Search Results

You are looking at 1 - 10 of 1,002 items for :

Clear All
Restricted access

Kunkun Li, Weiqi Dong, Yun Zhao, Hongxia Xu, Junwei Chen and Changjie Xu

endogenous ABA content. In addition, the effect of ethanol disinfection on aseptic seed germination and the prospect of supplying PPM, a broad-spectrum biocide/fungicide ( Niedz, 1998 ), to the germination medium for controlling contamination were evaluated

Free access

Eliahou Cohen, Yavin Shalom and Ida Rosenberger

Britex and Zivdar, water-based polyethylene waxes, were applied in commercial and experimental formulations as spray coating, a single dip, or double dips on `Murcott' tangerine (Citrus reticulate Blanco) fruits. Postharvest waxing of `Murcott' tangerine reduced weight loss but affected the sensory characteristics of the fruit. Charges in fruit weight loss and juice composition occurred in the waxed fruits after 4 weeks of storage at 5C plus 1 week of simulated retail handling at 17C. Changes in internal fruit atmosphere were related to fruit flavor quality.

Free access

Jian Xin Shi, Joseph Riov, Raphael Goren, Eliezer E. Goldschmidt and Ron Porat

Pyruvate decarboxylase (PDC) and alcohol dehydrogenase (ADH) are two enzymes specifically required for ethanol fermentation. Pyruvate decarboxylase catalyzes the irreversible conversion of pyruvate to acetaldehyde (AA), and ADH subsequently

Free access

Corinne F.J. Rutzke, Alan G. Taylor and Ralph L. Obendorf

mitochondrial respiration and oxidative phosphorylation. Under anaerobic or hypoxic conditions (in the absence of oxygen or under conditions of low oxygen, respectively) ethanol is produced from pyruvate in the ethanol fermentation pathway of metabolism

Restricted access

Yosef Al Shoffe, Abdul Sattar Shah, Jacqueline F. Nock and Christopher B. Watkins

relation to disorder incidence. At harvest and under aerobic storage conditions, apples usually have low acetaldehyde and ethanol concentrations, as well as low pyruvate decarboxylase (PDC) and alcohol dehydrogenase (ADH) activities ( Pesis, 2005 ). Both

Free access

Pimjai Seehanam, Danai Boonyakiat and Nithiya Rattanapanone

such as acetaldehyde and ethanol in citrus fruit can lead to the production of off-flavor ( Chen and Nussinovitch, 2000 , 2001 ; Shaw et al., 1991 ). Coated mandarin fruit are very susceptible to anaerobic respiration ( Cohen et al., 1990

Free access

Mikal E. Saltveit Jr., Mark Ritenour, Mary E. Mangrich and John C. Beaulieu

Exogenous application of ethanol (EtOH) vapor to whole tomato fruit or excised pericarp discs inhibits ripening without affecting subsequent quality. Inhibitory EtOH levels are induced in whole tomatoes by a 72 h exposure to anaerobic atmospheres at 20C. In contrast to tomatoes, exposure to EtOH vapor (0 to 6 ml EtOH/kg FW, for 3 to 6 h at 20C) did not retard ripening (e.g., changes in external color, flesh firmness, and soluble solids) of avocado, banana, cucumber, melon, peach, or plum fruit. When the blocked replicates for nectarines were sorted by the firmness of the control fruit, higher levels of EtOH vapor appeared to delay softening of the firmer fruit. From 0 to 4 ml EtOH/kg FW was injected as 95% EtOH into the seed cavity of melon fruit through a surface sterilized area near the equator of the fruit with a plastic syringe fitted with a 7.5 cm long hypodermic needle. Injection of 1 to 4 ml EtOH/kg FW inhibited the softening of `Honey Dew' and muskmelons. Slight tissue necrosis near the site of injection was noted in a few fruit. Unlike the ripening inhibition of tomatoes which is relatively insensitive to the stage of maturity, the inhibition of melon ripening by EtOH appeared to be significantly affected by the maturity of the fruit.

Free access

Luís Carlos Cunha Júnior, Ângelo Pedro Jacomino, Marcos José Trevisan and Gustavo Henrique de Almeida Teixeira

disruption and lead to increased levels of acetaldehyde, ethanol, ethyl acetate, and ethyl lactate, which confer undesirable aromas to the fruit ( Kader, 2003b ). In an attempt to reduce the risks caused by CAs with high levels of CO 2 , other gases have been

Free access

Charles F. Forney and Michael A. Jordan

Fresh fruits and vegetables produce ethanol when they are held in atmospheres containing low concentrations of oxygen. Ethanol concentrations in the headspace of fresh Brassica vegetables held 24 hours in nitrogen at 20°C ranged from 5 to 110 mmol·m–3. The absence of oxygen induced anaerobic respiration and the production of ethanol in these vegetables. However, other stresses, including heat and high concentrations of carbon dioxide, can also stimulate the production of ethanol in fresh fruits and vegetables held in aerobic atmospheres. Fresh heads of broccoli dipped in 52°C water had increased concentrations of headspace ethanol 2 hours after treatment when held at 20°C in air. Concentrations were 6, 160, and 490 times greater in broccoli treated for 1, 2, or 3 minutes than in nontreated controls, respectively. Fruit of three highbush blueberry cultivars held in 25% carbon dioxide for 6 weeks at 0°C had 80 to 190 times more ethanol than fruit held in air. The 25% carbon dioxide atmosphere also induced blueberries to soften and develop off-flavors. Ethanol may be a fast and easy-to-measure indicator of physiological stress in stored fresh fruits and vegetables. Monitoring induced ethanol production could identify injurious storage environments or postharvest treatments. Possible mechanisms of stress-induced ethanol production will be discussed.

Free access

F. Mencarelli, P. Savarese and M.E. Saltveit Jr.

Exposure to acetaldehyde (M) vapors that produced tissue levels of 0.02% AA (w/w) stimulated ripening of `Hayward' kiwifruit (Actinidia deliciosa L.) much more effectively than exposure to ethanol vapors that produced tissue levels of 0.18% ethanol. Tissue levels of 0.02% and 0.18% ethanol stimulated ripening, while the ripening rate of tissue with 0.04% was similar to the controls. Ethylene and CO production from M-treated tissues were, respectively, 23 times and 60% higher than from control tissues. AA induced a rapid softening that was localized in the core tissue and rendered the fruit unmarketable for 7 days after treatment.