Ten kilogram of high-quality beef was collected from a local abattoir in Delta State, Nigeria on August 18th, 2023. The samples were placed in sterilized, ice-cooled plastic containers, and promptly transported to the microbiology laboratory for analysis at Delta State University of Science and Technology, Ozoro, Nigeria, and Docchy analytical laboratories and environmental services limited, Nigeria.

The HPLC system, Plate Count Agar (PCA), Salmonella-Shigella (SS) agar, Baird-Parker Agar (BPA), Potato Dextrose Agar (PAD), methanol, helium (99% purity) and other solvents used for the analyses were manufactured by Thermo Fisher Scientific Inc. USA. All the materials and equipment used were sterilized to prevent cross-contamination. All measurements were conducted in triplicate, and the relative standard deviation was less than 4% across the measurements.

The onion bulb peels and plantain peels were sorted to eliminate contaminants, sun-dried and then ground into powder form using the laboratory mill (Ultra Centrifugal Mill ZM 300, produced by Retsch GmbH Ltd. Germany). Thereafter, the onion bulbs peels extract (OPE) and plantain peels extract (PPE) were prepared in accordance with standard procedures, through cold maceration approach using ethanol as the carrier solvent. 100 g of the pulverized onions and plantain peels wastes were soaked in 1 L of ethanol for four days, and filtered using a 0.22 μm membrane. Thereafter, the filtrate was evaporated (concentrated) utilizing a rotary evaporator (model Rotavapor R-300, manufactured by Thermo Fisher Scientific Inc. America) at 45°C, to evaporate the excess methanol leaving the onion bulbs peels extract (OPE) and plantain peels extract (PPE) behind.

Additionally, the onion bulbs peels oil (OPO) and plantain peels oil (PPO), were extracted through the solvent extraction technique, and using n-hexane as the solvent. 200 g of the sieved plants materials were poured into a Soxhlet extractor, containing 600 mL of n-hexane. The mixture was subjected to temperature of 67°C for 6 h, ensuring constant n-hexane cycling, and the high quality oil obtained was collected into a cylinder (Ashraf et al., 2025). Thereafter, the excess solvent in the EO was evaporated at 40°C, and dried with anhydrous sodium sulfate, and kept in cool dark environment.

The following treatment plans as presented in Table 1, was used to achieve the goals of this research. The experimental design was generated by Design Expert Software (Version 23.1), through CCD and considering these factors: storage duration, treatment concentration, treatment hybridization, and their interactions. Additionally, the PI analysis was employed to confirm (validate) the experiment results.

The optimization will involve all the treatments of T0–T9, and storage durations of 0–10 weeks. The extract and oil concentrations used as treatments in this research, were selected based on the range of concentrations previously applied by other authors (Kunová et al., 2021; Kačániová et al., 2024). This approach controls existing research to optimize their effectiveness and public safety in the stored beef quality control.

Approximately 30 g of each meat sample was diced into 0.05 m x 0.05 m pieces. The cook-dried method was adopted for Treatments 1, 3, 5, 6, 7, and 8. For treatments involving plant extract application (Treatments 1 and 3), the meat was diced into 0.05 m × 0.05 m pieces, steamed with the appropriate extract concentration for 20 min, and then immediately cooled to room temperature. Also, for the treatments involving hybridized EO and extract application (Treatments 5, 6, 7, and 8), the meat pieces, already prepared and inoculated with the extract, were then sprayed with the appropriate volume of oil. The data indicated that, for treatments involving only oil application (Treatments 2, 4, and 9), the oil-dried method was utilized: the meat cubes were blanched for 20 min, cooled and coated with the essential oils. Afterward, all the prepared meat samples were dried in a laboratory oven at 105°C to a moisture content of approximately 7%.

The dried meat samples were stored in a dry ambient environment (30 ± 5°C, 80 ± 11% RH), covered with netting to protect them from direct insect and pest exposure. This is similar to traditional storage practices commonly used in markets and households across many developing and underdeveloped nations. The nutritional quality of the meat and microbial analyses were conducted every 2 weeks over a 10-week period.

