Quality Of Broccoli Research Articles

Effect of foliar urea application on quality, growth, mineral uptake and yield of broccoli (Brassica oleracea L., var. italica)

The objective of this study was to determine the effect of foliar urea applications on quality, growth, mineral content and yield of broccoli under field conditions in 2003, 2004 and 2005. Broccoli cultivars AG 3317 and AG 3324 were treated with foliar urea applications at different concentrations (0.0, 0.4, 0.8 and 1.0%). Foliar applications of urea, especially 0.8 and 1.0% resulted in larger heads, weightier heads and plants as well as higher plants. Conversely, the greatest head and leaf dry matter contents were obtained with no fertilizer-nitrogen application. SPAD chlorophyll readings that were measured in the third year increased with elevated urea concentrations. In regard to the nutrient content, it can be interfered that soil nitrogen fertilization and foliar urea applications increased the content of almost all nutrients in leaves and heads of both broccoli cultivars in three experiment years. Generally, the greatest values were obtained from 1.0% urea application for both cultivars. It results from the study that for optimum yields 0.61 and 0.96% concentrations of urea sprays could be successfully used to obtain better growth and yield in broccoli cultivars AG 3317 and AG 3324, respectively.

Growth, Yield, and Dietary Antioxidants of Broccoli as Affected by Fertilizer Type

The source of nutrition available to plants can affect yield quantity and quality. Incorrect use of synthetic fertilizers can cause serious damage to the soil, the ecosystem, and quality of produce. Field experiments were conducted for two consecutive winter seasons from 2003 to 2005 in an Alfisol at Umiam, Meghalaya, India to study the effect of type of fertilizer on growth, yield and quality of broccoli in comparison with synthetic fertilizer (Control). Yields with some organic materials were higher than those produced with synthetic fertilizer. Use of solid organic materials and compost teas, in some cases, enhanced yield and quality, and reduced input costs. Application of organic materials reduced soil acidity, and improved the organic matter and available nutrients of the soil. Use of organics in vegetable production appears to provide an alternative to conventional methods.

The microbiological quality of hot water-washed broccoli florets and cut green beans

To determine the effect of hot water washing on the microbiological quality of cut broccoli florets and trimmed green beans. Broccoli florets and trimmed beans were washed for 90 s in tap water at either 20 degrees C or 52 degrees C and stored at 7 and 10 degrees C. The numbers of naturally occurring aerobic mesophilic organisms, Pseudomonas spp., Enterobacteriaceae, yeast and moulds and lactobacilli or lactic acid bacteria were enumerated at intervals for up to 2 weeks. The ability of Listeria monocytogenes, Bacillus cereus and Escherichia coli O157:H7 inoculated onto the tissue post heat treatment to survive or grow was also measured to mimic the effect of postprocess contamination. Using a hot wash treatment improved the initial appearance of the vegetables and resulted in a small, but significant, reduction in populations of all groups of endogenous flora measured. The number of yeast and moulds on the vegetables washed at 52 degrees C remained below the levels observed on the 20 degrees C washed vegetables throughout the observation period, but Pseudomonas spp., lactobacilli and Enterobacteriaceae were better able to grow on the hot-washed vegetables such that the counts at the end of storage were greater on hot-washed than ambient-washed vegetables. All three of the pathogens tested were better able to grow on hot-washed broccoli and beans than on equivalent product washed at 20 degrees C. Hot water washing can be used to control enzymic browning or yeast and moulds growth but it can also allow more rapid and extensive growth by pathogens and spoilage organisms. Reduced protection against growth by pathogens means that the hot wash treatment of vegetables should be used with caution and requires careful assessment of risk.

Maintenance of broccoli quality and functional properties during cold storage as affected by modified atmosphere packaging

Broccoli ( Brassica oleracea L. var. Italica) heads were packaged using 3 types of polypropylene films: macro-perforated (Ma-P), micro-perforated (Mi-P) and non-perforated (No-P), and then stored at 1 °C for 28 days to study the effects of modified atmosphere packaging (MAP) on the maintenance of quality and functional properties by comparison with non-wrapped heads. Results revealed that deterioration occurred quickly in control broccoli, manifested mainly by weight loss, yellowing, chlorophyll degradation and stem hardening. Also, a rapid decrease in total antioxidant activity (TAA), ascorbic acid and total phenolic compound concentration was observed. Conversely, in those heads packaged under MAP, especially for Mi-P and No-P, all changes related with loss of quality were significantly reduced and delayed with time. Additionally, TAA, ascorbic acid and total phenolic compounds remained almost unchanged during the whole period. Thus, broccoli packaged with Mi-P and No-P films had prolonged storability up to 28 days with high quality attributes and health-promoting compounds, this period being only 5 days in unwrapped control broccoli.

