Search Results

You are looking at 1 - 10 of 145 items for :

  • "mechanical damage" x
  • Refine by Access: All x
Clear All
Free access

K.A. Sanford, P.D. Lidster, K.B. McRae, E.D. Jackson, R.A. Lawrence, R. Stark, and R.K. Prange

Postharvest response of wild lowbush blueberry (Vaccinium angustifolium Ait. and V. myrtilloides Michx.) to mechanical damage and storage temperature was studied during 2 years. Fruit weight loss and the incidence of shriveled or split berries were major components that contributed to the loss of marketable yield resulting from mechanical damage and storage temperature. Decay of berries resulted in only 1% to 2% of the total marketable fruit loss. In general, the major quality attributes (firmness, microbial growth, hue, bloom, split, and unblemished berries) deteriorated with increasing damage levels and increasing storage temperature without significant interaction. Temperature had consistent effects in both years on moisture content, soluble solids concentration, titratable acids, weight loss, shriveled and decayed berries, Hunter L values, and anthocyanin leakage, while damage level had inconsistent or no significant effect.

Free access

M. Landrigan, S.C. Morris, and K.S. Gibb

The effect of enzymic action, mechanical damage, and relative humidity (RH), on browning of stored rambutan was investigated. Mature rambutan fruit (`R 134') were infiltrated with known enzyme inhibitors, then either mechanically damaged or left undamaged, before storage at 20 °C with 95% or 65% RH. Fruit were visually scored for browning and weight loss was measured. All fruit at low RH browned severely. At high RH, infiltration with water, but not with the enzyme inhibitors, salicylhydroxamic acid and catalase, led to a large increase in browning. We infer that enzymes were involved in browning in damaged tissue under high RH. At low RH, inhibitors were ineffective as desiccation was the dominant causative factor of browning.

Free access

F. Mencarelli, L. Lanzarotta, R. Massantini, and R. Botondi

Kiwifruits were picked by hand and gently placed in pulp trays. Impact tests were conducted by dropping the fruits from heights of 30 cm onto different sandpapers to provide a uniform abrasion surface. Abrasion tests were conducted by compressing the fruits with a fixed load of 3.5 N (Instron equipment) onto different sandpapers and pulling out the fruits. Compression test was performed by using the previous procedure with a fixed load of 4.5 N for different period of time (minutes). Increase of transpiration rate and ethylene production was observed in fruits abraded with sandpaper which slight wounded the peel. Impact onto sandpaper, caused the appearance of white lignifted filaments in the flesh. Increase in soluble solids and softness of flesh and core was observed in injured fruits. Healing process and polyamines effect will be discussed.

Full access

John R. Duval, Craig K. Chandler, Daniel E. Legard, and Peter Hicklenton

Transplant quality can have a major effect on the productivity of many crops. Bare-root, green-top transplants for Florida winter strawberry (Fragaria ×ananassa) production are produced mainly in highlatitude (>42° N) nurseries. Mechanical digging machines are used to remove plants from the soil at these nurseries before transport to production fields in Florida. In the course of this operation, crowns, petioles, and leaves may be crushed and broken. Machine and hand-dug bare-root transplants of `Camarosa' and `Sweet Charlie' were obtained from a Nova Scotia, Canada nursery, planted at the Gulf Coast Research and Education Center, Dover, Fla. field facility on 2 Nov. 1999 and 10 Oct. 2000, and grown using standard annual-hill production practices. Plots were harvested twice weekly beginning 5 Jan. 2000 and 15 Dec. 2000. Hand-dug transplants produced significantly higher monetary returns both seasons. Therefore, fruit producers may consider paying the higher cost associated with changes in harvesting and packing operations needed to reduce damage to transplants.

Free access

Astrid C. Newenhouse

Plants respond to wind in a manner similar to drought, but, in addition, leaves suffer physical or mechanical damage. Long-term wind stress results in smaller plants, less total leaf area, skewed tree growth because most of the branches grow toward the leeward side, and less yield than plants protected from wind. A simple procedure to simulate abrasion damage to leaves helps growers recognize wind damage to several fruit crops.

