Impact of non-thermal plasma on betel leaf powder for essential oil extraction and its quality characteristics.

BACKGROUND: Betel leaf is an essential oil (EO)-rich plant from the Piperaceace family used as traditional herbal medicine. The minimum EO yield by the conventional extraction method was increased by adopting cold plasma (CP) as pretreatment. Thus, the present study involved optimizing the CP conditions and analyzing the EO's qualities. RESULTS: Optimization of the CP parameters like electric voltage (A = 25-35 kV), treatment duration (B = 4-12 min) and extraction time (C = 60-180 min) was done for maximum EO yield (R1) and total phenolic content (TPC; R2) using response surface methodology with Box-Behnken design. Maximum EO yield (20.76 ± 1.15 g kg-1 ) and TPC (29.43 ± 1.7 mg GAE mL-1 ) were derived under optimal conditions: A = 34 kV, B = 10 min and C = 110 min. A quadratic polynomial model developed by multiple regression analysis revealed that the three independent variables significantly influenced the oil yield and TPC with R2 values of 0.9909 and 0.9962, respectively. The CP treatment significantly altered the betel leaf powder morphology and increased the EO's radical scavenging capacity and bioactive compounds like chavibetol, chavibetol acetate, hydroxychavicol and γ-muurolene. Conversely, the functional groups, refractive index and specific gravity were unaffected by CP treatment. CONCLUSION: The EO yield and its qualities were improved by applying CP under optimal conditions which can be helpful for scaled-up industrial processes with further studies. The identified bioactive compounds are valuable in the food and pharmaceutical industries. © 2023 Society of Chemical Industry.

Effect of high voltage dielectric barrier discharge (DBD) atmospheric cold plasma treatment on physicochemical and functional properties of taro (Colocasia esculenta) starch.

The goal of the proposed study is to investigate the effects of three different power levels (30, 32 and 34 kV) and exposure time (2, 4 and 8 min) of dielectric barrier discharge (DBD) atmospheric cold plasma treatment on the functional and physicochemical characteristics of taro starch. Investigations were done into how different treatments impact the multi-structural, functional and physicochemical attributes of taro starch. The findings showed that cold plasma treatments substantially impacted starch granule shapes (3.60-2.54 µm), such as reduced aggregations and developed fissures on granule surface due to the generation of an etching by plasma species and enhancement in the surface topography and roughness of treated starch as compared with native by SEM and AFM analysis. Besides this, no variations were detected in the functional groups of taro starch using FT-IR analysis after cold plasma treatments. However, the A-type pattern in the XRD did not affect it, while a reduction in relative crystallinity (14.20-11.50 %) was seen as a function of the active plasma species depolymerization. Furthermore, depending on the cold plasma voltage and treatment time, amylose content (20.12-15.98 %), paste clarity (24.48-31.27 %), solubility (0.41-65.53 %), freezing thaw stability (% syneresis) (32.10-42.58 %), color properties (L*, 94.79-97.52), whiteness index (79.37-84.66), molecular weight distribution (Peak 1, 12.79-5.35 × 108 g/mol; Peak 2, 4.20-1.56 × 107 g/mol) and in vitro digestibility (RDS, 64.10-64.08 %) significantly changed. So, based on these excellent properties, this study suggested that cold plasm-treated taro starch can be used in the field of food packaging material, functional food and pharmaceutical products. Therefore, a potential approach for physically altering starch is plasma treatment.

Technique for order preference by similarity to ideal solution (TOPSIS): a MCDM approach for selecting suitable solvent considering biochemical profiles and in vitro antibacterial efficacy of petioles of betel leaf (Piper betle L.).