Impact of Soil Amendments on Broccoli Quality and Napropamide Movement Under Field Conditions

Impact of Soil Amendments on Broccoli Quality and Napropamide Movement Under Field Conditions

Reversible and Irreversible Emission of Methanethiol and Dimethyl Disulfide from Anaerobically Stored Broccoli

The reversible and irreversible emission of methanethiol (MT) and dimethyl disulfide (DMDS) from broccoli florets was demonstrated during anaerobic storage at 20 degrees C for up to 24 h. Reversible emission of MT and DMDS was feasible only in broccoli stored for between 0 and 12 h under entirely anaerobic condition. Beyond that, the emission was completely irreversible. This irreversible process was demonstrated through significant reductions in the chlorophyll fluorescence values and rate of carbon dioxide production and significant increase in the membrane permeability of induced broccoli tissues after exposure to air and incubation. Irreversible emission was also demonstrated through significant change in color from the characteristic bright green to olive green as well as the conversion of chlorophyll a to pheophytin a and chlorophyll a' contents of the induced florets after hot-water treatment. These findings suggest that the irreversible emission of MT and DMDS is a function of permanent membrane damage and loss of intracellular compartmentation in the broccoli tissues as a result of the anaerobic induction. The off-odor formation can still be reversed if the affected tissue is only temporarily impaired by anaerobic condition, thereby maintaining the quality of stored broccoli.

Influence of packaging material and storage condition on the sensory quality of broccoli

The sensory quality of broccoli stored in modified atmosphere packages was studied. Oriented polypropylene (OPP), polyvinyl chloride (PVC) and low-density polyethylene (LDPE) were used as packaging materials. The LDPE contained an ethylene-absorbing sachet. The samples were stored for 1 week, either at a constant temperature of 10 °C or for 3 days at 4 °C, followed by 4 days at 10 °C. The atmospheres that were developed inside the different packaging materials during storage differed significantly. After storage, the broccoli was evaluated both raw and cooked using a triangle test and a quantitative descriptive analysis. The triangle test showed significant differences in the smell of broccoli stored in different packaging materials after cooking. No differences were detected in the raw broccoli. The quantitative descriptive analysis showed significant differences in the fresh smell and flavour, the chewing resistance, and the crispness, between samples after cooking. Overall, including all the sensory properties studied, broccoli packaged in LDPE (5% O 2, 7% CO 2) that contained an ethylene absorber was perceived to be the sample most similar to fresh broccoli. There were no differences in weight loss between broccoli stored in the different packaging materials.

Ozone and 1-Methylcyclopropene Alter the Postharvest Quality of Broccoli

Fresh broccoli (Brassica oleracea L. Italica group) florets untreated or treated with 1 μL·L-1 1-methylcyclopropene (1-MCP) for 14 h, were stored at 12 °C with 0, 200, or 700 nL·L-1 ozone. Senescence parameters were evaluated after 0, 1, 2, 5, 8, or 12 days of storage. Treatment with 1-MCP delayed the yellowing of florets, and at day 5 the hue angle of 1-MCP treated florets was 116° (green) compared to 102° (yellow) for the control. Respiration rates of florets were reduced by 1-MCP for the first 5 days. The 1-MCP treatment maintained higher chlorophyll fluorescence expressed as Fv/Fm during 12 days of storage. Also, 1-MCP reduced dimethyl trisulfide production, which contributes to off-odor development in broccoli florets. Compared with the controls, florets stored in 200 nL·L-1 ozone had less mold growth and yellowed more slowly, but no differences were observed in respiration, ethylene production, or Fv/Fm. Florets stored in 700 nL·L-1 ozone were greener than florets held in air or 200 nL·L-1 ozone. Interestingly, chlorophyll fluorescence of the florets stored in 700 nL·L-1 ozone decreased significantly and at day 12, Fv/Fm was only 30% of its initial value. Ozone at 700 nL·L-1 stimulated respiration and ethylene production of florets after 1 day of storage, and caused visible damage in the form of increased weight loss and browning of the floret stem ends. Treatment of broccoli with 1-MCP alone or in combination with 200 nL·L-1 ozone maintained the quality and extended the shelf life of broccoli florets.

