Flavor retention of peppermint (Mentha piperita L.) essential oil spray-dried in modified starches during encapsulation and storage

The effect of different commercial modified food starch carrier materials on the flavor retention of the essential oil (EO) of peppermint (Mentha piperita L.) during spray drying and storage was evaluated. The obtained results revealed that the emulsification and encapsulation efficiencies of peppermint EO were higher for all n-octenyl succinic anhydride (OSAN)-modified starches as compared to those of hydrolyzed starches (dextrins). The compositions of pure, emulsified, and encapsulated peppermint EOs in different matrices were quite similar; however, some changes in the percentages of some individual compounds were observed. Larger differences in the compositions of surface oils from various encapsulation products were obtained. Flavor components were released at different rates by each of the encapsulated products. The aroma binding capacity of different modified starch matrices to lock EO droplets depends on the water activity, and the leakage of aromas from encapsulated powder products during storage increased with increasing water activity.     

Monoterpene composition of essential oil from peppermint (Mentha x piperita L.) with regard to leaf position using solid-phase microextraction and gas chromatography/mass spectrometry analysis.

Monoterpene compounds of leaf pairs and flowers of Mentha x piperita have been studied by direct headspace sampling using solid-phase microextraction coupled with gas chromatography/mass spectrometry (SPME-GC/MS). The content of peppermint-characteristic compounds such as menthol, menthyl acetate, and neomenthol increased in a basipetal direction (older plant parts), whereas menthone and isomenthone showed higher levels in the acropetal direction (younger plant parts). Higher levels of menthofuran were found in peppermint flowers in contrast to the leaves. SPME sampling resulted in relatively higher amounts of high-volatile monoterpenes and lower detection of less volatile compounds such as menthol and menthone, compared to solvent-based samples from essential oil distillation.     

Towards sustainable production of peppermint (Mentha piperita L.) through integrated use of vermicompost and cowpea green manuring with synthetic nitrogen fertilization

A field experiment with peppermint (Mentha piperita L.) was conducted in a sandy loam (Typic ustifluvent) soil during 2007 and 2008 at Lucknow, India. Ten treatments consisting of control (no synthetic or organic nitrogen fertilization), synthetic nitrogen fertilization (SN) 75, 150 and 225 kg ha^?1 alone, vermicompost (VC) 3 t + 37.5 kg SN ha^?1, VC 6 t + 75 kg SN ha^?1 and VC 9 t + 112.5 kg SN ha^?1 and intercropping of one, two and three rows of cowpea for green manuring in combination with 50, 100 and 150 kg SN ha^?1, respectively, were evaluated in a randomized block design. Integrated use of VC 9 t with 112.5 kg SN ha^?1 produced maximum essential oil (94.3 kg ha^?1), increased the herb and essential oil yields by 104 and 89%, respectively, over control and reduced SN use by 50%, without affecting the quality of essential oil. Application of VC and intercropping of cowpea for green manuring significantly improved the organic carbon, available N, P and K content in soil over SN alone. To get sustainable production of peppermint, application of VC 9 t ha^?1 along with 112.5 kg N ha^?1 through synthetic fertilizer is recommended for light textured sandy loam soils.     

Sufficiency ranges and crop nutrient removals for peppermint (Mentha X piperita L.) established from field and pot fertilizer experiments

Peppermint is an important aromatic and medicinal plant used across the world in pharmaceutical, cosmetic and food industries. However, there is a lack of agronomic research on this crop which hinders the implementation of best agricultural practice at farm level. Plant analysis, for instance, cannot be used as a tool to implement a suitable fertilizer recommendation program, since sufficiency ranges and crop nutrient removals have not yet been established. Thus, the main objectives of the present work were to assess the response of peppermint to varying nitrogen (N), phosphorus (P), potassium (K) and boron (B) rates, to establish sufficiency ranges from macro, micronutrients and SPAD-readings and to estimate crop nutrient removals in the aboveground biomass. Field trials and pot experiments were conducted from 2013 to 2015 in a wide range of conditions involving 12 N, P, K or B fertilizer trials and a total of 48 cuts of biomass. Nitrogen fertilization increased dry matter yield of peppermint on the vast majority of sampling dates. In contrast, P, K, or B did not produce a significant effect on dry matter yield in any of the experiments. The sufficiency ranges set for macronutrients N, P, K, Ca and Mg are respectively 32.0 – 42.0, 1.2 – 4.5, 10.0 – 30.0, 7.0 – 23.0, and 4.0 – 10.0 g kg^?1. Those for micronutrients B, copper (Cu), iron (Fe), zinc (Zn), and manganese (Mn) are respectively 20 – 200, 5 – 25, 100 – 600, 25 – 300, and 30 – 200 mg kg^?1. Sufficiency range for SPAD-readings is 45 – 50 SPAD units. All these ranges were established for the commercial harvesting date. The amounts of N, P, K, calcium (Ca), and magnesium (Mg) removed in aboveground biomass are respectively 22.7, 1.6, 26.4, 16.4 and 4.8 kg Mg^?1 of dry biomass.     

