Persimmons are becoming popular in Australia. Recently tried some from a grower down in Coffs Harbour, NSW and they were a delightful surprise, especially when fully ripe.
Astringent versus non-astringent
One can grow an old-fashioned astringent variety or one of the newer non-astringent types. According to Maggie Beer from the 2010 Gardening Australia Magazine, “Astringent persimmons can only be eaten when they’re completely ripe and squishy-soft. Otherwise, the bitter tannins make your mouth pucker in the most violent way. Often sold as Fuji fruit, non-astringent persimmons still contain tannins, but they can be eaten as soon as they colour up when the texture is crunchy like an apple or left like the other type until they’re very soft and ripe.”
There is a goodly amount of information, from the Persimmon growing in New South Wales report.
“Persimmons belong to the genus Diospyros in the ebony family and are fairly common trees in the warmer regions of the world, particularly in Asia and North America. The genus contains almost 190 species, of which three are used in commercial fruit growing: D. kaki (oriental or Japanese persimmon), D. lotus (the date plum) and D. virginiana (native American persimmon). PDF is here for those interested.
The generous copper and manganese levels can contribute to important antioxidant functions in the human body. An enzyme called Superoxide Dismutase exists in several forms in human cells and uses both copper and manganese to deactivate toxic levels of the superoxide anion radical, which can build up as part of normal cell functioning. That nice squiggly looking thing above a representation of the SOD enzyme.
Persimmon fruits contain phytochemicals, such as catechin, gallocatechin and betulinic acid. And, as a warning against eating too much of the unripe fruit, an article from 1989 entitled “Small-bowel phytobezoars: detection with radiography” by Verstanding et al, in the Journal Radiology and quoted in Wikipedia -“Unripened persimmons contain the soluble tannin shibuol, which, upon contact with a weak acid, polymerizes in the stomach and forms a gluey coagulum, a “foodball” or phytobezoar, that can affix with other stomach matter.” Nothing to serious but can produce some gastrointestinal issues.
The rich Fibre content is wonderful for cultivating friendly gut microbes. And while the carbohydrate content is high, including glucose, the quoted journal paper at the end of this article provides some antidote to those avoiding sugar intake due to insulin resistance. Not sure how well the skin is tolerated but nevertheless we can see that nature is marvelous in how it gives bountiful sweetness in one part of the fruit and then provides substances that attenuate the sugar’s harmful physiological effects in another.
We have nutrient profiles below for the Japenese D. kaki and the native American persimmon
Nutrient profile for D. kaki (oriental or Japanese persimmon) follows
“The characteristic astringency of unripe persimmons is caused by soluble tannin in the flesh. This astringency disappears in some cultivars when the fruit ripens (softens) and in others when the flower is pollinated, and the fruit contains seeds. Non-astringent persimmon cultivars also occur in Japanese cultivars. These may be eaten when crisp like an apple or allowed to go soft.”
Australia grows about 350,000 trees of non-astringent cultivars. This is equivalent to an annual production of 2500 tonnes.
Nutrient profile for D. virginiana (native American persimmon) follows-
“Persimmon (Diospyros kaki) is a very popular fruit in East Asian countries, but its peels are not consumed despite the fact that they contain many antioxidants such as carotenoids and polyphenols. We prepared a fat-soluble extract from persimmon peel (PP) and fed type 2 diabetic Goto-Kakizaki (GK) rats an AIN-93G rodent diet supplemented with persimmon peel extract (PP diet) for 12 weeks.
Compared with the control AIN-93G diet, the PP diet significantly reduced plasma glutamic-pyruvate transaminase activity, with an accumulation of β-cryptoxanthin in the liver. DNA microarray analysis revealed that the PP diet altered hepatic gene expression profiles.
In particular, expression of insulin signaling pathway-related genes was significantly enriched in differentially expressed gene sets. Moreover, Western blotting analysis showed an increase in insulin receptor beta tyrosine phosphorylation in rats fed the PP diet. These data suggest that the PP diet improves insulin resistance in GK rats.
From – Hepatic Gene Expression of the Insulin Signaling Pathway Is Altered by Administration of Persimmon Peel Extract: A DNA Microarray Study Using Type 2 Diabetic Goto-Kakizaki Rats” Ryoichi Izuchi et al, J. Agric. Food Chem., 2011, 59 (7), pp 3320–3329, 2011