Effect of absorbent pad containing chamomile essential oil on the quality of Cyprinus carpio fillets inoculated with Staphylococcus aureus during refrigerated storage

Effect of absorbent pad containing chamomile essential oil on the quality of common carp fillets inoculated with Staphylococcus aureus during refrigerated storage
Seyed Mohammad Heydari1, Ebrahim Alizadeh Doughikollaee1, Mohsen Shahriari Moghadam*2, Mostafa Yousef Elahi3
1Department of Fisheries, Faculty of Natural Resources, University of Zabol, Zabol, Iran.
2Department of Environmental Science, Faculty of Natural Resources, University of Zabol, Zabol, Iran.
3Department of Animal Science, Faculty of Agriculture, University of Zabol, Zabol, Iran.
*Corresponding author: Mohsen.shahriari@uoz.ac.ir
Introduction
Food poisoning remains a critical global challenge in food production, prompting producers to implement strategies to prevent contamination throughout production, storage and distribution. Despite the application of various preservation methods, there is a increacing interest in natural antibacterial agents such as plant-derived essential oils for food preservation (Huang et al., 2018). Essential oils are recognized for their diverse biological properties, including antioxidant and antimicrobial activities, attributed to their bioactive compounds. Incorporating these compounds into food systems aligns with the rising demand for clean-label products (Kunová et al., 2022).
During cold storage, the water-holding capacity of meat muscle tissue gradually declines, resulting in the release of fluids - a phenomenon known as drip loss. This accumulation of exudates negatively affects meat quality by promoting microbial and enzymatic activity as well as lipid oxidation during storage, transportation, and distribution (Dai et al., 2024). Active packaging systems enriched with antimicrobial compounds have been developed to decrease these issues. By quickly absorbing exudations, such systems create a drier environment that inhibits microbial growth, preserves sensory evaluation, and extends shelflife (Tian et al., 2023). Consequently, there is nessaisary for innovative designs of absorbent storage pads with enhanced performance to increase the shelf life of meat products (Wang et al., 2025).
Fresh food products, including fish are potential to contamination by foodborne pathogens at various stages of production. Among the most prevalent bacterial pathogens is Staphylococcus aureus (Gurtler et al., 2022).
Chamomile (Matricaria chamomilla L.), a widely recognized medicinal plant, has been traditionally employed to treat a range of ailments. This plant exhibits a variety of biological activities, including antioxidant, antibacterial, antifungal, antiparasitic, antidiabetic, anticancer, and anti-inflammatory effects. These properties make chamomile as a valuable resource in medicine, veterinary medicine, food preservation, and herbal therapy (El Mihyaoui et al., 2022).
According to literature review, this study aims to evaluate the effect of absorbent pad containing Matricaria chamomilla essential oil to prevent the growth of Staphylococcus aureus inoculated in Cyprinus carpio fillets. In addition, the chemical and microbial changes of fillets is investigated during refrigerated storage.
Material and Methods
Chamomile essential oil was extracted using a Clevenger apparatus. During this process, volatile compounds were carried with water vapor, and after cooling, a distinct layer of essential oil appeared on the water surface in the graduated tube of the apparatus. To determine the maximum concentration of essential oil that could be applied to common carp fillets without causing undesirable organoleptic effects, fillets were placed on absorbent pads containing essential oil at the concentrations of 1%, 1.5%, and 2%, then stored in refrigerator for 24 hours. The organoleptic evaluation was performed by a trained sensory panel. Fillets were steamed for 15 minutes in a home steamer at 90°C to serve the panelist (Ojagh et al., 2010). The maximum concentration of chamomile essential oil with no adverse sensory effects was determined by panelist. The treamtments of this research include, fillets inoculated with Staphylococcus aureus (10³ CFU/g) were put on absorbent pads without chamomile essential oil (Control), absorbent pads infused with 10 ml of essential oil at concentrations of 1% (Treatment 1), 1.5% (Treatment 2), and 2% (Treatment 3) respectively. Fillets after treated packaged and stored in refrigerator (4°C). Chemical (pH, peroxide value (PV), thiobarbituric acid (TBA) and Total volatile basic nitrogen (TVB-N) and microbial (Staphylococcus aureus, Total viable count (TVC) and Psychrotrophic count (PTC)) parameters were measured on days 0, 2, 4, 6, 8, and 10. After the experiment, the data were tested for normality. A completely randomized design and one-way analysis of variance (ANOVA) was used to evaluate the effects of treatments and storage time. To detemined significant differences, Duncan's multiple range test was performed at the 5% significance level. Sensory data that did not conform to a normal distribution were analyzed using the nonparametric Kruskal-Wallis test.