Influence of drying on the flavor quality of spearmint (Mentha spicata L.)

Spearmint (Mentha spicata L.) was dried using three different drying methods: oven-drying at 45 degrees C, air-drying at ambient temperature, and freeze-drying. The effect of the drying method on the volatile compounds and on the structural integrity and sensory characteristics of the spice was evaluated. The volatile components from fresh and dried spearmint samples were isolated by simultaneous distillation-extraction (SDE) and analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 28 compounds were identified, carvone, limonene, and 1,8-cineole, in that order, being the main components in all of the samples. Oven-drying at 45 degrees C and air-drying at ambient temperature were the methods that produced the best results. An increase in monoterpenes was observed in all of the dried samples, except in the freeze-dried samples that underwent freezing at -198 degrees C. Freeze-drying resulted in substantial losses in oxygenated terpenes and sesquiterpenes. The effect of each drying method on leaf structure was observed by scanning electron microscopy. From a sensory standpoint, drying the spearmint brought about a decrease in herbaceous and floral notes together with an increase in minty odor.     

Dissipation of propiconazole and tebuconazole in peppermint crops (Mentha piperita (Labiatae)) and their residues in distilled oils

The broad-spectrum, systemic fungicides propiconazole (1) and tebuconazole (2) are used to control rust in peppermint (Mentha piperita L.). An analytical method, using gas chromatography combined with detection by high-resolution mass spectrometry, was developed to allow for the simultaneous monitoring of both pesticides in peppermint leaves and oil. Field trials were established to determine the rate of dissipation of tebuconazole and propiconazole in peppermint crops. Three applications of each fungicide were trialed at two rates (125 and 250 g of active ingredient (ai)/ha). At harvest, 64 days after the final application, propiconazole was detected at levels of 0.06 mg/kg and 0.09 mg/kg of dry weight, and tebuconazole was detected at 0.26 and 0.80 mg/kg dry weight, in identical trials. Rates of dissipation of propiconazole and tebuconazole were lower at a second trial site, where three applications of 125 g/ha ai for each fungicide resulted in residue levels of 0.21 mg/kg for both pesticides, detected 89 days after the last application. Propiconazole and tebuconazole were detected in the distilled oil at levels between 0.02 and 0.05 mg/kg and between 0.011 and 0.041 mg/kg, respectively. Propiconazole had a higher tendency to co-distill with the peppermint oil, with 0.7% of that present in the vegetative material ending up in the oil, compared to 0.09% of tebuconazole.     

Influence of different dates of planting on growth,herb, oil yield and quality of essential oil of menthol mint (Mentha arvensis) in the North Indian Plain

A field experiment was conducted for two years (2007–2008 and 2008–2009) to study the effect of different dates of planting for three menthol mint (Mentha arvensis) cultivars (Saksham, Kushal and Kosi; developed by Central Institute of Medicinal and Aromatic Plants, Lucknow, India) on herb yield, oil yield and oil quality. All the cultivars produced higher herb and oil yields when planted on 18 February, compared with cultivars planted on other dates in both years. Average herb yield for Saksham increased by 12.89, 30.66, 54.01 and 85.71%, average herb yield for Kushal increased by 15.09, 30.57, 71.69 and 104.91%, and average herb yield for Kosi increased by 32.48, 53.28, 87.23 and 109.49% when planted on 4 January, 19 January, 3 February and 18 February, respectively, over cultivars planted on 20 December. Among the cultivars, Kosi produced a higher herb yield than Saksham and Kushal planted on 18 February. Saksham, Kushal and Kosi produced ～89.39, 152.04 and 170.22% higher oil yield, when planted on 18 February over their respective planting date of 20 December. Maximum menthol content was recorded in cultivar Saksham when planted on 18 February and in Kushal and Kosi when planted on 4 March.     

