Browsing by Author "Cools, Katherine"
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Item Open Access Characterization of industrial onion wastes (Allium cepa L.): dietary fibre and bioactive compounds.(2011-03-31T00:00:00Z) Benítez, Vanesa; Mollá, Esperanza; Martín-Cabrejas, María A.; Aguilera, Yolanda; López-Andréu, Francisco J.; Cools, Katherine; Terry, Leon A.; Esteban, Rosa M.The food industry produces a large amount of onion wastes, making it necessary to search for possible ways for their utilization. One way could be to use these onion wastes as a natural source of high-value functional ingredients, since onion are rich in several groups of compounds, which have perceived benefits to human health. The objective of this work is to gain knowledge of any differences between the different onion wastes obtained from industry and non-commercial bulbs to use them as food ingredients rich in specific compounds. The results showed that brown skin and top-bottom could be potentially used as functional ingredient rich in dietary fibre, mainly in insoluble fraction, and in total phenolics and flavonoids, with high antioxidant activity. Moreover, brown skin showed a high concentration of quercetin aglycone and calcium, and top-bottom showed high concentration of minerals. Outer scales could be used as source of flavonols, with good antioxidant activity and content of dietary fibre. However, inner scales could be an interesting source of fructans and alk(en)yl cystein sulphoxides. In addition, discarded onions (cvs Recas and Figueres) could be used as a good source of dietary fibre, and cv Recas also as a source of phenolics compounds.Item Open Access Continuous Exposure to Ethylene Differentially Affects Senescence in Receptacle and Achene Tissues in Strawberry Fruit(Cranfield University, 2020-02-20 13:41) Tosetti, Roberta; Elmi, Fardusa; Terry, Leon; Cools, Katherine; Pradas, InmaculadaStrawberry shelf life is limited, and little is known about the postharvest regulation of senescence in different fruit tissues. Strawberry is classified as a non-climacteric fruit, yet it is known that ethylene affects strawberry ripening. Here the effects of continuous exogenous ethylene (50 µL L-1) were investigated in cold stored strawberry (5° C). The physiological and biochemical responses of ripe strawberry were evaluated across six days, together with hormonal profiles of the whole fruit and individual tissues (achenes and receptacle). Continuous exposure to ethylene induced as a first response an accumulation of abscisic acid (ABA) in the receptacle tissue, followed by an increase in CO2 production. Ethylene also elicited sucrose hydrolysis and malic acid catabolism, with the major effect seen after 4 days of ethylene exposure. Additionally, accumulation of phenolics (epicatechin and chlorogenic acid) were also observed in ethylene treated strawberry. Achenes did not exhibit a response to ethylene, yet catabolism of both ABA and auxins increased by two thirds during air storage. In contrast, ethylene induced ABA accumulation in the receptacle tissue without ABA catabolism being affected. This hormonal disequilibrium in response to ethylene between the two tissues was maintained during storage, and therefore might be the precursor for the following biochemical variations reported during storage.Item Open Access Continuous exposure to ethylene differentially affects senescence in receptacle and achene tissues in strawberry fruit(Frontiers, 2020-03-12) Tosetti, Roberta; Elmi, Fardusa; Pradas, Inmaculada; Cools, Katherine; Terry, Leon A.Strawberry shelf life is limited, and little is known about the postharvest regulation of senescence in different fruit tissues. Strawberry is classified as a non-climacteric fruit, yet it is known that ethylene affects strawberry ripening. Here the effects of continuous exogenous ethylene (50 µl l−1) were investigated in cold stored strawberry (5°C). The physiological and biochemical responses of ripe strawberry were evaluated across 6 days, together with hormonal profiles of the whole fruit and individual tissues (achenes and receptacle). Continuous exposure to ethylene induced as a first response an accumulation of abscisic acid (ABA) in the receptacle tissue, followed by an increase in CO2 production. Ethylene also elicited sucrose hydrolysis and malic acid catabolism, with the major effect seen after 4 days of ethylene exposure. Additionally, accumulation of phenolics (epicatechin and chlorogenic acid) were also observed in ethylene treated strawberry. Achenes did not exhibit a response to ethylene, yet catabolism of both ABA and auxins increased by two thirds during air storage. In contrast, ethylene induced ABA accumulation in the receptacle tissue without ABA catabolism being affected. This hormonal disequilibrium in response to ethylene between the two tissues was maintained during storage, and therefore might be the precursor for the following biochemical variations reported during storageItem Open Access Discrete ex situ and continuous in situ real-time respiration rate measurements