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2.
Environ Sci Pollut Res Int ; 28(19): 24279-24290, 2021 May.
Article in English | MEDLINE | ID: mdl-32026184

ABSTRACT

Large quantities of spent coffee grounds (SCG) are generated the last decades, and their recycling is of research interest challenge. In the present study, SCG was tested to substitute peat (P) in substrate mixtures for the production of Brassica seedlings. Seeds of cauliflower, broccoli, and cabbage were placed in substrate mixtures containing 0-2.5-5-10% SCG. The mixture of SCG with peat affected several physicochemical characteristics of the growing media, providing also considerable amount of mineral elements for the seedling growth needs. Seed emergence was stimulated in 2.5-5% of SCG for cauliflower and at 2.5% of SCG for cabbage, while 10% of SCG decreased the percentage and increased the mean emergence time of the examined species. Plant biomass and leaf number were increased at 2.5% SCG for broccoli and cabbage but maintained at cauliflower when compared with control. The SCG at 10% decreased stomatal conductance of broccoli and cabbage (including 2.5-5% SCG in cauliflower) while chlorophyll content was increased at 10% of SCG media. The incorporation of SCG impacted the mineral content accumulated in plants with increases in nitrogen, potassium, and phosphorus and decreases in magnesium and iron content. Total phenolics and antioxidant activity (DPPH, FRAP) decreased at ≥ 5% SCG at cauliflower and cabbage or unchanged for broccoli when compared with the control. The cabbage seedlings grown in 10% SCG media subjected to stress with increases in the production of hydrogen peroxides and lipid peroxidation, and reflected changes in the antioxidant enzymatic metabolism (catalase, superoxide dismutase). The present study demonstrates that SCG (up to 5%) can be used for seed germination biostimulants and/or partially substitute the peat for Brassica seedling production.


Subject(s)
Brassica , Nurseries, Infant , Coffee , Humans , Infant , Seedlings , Soil
3.
Curr Pharm Des ; 26(16): 1816-1837, 2020.
Article in English | MEDLINE | ID: mdl-32013820

ABSTRACT

BACKGROUND: There is an increasing interest from the pharmaceutical and food industry in natural antioxidant and bioactive compounds derived from plants as substitutes for synthetic compounds. The genus Allium is one of the largest genera, with more than 900 species, including important cultivated and wild species, having beneficial health effects. OBJECTIVE: The present review aims to unravel the chemical composition of wild Allium species and their healthrelated effects, focusing on the main antioxidant compounds. For this purpose, a thorough study of the literature was carried out to compile reports related to health effects and the principal bioactive compounds. Considering the vast number of species, this review is divided into subsections where the most studied species are presented, namely Allium ampeloprasum, A. flavum, A. hookeri, A. jesdianum, A. neapolitanum, A. roseum, A. stipitatum, A. tricoccum, and A. ursinum, with an additional composite section for less studied species. METHODS: The information presented in this review was obtained from worldwide accepted databases such as Scopus, ScienceDirect, PubMed, Google Scholar and Researchgate, using as keywords the respective names of the studied species (both common and Latin names) and the additional terms of"antioxidants" "health effects" and "bioactive properties". CONCLUSION: The genus Allium includes several wild species, many of which are commonly used in traditional and folklore medicine while others are lesser known or are of regional interest. These species can be used as sources of natural bioactive compounds with remarkable health benefits. Several studies have reported these effects and confirmed the mechanisms of action in several cases, although more research is needed in this field. Moreover, considering that most of the studies refer to the results obtained from species collected in the wild under uncontrolled conditions, further research is needed to elucidate the effects of growing conditions on bioactive compounds and to promote the exploitation of this invaluable genetic material.


Subject(s)
Allium , Antioxidants/chemistry , Antioxidants/pharmacology , Plant Extracts/chemistry , Plant Extracts/pharmacology
4.
J Sci Food Agric ; 100(2): 732-743, 2020 Jan 30.
Article in English | MEDLINE | ID: mdl-31597201