Petioles of betel leaf (BLP) are the major industrial by-products of betel leaf industries sold at throwaway prices or used as cattle feed. The present work was taken up to evaluate suitable solvent based on yield, antioxidant, and antimicrobial properties to isolate extract of BLP using the Shannon entropy-TOPSIS method. Four solvents were chosen for the extraction process: hexane, toluene + ethanol (2:1), acetone, and ethanol. The findings showed that ethanol-based BLP extract had the highest TPC value, measuring 2193.71 ± 0.17 mg of gallic acid equivalence/g of dry extract, while acetone-based extracts had the highest TFC value, measuring 8.03 mg of quercetin equivalent/g of dry extract. Radical scavenging activities like DPPH (IC50 = 52.44 µg/mL), ABTS (IC50 = 62.41 µg/mL), and FRAP (8.03 mg QE/g of dry extract) were found best for acetone extract. The antibacterial study of the extracts revealed that acetone extract was more sensitive to Gram-positive and Gram-negative bacterial strains followed by ethanol, toluene + ethanol, and hexane extracts. Among five foodborne bacteria, B. subtilis showed the highest susceptibility against all extracts. GC-MS analysis showed that acetoxychavicol acetate (31.27%) (PubChem ID: 119,104), germacrene D (7.24%) (PubChem Id: 531,750), isoxylic acid (22.56%) (PubChem ID: 11,892), and cis-1,2-indandiol (43.92%) (PubChem ID: 20,758) are four major compounds among 22 components. TOPSIS analysis revealed that acetone extract had the highest relative closeness value (0.71) followed by ethanol (0.65), toluene + ethanol (0.53), and hexane (0.32). These results indicate that acetone extract of BLP can be considered an alternative to synthetic active ingredients in the future. These results indicated that TOPSIS method has computational robustness for selecting a solvent comparing yield, antioxidant, and antimicrobial activities of extract of a plant part.

Bio-actives of betel leaf (Piper betle L.): A comprehensive review on extraction, isolation, characterization, and biological activity.

Piper betle L., belonging to Piperaceae family, known as a traditional herbal medicinal plant and used for several health benefits in Asian countries. Currently, demand for its products such as herbal drugs, medicines, and natural herbal formulations has increased. The beneficial effects of betel leaves and its products have traditionally exploited for the treatment of several diseases like bad breath, cuts, injuries, inflammations, cold cough, indigestion, etc. Till now, a broad range of bioactive compounds including polyphenols, terpenes, etc., has been identified from the extracts and essential oil (EO) of betel leaves. The structural and functional characterization of the extract and EO bio-actives has been derived by various advanced standard methods. Most of the health-related benefits of betel leaves have been associated with their bioactive phenolic compounds. The extract of this highly perishable product can be used in organic synthesis, food, and beverage industry, pharmaceuticals, etc., to the environmental issues. The present review provides information on extraction techniques, identification of bioactive compounds, and their biological activities. That apart, information on processing, preservation, and health benefits along with their mechanisms has also been added.

A review on antifungal activity and mode of action of essential oils and their delivery as nano-sized oil droplets in food system.

An escalated demand of minimally processed food and increased negative perception for synthetic preservative has led to a lookout for a natural preservative. Essential oils (EOs) are volatile and aromatic secondary metabolites of plants that have been tapped mainly for its flavour and fragrances and various biological properties such as antimicrobial and antioxidant. The constituents and antifungal potential of EOs have been reported widely in the present scientific literature. Moreover, the current scientific research dealing with the mode of action of EOs on fungal spores and mycelial cells are very scarce, unlike bacteria. The antimicrobial efficacy of EO in real food system may alter due to interaction with food matrix components. Besides, minimum alteration in sensory qualities while retaining its maximum activity is the most sought-after criteria for food preservation with EOs. If the oil is applied in excess to have better antimicrobial activity, it may end up having an unacceptable organoleptic impact on the food. Appropriate edible delivery systems of EOs as an emulsion is a probable approach to retain the maximum efficacy of EOs in the food system. Nano-emulsification of EO could increase its bioactivity due to increased bioavailability in the food matrix. The basis of this review is to provide an overview of current knowledge about the antifungal properties and antifungal mode of action of EOs, and to recognize the application of EO as nano-sized oil droplets in the food system.

Modelling the effect of guar gum on physical, optical, barrier and mechanical properties of potato starch based composite film.

