phytosanitary regulations for apples. The SA involves the cumulative effect of commercial operations to reduce the risk of possible pest infestation followed with validation by intense inspection. One area that can be exploited is the cold storage component
J.D. Hansen, M.A. Watkins, M.L. Heidt, and P.A. Anderson
Valeria Sigal Escalada and Douglas D. Archbold
Techniques that slow ripening of apple are valuable tools that can maintain fruit quality during cold storage. Aminoethoxyvinylglycine (AVG) inhibits the pyridoxal phosphate-linked enzyme aminocyclopropane synthase (ACS) activity ( Capitani et al
Valeria Sigal Escalada and Douglas D. Archbold
; Rupasinghe et al., 2000 ). These compounds are commonly used along with cold storage to manage apple fruit ripening. Several quality factors influence the acceptability of apples, including appearance, texture, and flavor. Flavor is a complex trait composed
Carolina A. Torres, Omar Hernandez, Maria A. Moya-León, Ivan Razmilic, and David R. Rudell
accumulate on sun-exposed peel in response to direct sunlight ( Felicetti and Schrader, 2008 ; Yuri et al., 2010 ). Phenolic compounds also appear to be directly involved in sunscald development in ‘Granny Smith’ apples during cold storage ( Hernandez et al
Giacomo Cocetta, Ilaria Mignani, and Anna Spinardi
). Winter pears need a long storage period at 0–1 °C to reach the right juiciness and to produce their typical aroma. However, physiological disorders can affect fruit quality during cold storage. Many of these disorders are due to a stressful condition that
Barbara M. Reed
In vitro cold storage of Rubus germplasm was investigated using several environmental conditons and types of storage containers. Shoot cultures of Rubus species and cultivars were grown in either tissue culture bags or 20 × 150 mm glass tubes and compared for plant condition and survival under various storage conditions. Cultures stored at 10 C in the dark were in poor condition after 6 months. Cultures kept at 4 C were in much better condition and had higher survival rates after 18 months when stored with a 12 h daylength rather than total darkness. Overall there were no differences in survival or condition between cultures in tubes and bags. Contamination rates were 15% in tubes and 0% in bags. Plants in tissue culture bags could be stored for 9 months at 25 C with 16 h light when the nitrogen level of the MS medium was reduced to 25% and the medium volume was increased from 10 to 20 ml per bag. Genotype differences were apparent under all conditions tested. The best storage condition for Rubus germplasm was 4 C with 12 h light. Plastic tissue culture bags were preferred over tubes due to lower contamination rates.
Aditi Satpute, Bryce Meyering, and Ute Albrecht
chilling-sensitive crops such as basil, which experience leaf injury and sometimes irreversible wilting or death when transported or stored at suboptimal temperatures. Different strategies have been investigated to reduce CI during cold storage. These
Federica Galli, Douglas D. Archbold, and Kirk W. Pomper
Pawpaw [Asimina triloba (L.) Dunal] has significant potential as a new fruit crop. During ripening, loss of firmness is extremely rapid, and this trait may be the biggest obstacle to the development of a broader market. Cold storage of pawpaw fruit seems limited to 4 weeks at 4 °C, though fruit softening merely slows during storage. A study of several cultivars with commercial appeal has shown that none have superior cold storage life. Extending the cold storage beyond 4 weeks resulted in increasing loss of fruit firmness, poor poststorage ripening, and development of quality traits, and many fruit exhibiting flesh and peel discoloration. Cold storage duration affected fruit volatile production. By 4 weeks of cold storage, ethyl hexanoate and ethyl octanoate were the major volatiles produced, replacing methyl hexanoate, which was the major volatile produced by ripe fruit after harvest. By 8 weeks of cold storage, volatile ester production was generally low and ethyl hexanoate became the only major volatile. This loss of volatile production was accompanied by a decrease in alcohol acetyl transferase activity. Also, during cold storage, there was an increase in total phenolic content, lipid peroxidation products, and polyphenol oxidase activity. These changes may contribute to the black discoloration that developed in fruit cold-stored for 8 weeks or more. It is apparent that cold storage alone may not be sufficient to extend the storage life of most, if not all, current pawpaw cultivars beyond 4 weeks.
L.J. von Mollendorff, G. Jacobs, and O.T. de Villiers
`Flavortop' nectarines [Prunus persica (L.) Batsch] were stored at -0.5C or 3C for 0, 1, 2, 3, or 4 weeks, after which the fruit was ripened at 15C. After ripening, fruit samples were tested daily or every second day for extractable juice, internal conductivity, and woolliness. The change in the percentage of extractable juice during ripening differed very little among the five storage periods. A rapid increase in internal conductivity occurred during ripening in fruit with or without cold storage, but the onset of the increase was advanced with longer cold-storage periods. No woolliness developed in fruit not placed in cold storage or in fruit cold-stored for 1 or 2 weeks at - 0.5C or 3C. Woolliness only developed during ripening of fruit cold-stored for 3 or 4 weeks at -0.5C or 3C. Incidence of woolliness increased to high levels during ripening and decreased thereafter to no woolly fruit by the 11th day. The lowest values for extractable juice coincided with the highest incidence of woolly fruit. Fruit stored for 4 weeks took longer to pass the woolliness stage. At the end of the ripening. period, cold-stored fruit were similar in appearance and juiciness to those ripened without cold storage. Nectarines stored at 3C generally developed woolliness earlier, had a lower incidence of woolliness, and took longer to overcome the problem than fruit stored at -0.5C. Incidence of browning of the mesocarp tissue was greater at 3C than at -0.5C.
Bahman Shafii and Danny L. Barney
Trials were conducted to determine the effects of air drying and cold storage on black huckleberry (Vaccinium membranaceum Douglas ex Hooker) seeds. Treatments included fresh seeds, seeds air-dried for 7 days, and those air-dried and stored at 2 to 3 °C for either 1 or 7 years. Germination was measured every 7 days. The time course of germination was modeled using a logistic growth curve from which days to 50% germination (T50), germination rate index, and maximum germination percentages were estimated. Germination curves of dried and of dried and cold-stored seeds were significantly different from that of fresh seeds. Seeds stored for 1 or 7 years had germination percentages similar to those for the fresh, nondried seeds. Air drying for 7 days reduced the maximum germination percentage from 73% to 59% (fresh seeds). This induced dormancy was gradually lost during cold storage of dry seeds. Cold storage of air-dried seeds was an effective method for preserving V. membranaceum germplasm for at least 7 years.