Effects of LED lighting recipes on postharvest quality of leafy vegetables grown in a vertical farm
Nicole, C.C.S. ; Mooren, J. ; Pereira Terra, A.T. ; Larsen, D.H. ; Woltering, E.J. ; Marcelis, L.F.M. ; Verdonk, J. ; Schouten, R. ; Troost, F. - \ 2019
Acta Horticulturae 1256 (2019). - ISSN 0567-7572 - p. 481 - 488.
LED lighting - Nitrate - Shelf life - Taste - Vertical farming - Vitamin C - Vitamin K
Vertical farming is a technology that controls climate, water, nutrients and light to grow food in a closed environment. This allows vegetables to grow pesticide free and without other contaminants. We investigated how to influence the postharvest quality by controlling the preharvest growth conditions while keeping a high production rate. Several standard LED lighting recipes (red/blue or red/white either with or without far red) are in use in commercial farms. For this research we used lettuce, baby leaf spinach, rocket and basil from various cultivars all grown in a vertical farm research facility. We used the standard red white LED light recipe as control, while we changed the spectrum with higher blue and/or higher far-red or apply few days of continuous light stimulation just before the harvest (preharvest). Quality at harvest and quality loss during postharvest storage was monitored. We observed that light quality affects shelf life of baby leaf spinach and rocket by several days. The best light recipe for shelf life had a high blue content (35%) while the worst was with a high far red (25%). In addition, contents of vitamin C, K, nitrate, chlorophyll and flavonols were different under various light quality. Nitrate (in lettuce, rocket and spinach) and vitamin C in rocket were strongly affected by preharvest continuous light, offering a way to reduce the nitrate and improve the antioxidant level. In addition, taste was also found to change as a function of light quality but magnitude of this change is shown to be strongly cultivar dependent.
Light regulation of vitamin C in tomato fruit is mediated through photosynthesis
Ntagkas, Nikolaos ; Woltering, Ernst ; Nicole, Celine ; Labrie, Caroline ; Marcelis, Leo F.M. - \ 2019
Environmental and Experimental Botany 158 (2019). - ISSN 0098-8472 - p. 180 - 188.
Ascorbic acid - Irradiance - Photosynthesis - Respiration - Spectrum - Vitamin C
Higher levels of irradiance result in higher accumulation of ascorbate in leaves and fruits. Photosynthesis and respiration are an integral part of the physiological mechanism of light regulation of ascorbate in leaves, but little is known about the light regulation of ascorbate in fruit. The aim of this study was to investigate whether fruit illumination alone is sufficient for ascorbate increase in tomato fruit and whether this light signal is mediated by respiration and photosynthesis. First the changes of ascorbate with the progress of fruit development were investigated and subsequently detached fruit of different tomato genotypes were exposed to different irradiances and spectra. Measurements were performed on ascorbate, respiration, photosynthesis and chlorophyll content of the fruit. When attached to the plant, there was no effect of development on ascorbate from the mature green to the red stage. Detached fruit stored in darkness did not accumulate ascorbate. However, when exposed to 300–600 μmol m−2 s-1 light detached mature green fruit (photosynthetically active) substantially accumulated ascorbate, while mature red fruit (non-photosynthetically active) did not respond to light. Photosynthesis correlated with this increase of ascorbate while no correlation between respiration and ascorbate was found. Spectral effects on ascorbate in detached tomato fruit were limited. These results indicate that the signal for light regulation of ascorbate is perceived locally in the fruit and that fruit illumination alone is sufficient for a considerable increase in ascorbate levels for as long as the fruit contains chlorophyll. It is shown that photosynthetic activity of the fruit is an integral part of the response of ascorbate to light in tomato fruit. The light induced increase in ascorbate levels occurred in a range of genotypes, indicating a universal effect of light to ascorbate in tomato fruit.