ABSTRACT

BACKGROUND: Using water with high salinity for plant fertigation may have detrimental effects on plant development and total yield and on the quality of the crop produced. As a possible means to alleviate the negative effects of salinity, silicon (Si) can be incorporated in the nutrient solution supplied to plants. In the present study, hydroponically grown tomato (Solanum lycopersicum Mill.) plants were subjected to two different salinity levels (0 and 50 mmol L-1 NaCl) with and without the application of Si (0 and 2 mmol L-1 K2 SiO3 ) in order to evaluate its possible positive impact on mitigation of salinity stress-induced symptoms. An additional experiment was implemented with postharvest Si application (sodium silicate) to investigate effects on the shelf-life of tomato fruit. RESULTS: Salinity (50 mmol L-1 NaCl) decreased plant size, total yield and fresh fruit weight while a high percentage of blossom end rot symptoms of tomato fruit was also observed. The application of Si in the nutrient solution counteracted these detrimental effects, generating a higher yield and healthier fruit (lower blossom end rot incidence) compared to the untreated plants (no application of Si). Salinity improved several quality-related traits in tomato fruit, resulting in higher marketability, whereas the addition of Si (pre- and postharvest) maintained fruit firmness following storage thereby increasing the shelf-life of tomato fruit. CONCLUSIONS: These findings indicate that Si application (pre- and postharvest) could provide an effective means of alleviating the unfavorable effects of using low-quality water in plant fertigation on tomato plant development, fruit yield and post-harvest quality, through increased fruit firmness. © 2019 Society of Chemical Industry.


Subject(s)
Crop Production/methods , Fruit/chemistry , Silicon/pharmacology , Sodium Chloride/pharmacology , Solanum lycopersicum/drug effects , Flowers , Fruit/drug effects , Fruit/metabolism , Hydroponics , Solanum lycopersicum/chemistry , Solanum lycopersicum/metabolism , Salinity
5.
Molecules ; 24(24)2019 Dec 08.
Article in English | MEDLINE | ID: mdl-31817970

ABSTRACT

In the present study, the effect of biostimulants application on the nutritional quality and bioactive properties of spinach cultivated in protected environment under water stress conditions was evaluated. For this purpose, four commercially available biostimulant products (Megafol (MEG), Aminovert (AM), Veramin Ca (V), Twin Antistress (TA), and two spinach genotypes (Fuji F1 and Viroflay) were tested under two irrigation regimes (normal irrigation (W+), and water-holding (W-). Fat and carbohydrates content was favored by water stress when Megafol (MEGW+) and Veramin (VW+) were applied on Fuji plants, while calorific value was also increased by MEGW+ treatment. In contrast, protein and ash content increased when AMW- and TAW+ were applied on Viroflay plants. Raffinose and glucose were the most abundant sugars, followed by sucrose and fructose, with the highest contents recorded for Fuji plants when AMW+ (fructose, glucose and total carbohydrates), CW- (sucrose), and TAW- (raffinose) treatments were applied. Regarding organic acids, oxalic and malic acid which had the highest contents for the TAW- (Viroflay plants) and AMW- (Fuji plants) treatments, respectively. α- and γ-tocopherol were the only isoforms detected with MEGW- and VW- inducing the biosynthesis of α-tocopherol, while AMW+ increased γ-tocopherol content in Fuji plants. The main fatty acids were α-linolenic and linoleic acids which were detected in the highest amounts in AMW-, AMW+, and TAW+ the former and in AMW-, VW-, and CW+ the latter. Regarding phenolic compounds content, peak 12 (5,3',4'-Trihydroxy-3-methoxy-6:7-methylenedioxyflavone-4'-glucuronide) was the most abundant compound, especially in Viroflay plants under normal irrigation and no biostimulants added (CW-). The antioxidant and cytotoxic activity of the tested samples did not show promising results when compared with the positive controls, while a variable antibacterial activity was recorded depending on the tested biostimulant, irrigation regime and genotype. In conclusion, a variable effect of the tested biostimulants and irrigation regimes was observed on bioactive properties and chemical composition of both spinach genotypes which highlights the need for further research in order to make profound conclusions regarding the positive effects of biostimulants under water stress conditions.


