Journal of Food Quality and Hazards Control
Volume:10 Issue: 2, Jun 2023

Edible insects are rich in protein, amino acids, fat, vitamins, and trace elements. However, they are the potential carriers of toxicants, allergenic substances, anti-nutrients, and pathogens. The present study aims to determine the proximate and nutritional, fatty acid, metal composition, and microbial load of palm weevil larvae (Rhynchophorus phoenicis Fabricius, (Coleoptera: Curculionidae)), an insect species commonly consumed in Nigeria.

Twenty five R. phoenicis were randomly collected in April, 2021 from different local farms. The insects were exterminated by freezing and thereafter defrosted at room temperature in the laboratory; with the exception of the samples for moisture analysis, they were oven dried to a constant weight at around 65 °C for 24 h, grounded, and analyzed for proximate content, fatty acids, metals, and microbial load following standard laboratory procedures.

The results show that R. phoenicis contained 45.60% crude fat, 15.79% crude fiber, and 5.25% crude protein by weight. Linoleic acid, oleic acid, and palmitic acid made up most of the fatty acid concentrations at 54.13, 23.86, and 14.19%, respectively. Iron (Fe) content was the highest metal (4.923 ppm), followed by manganese (Mn; 2.767 ppm) and zinc (Zn; 1.04 ppm). The isolated microorganisms were mold and yeast (5×10-5 Colony Forming Unit (CFU)/g), Staphylococcus sp. (33×10-5 CFU/g), and Micrococcus/Bacillus substilis sp. (5×10-5 CFU/g).

The high nutritional composition present in R. phoenicis evaluated in this study, compared to the dietary protein value obtained from other animal food sources, suggests the need for their adoption as animal protein and essential fatty acid sources in human diets.

With regard to health-threatening infections, Staphylococcus aureus is the leading cause of polymorphic infections varying from a banal tegumentary infection to numerous lethal illnesses. Furthermore, it is the third commonest bacterial cause of food-borne infections worldwide.This study aimed to investigate contamination, prevalence, and antibiotic resistance of S. aureus isolated from several widely marketed food products (raw and processed) in the region of Oran, Algeria.

A total of 350 food samples including prepared meals (n=110), dairy products (n=42), pastry (n=78), meat and its derivatives (n=97), and other commercially available foods (egg products, sweets, and sauces) (n=23) have been randomly purchased from diverse sale outlets and screened for S. aureus strains during the period from July 2021 to September 2022. The isolation and identication of S. aureus bacteria were preformed using conventional culture and biochemical tests such as catalase, coagulase, and DNase tests. Furthermore, the strains were screened for their resistance to five different antimicrobial drugs using the agar diffusion method.

The overall prevalence of S. aureus determined among the collecteded samples was 31.14% (109/350), where, pastry products harbored the highest contamination rate (43.59%), and prepared meals, the lowest contamination rate (18.18%). The strains presented a high level of resistance (58.71-39.44%) for gentamycin and oxacilin, respectively. Moreover, the lowest level of resistance was observed against erythromycin 16.51%, and about 83% of strains presented multidrug resistance.

The significative prevalence and the high level of multidrug resistant of S. aureus highlights the seriousness to improve food contamination prevention programs and underlines that good hygiene practices at sale outlets has a major impact on the sanitary quality of commercialized food products.

Contamination of food by microorganisms from the processing to the consumption stage has become a major health concern in this era, where a better approach for the elongation of food shelf life is explored. This study aims to evaluate the microbial and fungal contamination of different dried cocoyam flakes during storage.

The cocoyam (Colocasia esculenta) samples were properly cooked, peeled, sliced into thin shapes, and dried to constant weights. The drying methods used were sun, hot-air oven, and Nigerian Stored Products Research Institute (NSPRI) multi-crop dryer; samples were divided into three groups A, B, and C, respectively, and the dried samples were stored for three months. Moisture Content (MC) was conducted using the standard method. Colonial morphology, Gram staining, and biochemical test were used to identify and characterize microorganisms. Statistical analyses were performed using SPSS 20.0.

There was a significant increase in the MC of all the samples after the storage duration. The sun-dried sample had the highest MC (13.60%) while the oven-dried sample had the lowest MC (10.82%). The sun-dried samples had the highest viable bacteria count (7.2×105 Colony Forming Unit (CFU)/g) and the oven-dried sample had the lowest count (5.1×105 CFU/g). The four bacterial isolates identified were Bacillus subtilis, Pseudomonas aeruginosa, Micrococcus luteus, and Staphylococcus aureus. The heterotrophic fungal number was the highest (0.5×103 CFU/g) regarding sun-dried samples, whereas the samples dried with NSPRI multi-crop dryer and oven-dried samples had the same value (0.3×103 CFU/g). Aspergillus flavus, A. niger, Rhizopus, Penicillium, and Mucor were isolated from the samples. Rhyzopertha dominica was identified in sun-dried samples.