Metabolite variation in the lettuce gene pool : towards healthier crop varieties and food
Treuren, Rob van; Eekelen, Henriette D.L.M. van; Wehrens, Ron ; Vos, Ric C.H. de - \ 2018
Metabolomics 14 (2018)11. - ISSN 1573-3882
Crop improvement - Genetic resources - Lettuce - Phytochemical variation - Untargeted metabolomics - Vitamin C
Introduction: Lettuce (Lactuca sativa L.) is generally not specifically acknowledged for its taste and nutritional value, while its cultivation suffers from limited resistance against several pests and diseases. Such key traits are known to be largely dependent on the ability of varieties to produce specific phytochemicals. Objectives: We aimed to identify promising genetic resources for the improvement of phytochemical composition of lettuce varieties. Methods: Phytochemical variation was investigated using 150 Lactuca genebank accessions, comprising a core set of the lettuce gene pool, and resulting data were related to available phenotypic information. Results: A hierarchical cluster analysis of the variation in relative abundance of 2026 phytochemicals, revealed by untargeted metabolic profiling, strongly resembled the known lettuce gene pool structure, indicating that the observed variation was to a large extent genetically determined. Many phytochemicals appeared species-specific, of which several are generally related to traits that are associated with plant health or nutritional value. For a large number of phytochemicals the relative abundance was either positively or negatively correlated with available phenotypic data on resistances against pests and diseases, indicating their potential role in plant resistance. Particularly the more primitive lettuces and the closely related wild relatives showed high levels of (poly)phenols and vitamin C, thus representing potential genetic resources for improving nutritional traits in modern crop types. Conclusion: Our large-scale analysis of phytochemical variation is unprecedented in lettuce and demonstrated the ample availability of suitable genetic resources for the development of improved lettuce varieties with higher nutritional quality and more sustainable production.
Light regulates ascorbate in plants : An integrated view on physiology and biochemistry
Ntagkas, Nikolaos ; Woltering, Ernst J. ; Marcelis, Leo F.M. - \ 2018
Environmental and Experimental Botany 147 (2018). - ISSN 0098-8472 - p. 271 - 280.
Ascorbate - Light regulation - Vitamin C - Vitamin C biochemistry - Vitamin C physiology
l-ascorbate (vitamin. C, ASC) is an antioxidant that is essential for the proper function not only of plants but also animals. Light is a major regulatory factor for ASC levels in plants. In this paper, we review the regulation of ASC by light and the involved biochemical and physiological processes. Several biochemical pathways for ASC biosynthesis have been proposed to exist in plants. We aim to determine the contribution of these biochemical pathways on ASC levels and, locate the steps of them that are affected by light. From biochemical and genetic studies only evidence for ASC biosynthesis occurring via the d-mannose/L-galactose biosynthetic pathway was found. Alternative pathways might account for ASC biosynthesis only in transgenic plants. Apart from biosynthesis, recycling and turnover of ASC might affect the size of the ASC pool. Light regulation of ASC levels in plants occurs primarily via effects on biosynthesis. In addition, light affects ASC homeostasis and translocation within the plant. Light regulation of ASC has been studied for individual physiological processes without taking into account possible interactions. By establishing the physiological network behind light regulation of ASC for both leaves and fruit, we developed a novel hypothesis on interactions between the physiological processes that regulate ASC. We conclude that respiration and photosynthesis interact in light regulation of ASC biosynthesis via carbohydrate availability.
Health-promoting compounds in cape gooseberry (Physalis peruviana L.) : Review from a supply chain perspective
Olivares-Tenorio, Mary Luz ; Dekker, Matthijs ; Verkerk, Ruud ; Boekel, Tiny van - \ 2016
Trends in Food Science and Technology 57 (2016)part A. - ISSN 0924-2244 - p. 83 - 92.
Antioxidant activity - Flavonoids - Phenolic compounds - Phytochemicals - Supply chain - Vitamin C - β-carotene
Background The fruit of Physalis peruviana L., known as Cape Gooseberry (CG) is a source of a variety of compounds with potential health benefits. Therefore, CG has been subject of scientific and commercial interest. Scope and approach This review paper evaluates changes of such health-promoting compounds and antioxidant activity in CG, based on published literature and from a supply chain perspective, considering pre-harvest, post-harvest, processing (thermal and not thermal) and storage steps to give an insight of contents at consumption stage. Key findings and conclusions CG has vitamin C (20 and 35 mg 100 g−1 FW), β-carotene (up to 2.0 mg.100 g−1 FW), total phenolic compounds TPC (50–250 gallic acid equivalents.100 g−1 FW), phenolic acids (caffeic, gallic, chlorogenic, ferulic and p-cumaric acids), flavonoids (quercetin, rutin, myricetin, kaempferol, catechin and epicatechin) and antioxidant activity. There is not yet evidence of presence of physalins and withanolides in CG as previous review papers have stated. The ripeness stage of CG is a relevant factor affecting the content of many phytochemicals. Vitamin C and β-carotene contents are directly proportional to ripeness stage. The reported data in literature showed a large variation, likely caused by different raw material properties (origin, ripeness stage, growing conditions etc.) and differences in the employed analytical methods. Thermal and non-thermal processing have an effect on the extractability of the phytochemicals but also on the decrease of compounds and antioxidant activity. Relative stability to certain phytochemicals to processing suggest an opportunity to add value to supply chain with processed food containing health-promoting compounds.