Subject(s)
Antioxidants/chemistry , Spinacia oleracea/chemistry , Water/chemistry , Dehydration/genetics , Fertilizers , Genotype , Nutritive Value , Phenols/chemistry , Spinacia oleracea/genetics
6.
Antioxidants (Basel) ; 8(12)2019 Dec 04.
Article in English | MEDLINE | ID: mdl-31817206

ABSTRACT

During the last few decades, the food and beverage industry faced increasing demand for the design of new functional food products free of synthetic compounds and artificial additives. Anthocyanins are widely used as natural colorants in various food products to replenish blue color losses during processing and to add blue color to colorless products, while other compounds such as carotenoids and betalains are considered as good sources of other shades. Root vegetables are well known for their broad palette of colors, and some species, such as black carrot and beet root, are already widely used as sources of natural colorants in the food and drug industry. Ongoing research aims at identifying alternative vegetable sources with diverse functional and structural features imparting beneficial effects onto human health. The current review provides a systematic description of colored root vegetables based on their belowground edible parts, and it highlights species and/or cultivars that present atypical colors, especially those containing pigment compounds responsible for hues of blue color. Finally, the main health effects and antioxidant properties associated with the presence of coloring compounds are presented, as well as the effects that processing treatments may have on chemical composition and coloring compounds in particular.

7.
J Sci Food Agric ; 99(13): 6049-6059, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31342530

ABSTRACT

BACKGROUND: The scarcity of irrigation water is severely affecting global crop production. In this context, biostimulants are increasingly used as alternatives means against abiotic stress conditions. In this study, phenolic compounds composition and bioactive properties of common bean (Phaseolus vulgaris L.) plants grown under water stress conditions and biostimulants application were investigated. RESULTS: Sixteen individual phenolic compounds were detected in both pods and seeds with a notable difference in their compositional profile. A significant effect on phenolic compounds content and composition was also observed for the biostimulants tested. Regarding the antibacterial activity, pods of the second harvest and seed extracts showed significant efficacy against Bacillus cereus, especially in water-stressed plants, where all biostimulant treatments were more effective than positive controls. Moreover, all biostimulant treatments for seed extracts of water-stressed plants were more effective against Staphylococcus aureus compared with ampicillin, whereas streptomycin showed the best results. Extracts from pods of the second harvest from normally irrigated plants showed the best results against the fungi tested, except for Penicillium verrucosum var. cyclopium. Finally, no significant cytotoxic effects were detected. CONCLUSION: In conclusion, the biostimulants tested increased total phenolic compounds content compared with control treatment, especially in pods of the first harvest and seeds of water-stressed plants. Moreover, bioactive properties showed a varied response in regard to irrigation and biostimulant treatment. Therefore, biostimulants can be considered as a useful means towards increasing phenolic compounds content, and they may also affect the antimicrobial properties of pods and seeds extracts. © 2019 Society of Chemical Industry.


Subject(s)
Dehydration , Phaseolus/chemistry , Phaseolus/physiology , Phenols/pharmacology , Plant Extracts/pharmacology , Water/metabolism , Bacillus cereus/drug effects , Bacillus cereus/growth & development , Phaseolus/growth & development , Phaseolus/microbiology , Phenols/chemistry , Phenols/metabolism , Plant Extracts/chemistry , Plant Extracts/metabolism , Seeds/chemistry , Seeds/growth & development , Seeds/metabolism , Seeds/microbiology , Staphylococcus aureus/drug effects , Staphylococcus aureus/growth & development , Stress, Physiological , Water/analysis
8.
Food Microbiol ; 83: 200-210, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31202414

ABSTRACT

Fresh vegetables are important components of an everyday balanced diet making ready to-eat-salads (RTE) a commodity widely consumed. However, in the past few years these products have been linked with outbreaks of salmonellosis and listeriosis; thus the continuous investigation of their safety is an essential requirement. A total of 216 samples of ready-to-eat salads from the Cypriot market were analysed to determine the microbiological quality and safety, along with physicochemical attributes of the salads and identify possible correlations between them. The samples were randomly collected from four retail outlets and correspond to five different salad producing companies. Furthermore, the effects of season, salad producer and type of salad and/or their interactions with the tested parameters were investigated. The results revealed that the higher microbial load among seasons was observed in samples collected during spring. Escherichia coli was found in 11.57% of samples and 2.62% of isolates were found to be able to produce extended spectrum ß-lactamase (ESBL). All samples were found negative for Salmonella enterica, whereas Listeria monocytogenes was present in 3.70% of samples. Higher levels of spoilage bacteria (lactic acid bacteria and Pseudomonas spp.) were detected during winter and spring. Additionally, the %CO2 production was affected by the type of salad, while the interaction between producer and type of salad, affected total phenolic content and antioxidant activity of samples. A positive correlation of phenols and antioxidants with the presence of Staphylococcus spp., Pseudomonas spp., E. coli and Bacillus cereus was observed, suggesting that excessive handling increases microbial load and plant stress.