THE EFFECT OF PACKAGING MATERIAL ON THE SENSORY PROPERTIES OF BROCCOLI

Three different commercially available polymeric films were studied to determine their effect on the sensory properties of fresh broccoli (Brassica oleracea L. var. Italica cv. ‘Marathon’). The polymer materials investigated were oriented polypropylene (OPP), polyvinyl chloride (PVC) and one low density polyethylene (LDPE) which contained an ethylene absorber. The fresh broccoli was packaged and stored for one week at 10°C or 3 days at 4°C followed by 4 days at 10°C. The oxygen and carbon dioxide concentrations inside the packages were monitored during storage. After storage the broccoli was evaluated according to sensory analyses, i.e. triangle test and quantitative descriptive analysis, by an analytical panel. The panel judged the broccoli according to smell, taste, texture and appearance. The triangle test showed significant differences between the smell of the broccoli samples, stored in the different packaging materials, when cooked. However, no differences between the raw broccoli, stored in the different packaging materials could be detected. The quantitative descriptive analysis showed that the following attributes; fresh smell and taste, chewing resistance, and crispness, differed significantly between the packaged broccoli when cooked. The appearance was shown to be the sensory property of broccoli most affected by the storage conditions, i.e. packaging material used and storage temperature. The results indicated the importance of the packaging material for maintaining the broccoli quality. However, one packaging material that was able to maintain all the studied sensory properties could not be identified.

The influence of water stress during crop growth on the postharvest quality of broccoli

Two glasshouse experiments studied the effect of moisture stress on head and postharvest characters of broccoli. The work demonstrated that moisture stress occurring during head growth affected the postharvest shelf life of broccoli heads. The stage of head development at which moisture stress was applied determined which postharvest character was influenced. This suggests that the genes controlling these characters can be switched on at different times. Moisture stress imposed close to head maturity appeared to have a positive benefit in terms of both head colour and stem turgor.

Quality maintenance of broccoli (Brassica oleracea var. italica) stored in improved cardboard container

The cardboard shipping container for broccoli was improved to raise gas barrier. The broccoli packaged in expanded polystyrene container, cardboard shipping container, cardboard shipping container lining polyethylene, functional cardboard shipping container and the improved cardboard shipping container were stored at 15t for 8 days. The yellowing occurred after storage of 4 or 6 days with broccoli in the usual container or the functional container, but not in the improved cardboard shipping container during storage of 8 days. The level of decrease in chemical components including chlorophyll, total sugar and ascorbic acid of broccoli in the improved cardboard shipping container was also less than that in usual or functional cardboard shipping container. The concentrations of carbon dioxide and oxygen in the improved cardboard shipping container were 9-11% and 10-12%, respectively throughout the storage period. The oxygen concentration was lower and carbon dioxide concentration higher as compared to that in a usual cardboard shipping container or functional cardboard shipping container with both sides plastic film lining. These results suggest that the quality of broccoli in the cardboard shipping container was successfully kept due to modifying the atmosphere in the container.

Subsurface Drip Irrigation and Fertigation of Broccoli

Production of broccoli (Brassica olearaceaL.Italica) in the southwestern USA is highly dependent on inputs of water and N fertilizer to achieve optimum yields and quality. The water and N‐response characteristics of subsurface drip‐irrigated broccoli have not previously been reported. Field experiments were conducted in southern Arizona during 1993 through 1996. The objectives were to determine: (i) subsurface drip‐irrigated broccoli response to a range of soil water tension (SWT), (ii) effects and interactions of water and N fertilizer inputs on crop yield and quality, and (iii) seasonal and daily N uptake. Experiments consisted of factorial combinations of three irrigation regimes (low, medium, and high) and four N rates (60–500 kg N ha−1). Irrigation was applied daily to maintain target SWT, and all N was applied by fertigation. With respect to marketable yield, the optimum SWT was ∼10 kPa in this sandy loam soil, as indicated by response surface models. Marketable yields across all treatments ranged from <3 to >18 Mg ha−1Marketable yield was significantly affected by N rate during all three seasons, and by SWT during two of three seasons. There were no significant SWT × N interactions for marketable yield. Quality parameters (head weight and diameter) were much more responsive to N rate than to SWT, and there were few significant SWT × N interactions for broccoli quality. Broccoli accumulated up to 320 kg N ha−1in the aboveground biomass, and N uptake fluxes were as high as 5 kg N ha−1d−1at the first bud growth stage (825–1000 heat units after planting [HUAP]).

