0.027 mg/Kg) at a level above the EU-MRL, and at 9 DAS, no residue was detected. So, the PHI for chlorpyrifos was set at 9 DAS. On the other hand, the residue of quinalphos was detected upto 9 DAS, of which the level of residue was above EU-MRL upto 8 DAS (0.02 mg/kg). At 9 DAS, the quinalphos residue remained 0.009 mg/Kg, which was below EU-MRL. So, the PHI for quinalphos was set at 9 DAS.

The application of fipronil for the control of insect pests of different crops is increasing day by day. As a result, it is inevitable to remain residues of fipronil in the treated crops. Therefore, it is an urgent need to develop analytical method for the quantification of fipronil. Keeping this view, this study was initiated to develop and optimize an analytical method for the quantification of fipronil residue using Gas Chromatography triple quadrupole Mass Spectrometry (GC-MS/MS). A number of experiments has been conducted to select the parent ion and precusor ion and based on these findings, the analytical method for the determination of fipronil residue using GC-MS/MS was developed. The linearity of the developed analytical method was very good and it was 0.999. The optimization of MS/MS parameters has been done properly through direct injection of 100 ug/L standard solution of fipronil.

Majority of the people in Bangladesh are still not aware about the health hazards of antibiotic residues. In this research, farmer’s awareness has been investigated by a questionnaire in different poultry farms, retail sellers and poultry markets and spread out the knowledge of public health hazards of antibiotics residues. Poultry farmers were found well educated about health hazards of antibiotic residues and aware about the judicial use of antibiotics before selling the poultry for human consumptions. During this survey, sufficient samples (thigh muscle, breast muscle, liver etc., n=100) were collected from different poultry farms, retail sellers and poultry markets. Randomly 50 livers, 50 thigh muscle and 50 breast muscle samples respectively were evaluated by TLC analysis. Out of 50 samples for each 2 liver, 2 breast muscle and 2 thigh muscle samples were found positive for Amoxicillin antibiotic; 5 liver, 3 breast muscle and 3 thigh muscle samples were found positive for Ciprofloxacin; 3 liver, 3 breast muscle and 3 thigh muscle samples were found positive for Cefalexin; 2 liver, 2 breast muscle and 2 thigh muscle samples were found positive for Enrofloxacin; 4 liver, 2 breast muscle and 2 thigh muscle samples were found positive for Oxytetracycline. Gentamicin and Neomycin were found negative for any samples. Further investigation was done in indoor discriminate and indiscriminate use of antibiotics (Cefalexin) in broilers. Indoor experiment was investigated in poultry chicks. Day old chicks were collected and reared up to 30 days. On day 14^th, the chicks were randomly divided into three groups namely control group (n=10), discriminate antibiotic group (n=10) and indiscriminate antibiotic group (n=10). Discriminate antibiotic group was treated with antibiotics (Cefalexin) for one week followed by withdrawal period for one week, whereas; indiscriminate antibiotic group was treated with antibiotic (Cefalexin) for two weeks until the day of sacrifice. Liver, thigh muscle and breast muscle samples were collected and evaluated by TLC method. Control and discriminate antibiotics birds were found negative for any antibiotics residues. On the other hand, ten liver samples, eight thigh muscles and eight breast muscles were found positive for Cefalexin in indiscriminate group. Indiscriminate uses of antibiotic indicated that antibiotic residue mitigation for human safe meat production depends on withdrawal period and farmers awareness. Therefore, poultry treated with antibiotics are required for specific withdrawal period until all residues are depleted to safe levels before human consumption.

Nutrition style and preference is one of the priority issues on which health-protective and disease-preventive measures are taken for a healthy life. For this purpose, functional foods that show beneficial effects on health as well as the nutrional value have become increasingly important. Among functional foods, probiotic foods which are produced by using probiotic microorganisms constitute the most important and interesting group. In order for a probiotic food to show its beneficial effect on health, it must contain minumum 10⁶-10⁷ cfu of microorganisms in grams or mililitres during its shelf life. Milk and dairy products are the foods in which probiotics are commonly used. However, the development of probiotic dairy products seems to focus on fermented milk (e.g., kefir) and yoghurt. Cheese has more advantages over fermented milk or yoghurts as a carrier food to intestinal environment due to the fact that it has a low oxygen content, high pH, high fat content and a firmer texture. In this review, the general characteristics of functional foods and probiotics are explained and evaluations are made using the potential of cheese as a probiotic carrier product. This study can shed light on new studies on the use of cheese as a functional probiotic food.

