No systematic curing and storage techniques are currently used with onions in Honduras; postharvest losses occur rapidly. The objective of this study was to evaluate the use of storage bins (maximum capacity 7t) that use forced ambient air ventilation to manipulate the atmospheric conditions around the onions. The desired storage conditions were 26 to 30C and 60% to 75% relative humidity. Ventilation regimes were manipulated in an attempt to obtain these conditions. The rate of deterioration in four varieties of onions over a 3-month period was determined and compared with onions stored under normal ambient conditions. Marketable onions in the forced-air storage bin compared to the controls stored under ambient conditions after 13 weeks were 82% vs. 37% for `Granex 33'; 71% vs. 40% for `Granex 429'; 63% vs. 31% for `Granex 438'; and 90% vs. 44% for `Texas Grano 502'. This represents a significant increase in the number of marketable onions after storage. All losses were increased by rain and tornado damage after 1 month of storage. The methods used to maintain uniform temperature and humidity conditions in the storage bin are discussed together with the problems encountered. The construction and operating costs are given together with the market prices and the required returns to cover the bin costs.
A. Medlicott, J. Brice, T. Salgadol, and D. Ramirez
Yosef Al Shoffe, Abdul Sattar Shah, Jacqueline F. Nock, and Christopher B. Watkins
chart in which 1 represents 100% stained starch and 8 represents 0% stained starch ( Blanpied and Silsby, 1992 ). Five fruit were sampled from each replicate at 0, 2, 5, 7, 8, 14, 21, 35, 56, 77, 105, and 140 d (during conditioning and during air storage
Harwinder Singh Sidhu, Juan Carlos Díaz-Pérez, and Daniel MacLean
mitigation of fruit deterioration processes ( D’Aquino et al., 2010 ). Our finding of reduced fruit decay in CA storage compared with ambient air storage is consistent with reports on other fruit. Apples stored under CA storage had less fungal damage compared
R.J. Bender, J.K. Brecht, E.A. Baldwin, and T.M.M. Malundo
To determine the effects of fruit maturity, storage temperature, and controlled atmosphere (CA) on aroma volatiles, mature-green (MG) and tree-ripe (TR) `Tommy Atkins' mangoes (Mangifera indica L.) were stored for 21 days in air or in CA (5% O2 plus 10% or 25% CO2). The MG fruit were stored at 12 °C and the TR fruit at either 8 or 12 °C. Homogenized mesocarp tissue from fruit that had ripened for 2 days in air at 20 °C after the 21-day storage period was used for aroma volatile analysis. The TR mangoes produced much higher levels of all aroma volatiles except hexanal than did MG fruit. Both MG and TR mangoes stored in 25% CO2 tended to have lower terpene (especially p-cymene) and hexanal concentrations than did those stored in 10% CO2 and air-stored fruit. Acetaldehyde and ethanol levels tended to be higher in TR mangoes from 25% CO2 than in those from 10% CO2 or air storage, especially at 8 °C. Inhibition of volatile production by 25% CO2 was greater in MG than in TR mangoes, and at 8 °C compared to 12 °C for TR fruit. However, aroma volatile levels in TR mangoes from the 25% CO2 treatment were in all cases equal to or greater than those in MG fruit treatments. The results suggest that properly selected atmospheres, which prolong mango shelf life by slowing ripening processes, can allow TR mangoes to be stored or shipped without sacrificing their superior aroma quality.
Anne Plotto, Mina R. McDaniel, and James P. Mattheis
Aroma and flavor characters of `Gala' apples [Malus sylvestris (L.) Mill. var. domestica (Borkh.) Mansf. `Gala'] were identified by 10 trained panelists. A vocabulary of 13 aroma descriptors and 16 flavor descriptors were used to characterize changes in controlled atmosphere (CA) and air, or regular atmosphere (RA) storage over 20 weeks. When compared with RA storage, the intensity of fruity (pear, banana, and strawberry) and floral descriptors decreased after 10 weeks in CA for whole and cut fruit aroma and flavor. During the entire storage period under CA, aroma of cut apples retained high vegetative and citrus characters but had a less intense anise aroma. Sourness and astringency were significantly higher for CA-stored apples, and sweetness was significantly lower. A musty note was perceived in whole apples stored in CA for 20 weeks. Aroma of whole fruit stored for 16 weeks in CA followed by 4 weeks in RA was higher in fruitiness, banana, floral, and anise characters when compared with apples stored 20 weeks in CA. There was no difference between fruit stored in CA followed by RA versus CA stored apples for flavor and aroma of cut fruit. Changes in descriptor ratings during storage are discussed in relation to gas chromatography and olfactometry data obtained with the Osme method.