Subject(s)
Bacterial Load , Food Contamination/analysis , Food Microbiology , Raw Foods/microbiology , Vegetables/microbiology , Antioxidants/analysis , Colony Count, Microbial , Consumer Product Safety , Cyprus , Escherichia coli/isolation & purification , Fast Foods/microbiology , Listeria monocytogenes/isolation & purification , Phenols/analysis , Seasons
9.
Food Chem ; 289: 404-412, 2019 Aug 15.
Article in English | MEDLINE | ID: mdl-30955630

ABSTRACT

In the present study, the nutritional value, bioactive properties, and chemical composition of various cardoon (Cynara cardunculus L.) genotypes cultivated in central Greece were investigated. The results demonstrated that Cynara seeds are a good source of fat and protein, while they also contain considerable amounts of K, Mg, and Fe and low amount of Na. Sucrose, oxalic acid, and α-tocopherol were the only free sugar, organic acid, and tocopherol isoform respectively, found among the studied genotypes. The most abundant fatty acids were linoleic, oleic and palmitic acid, while PUFA was the most abundant fatty acid class. All the tested seeds contained only two phenolic compounds, namely 5-O-caffeoylquinic acid and 3,5-O-caffeoylquinic acid, while significant antioxidant activities and cytotoxicity against tumor cell lines and antimicrobial effects were also observed. In conclusion, cardoon seed extracts could be exploited in the food and pharmaceutical industries as alternative sources of natural compounds with bioactive properties.


Subject(s)
Cynara , Nutritive Value , Seeds/chemistry , Antineoplastic Agents, Phytogenic/analysis , Antioxidants/analysis , Carbohydrates/analysis , Chlorogenic Acid/analogs & derivatives , Chlorogenic Acid/analysis , Cynara/chemistry , Cynara/genetics , Fatty Acids/analysis , Genotype , Greece , Phenols/analysis , Plant Proteins/analysis , Quinic Acid/analogs & derivatives , Quinic Acid/analysis
10.
J Sci Food Agric ; 99(7): 3644-3652, 2019 May.
Article in English | MEDLINE | ID: mdl-30637758

ABSTRACT

BACKGROUND: Edible flowers have both great nutritional value and sensory appeal; however, their shelf-life is limited to a few days because they are highly perishable. RESULTS: The impact of postharvest ethanol (ET) treatment and modified atmosphere packaging (MAP) on the quality and storage of edible flowers collected from short-term salt-stressed plants was tested. Hydroponically grown petunia (Petunia x hybrita L.) plants were subjected to salinity (0-50-100 mmol L-1 NaCl) and harvested flowers were stored for up to 14 days in MAP and/ET vapours. The salinity of 100 mmol L-1 NaCl decreased plant biomass and negatively affected physiological processes as a result of stomata closure. Flower polyphenols, antioxidants, carotenoids and anthocyanins increased with 50 mmol L-1 of NaCl, indicating a higher nutritional value. Short-term exposure of petunia to salinity decreased the flower N, K and Ca concentrations. During storage for 7 days, salinity lead to deteriorated flowers that showed browning as a result of tissue breakdown, whereas CO2 production and weight loss were unaffected by salinity. After 14 days of storage, salinity decreased flower respiration and increased weight loss, whereas ET application completely destroyed the flowers. Carotenoids and anthocyanins were decreased by a combination of salinity and ET. Petunia flowers revealed the induction of both non-enzymatic (i.e. proline content) and enzymatic (catalase) mechanisms to overcome the stress caused by salinity at harvest stage and/or ethanol at storage. CONCLUSION: The results of the present study demonstrate that a short-stress salinity of 50 mmol L-1 NaCl can be used for petunia growth and also that flowers of nutritional value can be stored for up to 7 days, whereas ET application failed to preserve petunia flowers. © 2019 Society of Chemical Industry.