of fresh produce using a novel automated dynamic approach(International Society for Horticultural Science (ISHS), 2018-04-04) Collings, Emma; Alamar, M. Carmen; Cools, Katherine; Ordaz-Ortiz, J. J.; Terry, Leon A.Fresh produce respiration rate is a useful indicator of metabolic state often used in postharvest research to determine physiological differences between factors. Static (no flow) and dynamic (constant flow) measurements are two types of methods that exist for determining respiration rate in fresh produce. Implementation of an automated real-time respiration method, using a dynamic measurement, for measuring respiration rates of fresh produce in discrete (ex situ) and continuous (in situ) set-ups has been established. Discrete methods were performed on fresh (green) black pepper within 3 L hermetically sealed containers with constant flow rates of 400 mL min-1 and 1 L min-1, respectively. Continuous respiration measurements were also obtained in situ for fresh black pepper stored under air (1.8 L min-1) at 5°C, and avocado fruit stored under air and controlled atmosphere environment (ca. 10 kPa CO2 and 10 kPa O2; 400 mL min-1), at 20°C. In addition, simultaneous automated recordings of O2 and CO2 enabled accurate respiratory quotient (RQ) values to be determined for avocado throughout storage. Application of the continuous dynamic in situ measurements can also provide a more realistic assessment of physiological change / behaviour under real-world storage conditions. In this paper, we discuss the application of both discrete and continuous dynamic methods as powerful research techniques for measuring respiration rate in postharvest research.Item Open Access The effect of processing on the glucosinolate profile of mustard seed(Elsevier, 2018-01-16) Cools, Katherine; Terry, Leon A.Brassica juncea mustard seed are used to make mustard paste or condiment. Mustard seed contains glucosinolates which are converted to isothiocyanates following cell disruption by the enzyme, myrosinase. Isothiocyanates are sulphur-containing compounds which give a pungent flavour to the mustard condiment. Three mustard seed cultivars from two seasons were processed into Dijon- and wholegrain-style mustard and glucosinolates and isothiocyanates analysed. Canadian cv. Centennial tended to contain higher glucosinolates compared with the French cv. AZ147 and Ukrainian cv. Chorniava. Conversion of the mustard seed into a wholegrain condiment had a lesser effect on total isothiocyanates and sinigrin content compared with the Dijon-style preparation. The Canadian mustard cultivars produced wholegrain-style mustard with higher total isothyocyantes and sinigrin compared with the French and Ukrainian cultivars. In summary, results herein suggest that Canadian mustard seed cvs. Centennial and Forge, and wholegrain processing may result in a condiment with greater bioactive composition.Item Open Access Effect of UV-C on the physiology and biochemical profile of fresh Piper nigrum berries(Elsevier, 2017-11-10) Collings, Emma R.; Gavidia, M. Carmen Alamar; Cools, Katherine; Redfern, Sally P.; Terry, Leon A.Application of UV-C has been shown to enhance the biochemical profile of various plant materials. This could be used to increase biochemical load, reducing the amount of material required but still impart equivalent flavour. As spices, such as black pepper (Piper nigrum L.), are typically dried to low moisture content to create a stable product for transportation and storage, little work has explored the use of modern postharvest treatments to enhance flavour. In this work, fresh P. nigrum berries were exposed to four UV-C doses (0, 1, 5 and 15 kJ m−2) and subsequently stored at 5 °C for ca. 4 weeks. Two separate experiments (early and late season) were conducted across one season. Replicate P. nigrum berry clusters were stored separately within continuously ventilated 13 L boxes. Real-time respiration rate (ex situ), ethylene production, fruit colour and water potential were measured at regular intervals during storage. In addition, piperine and essential oils were assessed using a simple newly developed method which enabled both compound groups to be simultaneously extracted and subsequently quantified. UV-C was found to cause significant changes in colour (from green to brown) whilst also altering the biochemical composition (piperine and essential oils), which was influenced by UV-C dose and berry maturity. Low to medium UV-C doses could potentially enhance flavour compounds in black pepper enabling processors to create products with higher biochemical load.Item Open Access Ethylene and 1-methylcyclopropene differentially regulate gene expression during onion sprout suppression.