Harvest of green willow biomass for feed – effects of harvest time and frequency on yield,nutrient concentration,silage quality and regrowth

ABSTRACT

This study investigated the effects of harvest time during the growth season on yield, quality and regrowth of willow. An eight-year-old willow field was harvested in April 2017, and biomass was harvested either once during 2017 on five dates from 13 June to 27 October, harvested twice in June and October or not harvested in 2017. Biomass yield, nutrient uptake and silage quality were measured for 2017 harvests, and regrowth yield was measured in November 2018. Postponing harvest from June to October increased dry matter (DM) mass fraction from 17.4 to 42.8% and decreased the concentration of ash, N, P and K in DM with N decreasing from 33.3 to 9.7?g kg^?1. pH in willow silage decreased with the later harvest. DM yield increased from 1.1 to 5.8 Mg ha^?1 from June to September and decreased to 4.5 Mg ha^?1 in October, and two harvests in 2017 only yielded 2.2 Mg ha^?1 in total. The sum of DM yields in 2017 and 2018 were 11.4 Mg ha^?1 without harvest in 2017 and ranged between 5.2 and 9.8 Mg ha^?1 when harvested in 2017.     

Improvement of yield,yield components and oil quality in sesame (Sesamum indicum L.) by N-fixing bacteria fertilizers and urea

Experiments were conducted in 2009–2010 at the Agricultural and Natural Resources Research Center of Yazd, Iran, to study the effect of nitrogen levels and plant growth-promoting rhizobacteria (PGPR) containing Azotobacter sp. and Azospirillum sp. on seed yield, its components and quality traits of sesame cultivars. Treatments were arranged in a factorial experiment based on randomized complete block design with nitrogen rates (0 (control), 25 and 50 kg N ha^?1), cultivars (Darab-14, GL-13 and local) and N-fixing bacteria levels (non-inoculation and inoculation) were applied with three replications. Nitrogen fertilizer significantly increased yield and yield components, but reduced oil content in 2010. Inoculating seeds with PGPR increased yield and yield components of sesame cultivars compared to the control treatment. Seed yield in PGPR inoculation with half a rate of N fertilizer treatment was more than seed yield in the full rate of N fertilizer without a PGPR inoculation treatment. N fertilizer and PGPR application significantly decreased saturated fatty acids (palmitic and stearic acid) while it significantly increased unsaturated fatty acids (oleic and linoleic acid). Oleic acid had a significant negative correlation with linoleic acid (r = ?0.79). The result showed that an application of PGPR could be usefully applied to reduce use of chemical fertilizer.     

Production of yarrow (Achillea millefolium L.) in Norway: essential oil content and quality

In 1996, the production of Achillea millefolium L. at different locations in Norway was investigated with regard to the developmental stage. The oil content differed greatly between the vegetative stage (0.13%) and the stage of full bloom (0.34%). Changes in the composition of yarrow essential oil were found to be related to maturation of the plant, with increasing amounts of monoterpenes in relation to the sesquiterpene. However, a clear trend could be detected only for the monoterpenic compounds with increasing levels of alpha- and beta-pinene and alpha-thujone and decreasing levels of sabinene, borneol, and bornyl acetate. Previously reported as major compounds, chamazulene and germacrene D could be found only in insignificant amounts. A solid-phase microextraction (SPME) procedure was applied for screening of the terpenic composition. Sesquiterpenic compounds such as beta-bisabolene, alpha-bisabolol, and delta-cadinene were detected in substantial amounts by SPME in contrast to the steam-distilled samples.     

Effect of drying method on the volatiles in bay leaf (Laurus nobilis L.)

The effect of different drying treatments on the volatiles in bay leaf (Laurus nobilis L.) was studied. Simultaneous distillation extraction (SDE) and solid-phase microextraction (SPME) were compared by gas chromatography-mass spectrometry (GC-MS) of the volatile components in bay leaves. SDE yielded better quantitative analysis results. Four drying treatments were employed: air-drying at ambient temperature, oven-drying at 45 degrees C, freezing, and freeze-drying. Oven drying at 45 degrees C and air-drying at ambient temperature produced quite similar results and caused hardly any loss in volatiles as compared to the fresh herb, whereas freezing and freeze-drying brought about substantial losses in bay leaf aroma and led to increases in the concentration levels of certain components, e.g., eugenol, elemicin, spathulenol, and beta-eudesmol.     

