Postharvest science

Science programme: Postharvest science

Over the past 25 years New Zealand horticulture has lifted export receipts from $115 million to well over $2 billion. HortResearch has played a key role by providing effective postharvest solutions.

Core science drivers are fruit responses to stresses such as temperature and oxidative stress (O₂ and CO₂), ethylene (a key gaseous plant hormone), and water relations. In addition, fruit texture and the nature of cell wall changes during ripening and in relation to peelability are strengths of the team. This work is carried out in collaboration with members of a wide range of other Science Programs within HortResearch.

Our areas of research include:

• New Crop and Cultivar Development
• Controlled Atmosphere (CA) and Modified Atmosphere/Packaging (MA or MAP)
• Temperature Optimisation and Novel Manipulations
• Ethylene Treatments ('Pre-Ripening' or 'Ethylene Conditioning')
• Ethylene antagonists (1-MCP - SmartFresh™ and AVG - ReTain®)
• Storage Technologies
• Texture, Health and Quality Properties
• Convenience; Fresh-cut, Peelability
• Molecular Control of Fruit Ripening
• Fruit Physiology and Stress Response
• Maturity
• Heat Treatment Research (Disinfestation,  Quality, Pathology)
• Fruit Oils (Avocado, Olive)

Our postharvest facilities in Auckland are world class and extensive by any measure. This, along with the depth and breadth of capability of the team, and its internal and external collaborations and ability to deliver on both foundation and commercial revenue are some of the key reasons for the international reputation and recognition of the team.

Resources:

• Over 70 temperature controlled rooms: 27 standard  coolstores, 13 small temperature controlled cabinets, 16 CA rooms (2-10 pallets), 17 temperature controlled rooms
• Extensive heat treatment facilities: Waterbaths (insect, fruit and large scale), Hot air units (moderate and large scale, simultaneous high-temperature and CA treatment)
• 'Matrix type' CA mixing systems, multiple treatments
• Laboratories (physiology, biochemistry, pathology, molecular)
• Ethylene treatment systems and 3 large evaluation rooms
• Gas chromatograph facilities (Ethylene, CO2/O2, ethanol, AA and total volatiles)
• Quality and texture measurement equipment and facilities
• Supporting Sensory and Consumer Science (18 booths)

We are optimising quality and value for a diverse range of crops worldwide:

Our key crops are kiwifruit, apples, avocados, summerfruit, citrus, and persimmons. Other crops include pears, berryfruit, asian pears, tamarillos and feijoas. Our team collaborate with other researchers on overseas crops and have experience in mango and lychees (Thailand and New Caledonia), dragon fruit  (Viet Nam), and bayberry and loquot (China). We also work on some vegetable crops including onion, potato and capsicum (bell pepper).

ripeSense™ :

Created by HortResearch scientists as part of specialist work in cool chain monitoring, ripeSense™  was voted one of “the most amazing inventions of 2004” by TIME magazine. Supporting our reputation for innovation in produce handling, storage and presentation.

For a better understanding of our research, we recommend the following documents:

Allan AC, Maddumage R, Simons JL, Neill SO, Ferguson IB 2006. Heat-induced oxidative activity protects suspension-cultured plant cells from low temperature damage . Functional Plant Biology 33(1): 67-76

Burdon J, Lallu N, Billing D, Burmeister D, Yearsley C, Wang M, Gunson A, Young H 2005. Carbon dioxide scrubbing systems alter the ripe fruit volatile profiles in controlled-atmosphere stored 'Hayward' kiwifruit . Postharvest Biology and Technology 35(2): 133-141.

Harker FR, White A, Gunson FA, Hallett IC, De Silva HN 2006. Instrumental measurement of apple texture: a comparison of the single-edge notched bend test and the penetrometer . Postharvest Biology and Technology 39(2): 185-192.

Schroeder R, Wegrzyn TF, Bolitho KM, Redgwell RJ 2004. Mannan transglycosylase: a novel enzyme activity in cell walls of higher plants . Planta 219(4): 590-600.

White A, de Silva N, Requejo-Tapia C, Harker FR 2005. Evaluation of softening characteristics of fruit from 14 species of Actinidia. Postharvest Biology and Technology 35(2): 143-151.

Contact Allan Woolf