Variations in photoperiods and their impact on yield, photosynthesis and secondary metabolite production in basil microgreens.

BACKGROUND: The effects of different photoperiods on plant phytochemical synthesis can be improved by adjusting the daily light integral. Photoperiod is one of the most important environmental factors that control growth, plant's internal rhythm and the synthesis of secondary metabolites. Information about the appropriate standard in terms of photoperiod for growing basil microgreens as one of the most important medicinal plants is limited. In this study, the effects of five different photoperiods, 6 (6 h × 3 cycles), 8 (8 h × 2 cycles), 16, 18, and 24 h day- 1 on the yield, photosynthesis and synthesis of secondary metabolites of three cultivars and one genotype of basil microgreens in floating system were evaluated. The purpose of this research was to determine the feasibility of using permanent light in growing basil microgreens and to create the best balance between beneficial secondary metabolites and performance. RESULTS: The results showed that the effects of photoperiod and cultivar on all investigated traits and their interaction on photosynthetic pigments, antioxidant capacity, total phenolic compounds, proline content and net photosynthesis rate were significantly different at the 1% level. The highest levels of vitamin C, flavonoids, anthocyanins, yield and antioxidant potential composite index (APCI) were obtained under the 24-h photoperiod. The highest antioxidant capacity was obtained for the Kapoor cultivar, and the highest total phenolic compound and proline contents were measured for the Ablagh genotype under a 24-h photoperiod. The highest yield (4.36 kg m- 2) and APCI (70.44) were obtained for the Ablagh genotype. The highest nitrate content was obtained with a photoperiod of 18 h for the Kapoor cultivar. The highest net photosynthesis rate was related to the Violeto cultivar under a 24-hour photoperiod (7.89 µmol CO2 m- 2 s- 1). Antioxidant capacity and flavonoids had a positive correlation with phenolic compounds and vitamin C. Yield had a positive correlation with antioxidant capacity, flavonoids, vitamin C, APCI, and proline. CONCLUSIONS: Under continuous light conditions, basil microgreens resistance to light stress by increasing the synthesis of secondary metabolites and the increase of these biochemical compounds made basil microgreens increase their performance along with the increase of these health-promoting compounds. The best balance between antioxidant compounds and performance was achieved in continuous red + blue light. Based on these results, the use of continuous artificial LED lighting, due to the increase in plant biochemical with antioxidant properties and yield, can be a suitable strategy for growing basil microgreens in floating systems.

Effective Inhibition of Listeria monocytogenes Biofilm Formation by Satureja rechingeri Essential Oil: Mechanisms and Implications.

Biofilm formation by foodborne pathogens, particularly Listeria monocytogenes, poses a significant challenge in food industry facilities. In this study, we investigated the inhibitory potential of Satureja rechingeri essential oil (Sr-EO) against L. monocytogenes growth and biofilm formation. Gas chromatography-mass spectrometry analysis revealed a high carvacrol content in Sr-EO, a compound with known antimicrobial properties. We examined the effects of Sr-EO on initial attachment and preformed biofilms, using crystal violet and MTT assays to quantify attached biomass and metabolic activity, respectively. Our results demonstrated that Sr-EO not only prevented initial attachment but also effectively disrupted preformed biofilms, indicating its potential as a biofilm-control agent. Microscopy analysis revealed alterations in bacterial cell membranes upon Sr-EO treatment, leading to increased permeability and cell death. Additionally, Sr-EO significantly suppressed bacterial motility, with concentrations exceeding 0.25 µL/mL completely inhibiting motility. Furthermore, gene expression analysis revealed the down regulation of genes associated with biofilm formation, attachment, and quorum sensing, suggesting that Sr-EO modulates bacterial gene transcription. These findings suggest that Sr-EO can be a promising candidate for controlling biofilm formation and bacterial contamination in food processing environments.

A Review on Torilis japonica: Ethnomedicinal, Phytochemical, and Biological Features.

The present study was aimed at comprehensive overviewing a phytochemically and biologically important species namely Torilis japonica (Apiaceae family). Treatment of dysentery, fever, haemorrhoids, spasm, uterine tumors, lymphadenitis, rheumatism, impotence, infertility, women's diseases, and chronic diarrhea are reported as the main folk medicinal applications of the T. japonica fruits. So far, the plant is phytochemically characterized for its diverse terpene derivatives, predominantly sesquiterpenes. The plant's fruit is a rich source of torlin, a guaiane-type sesquiterpene, possessing various potent bioactivities. To date, anticancer, anti-inflammatory, antimicrobial, antioxidant, skin photoaging activities of the plant extracts and its constituents have been evaluated. Further investigation of the plant, specifically bioassay-guided isolation and identification of its major bioactive constituents can lead to discover potential phytopharmaceutical candidates.