Quality of broccoli as influenced by film wrapping during shipment

'Shogun' broccoli florets were film-wrapped and stored for 7 days at 1 °C to simulate a maximum period of commercial shipment. After cold storage, florets were kept for 2.5 days at 20 °C to simulate a retail sale period. For wrapping, polyvinyl chloride (PVC) 9 µm thickness and low-density polyethylene (LDPE) 11, 15, and 20 µm thickness were used. Soluble solids content, pH, titratable acidity, weight loss, physiological disorders, visual quality, and gas composition within packages were monitored. Gas composition (about 18% O2 and 1% CO2 during cold storage and about 16% O2 and 2–3% CO2 during shelf life), overall quality, and yellowing and browning of the florets were at similar levels among the films studied. However, weight loss was about sixty times lower for all LDPE films than for PVC film. After shelf life the best results were obtained by using 15 µm LDPE. This polymeric film could be a good alternative to PVC for wrapping broccoli for commercial shipment purposes, particularly to those countries where use of PVC has been forbidden.

Chlorophyll fluorescence, fermentation product accumulation, and quality of stored broccoli in modified atmosphere packages and subsequent air storage

Abstract Earlier work showed that chlorophyll fluorescence changes of broccoli (Brassica oleracea L., Italica group) were associated with the accumulation of CO2 in modified atmosphere packages (MAP) during storage. This work was initiated to determine whether the chlorophyll fluorescence changes in broccoli from high CO2 MAP are persistent after the packages are opened and the broccoli is allowed to aerate. PD-961EZ bags, which allow the CO2 to accumulate (∼11 kPa CO2), were used in this study. During 28 days in MAP at 1°C, the broccoli gradually developed slight to moderate alcoholic off-odors and accumulated ethanol, acetaldehyde, and ethyl acetate in the tissues. These levels dissipated slightly on opening of the bags and holding the broccoli in 1°C air storage for 4 days. Chlorophyll fluorescence measurements (Fv/Fm, T 1 2 , Fmd, and ΦPSII) declined for broccoli with the accumulation of these anaerobic products and the fluorescence measurements recovered slightly after the bags were opened and the broccoli was held in air at 1°C for 4 days. Chlorophyll fluorescence measurements were found to be highly correlated with the anaerobic volatile content in broccoli during MAP storage and after opening of the MAP. Chlorophyll fluorescence measurements were also highly correlated with the perceived off-odors that were noted for the broccoli after longer storage durations in MAP.

Chlorophyll Fluorescence as a Nondestructive Indicator of Broccoli Quality during Storage in Modified-atmosphere Packaging

The objective of this study was to determine if chlorophyll fluorescence could be used as an indicator of anaerobic respiration in broccoli (Brassica oleracea L., Italica group) during modified-atmosphere packaging (MAP). Two types of packages were used, PD-941 bags, which provided optimum MAP conditions for broccoli (≈3 kPa O2 plus 5 kPa CO2), and PD-961EZ bags, which allowed the CO2 to accumulate (≈11 kPa CO2). After 28 days in MAP at 1 °C, the broccoli from both types of bag had similar appearances and weight losses. However, broccoli held in the PD-961EZ bags had developed slight to moderate alcoholic off-odors and had higher ethanol, acetaldehyde, and ethyl acetate content, as compared with broccoli in PD-941 bags. Chlorophyll fluorescence parameters (Fv/Fm, T1/2, Fmd, and ΦPSII) were lower for broccoli held in the PD-961EZ bags than in PD-941 bags, and these differences increased with storage duration. These results indicate that chlorophyll fluorescence is a reliable, rapid, nondestructive indicator of broccoli quality during MAP, and that it could be used to determine if broccoli has developed off-odors without opening the bag and disrupting the package atmosphere.

The effect of nitrogen and the method of application on yield and quality of broccoli

The effects of the rate and the method of N application on yield and quality of broccoli cv. Emperor were studied during 3 seasons at Andijk and Lelystad, Netherlands. Different amounts of N fertilizer were applied broadcast or band placed at planting. Band placement of fertilizer increased the yield in 5 out of 8 experiments. Application of N resulted in larger heads. No relationship was found between soil mineral N at planting and optimum N application because of the narrow range of soil mineral N at planting. Split application had no or a negative effect on yield and therefore is not recommended. For optimum yields a rate of 270 kg N/ha is recommended, minus the mineral N in the 0-60 cm soil layer, band placed at planting. For broadcast application 275 kg N minus the soil mineral N is recommended at planting, but yields will be lower than with band placement of fertilizer.

