I found the below on the web, about new fruits.
"Another interesting fruit, which has not reached the R&D stage, is the monkey orange. It consists of three main species as follows: Strychnos cocculoides Backer; S. spinosa Lam.; and S. pungens Solereder, Loganiaceae, all native to Southern Africa (Wehmeyer 1966; Fox and Norwood-Young 1982; Taylor 1986). Strychnos pungens did not survive in any of our introduction orchards. Strychnos cocculoides which is considered the best of the three (in terms of eating quality), survived only in the Besor region (good quality water and moderate temperatures) and some trees started to bear fruits not of very high quality. It is too early to judge its performance. So far the best of the three under our conditions is S. spinosa. It survived in three of our introduction orchards and performed very well in the Besor area (Fig. 7). We have around 15 fruiting trees with high variability for growth, yields, fruit size, ripening season, and taste. Some of the seedlings bear astringent, bitter fruits, other bear very sour ones but two of the trees bear excellent tasty fruits. In organoleptic taste tests, people were requested to compare the monkey orange fruit with familiar fruits; the most common answers were, orange, banana, and apricot, and all possible combinations among them. The fruits emit a delicate aroma reminiscent of the spice clove. GC/MS analysis performed by Ephraim Lewinson of Newe Ya’ar, (ARO Israel) found eugenol, the essential oil found in clove (unpubl. results). Over 90% of the panel claimed that it was very tasty. Various products such as juices and dry fruit rolls are potential uses for this fruit. The fruit is large (400–1200 g), (Fig.
, round, has a thick shell 4–7 mm, and contains 30%–45% juicy flesh with over 20% total soluble solids, and high acidity (over 200 µeq H+/gFW)."
And also this on wikipedia
The tree is a close relative of Strychnos nux-vomica, the source of strychnine.
When we visited Kruger we stayed a night at Timbavati, in the village there we were shown two big trees of Monkey Orange that they were proud of, I don't remember more than that one of them was said to be rare. I must look up our photos.