Quality Management

Quality Management

Quality management refers to maintaining quality throughout the logistical chain to the end consumer. With reference to stone fruit, shrivel due to moisture loss is the main post-harvest defect and therefore the key research focus area. Dr Elmi Lötze and PhD student Dr Imke Kritzinger investigated peel properties affecting cultivar and fruit susceptibility to shrivel. They found that moisture loss, although a key driver of shrivel, doesn’t necessarily determine whether shrivel develops or not. The peel properties and components of some cultivars decrease their susceptibility to shrivel despite considerable moisture loss. This information can potentially be used in the selection of new cultivars and may also in future allow us to predict the shrivel risk in particular seasons.

Expertise:
Quality management workgroup

Projects list

POME FRUIT PROJECTS
  • Assessment of malic acid equivalents of Forelle pears on the storability and taste thereof. (D Viljoen)
  • The effect of over-irrigation at different phenological stages on productivity, profitability and storability of various apple cultivars. (S Daiber)
  • Integrated post-harvest ethylene management along the value chain: From the farm to the consumer (O Caleb, Z Belay and M Nkohla) [Abstract]
  • The effect of a water deficit on fruit tree phenology, fruit production, fruit quality and storability of Fuji and Cripps’ Pink apples. (S Midgley and S Daiber) – also Irrigation and Nutrition [Abstract]
  • The use of HarvistaTM (pre-harvest 1-MCP) application to prevent green colour loss and reduce blush of Granny Smith apples. (D Viljoen) [Abstract]
  • Revision of FEMA release standards when fruit do not make FEMA firmness or sugar criteria. (D Viljoen) [Abstract]
  • To develop marketing protocols for FEMA designated orchards that are harvested two to three weeks after normal release but do not qualify for FEMA release. (D Viljoen) [Abstract]
  • Thermal and non-thermal treatments of stone and pome fruit: Towards efficient phytosanitary measures. (O Caleb, Z Belay and N Nyamende) – see Pre and Post-Harvest Pathology [Abstract]
  • Moisture loss studies in pears. (A Botes)
  • Quantifying the effect of bag perforations on forced-air cooling cycles and post storage quality of apples. (D Viljoen) [Abstract]
  • The effect of DPA on fruit quality in pome fruit. (A Botes) [Abstract]
  • The use of HarvistaTM (pre-harvest 1-MCP) application to control superficial scald on Packham’s Triumph pears. (D Viljoen) [Abstract]
STONE FRUITS PROJECTS
  • Technology testing for the ability to control shrivel in cold-stored plums and nectarines. (H Viljoen)
  • Survey of commercial stone fruit cold room relative humidity and temperature to ascertain possible impact on moisture management. (H Viljoen)
  • Application of postharvest bioactive edible coatings and natural antimicrobial peptides as a green solution to alleviate shrivel and extend storage life of plums. (O Fawole and N Jenneker) [Abstract]
  • Develop a storage protocol for plums harvested from week 5 onwards for 6 weeks in bins - decay control using alternative gas regimes of CO2 and O2 manipulation, UV treatment of air supply and a GRAS product drench. (H Viljoen) [Abstract]
  • Evaluation of the 8mm penetrometer plunger to determine harvest maturity on plums. (A de Kock) [Abstract]
  • Effect of irradiation as a mitigation treatment on storage quality of early peaches and nectarines for airfreight consignments. (H Viljoen) – see Phytosanitary and Market Access 
  • Thermal and non-thermal treatments of stone and pome fruit: Towards efficient phytosanitary measures. (O Caleb, Z Belay and N Nyamende) – see Pre and Post-Harvest Pathology [Abstract]
  • Develop optimum ripening protocols for nectarines and plums arriving too green (skin colour) or too firm in market. (H Viljoen) [Abstract]
  • Identify and test improved packaging as well as humidity control in cold stores to reduce moisture loss and shrivel in nectarines. (H Viljoen) [Abstract]
  • Identify and test improved packaging as well as humidity control in cold stores to reduce moisture loss and shrivel in plums. (H Viljoen) [Abstract]
  • Postharvest moisture loss studies in Japanese plums (Prunus salicina Lindl). (E Lötze and I Kritzinger) [Abstract]
  • Determine the CO2 sensitivity of the four main plum cultivars. (A de Kock) [Abstract]
  • Evaluation of micro-perforated LDPE bags for reduction of postharvest moisture loss and shrivelling in Japanese plums (E Lötze)*
  • Peel water vapour permeance of Japanese plums as indicator of susceptibility to postharvest shriveling (I Kritzinger)*