Results and Discussion
The organoleptic evaluation revealed no significant differences between treatments containing various concentrations of chamomile essential oil. But, the treatment containing 10 ml of 2% chamomile essential oil was obtained higher score than the other treatments and indicat the acceptability of organoleptic evaluation. Accorning to this results, there is not any lilmited to apply different concentrations of essential oil in absorbent pads.
Food poisoning caused by Staphylococcus aureus is a common concern, particularly when the bacterial count in protein-based foods exceeds 105 log CFU/g (Macori et al., 2016). In the current study, Staphylococcus aureus counts in control and the treatment containing 10 ml of 1% chamomile essential oil exceeded the limit after six days storage in refrigerator. But, the treatments containing 1.5% and 2% chamomile essential oil exceeded the limit after eight and ten days storage in refrigerator respectively. This results show that the chamomile essential oil had potential inhibitory effetcts on Staphylococcus aureus (Stanojevic et al., 2016).
The lowest TVC and PTC were observed in the treatment containing 2% chamomile essential oil (p < 0.05) during all storage time. In addition, bacterial counts in control and the treatment containing 1% exceeded the limit after eight days' storage in refrigerator, whereas the treatments containing 1.5% and 2% chamomile essential oil exceeded this threshold only at the end of refrigerated storage. This results shown the antibacterial efficacy of absorbent pads containing chamomile essential oil. Similar results was obtained by Bakhtiari et al. (2019), they demonstrated that Carum copticum essential oil effectively controlled mesophilic and psychrophilic bacterial growth in Oncorhynchus mykiss fillets during refrigerated storage. Hassanian et al. (2015), have confirmed the efficacy of chamomile extract in reducing bacterial growth in chicken meat during refrigerated storage.
There is a significant properties of essential oils is its antioxidant activity, which has driven their increase application in the food industry to prevent oxidation and delay of spoilage (Zengin et al., 2022). In this study, peroxide values (PV) increased during refrigerated storage and a significant different was observed between all treatments (p < 0.05). The increase of PV was lower in treatments containing higher concentrations of chamomile essential oil. This results shown the antioxidant activity of chamomile essential oil. Similar results were observed by Pudineh et al. (2010), they showed that absorbent pads containing thyme essential oil inhibited fat oxidation in silver carp (Hypophthalmichthys molitrix) fillets and improved the product quality during refrigerated storage.
The thiobarbituric acid (TBA) index is an indicator of secondary lipid oxidation. The TBA value of treatment containing 2% chamomile essential oil was lowest in all time of refrigerator storage (p < 0.05). This decreaes is attributed to the ability of chamomile essential oil and its extracts to neutralize free radicals such as 1, 1-diphenyl-2-picrylhydrazyl and hydroxyl radicals, due to the presence of compounds like flavonoids and polysaccharides (Pastare et al., 2023).
The total volatile basic nitrogen (TVB-N) index is an indicator of microbial spoilage in the meat and fisheries product. TVB-N was lower in treatments containing chamomile essential oil compared to the control. High bacterial loads in treatments are associated with the production of compounds such as trimethylamines, peptides and amino acids, which elevated TVB-N level. The results suggest that absorbent pads containing chamomile essential oil effectively decrease increasing level of TVB-N during refrigerated storage. This results similar to the use of rosemary essential oil in silver carp surimi (Vahedi Serigani et al., 2017) and agarwood essential oil in ground common carp meat (Faramarzapour Darzini et al., 2018).
The observed pH increase during refrigerated storage is typically attributed to the production of alkaline volatile compounds, such as ammonia and trimethylamines, resulting from spoilage bacteria activity. The treatments containing chamomile essential oil showed lower pH values, reflecting its antimicrobial effects and its role in preserving meat quality.
According to results of this researche can be concluded the absorbent pads containning chamomile essential oil effectively inhibited the growth of Staphylococcus aureus inoculated in common carp fillets during refrigerated storage. They also demonstrated a positive impact on microbial and chemical parameters. Thus, chamomile essential oil is recommented as a potential to apply in fisheries product and food industry.
Keywords: Staphylococcus aureus, absorbent pad, Cyprinus carpio, essential oil, Chamomile