(American Society of Plant Biologists, 2011-07-31T00:00:00Z) Cools, Katherine; Chope, Gemma Amy; Hammond, John P.; Thompson, Andrew J.; Terry, Leon A.Onion (Allium cepa) is regarded as a nonclimacteric vegetable. In onions, however, ethylene can suppress sprouting while the ethylene-binding inhibitor 1- methylcyclopropene (1-MCP) can also suppress sprout growth; yet, it is unknown how ethylene and 1-MCP elicit the same response. In this study, onions were treated with 10 μL L(-1) ethylene or 1 μL L(-1) 1-MCP individually or in combination for 24 h at 20°C before or after curing (6 weeks) at 20°C or 28°C and then stored at 1°C. Following curing, a subset of these same onions was stored separately under continuous air or ethylene (10 μL L(-1)) at 1°C. Onions treated with ethylene and 1-MCP in combination after curing for 24 h had reduced sprout growth as compared with the control 25 weeks after harvest. Sprout growth following storage beyond 25 weeks was only reduced through continuous ethylene treatment. This observation was supported by a higher proportion of down- regulated genes characterized as being involved in photosynthesis, measured using a newly developed onion microarray. Physiological and biochemical data suggested that ethylene was being perceived in the presence of 1-MCP, since sprout growth was reduced in onions treated with 1-MCP and ethylene applied in combination but not when applied individually. A cluster of probes representing transcripts up-regulated by 1-MCP alone but down-regulated by ethylene alone or in the presence of 1-MCP support this suggestion. Ethylene and 1-MCP both down- regulated a probe tentatively annotated as an ethylene receptor as well as ethylene-insensitive 3, suggesting that both treatments down-regulate the perception and signaling events of eItem Open Access Impact of controlled atmosphere scheduling on strawberry and imported avocado fruit(Elsevier, 2017-09-01) Alamar, M. Carmen; Collings, Emma; Cools, Katherine; Terry, Leon A.British grown strawberry cv. Sonata and Chilean avocado cv. Hass were exposed to controlled atmospheres (CA) of 15 kPa CO2 + 5 kPa O2 (5 °C) and 10 kPa CO2 + 5 kPa O2 (5 or 20 °C), respectively, at early, middle or late stages during postharvest storage of avocados and at early and middle stages for strawberries. Real-time respiration rate (RR) was measured during CA storage and regular fruit sampling carried out to assess disease severity, objective colour, ethylene production and firmness. The automated in situ set-up used allowed continuous recordings of real-time respiration measurements without disruption to the CA environment. Cold stored strawberry fruit treated for 2.5 d with CA midway through the storage period were firmer and maintained a more vibrant colour despite bursts of increased RR. Furthermore, just 2.5 d of CA was sufficient to extend the shelf-life of strawberries (based on disease incidence) by a further 3 d, as compared to control. Irrespective of timing, RR of avocado stored at 20 °C was reduced while under CA environment; and early CA exposure maintained firmness yet increased the incidence of internal discolouration 7 d after removal from CA. At 5 °C, avocado skin colour and internal discolouration were positively affected by the mid CA treatment. These results are discussed in the context of the targeted use of CA, compared to control, for extending shelf-life, and reducing waste of these two different fruit produces. Furthermore, reducing the length of time required for CA application, which has not previously been explored in avocado or strawberries, would potentially be more energy efficient/cost effective.Item Open Access New insights into the effects of ethylene on ABA catabolism, sweetening and dormancy in stored potato tubers(Cranfield University, 2020-12-09 18:00) del carmen Alamar Gavidia, Maria; Thompson, Andrew; Tosetti, Roberta; A. Chope, Gemma; Cools, Katherine; Waters, Amanda; McWilliam, S.; Terry, LeonUnderlying data for this paper includes: respiration rate, sprout assessment, sprout incidence, and abscisic acid (ABA) and ABA-metabolites concentration for potato tubers during postharvest storage.Item Open Access Spatial changes in leaf biochemical profile of two tea cultivars following cold storage under two different vapour pressure deficit (VPD) conditions(Elsevier, 2018-10-22) Collings, Emma R.; Alamar, M. Carmen; Redfern, Sally P.; Cools, Katherine; Terry, Leon A.Withering is considered a crucial stage of black tea processing. In this study, tea shoots from two cultivars (cvs. Yabukita and Clone 2) were stored at 5 °C, in either a low or high vapour pressure deficit (VPD) environment, to determine the impact of different withering rates on physiology (viz. respiration rate [RR], colour and moisture loss) and biochemical profile (viz. individual catechins, methylxanthines) of tea shoots (Camellia sinensis). Low VPD and high VPD conditions during withering increased caffeine levels in Clone 2 and Yabukita, respectively (p < 0.05). Caffeine levels steadily increased over time in both cultivars (p < 0.05), coinciding with a rapid decline in theobromine (TB). Furthermore, stems contained lower epigallocatechin gallate (EGCG) and caffeine (ca. 75 and 56%, respectively) compared to bud and larger leaf (LL) (p < 0.05). Overall, the results of this study highlight factors such as mechanical harvesting, and hard or soft withering, which could affect final tea beverage quality.