Effect of nutrient solution salinity and ionic concentration on parsley (Petroselinum crispum Mill.) essential oil yield and content

The growth and essential oil (EO) production of parsley were evaluated in response to salinity and nutrient solution concentrations in a soilless culture. Parsley plants that were 60 days old were potted in a coconut fiber and peat moss medium and were treated with four different nutrient solutions, including T1, T2, T3 and T4. The T1 nutrient solution was the standard, the T2 and T3 solutions contained incremental macronutrient concentrations with an electrical conductivity (EC) of up to 2.2 and 3.2 dS m^?1, respectively, and the T4 solution was the same as T2 but with sodium chloride (NaCl) and an incremental macronutrient concentration with an EC of 3.2 dS m^?1. Next, these plants were grown for 90 days in a greenhouse with natural daylight in Nador, Morocco. Shoot and root growth significant decreased with increasing EC. However, the salinity that resulted from the addition of NaCl did not affect plant growth in the nutrient solutions. The optimum obtained growth and EO production were 1.2 and 2.2 dS m^?1, respectively. Consequently, the optimum EC value (based on the EO production) of parsley in the soilless culture was 1.2–2.2 dS m^?1.     

Influence of organic mulching and nitrogen application on essential oil yield and nitrogen use efficiency of rosemary (Rosmarinus officinalis L.)

In a field study conducted at Bangalore, India for two years (2003–2004 and 2004–2005), eight treatment combinations consisting of two variables, organic mulch (lemongrass spent material as mulch at 7.5 t ha^?1 and no mulch) and four levels of nitrogen fertilizer (0, 100, 200 and 300 kg ha^?1) were examined to observe the effect of organic mulching on nitrogen use-efficiency, and herb and essential oil yield in a multiharvested rosemary crop. The results revealed that application of lemongrass spent material as mulch increased the herb and essential oil yields in rosemary by 16.2 and 24.2%, respectively, over the non-mulched control at first harvest. Corresponding values for the regenerated crop harvest were 18.8 and 16.8%. A significant response to N was observed with 300 kg N ha^?1 in non-mulched plots compared with 200 kg N ha^?1 in mulched plots. Using lemongrass spent material as mulch, nitrogen uptake by the rosemary crop increased by 15.1% over the non-mulched control. At 200 kg N ha^?1, apparent recoveries by the crop were estimated to be 33.64% for the non-mulched control, and 37.79% with mulch. The quality of the rosemary essential oil, in terms of the concentrations of its major constituents, α-pinene, 1 : 8 cineole, camphor and verbenone, was not affected by the use of organic mulching and nitrogen fertilization, and these constituents were found to be of astandard acceptable in international trade.     

Nutrient solution concentration and collection time in phytomass production,content, yield and chemical composition of essential oil of rosemary

Rosmarinus officinalis L. (rosemary), is a medicinal and aromatic species used in the cosmetics and food processing industries. The present study aimed to evaluate the biomass production, content, yield and chemical composition of the essential oil of rosemary in cultivation out of soil with different concentrations of nutrient solution in both harvests. The cultivation of rosemary was conducted in a protected system off the ground, with concentrations of nutrient solutions of 1, 2, 3, 4 and 5 dS.m^?1 for fertigation with collections of leaves 100 and 160 days after planting. Nutrient solution concentration influences phytomass production and the content and yield of essential oil of rosemary, though not its chemical composition. The collection time does not interfere in the content of essential oil; however, does interfere in the chemical composition; the production of phytomass and the yield of oil per plant are higher in collections at 160 days after planting.     

Genotype and harvest time influence the phytochemical quality of Fino lemon juice (Citrus limon (L.) Burm. F.) for industrial use

Two clonal selections of lemon tree (Citrus limon Burm. f. cv. Fino), named Fino-49-5 and Fino-95, were studied to ascertain the influence of genetic (clone) and environmental (season) factors on the human-health bioactive compounds of lemon juice (vitamin C and flavonoids) and the possible relationship between composition and in vitro antioxidant capacity (2,2-diphenyl-1-picrylhydrazyl, 2,2'-azino-bis(3-ethyl-benzothiazoline-6-sulfonic acid), and ferric reducing antioxidant power) of the juice. The cultivar Fino-49-5 performed better in terms of flavonoid and vitamin C contents. Variability in the weather conditions determined, at least in part, differences in the content of lemon juice bioactives more importantly than the genetic background did. Therefore, the food industry would have phytochemically rich and nutritive lemons with practically complete independence of the harvest time and the selected cultivar.     

Seasonal changes in microbial biomass in soils cropped with palmarosa (Cymbopogon martinii L.) and Japanese mint (Mentha arvensis L.) in subtropical India

Changes in microbial C, N, and P were investigated for 1 year in two soils with similar physicochemical properties but supporting different crops under subtropical conditions. One was cropped with palmarosa (Cymbopogon martinii L.) and the other with Japanese mint (Mentha arvensis L.). Both the season and the type of cropping had a significant influence on changes in the soil microbial biomass. In general, soil microbial biomass C, N, and P were highest in summer months and lowest in midwinter. Soil microbial biomass levels and microbial C:N and C:P ratios were higher and N:P ratios lower under palmarosa soil than under mint.     

