Prolonging broccoli shelf life through controlled release of plai essential oil using palm wood sachet as a novel absorbent material with reusable properties.

Palm wood powder derived from palm wood waste was utilized as a novel absorbent material. The investigation involved exploring its pore structure and size to achieve the controlled release of bioactive compounds from plai oil, providing protection against pathogenic bacteria and thereby extending the shelf life of broccoli. The palm wood sachet was prepared before being placed into the broccoli bag. The process to create the sachet involved freezing the palm wood at -10°C and then drying it at a temperature of 200°C. After drying, the material was ground to achieve a particle size of 20 mesh and then packaged into sachets made from wood pulp. The optimized palm wood plai oil sachet (PWPS), measuring 5 × 7 cm, with a thickness of 0.58 µm, was produced by soaking 2 g of palm powder in plai oil at a concentration of 30 µL/mL before drying and packing it inside a 5-L polyethylene plastic bag (24 × 34 cm) along with broccoli (150 g). The packages were kept at 4°C for 20 days to determine the antimicrobial activity of the PWPS and broccoli quality. PWPS significantly inhibited the growth of Escherichia coli, Salmonella Typhimurium, Staphylococcus aureus, and Listeria monocytogenes in broccoli for at least 20 days. The sachet demonstrated complete inhibition of all bacteria when reused at least two times and an 80% reduction in efficacy after three uses. Moreover, the PWPS controlled the growth of total aerobic bacteria and yeast and mold in broccoli, meeting microbiological criteria for up to 14 days. Broccoli stored with PWPS showed good quality results and contained high antioxidant value. These results demonstrate the potential application of PWPS in controlling food pathogens and spoilage microbes during storage. PRACTICAL APPLICATION: This study introduces a novel absorbent material made from palm wood powder, addressing the need for utilizing abundant waste palm wood in the food industry. The material benefits the safe transportation of vegetables from farms to markets. Its porous structure allows efficient absorption of plai oil emulsion, ensuring pathogen-free and high-quality treated broccoli. The reusable sachets benefit farmers seeking to extend the shelf life of fresh produce. This cost-effective method utilizes plai oil vapor, making it suitable for large-scale production.

Development of an antimicrobial fungal egg tray containing orange oil and smoke for eggs preservation at room temperature.

The prevention and controlled growth of pathogenic bacteria on eggs during storage and distribution at room temperature is important to ensure commercial eggs and egg products are safe for consumer. This study investigated the combined effects of orange oil (0.001%-0.004% v/w) and smoke for 10 min in paper egg tray packaging produce from the fungal pulp of Trametes versicolor. Eggs were kept in the developed paper egg tray at room temperature (30 ± 2°C). The mechanism of the combined antibacterial effects against Escherichia coli, Salmonella Typhimurium, and Staphylococcus aureus and egg quality were investigated. The combination of orange oil (0.004%) and smoke delayed all bacteria and suppressed changes in weight loss and the quality factor of eggs (Haugh unit, yolk index, albumen index) for at least 14 d. It was found that the volatile orange oil smoke in the egg tray could be passed through the structure of the cell wall and membrane of bacteria, giving rise to loss of cell viability by irreversibly damaging the cell membranes of all the bacteria in this test. Moreover, higher antioxidant activity was found on the eggs than on the eggshells, which is linked to greater shelf-life of treated eggs. The study demonstrates an improved paper egg tray packaging system and the possibility of combining released essential oils and smoke, which can be extended to egg products. Smoke can also be modified on the surface of paper egg trays easily, which shows potential in functionalizing implanted materials with antibacterial properties.

Combined effects of tangerine oil vapour mixed with banana flavour to enhance the quality and flavour of 'Hom Thong' bananas and evaluating consumer acceptance and responses using electroencephalography (EEG).

