Year: 2012
Type: dissertation
Abstract: We aimed to determine how canopy microclimate influences fruit quality and consumer preference in apples.Our postulate was that consumer preference would be higher for the taste, but not necessarily for the appearance of outer canopy fruit.Outer canopy fruit, exposed to higher irradiance and temperatures, accumulated more phenolics and ascorbic acid, and had higher antioxidant capacities in their peel compared to inner canopy fruit.Phenolic levels and antioxidant capacity were also higher in the flesh of outer canopy fruit while ascorbic acid was higher in the flesh of outer canopy 'Granny Smith'.From a marketing perspective, outer canopy fruit can be seen as possessing greater potential health benefits.Outer canopy fruit were higher in dry matter content (DMC), sugars and TSS, but lower in TA in the first season of the study.The sweeter and less sour taste of outer canopy fruit was preferred in all three cultivars over two years of study.Sunburnt fruit were higher in DMC, TSS:TA ratio, lower in TA and were perceived to be the sweetest, least sour and lowest in apple flavour and textural attributes.The effect of canopy position on apple flavour and textural attributes was inconsistent.The redder outer canopy 'Starking' fruit were preferred by consumers because this cultivar is marketed with full red colour.The appearance of blushed, outer canopy 'Granny Smith' and 'Golden Delicious', and sunburnt 'Golden Delicious' were not preferred by consumers.Consumers are not familiar with such fruit.Blushed 'Granny Smith' is downgraded and sometimes sold at a lower price while sunburnt apples are processed or dumped depending on sunburn severity.The consistency of these results was investigated in one season for 'Golden Delicious' from five locations.The consumer taste preference differential for inner and outer canopy fruit diminished as canopy size decreased.This indicates that there generally would be no benefit in harvesting and marketing outer and inner canopy 'Golden Delicious' separately.We investigated the effect of familiarity on consumer preference by utilising an "experienced" consumer group of farm labourers from Ceres who are familiar with all fruit on a tree compared to an "inexperienced" consumer group of Stellenbosch consumers who are only exposed to fruit on the commercial market and eat apples less frequently.Both groups preferred the taste and appearance of outer canopy 'Starking'.The taste of sunburnt fruit was preferred by a substantial segment of both consumer groups, but the appearance was preferred Stellenbosch University http://scholar.sun.ac.zaOPSOMMING Ons het ondersoek hoe vrugkwaliteit en verbruikersvoorkeur in appels deur die blarekoepel mikroklimaat beïnvloed word.Ons vermoede was dat verbruikersvoorkeur hoër sou wees vir die smaak, maar nie noodwendig vir die voorkoms van vrugte aan die buitekant van die boom (buitevrugte) nie.Buitevrugte was blootgestel aan hoër ligstraling en temperature en hul skil het meer fenole en askorbiensuur geakkumuleer asook ʼn hoër antioksidantkapasiteit gehad vergeleke met binnevrugte.Fenole en die antioksidantkapasiteit was ook hoër in die vleis van buitevrugte terwyl askorbiensuur hoër was in die vleis van 'Granny Smith' buitevrugte.Vanuit ʼn bemarkingsperspektief kan buitevrugte gesien word as vrugte met hoër potensiële gesondheidsvoordele.Buitevrugte was hoër in droë materiaal inhoud (DMC), suikers en TSS, maar laer in TA, laasgenoemde slegs in die eerste seisoen van die studie.Verbruikers het die soeter en minder suur smaak van buitevrugte verkies in beide jare van die studie.Vrugte met sonbrand was hoër in DMC, TSS:TA verhouding, laer in TA en was die soetste, minste suur en laagste in appelgeur en tekstuureienskappe.Die effek van blaredakposisie op appelgeur en tekstuureienskappe was variërend.Verbruikers het die rooier buitevrugte van 'Starking' verkies.Ons reken dit is omdat hierdie kultivar as 'n volrooiappel bemark word.Verbruikers het minder van die voorkoms van rooiblos 'Granny Smith' en 'Golden Delicious' asook van 'Golden Delicious' met sonbrand gehou.Verbruikers is nie vertroud met sulke vrugte nie.Rooiblos 'Granny Smith' appels word afgradeer en word soms teen laer pryse verkoop terwyl sonbrand appels geprosesseer of uitgeskot word afhangend van die graad van sonbrand.Die konsekwentheid van ons resultate is ondersoek met 'Golden Delicious' van vyf lokaliteite.Die smaakvoorkeur differensiaal tussen binne-en buitevrugte het afgeneem met ʼn afname in boomgrootte.Oor die algemeen sou daar dus geen voordeel wees om 'Golden Delicious' binne-en buitevrugte apart te oes en te bemark nie.Ons het die effek van vertroudheid op verbruikervoorkeur ondersoek deur gebruik te maak van ʼn "ervare" verbruikergroep bestaande uit plaasarbeiders in Ceres en ʼn "onervare" verbruikersgroep van Stellenbosch.Die Ceres verbruikers is vertroud met al die appels op die boom vergeleke met die Stellenbosch verbruikers wat net blootstelling het aan vrugte op die kommersiële mark en ook minder gereeld appels eet.Beide verbruikersgroepe het die
Author: Esnath Hamadziripi
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: green
OpenAlex ID: W2147218844