Subject(s)
Flowers/chemistry , Flowers/drug effects , Food Preservation/methods , Petunia/growth & development , Anthocyanins/analysis , Anthocyanins/metabolism , Antioxidants/analysis , Antioxidants/metabolism , Carotenoids/analysis , Carotenoids/metabolism , Ethanol/pharmacology , Flowers/growth & development , Flowers/metabolism , Food Packaging , Petunia/chemistry , Petunia/drug effects , Petunia/metabolism , Sodium Chloride/metabolism
11.
Environ Sci Pollut Res Int ; 26(35): 35461-35472, 2019 Dec.
Article in English | MEDLINE | ID: mdl-30673946

ABSTRACT

In the Mediterranean region, olive-stone waste (OSW) is accumulated and considered of environmental and human health constraints. In this study, OSW was used for peat (P) replacement in growing media for Brassica seedling production. Cauliflower, broccoli, and cabbage were seeded in growing media consisted of 0-20-40-60% OSW. The mixture of OSW with peat increased growing media bulk density and reduced the total pore space and available water and air at root system. A Considerable amount of minerals were provided into the growing media with the OSW, while their availability was increased with the raised pH values. Seed emergence percentage decreased with high ratio of OSW which also increased mean emergence time. The addition of OSW decreased plant height, leaf number, and fresh weight in all three examined species. The OSW decreased stomatal conductance (in cauliflower and cabbage) and chlorophylls content (including broccoli). The insertion of OSW affected the mineral accumulation in plants with decreases in nitrogen and sodium content and increases in potassium and calcium. OSW increased to some extent for cauliflower and broccoli or unchanged for cabbage polyphenolic content and antioxidant activity (ABTS, FRAP). Cellular damage was caused by the addition of OSW by increasing the lipid peroxidation and the production of hydrogen peroxide, and as a consequence, the plant antioxidative (catalase, superoxide dismutase) enzyme metabolism increased. The current study demonstrates that up to 20% of OSW can substitute peat for cauliflower, broccoli, and cabbage seedling production while cabbage was performed better under the increased OSW-caused stress.


Subject(s)
Brassica/metabolism , Olea/metabolism , Seedlings/metabolism , Antioxidants/metabolism , Brassica/chemistry , Catalase/chemistry , Catalase/metabolism , Chlorophyll/chemistry , Chlorophyll/metabolism , Humans , Lipid Peroxidation , Olea/chemistry , Plant Leaves/metabolism , Seedlings/chemistry , Soil/chemistry , Superoxide Dismutase/metabolism
12.
J Plant Physiol ; 232: 27-38, 2019 Jan.
Article in English | MEDLINE | ID: mdl-30530201

ABSTRACT

Marginal water, including saline water, has been proposed as an alternative source of irrigation water for partially covering plant water requirements due to scarcity of adequate water supply in hot arid and semi-arid areas, such as those usually found in the Mediterranean basin. In the present study, spearmint plants (Mentha spicata L.) were grown in a deep flow hydroponic system under saline conditions, namely 0, 25, 50, and 100 mM NaCl. Moreover, foliar application of specific cations (K, Zn, Si) was tested as a means for alleviation of salinity stress under a plant physiological and biochemical approach. The results indicated that the highest salinity level of 100 mM NaCl severely affected plant growth, photosynthetic rates, leaf stomatal conductance, content of total phenolics and antioxidant status, while low to moderate salinity levels (25-50 mM NaCl) did not significantly affect plant growth and biochemical functions. In addition, leaf potassium and calcium accumulation decreased in saline-treated plants. Cations foliar application had small to no effect on plant growth, although it increased antioxidant activity and detoxified oxidative stress products/effects, through the increased enzymatic activities and proline accumulation. The present results have demonstrated that spearmint could be considered as a salinity tolerant species which is able to grow successfully under moderate salinity levels, while cation enrichment through foliar sprays was proved as a useful means to alleviate the stress effects caused by high salinity.


Subject(s)
Mentha spicata/physiology , Plant Leaves/drug effects , Antioxidants/metabolism , Mentha spicata/drug effects , Mentha spicata/metabolism , Photosynthesis/drug effects , Photosynthesis/physiology , Plant Leaves/metabolism , Plant Leaves/physiology , Plant Transpiration/drug effects , Plant Transpiration/physiology , Potassium/pharmacology , Salt Stress , Silicon/pharmacology , Zinc/pharmacology
13.
Front Plant Sci ; 9: 489, 2018.
Article in English | MEDLINE | ID: mdl-29731759