The objectives of this study were to investigate the effect of tangerine oil (TO) at 25, 50 and 75 µL mixed with banana flavour (BF) at 25, 50 and 75 µL to protect the quality and enhance the flavour of bananas. Then, 25 µL TO + BF 50 µL were selected for studying the quality of bananas stored at 13 °C ± 2 °C for 7 days, and was used to test consumer brain responses using an electroencephalography (EEG). Results showed that mould grew and decomposition occurred in 10 and 50% of the 25 µL TO + 50 µL BF mixture and control, respectively, after 7 days. Furthermore, this ratio increased ripening by having higher L*, b*, firmness and total soluble solid than the control (p < 0.05), whereas titratable acidity and pH were maintained (p > 0.05). The EEG demonstrated that consumption of TO-treated banana could increase brain alertness using stimulating the beta wave activity on banana stimulations for human brain. Limonene, one of the main components of TO, was found in the flesh of treated banana after storage for 4 weeks and possibly interacted with other components to improve antifungal activity and brain response.

Effects of Thai Local Ingredient Odorants, Litsea cubeba and Garlic Essential Oils, on Brainwaves and Moods.

The functional food market is growing with a compound annual growth rate of 7.9%. Thai food recipes use several kinds of herbs. Lemongrass, garlic, and turmeric are ingredients used in Thai curry paste. Essential oils released in the preparation step create the flavor and fragrance of the famous tom yum and massaman dishes. While the biological activities of these ingredients have been investigated, including the antioxidant, anti-inflammatory, and antimicrobial activities, there is still a lack of understanding regarding the responses to the essential oils of these plants. To investigate the effects of essential oil inhalation on the brain and mood responses, electroencephalography was carried out during the non-task resting state, and self-assessment of the mood state was performed. The essential oils were prepared in several dilutions in the range of the supra-threshold level. The results show that Litsea cubeba oil inhalation showed a sedative effect, observed from alpha and beta wave power reductions. The frontal and temporal regions of the brain were involved in the wave alterations. Garlic oil increased the alpha wave power at lower concentrations; however, a sedative effect was also observed at higher concentrations. Lower dilution oil induced changes in the fast alpha activity in the frontal region. The alpha and beta wave powers were decreased with higher dilution oils, particularly in the temporal, parietal, and occipital regions. Both Litsea cubeba and turmeric oils resulted in better positive moods than garlic oil. Garlic oil caused more negative moods than the others. The psychophysiological activities and the related brain functions require further investigation. The knowledge obtained from this study may be used to design functional food products.

The effects of Michelia alba oil against mould on brown rice and assessing the brain response using electroencephalogram (EEG).

The objective of this study was to develop antifungal fragrant brown rice using the vapour phase of Michelia alba oil and to understand the effects of fragrant brown rice on consumer reactions using an electroencephalography (EEG) technique. The effect of M. alba oil vapour (300-900 µL/L) on the growth of moulds was studied in brown rice. Then, optimisation of the M. alba oil vapour (300-900 µL/L) was studied through sensory evaluation. Next, EEG was used to investigate the effect of fragrant cooked brown rice on human brain activity. In addition, the key components of M. alba oil on the sensory effects were determined. The results indicated that M. alba oil vapour ≥ 450 µL/L provided effective antifungal activity against natural moulds on brown rice for at least 90 days of storage at 25 °C at 100% RH. Furthermore, the optimal concentration of M. alba oil vapour for enhancing consumer preference and acceptance of cooked brown rice was 300-600 µL/L with a rejection threshold of 2,052 µL/L. Moreover, it was found that linalool was the main key component and caryophyllene and ß-elemene were the minor components affecting the sensory quality enhancement. Interestingly, the EEG results showed that fragrant cooked brown rice could increase the power of alpha and beta waves in the human brain, indicating anti-stress effects and a relaxed mood. Therefore, M. alba oil vapour demonstrated good potential to enhance consumer acceptance and preference for cooked brown rice while controlling the significant growth of moulds in brown rice.

Effects of Tangerine Essential Oil on Brain Waves, Moods, and Sleep Onset Latency.