The increase of MC and the nature of the storage material may have contributed to high bacterial and fungal counts of stored dried cocoyam flakes, especially sun-dried ones, thereby exposing consumers to potential health risks.

Sesame cake extract is the by-product left behind after sesame oil extraction including almost 30% of protein and phytochemicals, which possess free radical scavenging activity. In this study, antioxidant activity of sesame cake extract on the quality of refined sesame oil has been evaluated under 60 ◦C during storage time.

After extraction of ethanolic extract, sesame oil was treated with concentrations of 0, 20, 50, and 100 ppm of sesame cake extract and stored at 60 °C for 30 days. The sesame cake and refined sesame oil were taken from Yazd province and extracted with ethanol. Total Phenolic Content (TPC) (at the beginning of the study) and 2,2-Diphenyl-1-Picrylhydrazyl (DPPH) radical scavenging capacity (30 days after inoculation) were evaluated. The antioxidant activity of various dilution of the Sesame Cake Ethanol Extract (SCEE) was assessed by measuring, rancimat analysis, Peroxide Value (PV), and Thiobarbituric Acid (TBA) assay, and also evaluation of the TPC. Butylated Hydroxyanisole (BHA) as a synthetic antioxidant was used. Experiments were carried out in triplicates and data were processed with ANOVA test by SPSS Software.

Radical-scavenging capabilities of SCEE were significantly larger than the group without SCEE but it was detected to be lower than the BHA group. The induction period (IP) of sesame oil raised as the concentration of SCEE increased. All concentrations of SCEE were able to decline the PV and TBA value. Also, the group containing BHA and 100 μg/ml of SCEE significantly showed the same antioxidant activity (p≤0.05).

The SCEE as a natural substance can prevent lipid oxidation of the refined sesame oil like synthetic antioxidants.

Spirulina platensis (S. platensis) is a microalga. It has high levels of protein, essential amino acids, fatty acids, high concentrations of vitamins, and minerals. This study aims to evaluate the effect of adding S. platensis on the quality characteristics of camel burger.

Spirulina was added at different levels (0.5, 1, and 1.5%) to the formulation of camel burger and its effect was studied on fatty acids profile, amino acids content, lipid oxidation, physical, and microbiological quality during frozen storage at -20 ºC for 90 days. Data were analyzed using statistical analysis system (SAS, 2000).

Significant changes (p<0.05) were found in fatty acids profile and amino acids content of formulated camel burger. The highest fat retention and moisture retention was found in camel burger formulated with Spirulina. PH value increased as the level of Spirulina increased. Fresh camel burger formulated with Spirulina significantly (p<0.05) reduced color parameters (L*, a*, and b*) more than that of the control burger. No significant differences (p>0.05) were found in cooking loss, shear force, and microbiological profile of fresh camel burger treatments.

Addition of different levels of Spirulina in the formulation of camel burger improved fatty acids and amino acids profile, increased water retention and fat retention, and delayed lipid oxidation during frozen storage, without any negative effects on shear force values, cooking loss, and microbiological quality.

Given that controlling Listeria contamination is very important in food chain system, the knowledge of their prevalence in food is very important. Therefore, this study aims to examine the prevalence of important Listeria species in various food types and evaluate serotype distribution, as well as the study of the virulence factors of L. monocytogenes.

During July 2018 and January 2020, 900 food samples were collected in the North of Iran, including beef, chicken, fish, shrimp, milk and yogurt, green vegetables, mixed vegetable salad, Olivier salad, and cottage cheese. After isolation and identification steps, each bacterial DNA was extracted. Then, using specific primers, species, serotypes, and virulence genes of Listeria isolates were evaluated in the samples by Polymerase Chain Reaction (PCR) method.

The test results of 136 samples (15.1%) were positive for Listeria spp. and the most contaminated food was beef (35%) followed by chicken (29%) and green vegetables (23%). The most isolated Listeria spp. was L. monocytogenes and L. ivanovii. Among L. monocytogenes isolates, the dominant serogroups were 1/2a and 4b; furthermore, all of the isolates of this species harbored four virulence genes, including hlyA, plc, iap, and actA.

These reports highlighted the importance of food safety in various food products, particularly raw meats and vegetables. Moreover, contamination of healthy foods such as fish and vegetables with Listeria is an indicator of public health.