Microgreens are an excellent source of health-maintaining compounds, and the accumulation of these compounds in plant tissues may be stimulated by exogenous stimuli. While light quality effects on green basil microgreens are known, the present paper aims at improving the quality of acyanic (green) and cyanic (red) basil microgreens with different ratios of LED blue and red illumination. Growth, assimilatory and anthocyanin pigments, chlorophyll fluorescence, total phenolic, flavonoids, selected phenolic acid contents and antioxidant activity were assessed in microgreens grown for 17 days. Growth of microgreens was enhanced with predominantly blue illumination, larger cotyledon area and higher fresh mass. The same treatment elevated chlorophyll a and anthocyanin pigments contents. Colored light treatments decreased chlorophyll fluorescence ΦPSII values significantly in the green cultivar. Stimulation of phenolic synthesis and free radical scavenging activity were improved by predominantly red light in the green cultivar (up to 1.87 fold) and by predominantly blue light in the red cultivar (up to 1.73 fold). Rosmarinic and gallic acid synthesis was higher (up to 15- and 4-fold, respectively, compared to white treatment) in predominantly blue illumination. Red and blue LED ratios can be tailored to induce superior growth and phenolic contents in both red and green basil microgreens, as a convenient tool for producing higher quality foods.

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Conventional management of sweet pepper is based on farming practices characterized by the use of chemicals with harmful environmental impact. In order to investigate innovative production, research was carried out in order to assess the effects of two pepper cultivars (‘Brillant’ and ‘Yolo Wonder’) in combination with four farming systems (Conventional control-C; Conventional with microorganism-enriched fertilization-CMF; Organic control-O; Organic with microorganism-enriched fertilization-OMF) on plant physiological parameters, yield and fruit quality. Conventionally grown plants showed higher values of assimilatory pigments and of photosynthetic rate compared to the Organically ones. The CMF resulted in the highest early and total yield, followed by the OMF, due to higher fruit number. Higher values of carotenoids, ascorbic acid and α-tocopherol were recorded in ‘Yolo Wonder’ red fruits compared to ‘Brillant’ yellow berries. The highest total polyphenols concentration was recorded under the CMF, whereas OMF resulted in the highest flavonoids concentration and antioxidant activity.

In recent years, rhubarb is being increasingly cultivated, as it provides early yields when the vegetables supply to market is deficient and shows high levels of both polyphenols content and antioxidant capacity in edible parts. In 2017, we investigated crops of the rhubarb cultivar Victoria to the fifth year of production. Comparisons were performed between three root phase fertilizations—chemical (NPK 16-16-16®), organic (Orgevit®), and biological (Micoseeds MB®)—plus an unfertilized control. The determinations of polyphenols, the antioxidant capacity, and the yield indicators from the stalks (petioles) of rhubarb were made at each out of the 10 harvests carried out. The highest yield (59.16 t·ha−1) was recorded under the chemical fertilization. The total polyphenols content and antioxidant capacity varied widely from 533.86 mg GAE·g−1 d.w. and 136.86 mmol Trolox·g−1 d.w., respectively in the unfertilized control at the last harvest, up to 3966.56 mg GAE·g−1 d.w. and 1953.97 mmol Trolox·g−1 d.w. respectively under the organic fertilization at the four harvest. From the results of our investigation, it can be inferred that the chemical fertilization was the most effective in terms of yield, whereas the sustainable nutritional management based on organic fertilizer supply led to higher antioxidant compounds and activity.

Currently, wastewater treatment plants produce large amounts of sewage sludge. Due to the rich content of organic matter and minerals, sewage sludge can be used as soil amendments for eroded soils. The aim of this work was to assess sewage sludge (SS) in combination with an eroded soil (ES) collected from the North Eastern Romania as growth substrate for sweet basil, and their effect on basil growth and physiology. The experiment was conducted in a greenhouse under controlled environment conditions. The tested substrates were: (1) eroded soil, ES; (2) mixture of eroded soil (15%) + sewage sludge, ES + SS (85%); and (3) sewage sludge, SS (100%). Three types of parameters were studied: morphological traits, physiological, and biochemical parameters. The maximum quantum yield of Photosystem II Fv/Fm was reduced in basil leaves grown on eroded soil (0.80) and was close to the normal value in ES + SS (0.83). Chlorophyll a and the carotenoids content were higher for plants grown on SS and significantly higher for those grown in ES + SS compared with the one of plants grown on ES. The fresh biomass yield and height of basil increased with 44% and 34.5% under ES + SS over ES. Total phenolic content was higher in plants grown on ES (7.34 mg/g dry weight Gallic acid equivalent), which also led to an increased antioxidant activity (44.4%) evaluated by the DPPH (2,2-diphenyl-1-picrylhydrazyl) method. Fourier-Transform Infrared (FT-IR) (4000-400 cm −1 ) spectra of basil did not show significant qualitative differences among the plants from different treatments. The results of this study demonstrated that SS application led to the improvement of the basil morpho-physiological parameters, allowing the growth of basil on ES + SS.

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The aim of this study was to establish the kinetics regression models for yield and composition of Ruta graveolens fruit and Hyssopus officinalis subsp. aristatus aboveground biomass essential oil (EO), collected at different time intervals during the hydrodistillation process. The hypothesis was that collecting the EO fractions during specific time frames may result in EOs with dissimilar composition that may have differential use by the industry. Furthermore, we calculated the kinetics regression models for the composition of EO, isolated by hydrodistillation in a Clevenger-type apparatus and characterized by GC-MS and GC-FID analyses. The EO yield of R. graveolens fruits was 0.39% (relative area % of GC-FID chromatogram), with major constituents in the Control fraction (0–90 min) being 2-nonanone, 2-undecanone, and 2-undecanol, representing 65% of the total oil. The highest concentration of 2-nonanone (60%) was found in the 30–60 min oil fraction, the concentration of 2-undecanone (35%) was highest in the Control (0–90 min) fraction, and the concentration of eucalyptol (19%) was highest in the 5–10 min fraction. The EO yield of H. officinalis subsp. aristatus dried biomass was 1.12%. The major constituents in the Control fraction (0–90 min) of H. officinalis biomass were eucalyptol, α-pinene, sabinene, β-pinene, and cis-3-pinanone, representing 86% of the total. Eucalyptol (58%) was the highest in the 0–5 min fraction. The highest β-pinene (15%) and cis-3-pinanone (20%) contents were found in the 20–40 min fraction. The kinetics regression models that were developed for EO composition of R. graveolens were second-order polynominal, Michaelis–Menten, and Exponential decay, while for EO composition of H. officinalis subsp. aristatus biomass were Exponential decay and Power. The results from this study could benefit the EO industry.