ABSTRACT

Saline water has been proposed as a solution to partially cover plant water demands due to scarcity of irrigation water in hot arid areas. Lavender (Lavandula angustifolia Mill.) plants were grown hydroponically under salinity (0-25-50-100 mM NaCl). The overcome of salinity stress was examined by K, Zn, and Si foliar application for the plant physiological and biochemical characteristics. The present study indicated that high (100 mM NaCl) salinity decreased plant growth, content of phenolics and antioxidant status and essential oil (EO) yield, while low-moderate salinity levels maintained the volatile oil profile in lavender. The integrated foliar application of K and Zn lighten the presumable detrimental effects of salinity in terms of fresh biomass, antioxidant capacity, and EO yield. Moderate salinity stress along with balanced concentration of K though foliar application changed the primary metabolites pathways in favor of major volatile oil constituents biosynthesis and therefore lavender plant has the potential for cultivation under prevalent semi-saline conditions. Zn and Si application, had lesser effects on the content of EO constituents, even though altered salinity induced changings. Our results have demonstrated that lavender growth/development and EO production may be affected by saline levels, whereas mechanisms for alteration of induced stress are of great significance considering the importance of the oil composition, as well.

14.
J Sci Food Agric ; 98(15): 5861-5872, 2018 Dec.
Article in English | MEDLINE | ID: mdl-29797323

ABSTRACT

BACKGROUND: Potassium (K) deficiency in leafy vegetables such as lettuce is a major concern regarding quality. Seaweed (SW) extracts, as biostimulants, are biodegradable materials and have become increasingly popular as they are reported to enhance crop growth and yield. RESULTS: In order to overcome K deficiencies (i.e. 375 vs 125 mg L-1 ), alternative foliar applications with extracts of Ascophyllum nodosum SW or K were examined using lettuce plants which were grown hydroponically. Potassium deficiency (at 125 mg L-1 ) reduced plant biomass, photosynthetic rate, leaf stomatal conductance, lettuce potassium content and tissue antioxidant capacity as compared with the higher K level (375 mg L-1 ). Application of SW increased the relative growth of lettuce in the low-K treatment. The K level and/or SW application altered the plant's enzyme protective activity (superoxide dismutase, SOD; catalase, CAT; peroxidase, POD) against oxidative stress and hydrogen peroxide (H2 O2 ) production. Spray applications of SW mitigated the effects of K deficiency on indicators of enzyme activity and plant damage, back to levels of high K content (375 mg L-1 ). The high K level, but also SW application, increased the antioxidant activity of the processed lettuce before storage. Foliar application of the SW extract increased the quality of cut lettuce grown in 125 mg L-1 K conditions by reducing the rate of respiration and increasing consumer preference. CONCLUSION: The SW application could alter the detrimental effects of K deficiency during lettuce growth and storage of processed products. © 2018 Society of Chemical Industry.


Subject(s)
Ascophyllum/chemistry , Lactuca/growth & development , Lactuca/metabolism , Oxidative Stress/drug effects , Plant Extracts/pharmacology , Potassium/metabolism , Seaweed/chemistry , Catalase/metabolism , Food Storage , Lactuca/chemistry , Lactuca/drug effects , Plant Extracts/isolation & purification , Plant Proteins/metabolism , Potassium/analysis , Superoxide Dismutase/metabolism
15.
J Environ Manage ; 216: 89-95, 2018 Jun 15.
Article in English | MEDLINE | ID: mdl-28412057

ABSTRACT

Biochar can be produced from several organic sources with varying nutrients and metal concentrations. Four commercial grade biochars were evaluated as peat substitute. Biochars were characterised for plant nutrients and for biological stability. The results showed that there were negligible quantities of N and P and generally high levels of K and high biological stability. When these materials were mixed with peat at 10, 25 and 50% and nutrients were added to bring them to the same level of nutrients as in fertilized peat, it was found that biochar mixtures considerably reduced the levels of calcium chloride/DTPA (CAT) extractable N (including nitrate), P, and electrical conductivity- greater extent with higher rates of biochar addition except for K. The pH and K levels were increased with biochar addition. The drop in EC has important implications regarding the use of other materials used to dilute peat, for example, composted green waste, the rate of dilution is limited due to high EC and biochar addition gives the potential for higher peat dilution of these materials. Nitrate and phosphorus are very vulnerable to leaching of these nutrients in the environment in peat substrates and the binding of these by biochar has implication for leaching and nutrient application strategy. Root development using Cress test and tomato plant height and biomass using containers, were in some cases better than peat indicating that biochar could be used to dilute peat e.g. for seedling production where root development and rapid growth are very important. Application of biochars resulted in a marked reduction of N (and P) in the plant. There were significant correlation between CAT extractable N and P and corresponding plant concentration, indicating the standard growing media test, CAT, would be suitable for assessing the nutrient status of peat biochar mixes.


