Thesis (M.Sc. (Plant Production)) -- University of Limpopo, 2014 / Wild medlar (Vangueria infausta subsp. infausta) is a popular indigenous fruit available and consumed by rural communities in Limpopo Province, South Africa. Inadequate post-harvest practices in indigenous fruit plants including V. infausta fruit forms major constrains in expanding their production. There is scanty information documented on neither objective nor subjective harvesting indices of indigenous fruit plants consumed by locals in sub-Saharan Africa. Thus, the objective of this study was to determine the effect of harvesting time on physico-chemical properties and selected nutritional composition of V. infausta fruit. Fruits were harvested twice, where two harvesting times were regarded as treatments and each tree as replication. The reduction for fruit weight, sugar content and sugar/acid ratio was highly significant (P ≤ 0.05), whereas for average fruit diameter, seed weight, acid ratio and pH content this may imply that the listed parameters are treatment which was non-significant (P ≤ 0.05). The treatment reduced P, K, Mn and Fe by 33%, 18%, 3% and 7%, respectively. On the other hand, treatments had no effect on N and Ca. The reduction of phosphorus was highly significant (P ≤ 0.05), whereas for N, K, Ca, Mn and Fe treatment impact was non-significant (P ≤ 0.05). Similarly, the treatment consistently reduced moisture content and increased dry matter and crude protein of V. infausta by 76%, 300% and 7%, respectively. The reduction of moisture content, increase in dry matter was highly significant (P ≤ 0.05), whereas crude protein treatment impact was non-significant (P ≤ 0.05). The data indicated that the best time to harvest V. infausta fruit was during January when fruits were cosmetically appealing and not wrinkled. This study demonstrated that there was less variation in some measured objective harvesting indices of V. infausta fruit harvested at two harvesting time. More work would be required to do physico-chemical properties and selected mineral elements analysis from wide growth habitat for conclusive recommendations.

The aim of this diploma thesis is determination of selected metals in unconventional fruit species, specifically in cornelian cherry (Cornus mas), sea buckthorn (Hippophae rhamnoides) and medlar (Mespilus germanica).There is informationabout 16 analysed metals – As, B, Be, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Se, Sn, Pb, V, Zn. There are described analytical techniques for elemental analysis and methods for destruction biological material. Samples for analysis are prepared by using microwave mineralization and ICP-MS for detection. This is described in the experimental part of the diploma thesis. Analysis confirmed that unconventional fruits are rich sources of trace elements.