Variation of Chemical Constituents and Antiradical Capacity of Nine Ferulago angulata Populations from Iran.

The present study was designed to assess the influence of geographical factors on essential oil (EO) composition, along with antiradical potential and phytochemical contents of Ferulago angulata (Schltdl.) Boiss (Apiaceae) extracts for the first time. The aerial parts were hydrodistilled by Clevenger apparatus and subjected to gas chromatography coupled with flame ionization detector (GC/FID) and mass spectroscopy (GC/MS). The EO yields were significantly different from populations 'Mongar' (south-slope, 3000 m) with 1.34±0.06 % and 'Male-Amiri' (north slope, 2600 m) with 0.18±0.05 % of total oil. Thirty-nine compounds were identified from the EOs of nine populations. α-Pinene was the predominant component ranging from 20.84 to 49.06 % in 'Gandomkar' (north-slope, 2500 m) and 'Mongar' (3000 m), respectively. The methanolic extract of 'Mongar' (north-slope at 2500 m) possessed the highest total phenolic contents. Also, this population logically exhibited potent antiradical activity using both 1,1-diphenyl-2-picrylhydrazyl (DPPH) and oxygen radical absorbance capacity (ORAC) assays with EC50 of 42.07±4.12 µg/mL and 8.34±0.21 mmol Trolox® equivalents/g, respectively. Due to its moderate free-radical scavenging potential and high α-pinene content, the population 'Mongar' might be considered as a perspective raw material in food and phytopharmaceutical industries.

Management of Secondary Metabolite Synthesis and Biomass in Basil (Ocimum basilicum L.) Microgreens Using Different Continuous-Spectrum LED Lights.

Different LED light spectra (LS) are absorbed by different plant photoreceptors and can control biomass and plant secondary metabolite synthesis. In this study, the effects of continuous-spectrum LED lights (red, blue, white, red + blue, and 12 h blue + 12 h red) on the production value, antioxidant compounds, and biomass of basil (Ocimum basilicum L.) microgreens (Red Rubin, Violeto, and Kapoor cultivars and the Ablagh genotype) were investigated. The results showed significant effects of LS on cultivar (Cv) and the interaction of LS and Cv on the studied traits. The highest quantitys of chlorophyll a, total chlorophyll, and nitrate were obtained in Violeto under blue lighting. Red lighting enhanced starch synthesis in Red Rubin and flavonoids in the Violeto Cv. The highest biomass (4.54 kg m-2) was observed in the Ablagh genotype and the highest carbohydrate synthesis in Violeto Cv in the red + blue treatment. The highest anthocyanin content (26.33 mg 100 g-1 FW) was observed for Red Rubin Cv under 12 h blue + 12 h red light. The greatest antioxidant capacity (83.57% inhibition), the highest levels of phenolic compounds (2027.25 mg GA 100 g-1 FW), vitamin C (405.76 mg 100 g-1 FW), proline, antioxidant potential composite index (APCI), and the greatest production values were obtained for the Ablagh genotype under blue lighting. Taken together, the experiment findings indicate that growing the Ablagh genotype under continuous blue lighting can increase the antioxidant capacity, phenolic compounds, and vitamin C and that this LED light spectrum can be used as a practical method to produce basil microgreens with high nutritional health value.

Monthly changes in contents and compositions of oil of Callistemon citrinus: a comparison study.

The essential oil components of fresh and dry aerial parts of Callistemon citrinus, monthly harvested from Iran during a year, were compared. The EO contents of dry plant samples were dramatically higher than the fresh materials. The dry sample collected in March with 1.10 ± 0.04% and fresh in August with 0.16 ± 0.01% (w/w), possessed the highest and lowest EO yields, respectively. From thirty-two identified aroma phytoconstituents, 1,8-cineole was the major compound with quantity variation of 60.01% in dry sample collected in January and 33.92% in fresh from August. In summer, the amount of α-pinene as the second predominant volatile terpenoid was raised, while dry sample in August (46.92%) was the richest. The present study explicitly demonstrates the impact of harvesting period on volatile oil contents of C. citrinus and the findings are considerable to obtain the favourite EO compositions for consuming in food and phyto-pharmaceutical industries.

Monoterpenes: Essential Oil Components with Valuable Features.

Medicinal plants have a wide range of secondary metabolites including monoterpene. These volatile compounds are the main components of essential oils, belonging to the isoprenoid group and possessing valuable features for plants and humans. This review provides comprehensive information on chemical structures and classification of monoterpenes. It describes their biosynthesis pathways and introduces plant families and species rich in noteworthy monoterpenes. Bio-activities, pharmacological and pesticide effects as well as their mechanism of action are reported. Applications of these compounds in various industries are also included.