Subject(s)
Charcoal , Plant Development , Phosphorus , Soil
16.
Front Plant Sci ; 9: 1765, 2018.
Article in English | MEDLINE | ID: mdl-30619383

ABSTRACT

Irrigation with saline water causes significant crop yield loss. However, short-term saline application might cause less negative effects on yield yet at the same time improve quality aspects of edible products. Tagetes (Tagetes patula L.) plants were subjected to salinity (0, 50, and 100 mM NaCl) and harvested flowers were stored up to 14 days in passive modified atmosphere packaging (with or without ethanol application). Salinity of 100 mM NaCl decreased plant biomass and plant size (i.e., height) and had a negative effect on physiological processes such as stomatal closure and chlorophylls content decrease. Salinity increased flower polyphenols, antioxidant activities, and total carotenoids but decreased anthocyanins, and greater impacts were found at salinity of 100 mM NaCl, providing higher antioxidant value of the edible flowers. Short-term saline exposure of tagetes plants activated metabolic processes and as a result there was an accumulation of minerals such as N, P, Na, and Zn on edible flowers. During storage, salinity maintained but ethanol application increased the flower CO2 production. Ethanol application decreased the decay of flowers subjected to 100 mM NaCl. Flower weight losses and marketability accelerated at salinity of 100 mM NaCl after 14 days of storage. Tagetes flowers demonstrated induction in both non-enzymatic (i.e., proline content) and enzymatic mechanisms (catalase) to overcome stress caused by salinity during harvest stage and/or ethanol at storage. Our results have shown that short-term exposure to salinity and/or ethanol is able to achieve higher carotenoids and anthocyanins levels and these compounds can be considered as a new source of nutraceuticals.

17.
Biomed Res Int ; 2014: 562679, 2014.
Article in English | MEDLINE | ID: mdl-25254209

ABSTRACT

Grey mould rot (Botrytis cinerea) development in vitro or in eggplant (Solanum melongena L.) fruit was evaluated after treatment with dittany (Origanum dictamnus L.) oil (DIT) and storage at 12°C and 95% relative humidity during or following exposure to the volatiles. DIT volatiles used in different concentration (0-50-100-250 µL/L) and times of exposure (up to 120 h) examined the effects on pathogen development as well as fruit quality parameters. In vitro, fungal colony growth was inhibited with the application of DIT oil (during or after exposure) and/or time of application. Continuous exposure to oils reduced conidial germination and production with fungistatic effects observed in 250 µL/L. In vivo, fungal lesion growth and conidial production reduced in DIT-treated fruits. Interesting, in fruits preexposed to volatiles before fungal inoculation, DIT application induced fruit resistance against the pathogen, by reduced lesion growth and conidial production. Conidial viability reduced in >100 µL/L DIT oil. Fruits exposed to essential oil did not affect fruit quality related attributes in general, while skin lightness (L value) increased in 50 and 100 µL/L DIT oil. The results of the current study indicated that dittany volatiles may be considered as an alternative food preservative, eliminating disease spread in the storage/transit atmospheres.


Subject(s)
Fruit/drug effects , Fungi/drug effects , Oils, Volatile/administration & dosage , Solanum melongena/drug effects , Fruit/microbiology , Fungi/growth & development , Origanum/chemistry , Solanum melongena/microbiology , Spores, Fungal/drug effects
18.
ScientificWorldJournal ; 2012: 285874, 2012.
Article in English | MEDLINE | ID: mdl-22649285

ABSTRACT

The possible use of municipal solid waste compost (MSWC) in the production of marigold and basil seedlings examined. Six medium prepared from commercial peat (CP) and MSWC (0, 15, 30, 45, 60, and 100% v/v). There was not any plant growth when MSWC used alone (100%). The addition of MSWC in low content (15% and 30%) improved seed emergence for marigold and basil respectively, while greater content revealed opposed impacts. Mean emergence time delayed as MSWC content increased into substrates. Addition of MSWC (especially in content greater than 30%) into CP reduced (from 34 to 64%) plant height, leaf number and stem diameter as a consequence reduced plant fresh weight (plant biomass) for both species. The number of lateral stems decreased (up to 81%) in basil when MSWC added into substrate mixtures. Chlorophyll b content decreased (up to 58%) in substrates with MSWC content greater than 15% or 30% while similar reduction observed in content of Chlorophyll a and total carotenoids for basil with MSWC > 60%. However, Chlorophyll a and total carotenoids content increased as MSWC content increased for marigold. K and Na leaf content increased but P equivalent decreased as MSWC content increased. Nursery-produced basil and marigold seedlings grown in 15% MSWC; displayed quality indices similar to those recorded for conventional mixtures of peat and may act as component substitute.