Free access

Celso L. Moretti, Steven A. Sargent, Donald J. Huber, Adonai G. Calbo, and Rolf Puschmann

`Solar Set' tomatoes (Lycopersicon esculentum Mill.) were harvested at the mature-green stage of development and treated with 50 μL·L-1 ethylene at 20 °C. Breaker-stage fruit were dropped from 40 cm onto a solid surface to induce internal bruising and held along with undropped fruit at 20 °C. At the ripe stage, pericarp, locule, and placental tissues were analyzed for soluble sugars, vitamin C, pigments, titratable acidity, soluble solids content, pericarp electrolyte leakage, extractable polygalacturonase activity, and locule tissue consistency. Bruising significantly affected chemical composition and physical properties of pericarp and locule tissues, but not placental tissue. For bruised locule tissue, carotenoids, vitamin C, and titratable acidity were 37%, 15%, and 15%, lower, respectively, than unbruised fruit. For bruised pericarp tissue, vitamin C content was 16% lower than for unbruised tissue, whereas bruising increased electrolyte leakage and extractable polygalacturonase activity by 25% and 33%, respectively. Evidence of abnormal ripening following impact bruising was confined to locule and pericarp tissues and may be related to the disruption of cell structure and altered enzyme activity.

Free access

Steven A. Sargent, Jeffrey K. Brecht, and Judith J. Zoellner

Internal bruising (IB) caused by handling impacts results in disruption of normal ripening in tomato (Lycopersicon esculentum Mill.) locular gel. It was selected as an injury indicator to investigate the effect of drop height (O, 10, 20, 30 cm) onto an unpadded surface and number of impacts (one or two) for three tomato cultivars. For mature-green (MG) tomatoes, significant incidence of IB (5% to 45%) was found in all cultivars for single drops on opposite sides of fruits from 20 cm; two drops on the same location from 20 cm caused 20% to 30% IB. Breaker-stage (BR) tomatoes were more sensitive to impacts than MG. Single drops from 10 cm on opposite sides of BR fruits caused 15% to 73% IB, depending on cultivar. Two drops on a single location from 10 cm caused 50% to 68% IB. `Sunny' was less susceptible to IB than `Solar Set' or `Cobia' (formerly NVH-4459).

Full access

Dale E. Marshall and Roger C. Brook

The tender skin of bell peppers (Capsicum annuum L.) covers a crisp, fragile flesh that is easily bruised, cracked or crushed. During commercial harvest and postharvest handling operations, bell peppers undergo several transfers, each of which has the potential for causing mechanical injury to the peppers. These mechanical injuries include abrasions, cuts, punctures, and bruises, which affect the market grade and reduce pepper quality and subsequent life. Previous research on handling fresh vegetables and fruits has shown that the instrumented sphere (IS) is a tool that can help identify potentially damaging impacts during harvest and postharvest handling operations. For the study reported, the IS was used to evaluate the damage potential for peppers being hand harvested, and for peppers on a packing line. Studies in the field attempted to duplicate how pickers harvest peppers into pails and then empty them into empty wooden pallet bins. For the packing line evaluated, the diverging roll-sizer had the greatest potential for damage. Adding cushioning to hard surfaces and removing the metal support from under the cross-conveyor would help to reduce pepper damage. Cushioned ramps, and hanging flaps or curtains should be used to help reduce acceleration and drop height between pieces of equipment. All locations should be cushioned where peppers impact a hard surface, and drop height should be limited to 3 inches (8 cm) on a hard surface and 8 inches (20 cm) on a cushioned surface. The speed of all components in the system should be checked and adjusted to achieve full line flow of peppers without causing bruising. Workers must receive instruction on the significance of bruising during the harvest and postharvest operations.

Full access

William Pelletier, Jeffrey K. Brecht, Maria Cecilia do Nascimento Nunes, and Jean-Pierre Émond

Strawberries are a very popular item in retail stores. However, they are highly perishable and have a relatively short shelf life, even when handled under optimum conditions. Poor temperature management during distribution and mechanical damage are

Free access

Randall H. Hagen and David A. Palzkill

Woody legumes used for landscape plants in the desert southwest are extremely variable when propagated from seed. Three Prosopis chilensis trees were air layered in early April, 1989. Stems diameters of 0,5 and 1.0 cm and IBA levels of 5,000 and 15,000 ppm IBA were compared. Except when mechanical damage occurred during the wounding stage or from wind, 100% of the layers at both 5,000 and 15,000 ppm IBA rooted. The 0.5 cm branches were more susceptible to mechanical damage from wounding than the 1.0 cm branches.

A second study begun in mid-August, 1989, compared 0 and 5,000 ppm IBA on the same three genotypes. After eight weeks, IBA treated layers had 83% and untreated layers only 13% rooting. Layers with IBA had thicker and more numerous roots.

Air layers of Cercidium, Parkinsonia, and other species of Prosopis were also successfully rooted.