Freeze-induced reduction of broccoli yield and quality

Summary. Sub-zero temperatures can result in freezing injury of broccoli (Brassica oleracea L. var. italica Plenck) plants and thereby reduce head yield and quality. In order to predict effects of frosts, it is desirable to know the stages of development at which broccoli plants are most susceptible to freezing injury. In this study, the effect of a range of sub-zero temperatures for a short period at different stages of crop development were assessed and quantified in terms of mortality, yield and quality of broccoli. Whole plants in pots or in the field were subjected to sub-zero temperature regimes from –1 to –19°C. Extracellular ice formation was achieved by reducing temperatures slowly, at –2°C per hour. The floral initiation stage was most sensitive to freezing injury, as yields (fresh and dry head weights) were significantly reduced at –1 and –3°C, and the shoot apices were killed at –5°C. There was no significant yield reduction when the inflorescence buttoning stage was treated at –1 and –3°C. Although shoot apices survived the –5°C treatment at buttoning, very poor quality heads of uneven bud size were produced as a result of arrested development. The lethal temperature for pot-grown broccoli was between –3 and –5°C, whereas the lethal temperature for field-grown broccoli was between –7 and –9°C. The difference was presumably due to variation in cold acclimation. Freezing injury can reduce broccoli head yield and quality and retard plant growth. With regard to yield and maturity prediction, crop development models based only on simple thermal time without restrictions will not apply if broccoli crops are frost damaged.

EFFECT OF ATMOSPHERE ON BROCCOLI SENSORY ATTRIBUTES IN COMMERCIAL MAP AND MICROPERFORATED PACKAGES1

ABSTRACTBroccoli was packaged using 2 microperforated (cross‐micro, SM60®) and 3 modified atmosphere packages (MAP) (polyethylene MAP, broccoli MAP, lettuce MAP). Packaged broccoli was stored 9 days at 2C and an additional 1, 3, 4 and 6 days at 13C, for a total storage 10, 12, 13 and 15 days, respectively. Concentrations of CO2 and O2 were determined after 12 days. Sensory analyses were conducted after 10, 12, 13, and 15 days. Broccoli quality was evaluated for ten sensory attributes by eight trained judges. Analysis of variance and principal component analysis were used to determine the effect of packaging and storage time. Broccoli packaged in lettuce MAP was most anaerobic (3.9% CO2, 1.2% O2) and developed sauerkraut‐like odors/flavors after 10 days of storage. The microperforated wraps did not alter the gas composition of the packages (16.3% O2, 0.2% CO2) and broccoli became yellow and limp after 15 days. In contrast, broccoli packaged in the polyethylene and broccoli MAP packages modified the CO2 and O2 concentrations and maintained the broccoli quality for the duration of the experiment (15 days).

Low-temperature Storage of Micropropagated Plantlets under Selected Light Environments

Broccoli (Brassica oleracea L. Botrytis Group `Green Duke') and Hosta tokudama F. Maekawa `Newberry Gold' plantlets, which were ready for transplanting after photoautotrophic (sugar-free) culture, were stored 4 to 6 weeks at 5C under various light qualities and photosynthetic photon fluxes (PPF). Illumination during storage maintained quality, photosynthetic ability, and regrowth potential of plantlets stored at low temperature. PPF affected quality of broccoli and Hosta plantlets. Broccoli plantlets responded to storage light quality, while Hosta did not. White light maintained the quality of broccoli plantlets better during 6 weeks of storage than did red or blue light. Red and blue light caused an increase in internode length and reduction in chlorophyll concentrations compared to white light. Photosynthetic and regrowth potentials of plantlets were not affected by spectral quality during storage. Considering changes in dry weight, stem length, and leaf yellowing, the quality of broccoli plantlets was best maintained under white light at 2 μmol·m–2·s–1 PPF. PPF and light quality were shown to be important factors in the preservation of transplant quality and suppression of growth of the plantlets during low-temperature storage.

Cooling Method Influences the Postharvest Quality of Broccoli

The effects of cooling method and packaging with perforated film on broccoli (Brassica oleracea L. Italica group) quality during 2C storage were studied. Broccoli was either room-cooled, top-iced, or hydrocooled before being placing into storage for 14 days. Hydrocooling was the most rapid cooling method and resulted in the lowest vapor pressure deficits between the broccoli and the surrounding air. Hydrocooling and top-icing resulted in similar firmness and color retention. Broccoli that was hydrocooled and then overwrapped with perforated film lost less weight, was firmest, and retained color better than either top-iced or room-cooled broccoli.