Tangerine (Citrus tangerina) is one of the most important crops of Thailand with a total harvest that exceeds 100,000 tons. Citrus essential oils are widely used as aromatherapy and medicinal agents. The effect of tangerine essential oil on human brain waves and sleep activity has not been reported. In the present study, we therefore evaluated these effects of tangerine essential oil by measurement of electroencephalography (EEG) activity with 32 channel platforms according to the international 10-20 system in 10 male and 10 female subjects. Then the sleep onset latency was studied to further confirm the effect on sleep activity. The results revealed that different concentrations, subthreshold to suprathreshold, of tangerine oil gave different brain responses. Undiluted tangerine oil inhalation reduced slow and fast alpha wave powers and elevated low and mid beta wave powers. The subthreshold and threshold dilution showed the opposite effect to the brain compared with suprathreshold concentration. Inhalation of threshold concentration showed effectively decreased alpha and beta wave powers and increased theta wave power, which emphasize its sedative effect. The reduction of sleep onset latency was confirmed with the implementation of the observed sedative effect of tangerine oil.

Controlled Release of Peppermint Oil from Paraffin-Coated Activated Carbon Contained in Sachets to Inhibit Mold Growth During Long Term Storage of Brown Rice.

The aim of the study was to control the release of peppermint oil (700 µL/L) by coating activated carbon (AC) contained in sachets with different solutions (tapioca starch, corn starch, gelatine, carnauba, paraffin, and mixed carnauba-paraffin) for inhibiting the growth of Aspergillus flavus on brown rice (BR). Paraffin-coated AC with adsorbed peppermint oil was then applied to extend the shelf life of BR during long-term storage (60 days) at 30 ± 2 °C. The mechanism of peppermint oil vapor release in this system was also studied using GC-MS. The result revealed that paraffin-coated AC with adsorbed peppermint oil present in sachets showed the highest antifungal activity against A. flavus growing on the surface of BR. In addition, paraffin-coated AC with adsorbed peppermint oil could prolong the shelf life of BR from 10 days (control) to at least 60 days under tropical climatic conditions. Moreover, storage of BR in the presence of sachets containing paraffin-coated AC with adsorbed peppermint oil at a concentration of 700 µL/L revealed no significant effects on major rice quality-related factors, such as moisture content, color, water uptake percentage, and gelatinization temperature. Peppermint oil component analysis by GC-MS indicated that paraffin could trap some minor components of peppermint oil and allow the major components such as menthone, menthol, and alpha-pinene, which are compounds that play an important role in mold growth inhibition, to be exposed to air. Thus, this research demonstrated the potential of paraffin-coated AC containing adsorbed peppermint oil for controlling the growth of molds during prolonged rice storage. PRACTICAL APPLICATION: Paraffin-coated activated carbon with adsorbed peppermint oil has the potential to be commercially applied to brown rice grains for facilitating long-term storage. This technique is beneficial for avoiding the occurrence of negative sensorial factors when peppermint oil vapors are used. This process is interesting and easy to apply during large-scale implementation of a rice storage system.

Innovative production of fungal pulp from Trametes versicolor and its application in a fungal paper box containing clove oil.

The aims of this study were to develop fungal pulp from Trametes versicolor (white-rot fungi) and apply it with clove oil in a paper box to inhibit mold growth on the surface of peanuts. Broken rice media with different sugar solutions (2-10% w w-1) were prepared and then inoculated with T. versicolor mycelium at amounts from 0.5 to 1.5% w w-1. Fungal pulp and commercial paper (50 g) at different ratios (100:0, 70:30, 50:50, 30:70 and 0:100) were mixed and prepared before being placed into a stainless box (5 cm long by 5 cm wide). For the antimicrobial activity against Aspergillus flavus on peanuts, a paper box was incorporated with 2.5, 5 and 7.5% w w-1 of clove oil, eugenol, caryophyllene, and a combination of eugenol and caryophyllene at ratios of 7:1, 4:4, and 1:7. Results indicated that the highest fungal pulp biomass of T. versicolor in broken rice media was found when using 6% sugar with 1% mycelium inoculums. Fungal pulp and commercial paper at the ratio of 70:30 produced the highest value of hardness. The paper box containing clove oil at 7.5% w w-1 inhibited A. flavus on peanuts for at least 28 days while the control had mold growth within 3 days. Combining eugenol and caryophyllene, the main components of clove oil, at the ratio of 7:1 (7.5% w w-1) in the paper box should be a key factor to inhibit A. flavus during storage.