The investigation was carried out through an experiment to examine how various quantities of mint leaves affect the production performance, carcass characteristics, immune parameters, and caecal microbial load of commercial broiler. A total of 225 one-day-old chicks of “Lohman Meat (Indian River)” strain having 43.00±0.66 g average body weight was divided into five investigational groups with three replications of 15 chicks each. The treatments were T₀= control (basal feed), T₁=basal feed + antibiotic, T₂=basal feed + 1.0% mint leaf, T₃=basal feed + 1.5% mint leaf and T₄=basal feed + 2.0% mint leaf. Weekly body weight, feed intake and FCR were recorded during the investigation stage and carcass characteristics, immune parameters and caecal microbial count were also studied after. The average live weight and body weight gain were notably increased in the 2.0% mint leaf treated group than the other groups. Significant improved FCR was perceived in birds fed with 2.0% mint leaf with basal diet. The results showed that, broilers feeding with 2.0% mint leaf have significant effects (P<0.05) on the thigh, wing, back, liver, neck, heart, gizzard intestine, spleen and bursa while it appeared insignificant (P>0.05) on dressing percentage, breast and drumstick. Significant (P<0.05) difference was observed for immune parameters (WBC, lymphocyte, granulocyte) in mint leaf treated groups than in the control which signifies better immunity in mint leaf treated groups. Addition of 2.0% mint leaf in the broiler diet results in a significant (P>0.05) lower amount of Escherichia coli and Salmonella counts than in the control group. This study concluded that, the addition of mint leaf resulted in improved growth performance, carcass yields, immunity and lower pathogenic microbes in broiler chickens. Therefore, the use of 2.0% of mint leaf in the diets of broilers has affirmative effects on their production performance and as an antibiotic alternative in broiler production can be recommended.

Ready-to-eat (RTE) foods are widely used at home, restaurants, and during festivals in Bangladesh. Foodborne illness is very common and mainly caused by the consumption of contaminated street foods. It is very important to investigate possible microbial contamination in RTE foods. The present study was conducted to isolate and characterize bacterial pathogens from RTE foods and to know the antimicrobial susceptibility patterns of the isolated bacteria. A total of 60 RTE food samples for instance, burger, fuchka, fried rice, and chicken grill (fifteen samples each) were collected aseptically from street food vendors of different locations at Dinajpur. Bacteria were isolated and identified based on cultural, staining, and biochemical properties following standard microbiological methods. Among four types of tested RTE foods, 100% comprised of bacterial contamination. The total viable count (TVC) in burger ranged from 4.2×10³ to 1.6×10⁴; in fuchka ranged from 4.5×10³ to 2.5×10⁴; in fried rice ranged from 4.7×10³ to 1.5×10⁴; and in chicken grill ranged from 4.9×10³ to 1.6×10⁴. Among the tested RTE food samples, Escherichia coli 6 (10%), Salmonella spp. 7 (11.66%), and Klebsiella spp. 2 (3.33%) were isolated. Antibiogram studies revealed that Streptomycin, Gentamicin, Tetracycline, and Neomycin were found sensitive for both of the isolated E. coli and Klebsiella spp. On the other hand, Streptomycin, Azithromycin, Gentamicin, Tetracycline, and Neomycin were found sensitive for Salmonella spp. Vancomycin, Penicillin, Erythromycin, Amoxicillin, and Ampicillin were found resistant for E. coli and Salmonella spp. isolates, whereas Vancomycin, Azithromycin, Penicillin, Erythromycin, Amoxicillin, and Ampicillin were found resistant for Klebsiella spp. The results of this study suggested that RTE foods should be manufactured under good hygienic practices.