The laboratory data evaluated using Analysis of Variance (ANOVA), by utilizing the SPSS software (version 20.0) to establish the impact of the treatments on the meat quality and stability. Also the differences between the means were investigated using the Duncan’s Multiple Range Test (DMRT), at 5% significance level (p ≤ 0.5). Furthermore, descriptive statistic was conducted on the data and the findings presented in tables, to provide a clear and organized summary of the results. The experiments were conducted in triplicate to ensure consistency.

The results of the oils and extracts phytochemical properties were presented in Table 2. The results indicated that in the OPE and OPO samples, the most prevalent phytochemicals were Naringenin, Quercetin, Artemetin, Baicalin, and Naringin. In contrast, the PPE and PPO samples contained Epicatechin, Naringenin, Robinetin, Ellagic acid, Baicalin, Lunamarin, and Tangeretin as their primary phytochemicals. The results illustrated that out of the parameters measured, the plants extracts generally had higher concentration of phytochemicals than the plants oils, which is in conformity with earlier reports on bioactive compounds availability in plants derivatives (Umaru et al., 2019). The high phytochemical concentrations in the extracts and oils contribute to their effectiveness in inhibiting microbial growth. This makes the OPE, PPE, OPO and PPO viable options for extending the shelf life of dried meat products. Apigenin, Ellagic acid, Naringenin, Cinnamic acid, and Resveratrol demonstrate antimicrobial properties against a wide range of bacteria and fungi, including Staphylococcus aureus, Escherichia coli, Candida albicans, Salmonella spp., and several yeast species (Kačániová et al., 2024; Mandal and Domb, 2024).

The results of the vitamins and protein levels of the beef before its preservation are presented in Table 3. It was noted that the Vitamin B1, B2, B3, B5 B9, and B12 of the raw beef was 0.051, 0.018, 0.015, 0.019, 0.052 and 0.029 mg/kg, respectively, while the total vitamin E and protein contents were 1.87 mg/kg and 52.73%, respectively. This is an indication that the raw meat flesh was rich in vitamins B and E; making beef a beneficial component of balanced diet. Vitamins and protein play crucial roles in energy production, nervous system functionality, and fetus development (Kačániová et al., 2024).

The microbiology results for the meat samples are presented in Tables 5, 6. The results highlight that both the storage duration and treatment plan, have significant effect on dried meat samples microbial growth (p ≤ 0.05). These findings confirmed earlier reports of these scholars (Gál et al., 2023; Ivane et al., 2024; Djenane et al., 2024), stating that EOs and extracts treatments, substantially retard microorganisms’ growth and survival. Notably, at the end of the experimental duration (tenth week), the total viable bacterial counts (TVBC) for the T1 to T9 samples were 167, 125, 142, 121, 86, 92, 55, 43, and 27 cfu/g, respectively; the Staphylococcus aureus populations in the T1 to T9 treated meat specimens were 25.67, 13.00, 21.67, 19.33, 12.00, 13.00, 7.67, 6.33 and 3.33 cfu/g, respectively; the Salmonella spp. counts in the T1 to T9 meat samples were 19.67, 14.00, 21.67, 16.33, 13.67, 17.00, 8.67, 6.00 and 4.00 cfu/g, respectively. In terms of the fungal contamination, the TFC recorded in the T1 – T9 samples were 134, 115, 106, 93, 92, 88, 52, 60 and 56 cfu/g, respectively; the afB1values among the treated samples ranged from 2.97 to 11.43 ppb, while the afB2 load varied from 2.60 to 10.17 ppb.