Effect of UV-C radiation and vapor released from a water hyacinth root absorbent containing bergamot oil to control mold on storage of brown rice.

The aims of this study were to develop absorbent material from a water hyacinth root containing bergamot oil and to improve its antifungal activity by using ultraviolet C (UV-C) against the growth of A. flavus on the brown rice. Process optimization was studied by the immersion of a water hyacinth root into a water and bergamot oil (300, 500 and 700 µl ml(-1)). The root (absorbent material) was dried at 50, 70, and 90 °C for 10 min. Then, ultraviolet C (UV-C) was used for enhancing the antifungal activity of bergamot oil for 10, 15, and 20 min. The shelf-life of the brown rice with the absorbent after incubation at 25 ° C with 100 % RH for 12 weeks was also investigated. A microscope and a Fourier transform infrared spectroscopy (FTIR) were used to find out possible mode of action. Results indicated that the absorbent material produced from the water hyacinth root containing bergamot oil at 500 µl ml(-1) in the water solution, dried at 70 ° C and UV for 15 min showed the highest antifungal activity in a vapor phase against A. flavus on the brown rice. A microscopy investigation confirmed that the water hyacinth root could absorb bergamot oil from an outside water solution into root cells. Limonene in vapor phase was shown to be a stronger inhibitor than essential oil after UV-C radiation and should be the key factor in boosting bergamot oil antifungal activity. A vapor phase of bergamot oil could be released and inhibit natural mold on the surface of the brown rice for up to 12 weeks; without the absorbent, mold covered the brown rice in only 4 weeks.

Improvement of the antifungal activity of Litsea cubeba vapor by using a helium-neon (He-Ne) laser against Aspergillus flavus on brown rice snack bars.

The aim of this study was to improve the antifungal activity of the volatile Litsea cubeba essential oil and its main components (citral and limonene) on brown rice snack bars by applying He-Ne laser treatment. Different volumes (50-200 µL) of L. cubeba, citral or limonene were absorbed into a filter paper and placed inside an oven (18 L). Ten brown rice snack bars (2 cm wide × 4 cm long × 0.5 cm deep) were put in an oven and heated at 180 °C for 20 min. The shelf-life of the treated snack bars at 30 °C was assessed and sensory testing was carried out to investigate their consumer acceptability. A count of total phenolic content (TPC) and Fourier transform infrared spectroscopy (FTIR) on the properties of essential oil, citral, and limonene before and after the laser treatment was studied for possible modes of action. It was found that the laser treatment improved the antifungal activity of the examined volatile L. cubeba and citral with Aspergillus flavus inhibition by 80% in comparison with those of the control not treated with the laser. L. cubeba vapor at 100 µL with the laser treatment was found to completely inhibit the growth of natural molds on the snack bars for at least 25 days; however, without essential oil vapor and laser treatment, naturally contaminating mold was observed in 3 days. Results from the sensory tests showed that the panelists were unable to detect flavor and aroma differences between essential oil treatment and the control. Laser treatment caused an increase in TPC of citral oil whereas the TPC in limonene showed a decrease after the laser treatment. These situations could result from the changing peak of the aliphatic hydrocarbons that was revealed by the FTIR spectra.

Inhibition of Aspergillus flavus on agar media and brown rice cereal bars using cold atmospheric plasma treatment.

This study aimed to optimize the operating parameters of cold atmospheric plasma treatment to inhibit the growth of Aspergillus flavus on agar media and brown rice cereal bars. The effects of argon plasma jet treatment on the growth of A. flavus on malt extract agar (MEA) at powers of 20 W and 40 W with exposure times at 5, 15 and 25 min were studied using response surface methodology (RSM) with a central composite face-centered (CCF) design. Multiple regression analysis indicated that plasma treatment at 40 W for 25 min is most effective for inhibiting growth of A. flavus on the agar medium. On brown rice cereal bars, plasma powered at 40 W for 20 min was capable of giving protection against A. flavus growth for up to 20 days under storage conditions of 25°C and 100% RH. These results demonstrated the potential of cold atmospheric plasma jet treatment to control mold growth on various food products.