Search Results
You are looking at 21 - 30 of 52 items for
- Author or Editor: Mikal E. Saltveit Jr. x
Abstract
Storage of large, mature artichoke buds (Cynara scolymus L., cv. Green Globe) in humidified air at 7°C for 1 week, 2.5° for 2 weeks, or 0° for 3 weeks resulted in significant quality losses. There was little or no beneficial effect of controlled atmosphere (CA) on quality retention when buds were stored at 0° under lowered O2 (1%, 2.5%, or 5%) and elevated CO2 (0%, 2.5%, or 5%) atmospheres. Bracts and receptacles blackened in all treatments after 4 weeks of storage. The degree of blackening was insignificant in air, but became severe as the O2 level decreased from 5% to 1% and CO2 increased from 2.5% to 5%. Thus, CA storage of large artichoke buds can not be recommended.
Abstract
In the article “Effects of Calcium and Auxin on Russet Spotting and Phenylalanine Ammonialyase Activity in Iceberg Lettuce” by Dangyang Ke and Mikal E. Saltveit, Jr. (HortScience 21:1169–1171, Oct. 1986), Dangyang Ke's name was spelled incorrectly.
Abstract
A method is presented for the rapid determination of O2 concentrations in which 1-ml gas samples are injected into a stream of N2 carrier gas flowing through a specific O2 sensor. Specifically, peaks were produced on a strip chart recorder within 2 sec of injecting 1-ml samples into a 15 liters·hr-1 flow of N2 through an Applied Electrochemistry Inc. Model S-3A O2 analyzer. The response to the injection of 10 O2 concentrations ranging from 0.5% to 18.9% was linear (r = 0.9996). The coefficient of variation was < 1.5% for measurements within each O2 concentration; ranging from 1.4% for concentrations <6%, to 0.7% for concentrations >15%. This corresponded to a resolution of better than 0.4 µl O2 in a 1-ml gas sample. Other nondestructive analyzers using similar N2 carrier gas flow rates (e.g., the Horiba PIR-2000 infrared CO2 analyzer) can be attached in series to analyze for other specific gases in the same injected sample.
Abstract
Tomato fruit (Lycopersicon esculentum Mill., cv. Castlemart) either harvested hot (e.g., 32°C) and chilled for 7 days at 7°, or harvested cool (e.g., 19°) and held in the laboratory at 37° for 7 hr before chilling at 2.5° for 4 days ripened slower (a symptom of chilling injury) than fruit that were either harvested cool (19°) or held at 12.5° for 7 hr before chilling.
Abstract
Leaf midrib tissue from six cultivars of iceberg lettuce (Lactuca sativa L.) was excised from 20- to 100-day-old plants and tested at 5C for russet spotting (RS) susceptibility under 10 μl ethylene/liter. There was no RS development in tissue excised from 20-day-old plants from any of the six cultivars. RS first developed in tissue from 50-day-old plants and tended to be more severe in tissue excised from older plants. ‘Winter Haven’ and ‘Salinas’ were most susceptible, while ‘Calmar’ was most resistant to RS; ‘Climax’, ‘El Toro’, and ‘Sea Green’ were moderately susceptible. Phenylalanine ammonia-lyase activity in the six cultivars at different developmental stages correlated with their degree of RS development. For ‘Winter Haven’, the increase in ionically bound POD and IAA oxidase activity, but not PPO activity, was associated with the increase in RS score during plant development. ‘Winter Haven’ tissue had much higher ionically bound peroxidase and IAA oxidase activities than ‘Calmar’ tissue from 100-day-old plants. Chemical names used: indole-3-acetic acid (IAA), phenylalanine ammonia-lyase (PAL), peroxidase (POD), polyphenol oxidase (PPO).
Abstract
A 1.5% O2 atmosphere, relative to normal air, dramatically inhibited ethylene-induced russet spot development, PAL, and ionically bound POD, and ionicaliy bound IAA oxidase activities and reduced soluble phenolic content in stored iceberg lettuce (Lactuca sativa L.). Low O2 also inhibited eythylene production and respiration. Polyphenol oxidase activity was slightly inhibited by low O2. The results suggest that low O2 inhibition of ethylene action and attendant effects on phenolic metabolism and IAA oxidase activity may be responsible for inhibition of russet spotting by 1.5% O2. Chemical names used: indole-3-acetic acid (IAA); phenylalanine ammonia-lyase (PAL); peroxidase (POD); polyphenol oxidase (PPO).
Abstract
Asparagus spears (Asparagus officinalis L. var altilis L.) were cut to 21, 14, and 7 cm in length and stored at 2.5°C for one week. Apical tissue had higher rates of respiration than basal tissue, and cuts to produce 7-cm apical sections caused a significant 15% increase in respiration that lasted a few days. Cuts made 14 cm from the apex had no effect on respiration. Over the 7-day storage period, CO2 production declined by 50%, with most of the decline occurring within the first 3 days. The composition of 3.5 cm incremental segments of the stored spears were analyzed. Storage resulted in significant declines in soluble carbohydrates along the entire 21 cm of the spear, in amino acids for 14 cm, and in protein along the apical 7 cm of the 21-cm spear. Apical 7-cm spears had at least double the rate of losses of these components during storage as did 21-cm spears.
Abstract
In the article “Ripening of Mature-green Tomato Fruit Slices”, by Fabio Mencarelli and Mikal E. Saltveit, Jr. [J. Amer. Soc. Hort. Sci. 113(5):742−745, September 1988], Table 4 is called out in the next-to-last paragraph. There is no Table 4 in this article.
Abstract
Exposure of whole fruit, slices, or pericarp disks of tomato (Lycopersicon esculentum Mill.) to 0.5 to 3.0 ml absolute ethanol vaporized in a 4-Iiter container for 3 hr significantly reduced the climacteric rise in CO2 and C2H4 production, lycopene synthesis, and chlorophyll loss. Inhibition of ripening occurred whether fruit were at the mature-green or breaker-turning stage. Whole fruit recovered and ripened normally after a delay that was related to the tissue ethanol concentration. Treated slices did not ripen normally, and exposure to 16 μl C2H4/liter did not promote ripening. The level of ACC was 14-fold higher in treated slices, while C2H4 production was reduced 70%. Treatments with AVG and ACC indicated that ethanol inhibited ACC conversion to C2H4. Chemical names used: 1-aminocyclopropane-1-carboxylic acid (ACC); [S-(E)]-2-amino-4-(2-aminoethoxy)-3-butyric acid (AVG).
Abstract
Equatorial 7-mm-thick slices of mature-green tomato fruit (Lycopersicon esculentum, Mill., cv. Castlemart) ripened normally, and changes in the concentrations of lycopene, soluble solids content, and titratable acids and in pH were analogous to, although in some cases significantly different from, changes in whole fruit that were harvested when mature-green and ripened. An untrained taste panel scored ripened slices acceptable to good, and no off-flavors were detected. Slices of mature-green tomato fruit can be ripened to an acceptable level of quality, and could provide an additional outlet for fresh-market tomatoes to the home and institutional markets.