Subject(s)
Asteraceae/growth & development , Ocimum basilicum/growth & development , Soil , Biomass , Chlorophyll/biosynthesis , Chlorophyll A , Plant Leaves , Plant Stems , Refuse Disposal , Seedlings/growth & development
19.
ScientificWorldJournal ; 2012: 973193, 2012.
Article in English | MEDLINE | ID: mdl-22645489

ABSTRACT

Municipal solid waste compost (MSWC) and/or fertigation used in greenhouse pepper (Capsicum annuum L.) cultivation with five different substrates with soil (S) and/or MSWC mixtures (0-5-10-20-40%) used with or without fertigation. Plants growth increased in 10-20% MSWC and fertigation enhanced mainly the plant height. Fruit number increased in S : MSWC 80 : 20 without fertilizer. Plant biomass increased as MSWC content increased. There were no differences regarding leaf fluoresces and plant yield. The addition of MSWC increased nutritive value (N, K, P, organic matter) of the substrate resulting in increased EC. Fruit fresh weight decreased (up to 31%) as plants grown in higher MSWC content. Fruit size fluctuated when different MSWC content used into the soil and the effects were mainly in fruit diameter rather than in fruit length. Interestingly, the scale of marketable fruits reduced as MSWC content increased into the substrate but addition of fertilizer reversed this trend and maintained the fruit marketability. MSWC affected quality parameters and reduced fruit acidity, total phenols but increased fruit lightness. No differences observed in fruit dry matter content, fruit firmness, green colour, total soluble sugars and EC of peppers and bacteria (total coliform and E. coli) units. Low content of MSWC improved plant growth and maintained fruit fresh weight for greenhouse pepper without affecting plant yield, while fertigation acted beneficially.


Subject(s)
Agriculture/methods , Capsicum/chemistry , Biomass , Chemistry, Physical/methods , Escherichia coli/metabolism , Fertilizers/analysis , Fruit , Microscopy, Fluorescence/methods , Models, Statistical , Plant Physiological Phenomena , Refuse Disposal , Seedlings , Soil
20.
Int J Food Microbiol ; 142(1-2): 14-8, 2010 Aug 15.
Article in English | MEDLINE | ID: mdl-20576303

ABSTRACT

Anthracnose rot (Colletotrichum coccodes) development in vitro or in tomato (Lycopersicon esculentum L.) fruit was evaluated after treatment with absolute ethyl alcohol (AEA), vinegar (VIN), chlorine (CHL) or origanum oil (ORI) and storage at 12 degrees C and 95% relative humidity during or following exposure to the volatiles. Fruit treated with vapours reduced fungal spore germination/production, but in the case of AEA- and VIN-treated fruits, fungal mycelium development was accelerated. Fruit lesion development was suppressed after fruit exposure to pure (100% v/v) AEA or ORI vapours which were accompanied by increased fruit cracking. Exposure to pure VIN-, CHL- and ORI vapours reduced (up to 92%) spore germination in vitro, but no differences were observed in the AEA treatment. The benefits associated with volatiles-enrichment were maintained in fruit pre-exposed to vapours, resulting in suppression in spore germination and spore production. However, studies performed on fungi grown on Potato Dextrose Agar revealed fewer direct effects of volatiles on fungal colony development and spore germination per se, implying that suppression of pathogen development was due in a large part to the impact of volatiles on fruit-pathogen interactions and/or 'memory' effects on fruit tissue. Work is currently focussing on the mechanisms underlying the impacts of volatiles on fruit quality related attributes. The results of this study indicate that volatiles may be considered as an alternative to the traditional postharvest sanitizing techniques. Each commodity needs to be individually assessed, and the volatile concentration and sanitising technique optimised, before the volatile treatment is used commercially.


Subject(s)
Acetic Acid/pharmacology , Colletotrichum/drug effects , Ethanol/pharmacology , Origanum/chemistry , Plant Diseases/prevention & control , Plant Oils/pharmacology , Solanum lycopersicum/microbiology , Colletotrichum/growth & development , Fruit/microbiology , Plant Diseases/microbiology , Spores, Fungal/drug effects , Spores, Fungal/growth & development
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