Chestnuts, Coconuts and Sago and gluten Intolerance

This last post should conclude my research about food and gluten intolerance. I would like in this last article to talk briefly about three minor type of flour that are extracted from unusual sources: chestnuts, coconuts and sago.

Since prehistory, chestnuts have been dried and ground into flour and used in the same way that starchy cereals are. Before the arrival of the potatoes and maize from the New World chestnuts were an essential subsistence food in the mountainous and marginal agricultural areas of France, Corsica and Italy. Its nutritional breakdown is as follow: Nutrient for 100gm of flour Calories 371 (calories from Total Fat 33) ; Total Fat 3.67 gm (Saturated Fat 0.7 gm (17.9%), Polyunsaturated Fat 1.6 gm (44.0%), Monounsaturated Fat 1.4 gm (38.1%) ) ; Cholesterol < gm =" grams" mg =" milligrams" iu =" international" re =" retinol">

Chestnut flour is poor in protein and gluten free. It is traditionally used to make gruels, breads, pastas, batters (great for pancakes!), cakes, polenta, and provides substance in soups.

Coconut flour refers to the screened food-grade product obtained after drying, expelling and/or extracting most of the oil or milk from sound coconut meat. The meat is either pared or unpared. It is sub-classified according to its fat content (low, medium and high), protein content (high protein) and fiber content (high fiber).
The manufacturing of virgin coconut oil and flour involves two processing methods either by the:

1) Dry process which involves drying of grinded coconut meat, oil extraction and pulverizing the meal. The process produces a high protein coconut flour (33%) which can be used as wheat substitute. The advantages of the this process is the high oil recovery at 88% based on the oil content of the meat (65%) or 58% of the dried granulated meat and good quality of the oil with a free fatty acid content of 0.1%. The dry process also produces high protein flour which can be used in making pan de sal and other baked products.

2) Wet process wherein the meat is extracted with milk, drying of the residue and grinding to produce the flour. In the wet process, almost 52% of the available oil in the fresh meat is recovered. To optimize the oil extraction efficiency of the wet process developed a technology to further extract the oil from the meal after milk extraction. The meal or residue that remains still contains a lot of oil 35-48% fat content in which 38% colorless oil is recovered and 40% coco flour is obtained as a by-product. Instead of selling the residue as feeds this can be further processed to produce two high-value products, VCO and flour. The coconut flour is high in fiber content 60% dietary fiber which can be used as a functional ingredient in the lowering of glycemic index and serum cholesterol levels.

1. Whole full fat coconut flour: Coconut flour prepared from unpared dehydrated and edible coconut kernels by pre-pressing and solvent extraction.
2. Coconut flour from pared Coconut flour prepared from pared, coconut dehydrated and edible coconut kernel.
3.Defatted coconut flour: Food Coconut flour obtained from food-grade grade copra meal or copra that has been defatted by solvent/mechanical extraction. The resulting flour is brownish in color Sub-classification: low fat Coconut flour with 10-15% fat ; medium fat Coconut flour with 16-25% fat ; high fat Coconut flour with 25-48% fat ; Low-fat, high-fiber coconut Coconut flour from finely ground coconut flour residue “sapal”. The fat content of the resulting flour range from 10-15% and has a total dietary fiber content of more than 60%.

4. High-protein, high-fiber Coconut flour prepared from dehydrated finely ground coconut meat.

5. Paring flour Coconut flour prepared from the paring or the testa of the coconut.

6. Copra meal Coconut meat obtained after extracting oil for granulated copra.

There is a proximate Composition of Coconut Flour From Fresh-Dry Process(1st figure), from wet-dry Process (2nd figure)
Moisture 4.5/ 6.7 ; Fat 10.7/ 10.9 ; Crude Fiber 40/ 60.9 (as dietary fiber) ; Protein 17.5/ 10.8 ; Ash 5.5/ 3.16 ; Carbohydrates 61.8/ 68.5.
Note that coconut flour is gluten free therefore suitable for coeliacs.

Coconut flour can be used to bake cakes and in the making of batters.

Sago is a powdery starch made from the processed pith (the word comes from the Old English word piþa, meaning substance, akin to Middle dutch pit, meaning the pit of a fruit) found inside the trunks of the Sago Palm metroxylon sagu. The genus name metroxilon is derived from Greek and means heartwood, while the species name sagu is from a local name for the food. Sago forms a major staple food for the lowland peoples of New Guinea and the Moluccas where it is often cooked and eaten as a form of pancake with fish.
Sago looks like tapioca and both are pearly grains of starch, but tapioca is made from the root of the cassava root.
This palm tree only flower and fruit once before they die. The stems are harvested just before the flower forms as it is only then that they are full of the stored starch which will be used for flowering and fruiting. The trunks are cut into sections and into halves and the starch is beaten or extracted from the "heartwood", the traditional methods is to collect the starch when it settles out of water. One palm yields 150 to 300kg of starch.
Sago flour is nearly pure carbohydrate (starch), and contains very little vitamins, or minerals. However, as sago palms are typically found in areas unsuited for other forms of agriculture, sago cultivation is often the most ecologically appropriate form of land-use.
A portion of 100 grams of dry sago yields 355 calories, including an average of 94 grams of carbohydrate, 0.2 grams of protein, 0.5 grams of dietary fiber, 10mg of calcium, 1.2mg of iron, and negligible amounts of fat, carotene, thiamine, and ascorbic acid (vitamin C). It is free from gluten making it a suitable substitutes for gluten intolerant people.
Sago flour can be use to make batters, unleavened flat breads, and noddles.
Useful links about gluten intolerance:


  1. Anonymous said,

    Interesting reading. Do you think it is practical to teach PNG village lowlanders to make coconut flour? It would need to be within an acheivable level of hygeine and a method that would avoid everything going mouldy? It would be interseting to know the glycaemic index of unprocessed sago.

    on 29 May, 2010  

  2. Yann_Chef said,

    Thanks for your comment. Well, I am just trying to explain how coconut flour is made. I don't expect anybody to try this at home. If my article sounds like that it is not what I intend to do.
    When it comes to the G.I of sago to my knowledge it has not been tested yet (source university of Sydney's glycaemic foundation) but it is acknowledged to be close to the G.I of tapioca which is between 70 and 93 depending on the way it is cooked.

    on 29 May, 2010