Nitrogen,phosphorus, and potassium effects on the physiology and biomass yield of baby spinach (Spinacia oleracea L.)

Baby spinach is a relatively new crop of commercial significance in South Africa with considerable health attributes. Three parallel trials to investigate its response to nitrogen (N), phosphorus (P), and potassium (K) were conducted. N and P (0, 45, 75, 105, and 120 kg·ha^?1) and K (0, 63, 85, 127, and 148 kg·ha^?1) treatments were applied to baby spinach in a randomized block design with four replications. After the parallel trial, NPK combination trial was also done. The biomass yield, chlorophyll content, and leaf area index increased significantly with increase in N and P rates; K had no effect on the yield, chlorophyll content, stomatal conductance, and leaf area index. Yield and chlorophyll content peaked at 75 kg·ha^?1 of N/P but growth was best optimized at the NPK combination of 45:45:60 kg·ha^?1.     

Effect of placement of urea and coated urea fertilizers on yield and quality of soybean (Glycine max (L.) Merr.) seeds

The objective of the present study was to record the seed yield and to examine visually the quality of soybean seeds cultivated under different types and placements of urea fertilizers. In addition to the conventional fertilizer application (including ammonium sulfate 16 kg N ha^-1 broadcasting (100 kg N ha^-1 of urea (0B) and X00-d type coated urea CU-100 (CUB), and deep placement (100 kg N ha^-1) of urea (UD) and 100-d type coated urea CU-100 (CUD) was conducted in separate plots in a paddy field converted to an upland field located at Shindori Experimental Station of Niigata University. Soybean plant growth was periodically analyzed and the quality of harvested seeds was also visually examined (hereafter referred to as “visual quality”). It was found that the deep placement treatments were more conducive 1o nitrogen (N₂)fixation, based on the relative mreide N concentration in the xylem sap, which is a good indicator of N~fixation by soybean. Also the total seed yield was the highest in CUD (82 g plant^-1) and 0D (81 g plant^-1), compared to the control (62 g plant^-1), UB (68 g plant^-1), and CUB (68 g plant^-1). The visual quality of harvested seeds showed that CUD enhanced the quality of seeds compared to the other treatments, in which the percentage of good quality seeds, hereafter referred to as "good seeds," based on the dry weight was 51 (control), 65 (K3B), 61 (CUB), 61 (0D), and 6696 (CUD). In terms of diseased seeds, the percentage of turtle wrinkle and broken seed coats was found to decrease by N application compared to the control. Thus, it is suggested that N fertilization management is important for maximum yield of soybean as well as for the enhancement of seed quality.     

不同栽培法和收割期对甘蔗单产及含糖量影响的分析

本研究利用1975～2008年33年间日本南大东岛甘蔗生产数据, 分析了甘蔗栽培方法[新苗种植(包括夏植和春植)、宿根]和收割时期对其产量、品质和经济性的影响.结果表明, 不同栽培法甘蔗多年平均产量依次为夏植>宿根>春植; 新植甘蔗的种植期越早产量越高; 宿根甘蔗产量与前茬甘蔗的收割期呈二次函数曲线关系, 前茬甘蔗收割过早或过迟均对宿根甘蔗生长不利; 宿根甘蔗产量随宿根次数增加呈下降趋势; 宿根甘蔗含糖量通常高于新植甘蔗, 且不同栽培法下3月下旬前收获的甘蔗含糖量随收割期后延而逐渐增加.在此基础上, 建立了依据栽培方法、收割时期预测甘蔗单产和含糖量的数学模型, 模型对我国甘蔗种植业具有理论和实际的参考价值.     

Composition,quality control,and antimicrobial activity of the essential oil of long-time stored dill (Anethum graveolens L.) seeds from Bulgaria

The essential oil of long-time stored seeds of dill (Anethum graveolens L.) from Bulgaria was analyzed by physicochemical methods, gas chromatography (GC), GC-mass spectrometry (MS) (achiral and chiral phases), and olfactometry, and its antimicrobial activity was tested by using different strains of microorganisms. More than 40 constituents of the essential dill oil, obtained from seeds stored for more than 35 years, could be identified as essential volatiles, responsible for the pleasant fresh (D-limonene) and spicy (D-carvone) odor of a high quality. As aroma impact compounds, D-carvone (50.1%) and D-limonene (44.1%) were found. Antimicrobial testings showed high activity of the essential A. graveolens oil against the mold Aspergillus niger and the yeasts Saccharomyces cerevisiae and Candida albicans.