Generally, the mean samples treated with essential oils demonstrated better preservative attributes, than those treated with the extracts, similar to the findings of Ashraf et al. (2025). This study’s outcomes depicted that meat samples preserved using hybridized treatments (T3–T9), exhibited a longer shelf life and stability, compared to those samples preserved with single treatments (T1 and T2). The hybridization of onion waste and plantain peel EOs at a concentration of 0.5% each (T9), demonstrated effective control over bacterial and fungal performance, particularly against afB1 and afB2. This could be attributed to the broad-spectrum antimicrobial properties of the oils (Alirezalu et al., 2019; Kačániová et al., 2024). The lower Staphylococcus aureus, Salmonella spp., and aflatoxins populations, observed in T9 meat sample can be attributed to the consistently low moisture content, this specimen maintained throughout the storage period. Lower moisture levels create an inhospitable environment, for microbial growth and toxin production (Uguru et al., 2023; Kačániová et al., 2024). The statistical analysis revealed no significant difference in the populations of fungi, afB1, and afB2 between Weeks 0 and 2 (p ≤ 0.05), an indication that the fungal growth and aflatoxins has very poor functionality during the initial storage period, which can be linked to the immediate effect of the organic additives (Beya et al., 2021).

The zero microbial count recorded at the first storage day, affirmed that the meat primarily picked up pathogenic microorganisms during storage, through contaminated environment and atmospheric depositions (Pleadin et al., 2021; Uguru et al., 2024’ Djenane et al., 2024). Similarly, the rapid microbial growth observed after sixth week storage period, can be associated with the substantial decline in the meat’s antimicrobial and antioxidant properties over time; hence, creating favorable conditions for pathogen proliferation (Punia et al., 2021). Similar findings were documented by Mojaddar et al. (2018), when sumac (Rhus coriaria) extract was able to inhibit bacteria and fungi survivability. According to Lupia et al. (2024), due to the volatile nature of essential oils, they have greater ability of penetrating and disrupting microbial cellular structures, and metabolic functions, leading to enhance antimicrobial actions.

This experimental outcome aligned with the previous reports of these authors (Barbosa et al., 2009; Yuan and Yuk, 2018; Petcu et al., 2023; Kačániová et al., 2024; Ashraf et al., 2025), which stated that EOs and extracts derived from edible portions of peppermint (Mentha piperita L), lemongrass (Cymbopogon citratus), ginger (Zingiber officinale Roscoe), clove (Syzygium aromaticum) and Syzygium antisepticum, successfully retarded Salmonella spp., Staphylococcus aureus and Coliform reproduction in chicken meat stored inside the refrigeration for 12 days. This affirms that EOs and extracts produced from agricultural waste materials, rather than the comestible plant parts, can be effectively utilized for meat preservation, thereby combating food insecurity problem, as well as waste valorization.

The fungal analysis depicted that Aflatoxins B1 (afB1) and Aflatoxins (afB2) presence were relatively small in T5, T8, and T9 samples, which can be linked to anti aflatoxins properties (bioactive compounds) of the extract and oil (Algammal et al., 2021; Baker, 2023). Specifically, the study revealed that the optimization and treatment combination provided by the CCD model revealed that, plants waste materials can be processed into EO and extract, with the capability of retarding aflatoxins formation within permissible limits for human safety, established by the European Council (EU) and World Health Organization (WHO). The WHO and European council approved maximum aflatoxins acceptable level of 10 ppb and 4 ppb, respectively, for food items (Bradford et al., 2020; Uguru et al., 2023). These outcomes underscore the importance of further research into pharmaceutical (antimicrobial) impact of agricultural waste materials, thereby ratifying the efficacy of the natural antioxidants as bio-preservation approach.

