pattern typical of a climacteric fruit: fruit show a dramatic respiratory increase, marked increase in ethylene production, and continued ripening after detachment from the tree ( Biale and Barcus 1970 ; Thompson et al. 1974 ; Williams and Golden 2002
Abstract
Gas chromatography and bioassays were used to identify ethylene (C2H4) in fruit emanations of mammee apple (Mammea americana L.). C2H4 production probably triggered the respiratory rise in preclimacteric fruit and its relationship to respiration was typical of that for a climacteric fruit. C2H4 production was however, independent of respiration in immature and postclimacteric fruits. C2H4 production increased to a peak and then declined with deterioration of fruit in spite of nearly constant rates of respiration in immature fruit and declining rates in postclimacteric fruit. Peak production of C2H4, 408 μl per kg per hr, from preclimacteric fruit is probably the highest reported among fruits.
Abstract
Chilling sensitivity of ‘Fuerte’ and ‘Hass’ avocados (Persea americana Mill.) is a function of the stage of the climacteric. The least sensitive stage is postclimacteric where fruit can be kept at 2°C for 6 to 7 weeks. ‘Hass’ avocados on the climacteric rise and at the climacteric peak were most sensitive to chilling and showed injury after 19 days of treatment at 2°. Postclimacteric fruit could be transferred to 2° at 36 to 48 hours after the climacteric peak. The time preclimacteric fruit could be held at 2° varied during the picking season but could be as long as 30 days.
individual use. As a climacteric fruit, kiwiberries are typically harvested when physiologically mature but not yet ripe (i.e., ready to eat). This practice has many advantages, including reducing mechanical damage to firmer fruit when harvesting and
Abstract
The parameters for optimum maturity of fruit of ‘Pairi’ variety mango, harvested near Mysore from 1964 to 1969, have been found to be 260 ± 20 g in weight, olive green surface color, and outgrown shoulders. In addition, pH and color of the pulp in terms of chromaticity coordinate x were useful indices. Other parameters were not consistent.
Respiration climacteric maximum was delayed in immature fruits and advanced in over-mature fruits. Fruits of optimal maturity recorded the climacteric maximum on the 9th day ± 1 at ambient storage of 26 ± 2°C and 45–65% RH. Sugar accumulation was maximum at about the time of the climacteric peak in respiration and sucrose was predominant. The chemical composition of the fruit was more or less similar over several seasons and harvests.
Abstract
The respiratory rates for eight stages of development of highbush and lowbush blueberry fruits ranging from immature green to senescence are presented. Based on these data, the blueberry exhibits a typical climacteric respiration curve. An increase in temperature from 15.5°C to 25.5°C resulted in an increase in the respiration rate.
Autocatalytic C2H4 biosynthesis in preclimacteric apple fruit (Malus domestica Borkh. `Golden Delicious') was prevented by storage in atmospheres of 20% CO2-enriched air (17% O2 + 63% N2) or 0.25% O2 (balance N2). In preclimacteric fruit, both treatments inhibited C2H2 biosynthesis by suppressing expression of ACC synthase (ACC-S) at the mRNA level. ACC oxidase (ACC-O) mRNA abundance and in vitro enzyme activity also were impaired by these treatments. However, the conversion of ACC to C2H4 never became the rate limiting step in C2H4 biosynthesis. C2H4 biosynthesis also was effectively inhibited in climacteric apple fruit kept in air + 20% CO2 or 0.25% O2. Climacteric apples also exhibited suppressed expression of ACC-S at the mRNA level, while ACC-O transcript abundance, enzyme activity, and protein abundance were reduced only slightly. ACC-S is the key regulatory enzyme of C2H4 biosynthesis and is the major site at which elevated CO2 and reduced O2 atmospheres inhibit C2H4 biosynthesis, irrespective of fruit physiological maturity. Chemical names used: 1-aminocyclopropane-1-carboxcylic acid (ACC).
Volatile aroma compounds produced by apple, banana, and tomato are produced throughout development, however, those associated with ripening and edible quality are dependent upon ethylene action. In apple and banana, characteristic aroma is, in large part, dependent upon the formation of volatile esters. In tomato, many of the characteristic aromas are dependent upon tissue disruption and result from aldehydes and alcohols following lipid degradation. For apple and banana, the enzyme alcohol acyl-CoA transferase (AAT, EC 2.3.1.84) is the enzyme responsible for the final reaction in the pathway for ester formation and catalyzes the union of an alcohol and the CoA derivative of fatty acids. In both tissues, AAT gene expression was detected prior to the onset of ester production. In apple, AAT expression was found to be closely tied with the onset of autocatalytic ethylene synthesis. In banana, ethylene synthesis peaked and began to decline well before ester synthesis began. However, the expression of AAT increased as ester production increased for both tissues. Tomato fruit, like apple and banana, produced characteristic aromas following the onset of the ethylene climacteric, suggesting changes in the activity of various components of the lipoxygenase pathway. In all three tissue types, there are continuous, significant shifts in the aroma profile as fruit ripen age, suggesting shifts in specific metabolic pathways associated with precursor synthesis or degradation.
Abstract
‘McIntosh’ and ‘Cortland’ fruits were harvested at 3—4 day intervals and ‘Delicious’ and ‘Golden Delicious’ fruits were harvested at 5 day intervals in several seasons. The respiration rate was measured 24 hr after each harvest in order to locate the position of the fruit on the respiratory climacteric curve. The optimum harvest dates for each variety were determined by evaluations of the quality and condition of the fruit after removal from storage. Optimum harvest dates were not found to be associated with any definite position on the climacteric curve.
Abstract
Highbush blueberries (Vaccinium corymbosum L.) of 7 cultivars were harvested and visually separated into color grades: immature green, mature green, green-pink, blue-pink, blue and ripe. The rates of respiration over a 5 year period and ethylene evolution over a 3 year period of each color grade were determined using an infrared gas analyzer and a gas chromatograph, respectively. The rate of respiration of the berries generally increased from the immature green to a peak at the green-pink or blue-pink stage. Ethylene generally increased to a peak at green-pink. Both patterns are characteristic of climacteric type fruit.