Illuminating tomato fruit enhances fruit Vitamin C content
Ntagkas, N. ; Min, Q. ; Woltering, E.J. ; Labrie, C. ; Nicole, C.C.S. ; Marcelis, L.F.M. - \ 2016
Acta Horticulturae 1134 (2016). - ISSN 0567-7572 - p. 351 - 356.
Ascorbic acid - LED - Light - Tomato - Vitamin C
L-ascorbate (AsA; Vitamin C) is an anti-and pro-oxidant phytochemical essential for the proper functioning of the human body. Field grown tomato fruit (Solanum lycopersicum) contain substantial amounts of AsA. When grown in the greenhouse, tomato fruit typically have low levels of AsA. Light is the major regulatory abiotic factor for AsA in plants. The introduction of light emitting diodes (LED) in horticulture provides the opportunity for improving quality of plant products. AsA levels of tomato fruit increase with additional light applied to the plant. In this work we examine the effects of irradiance on AsA levels of tomato fruit when light is applied to the fruit. Detached tomato fruit were treated with different irradiance levels provided by LEDs in a climate controlled environment. Tomato fruit treated with 263 μmol m-2 s-1 of white light for 13 days contained 32% more AsA than fruit kept at lower irradiances or in darkness. The light induced biosynthesis of AsA and the role of soluble carbohydrates in AsA regulation is discussed.
Food design strategies to increase vegetable intake : The case of vegetable enriched pasta
Oliviero, Teresa ; Fogliano, Vincenzo - \ 2016
Trends in Food Science and Technology 51 (2016). - ISSN 0924-2244 - p. 58 - 64.
Functional food - Glucoraphanin - Pasta - Vitamin C - β-carotene
Background: Public campaigns promoting consumption of fruits and vegetables had limited results as consumers habits are difficult to modify. The incorporation of fruits and vegetables into regularly eaten products is a food design strategy that leads to several advantages. Pasta is a staple food eaten daily or weekly that constitutes a dominant moiety of the diet in many countries. Moreover, dried pasta is an affordable, long shelf-life product that can well preserve phytochemicals. Scope and approach: With this viewpoint article, all the production and cooking steps of pasta enriched with vegetables are analysed, highlighting their effect on its quality. Alternative processing conditions are proposed based on the findings of the existing literature and on data obtained on pasta enriched with broccoli and with carrot. Finally, recommendations to food companies to design and manufacture such pasta are provided. Key findings and conclusions: Considering the portion size and the percentage of vegetables that can be added, vegetable pasta can significantly contribute to the recommended vegetable intake per day. However, production and cooking of pasta affect its nutritional value: bioactive compounds occurring in vegetables can leach into boiling water or can be thermally degraded. Moreover, the incorporation of vegetables has a dilution effect of the gluten network, leading to changing of pasta sensorial attributes and to a potential increase of the glycaemic index for a higher starch granules swelling. Therefore, such approach is successful only if processing conditions are optimized to keep in the final product the desired nutritional characteristics of the vegetables.
Impact of the industrial freezing process on selected vegetables -Part II. Colour and bioactive compounds
Mazzeo, Teresa ; Paciulli, Maria ; Chiavaro, Emma ; Visconti, Attilio ; Fogliano, Vincenzo ; Ganino, Tommaso ; Pellegrini, Nicoletta - \ 2015
Food Research International 75 (2015). - ISSN 0963-9969 - p. 89 - 97.
Asparagus - Chlorophylls - Green beans - Lutein - Polyphenols - Vitamin C - Zucchini
In the present study, the impact of the different steps (i.e. blanching, freezing, storage following the industrial freezing process and the final cooking prior to consumption) of the industrial freezing process was evaluated on colour, chlorophylls, lutein, polyphenols and ascorbic acid content of asparagus, green beans and zucchini. In addition, the domestic boiling of raw samples was compared with the boiling of frozen storage vegetables.Results showed that the blanching treatment retained phytochemicals in all studied green vegetables and the frozen storage up to 2. months did not negatively affected phytochemicals, in particular lutein and flavonoids in almost all samples. On the contrary, colour significantly changed during blanching and frozen storage. The changes of b* (yellowness) and the shift of H° (hue angle) were not coherent with the increase of pheophytin. In addition, the greenness (- a*) was found to increase with the exception of boiled samples in all vegetables. Generally, in boiled frozen vegetables there was a better or comparable retention of bioactive compounds with respect to raw ones, and this was especially true for green beans and zucchini. Colour changes after cooking did not exhibit the same trends among vegetables, being more remarkable for frozen asparagus in comparison with those boiled from raw, but overall comparable for green beans and zucchini.In conclusion, the overall results of the present study suggest that, when the industrial freezing process is well performed, the boiled frozen vegetables do not have a lower nutritional value than the fresh ones.