J.R. DeEll and P.M.A. Toivonen
When the gas concentrations of modified atmosphere packaging (MAP) become extreme for broccoli (<2 kPa O2 and >10 kPa CO2), off-odors and off-flavors may develop via anaerobic respiration, rendering it unmarketable. We recently showed that chlorophyll fluorescence decreases when broccoli switches to anaerobic behavior in MAP. The objectives of this study were to determine: 1) if chlorophyll fluorescence returns to normal levels after the package is opened and hence the broccoli is exposed to ambient air, and 2) if chlorophyll fluorescence is related to off-odors that develop. Broccoli heads were held in MAP (2 to 3 kPa O2 and >10 kPa CO2) at 0 to 1 °C for 4, 7, 14, 21, or 28 days, and then 5 days in ambient air at 0 to 1 °C. Chlorophyll fluorescence of the broccoli decreased dramatically in MAP, and remained low during the subsequent 5 days in ambient air. Similarly, off-odors became worse and acetaldehyde, ethanol, and ethyl acetate increased in the broccoli with time in MAP. However, these compounds slightly decreased during the subsequent 5 days of storage in ambient air. Chlorophyll fluorescence parameters correlated negatively with off-odor development and acetaldehyde, ethanol, and ethyl acetate levels in the tissue.
Robert A. Saftner, Judith A. Abbott, William S. Conway, Cynthia L. Barden, and Bryan T. Vinyard
Fruit quality, sensory characteristics, and volatiles produced by 'Gala' apples (Malus ×domestica Borkh.) were characterized following regular atmosphere (RA) storage without and with a prestorage heat treatment (38 °C for 4 days) or controlled atmosphere (CA) storage at 0 and 2 °C for 0 to 6 months plus 7-day shelf life at 20 °C. Static CA conditions were 0.7 kPa O2 plus 1.0 kPa CO2, 1.0 kPa O2 plus 1.0 kPa CO2, and 1.5 kPa O2 plus 2.5 kPa CO2. Most of the more abundant volatiles were esters; the rest were alcohols, an aldehyde, a ketone, and an aryl ether. Respiration and ethylene production rates, internal atmospheres of CO2 and ethylene, and volatile levels were reduced following CA storage compared with RA storage without and with a prestorage heat treatment. Magness-Taylor and compression firmness, titratable acidity, and sensory scores for firmness, sourness, apple-fruity flavor, and overall acceptability were higher for CA-than for RA-stored fruit. Soluble solids content and sensory scores for sweetness were similar among all treatments. Quality and sensory characteristics were generally similar in heated and nonheated RA-stored fruit, and between 0 and 2 °C in CA- and RA-stored fruit. While one CA regime had a higher CO2 concentration than the others tested, CA effects on quality and sensory characteristics were generally more pronounced at the lower O2 levels. Quality characteristics declined between 2 and 4 months storage. The results indicate that short-term CA storage can maintain instrumental and sensory quality of 'Gala' apples.
L. Yanez-Lopez and R.W. Buescher
Controlled atmospheres (CA) have been used as auxiliary to refrigeration for the storage and transportation of food crops. Commodities sensitive to high levels of CO2 experience fermentation. This study was focused upon the effects of CO2-enriched atmospheres on ethanol (ETOH) accumulation as an indicator of the sensitivity of 22 different produce to short-term exposure to 30% CO2 in air for 2 days at 7C. Commodities were obtained from a wholesale or grocer supermarket. ETOH was determined by gas chromatography (GC). Differences in response to 30% CO2 in air were observed among commodities. Kiwi fruit and broccoli had initial low levels of ETOH, which greatly increased after the first day of storage. Cherries and spinach maintained approximately a constant increase in ETOH accumulation during the whole period of storage. Pickling cucumber and zucchini squash had high ETOH accumulation at the early period of storage, which was even higher by the second day of exposure to 30% CO2 in air. In most of the commodities under study ETOH accumulation increased as a response to 30% CO2 levels in air. There was no apparent influence of plant organ on ETOH accumulation.
S.R. Drake, D.C. Elfving, M.A. Drake, T.A. Eisele, S.L. Drake, and D.B. Visser
This study was conducted over two crop seasons using `Scarletspur Delicious' and `Gale Gala' apple trees (Malus ×domestica). The bioregulators aminoethoxyvinylglycine (AVG), ethephon (ETH), and 1-methylcyclopropene (MCP) were applied at various times before or after harvest. Fruit response was evaluated at harvest and after regular atmosphere (RA) and controlled atmosphere (CA) storage [2.0% oxygen (O2) and <2.0% carbon dioxide (CO2) at 0 °C] and quality of whole and juice apple products evaluated. AVG reduced starch loss and ethylene production, enhanced firmness, and reduced cracking in `Gale Gala,' but reduced sensory acceptance of apples and apple juice. ETH intensified starch loss, ethylene production, and reduced firmness, but did not affect `Gale Gala' fruit cracking. AVG followed by ETH reduced starch loss, ethylene production, and cracking and maintained firmness. This combination also aided in sensory acceptance of apples but reduced sensory preference of apple juice. Exposure to postharvest MCP improved flesh firmness retention and reduced ethylene production after both RA and CA storage. MCP either favored or reduced sensory acceptance of whole apples, depending on the particular season, but reduced sensory preference of apple juice. Sensory scores for `Scarletspur Delicious' apples were more strongly modified by bioregulators than were `Gale Gala' apples.
Jennifer R. DeEll, Jennifer T. Ayres, and Dennis P. Murr
‘Delicious’, respectively) were established. Similar 1-MCP-treated and control ‘Empire’ and ‘Delicious’ samples were also placed in a cold room at 0 to 1 °C for air storage. Table 1. Harvest dates and maturity indices of ‘Empire’ and ‘Delicious’ apples upon