The results of the modeling and optimization of the meat storability, with respect to the treatment plans, were presented in Tables 7–9 and Supplementary Tables S1–S4. Table 7 displays the microbial results of the meat samples during storage for the 31 runs (based on Table 1), through the combination of these factors: treatment and storage duration. Table 8 shows the ANOVA values for response model and parameters. Staphylococcus spp., Salmonella spp. Aflatoxins B1 and B2 classified in the treated meat samples (Table 7) were active pathogenic microbes, which have been linked to serious foodborne diseases (Bradford et al., 2020; Petcu et al., 2023; Kačániová et al., 2024). The data shown that in experimental runs 1, 2, 5, 9, 10, 13, 16, and 27, regardless of the response investigated, the contamination level was 0.000 (0%), which is an indication that the particular treatment successfully inhibited the pathogen persistence, at that exact storage period. Furthermore, the optimal response surface result (Table 7) depicts that, the untreated experimental batch (T0), had the worst microbial prevalence and toxins formation; while T8 and T9 units were very persuasive in microbial suppression, further buttressing the worth of the treatment agents in meat preservation (Alirezalu et al., 2019; Ashraf et al., 2025). Based on the optimization outcomes, T9 had the optimal results, yielding almost 0% microbial growth and toxin formation after several storage weeks; though T6–T8 recorded appreciable anti- pathogenic actions, and T1–T3 demonstrated moderate antimicrobial management behaviors. Fascinatingly, the reliability evaluation outcomes performed with runs 19, 10, 25, and 26, affirmed the optimization model constancy.

Specifically, Supplementary Tables S1–S4 displayed the following - optimization model selection for responses, response model equations used for optimization, response models statistic and optimization solutions, respectively. The information provided by Supplementary Table S4 (optimization solutions) revealed that, the minimal values solutions can be achieved in serial numbers 5, 14, 19, and 23. This sustained the fact that the distill water used for this research, was devoid of microbial pollution. Additionally, Supplementary Table S4 pointed out that, some of the natural agents used for the meat treatment have traces of microbial contamination, which can be attributed to their mode of preparation and cross-contamination effects. Table 9 shows the constrain use for this study’s optimization action. The values in Table 9 provide safe and suitable boundaries, for the parameters investigated in this work, primarily by identifying the combinations–treatments and storage period, which will yield minimal pathogenic contamination. Also, the importance level (3) signifies moderate primacy meant for each restraint. These conditions facilitate the attainment of reliable storage and treatment results.

Furthermore, the results of the interactions between the responses, storage time and treatment plan are presented in Figures 1–6. The models and optimization Figures revealed that Treatments 5, 8, and 9 had the best inhibiting power against TBC survival; while T7 and T8 exhibited the optimal Staphylococcus and Salmonella spp. survival inhibition. Similarly, the results indicated that T8 and T9 effectively retard fungal performance within the specimens; while T6, T8 and T9, exhibited high efficiency against afB1 and afB2 survival. Regarding the stability and storability of the meat products, the Figures 5, 6 revealed the reproduction tracks of the microbial within the preserved meat samples, as the storage period progresses from week 0 to week 10. Generally, there was sharp increment in pathogenic microorganism’s performance, in the T0, T1, T2, T3, and T4 specimens, as storage progresses; which indicates that these treatments has poor preservation qualities. Also, the gentle slope curves, as reflected by T7, T8, and T9, are a sign of good microbial steadiness, irrespective of the microorganism examined in this research. Based on the treatments optimization outcomes, samples treated with T9 show the optimal microbial inhibition potential; though samples treated with Treatments 5 to 8, display good effectiveness in hindering microbial growth. Specifically, samples T5 to T9 can be considered to be more shelf-stable, due to the higher resistivity to microbial invasion, which can lead to food spoilage. The prediction and optimization outcomes established that, the treatments have different antimicrobial potencies. Therefore, some treatments were able to retard microbial resilience significantly, when compared to others, signifying superior microbial control. Conversely, the rapid surge in microbial growth in T0, recorded across microorganisms evaluated, suggested that the untreated meat product is more vulnerable to microbial contamination during storage.

The result of the confirmation test preformed on the model is presented in Table 10. Validation test is necessary in optimization process, as it helps to authenticate the consistency and reproducibility of the outcomes documented from the experimental procedures (Teja et al., 2023); hence, boosting the assurance level of the optimized final results. Table 10 establishes that all the authentication experimental outcomes, were within the 95% prediction ranges, portraying substantial microbial growth inhibition, and high functionality of the model used. Categorically, it can be seen that the system has high predictive precision, and does not require further improvement, since the microbial burden documented by the validation exercise, did not significantly surpassed the model expectations.