The composition of potato starch (PS) and guar gum (GG) based biodegradable composite film was optimised based on physical, optical, mechanical and barrier properties. The rotatable central composite design applying desirability function was used to assess the effect of PS (2.5-4.5%), GG (0.2-0.8%) and glycerol (15-35%). The optimisation was performed considering minimization of film solubility, opacity, yellowness index and water vapour permeability; and maximization tensile strength and percentage elongation at break. Viscosity of film forming solution; thickness, moisture content and whiteness index of the films were also evaluated. The optimum value of PS, GG and glycerol was 3.7%, 0.4% and 15% (of total solids), respectively. All the independent variables depicted significant effect on the responses (p < 0.05) except starch which did not exhibit any statistically significant effect on WVP. The structural characterisation of the optimised film was also analysed by FESEM and XRD which point to the semi-crystalline nature of the developed film.

Modelling the effect of essential oil of betel leaf (Piper betle L.) on germination, growth, and apparent lag time of Penicillium expansum on semi-synthetic media.

The current study aimed at characterizing the chemical components of betel leaf (Piper betle L. var. Tamluk Mitha) essential oil (BLEO) and modelling its effect on growth of Penicillium expansum on semi-synthetic medium. Gas chromatography-mass spectrophotometry (GC-MS) analysis of BLEO revealed the presence of different bioactive phenolic compounds in significant amounts. Among 46 different components identified, chavibetol (22.0%), estragole (15.8%), ß-cubebene (13.6%), chavicol (11.8%), and caryophyllene (11.3%) were found to be the major compounds of BLEO. A disc diffusion and disc volatilization method were used to evaluate antifungal activity of the oil against a selected food spoilage mould. The logistic model was used to study the kinetics of spore germination. Prediction and validation of antifungal effect of BLEO was performed on semi-synthetic medium (apple juice agar) using predictive microbiological tools. The Baranyi and Roberts model was used to estimate maximum growth rate (µmax in mm/day) and apparent lag time (λ in days) of the mould. Secondary modelling was performed using a re-parameterized Monod-type equation based on cardinal values to study the effect of different BLEO concentration on estimated growth parameters. Emax (minimum concentration of oil at which mould growth was inhibited) and MIC (minimum inhibitory concentration of BLEO at which lag time is infinite) value of BLEO against P. expansum was estimated to be 0.56 and 0.74 µl/ml, respectively, which was found to be similar on potato dextrose agar (PDA) as well as apple juice agar (AJA) medium. The correlation between estimated growth parameters of the mould on both the media was obtained with satisfactory statistical indices (R(2) and RMSE). This study revealed inhibitory efficacy of BLEO on spore germination, mycelial growth and apparent lag time of P. expansum in a dose-dependent manner. Hence, BLEO has potential to be used as a natural food preservative.

Development of a novel cup cake with unique properties of essential oil of betel leaf (Piper betle L.) for sustainable entrepreneurship.

Betel vine (Piper betle L.) is a root climber with deep green heart shaped leaves. It belongs to the Piperaceae family. There is a huge wastage of the leaves during glut season and it can be reduced by various means including extraction of medicinal essential oil which can be considered as GRAS (generally recognized as safe) materials. Therefore, attempts were made to develop a novel cup cake by incorporating essential oil of betel leaf. The textural properties of the cakes were measured by texture analyzer instrument; whereas the organoleptic properties were adjudged by human preferences using sensory tables containing 9-point hedonic scale. Price estimation was done considering all costs and charges. Finally, all parameters of the developed cake were compared with different cup cakes available in the market for ascertaining consumer acceptability of the newly developed product in terms of quality and market price. Results revealed that the Novel cup cake developed with 0.005 % (v/w) essential oil of betel leaf occupied the 1st place among the four developed novel cup cakes. However, it occupied 4th place among the nine cup cakes in the overall preference list prepared based on the textural and organoleptic qualities, though its market price was calculated to be comparable to all the leading cupcakes available in the market. This indicates that manufacturing of novel cup cake with essential oil of betel leaf would be a profitable and self-sustaining entrepreneurship.