Introduction
In botany and mycology, a haustorium (plural haustoria) is a structure that grows into or around another structure to absorb water or nutrients Anatomically, coconut is composed of four distinct parts; the outer fibrous exocarp or husk, the highly lignified endocarp or shell, the white solid endosperm or kernel, and a large central cavity filled with liquid endosperm i.e. coconut water. On germination, the basal part of the embryo, which is embedded in solid endosperm near the germinating pore of coconut, enlarges to form a cotyledonary structure called a haustorium. Haustorium enlarges and fills the entire water cavity in 20‑24 weeks after germination. During this period, it mobilizes nutrients in the endosperm and nourishes the germinating embryo. Coconut kernel, water, and haustorium are edible parts of the coconut. Analysis of coconut haustorium revealed that it contains proteins, minerals, alkaloids, polyphenols, and growth- promoting substances.
Most of the farmers are facing the problem of sprouting edible coconuts due to long-term storage. Most of the sprouted coconuts may fail to grow as a seedling. To improve the utilization of Coconut haustorium (Pongu), The Coconut Development Board Institute of Technology (CIT), Vazhakulam, Kerala, has undertaken a study of the processing of Coconut haustorium to develop some novel value-added products which are having commercial value and extended shelf life. CIT has succeeded in making products like Haustorium candy, Haustorium instant stew mix, and Haustorium-based health mix (Protein rich). The products developed were found to be organoleptically acceptable for their colour, appearance, flavour, taste, texture, and overall acceptability on the 9 points Hedonic scale by a panel of ten judges. Value addition of coconut haustorium will not only reduces losses but will also enhance the income of farmers. Nutritional analysis conducted at CIT, Vazhakulam revealed that coconut haustorium is rich in protein with around 2% protein content. So it has significance in the vegetarian diet as a rich source of protein.
Pre preparation of raw material
Sprouted dehusked coconuts were obtained from a coconut farmer and the rest of the ingredients were purchased from the open market. The nuts were cut open and haustorium was taken out, prewashed, and blanched to sterilize the raw material. Haustorium is now ready for the preparation of candy and health mix.
Haustorium Candy
Haustorium candy is a jelly-like product obtained by treatment of haustorium in sugar syrup. The washed haustorium is sliced into 1-inch sized pieces. Pretreatment with 1 % calcium hydroxide solution followed by 1 % alum solution is required for giving firmness to the meat. The pre-treated haustorium slices are washed in running water and drained. The slices are then dipped in 50° Brix sugar solution for 2-3 hours.
The mixture is boiled by adding citric acid until the solution attains 65° Brix and is kept for 24 hours. Osmotic dehydration will take place and the brix will come down to about 45°. This is again reheated to bring the Brix level to 70°. The next day, a decrease in the brix level is observed which is again reheated to bring the brix level to 70°. The mixture is then cooled, followed by the addition of food flavours and colours into the sugar solution. Flavours like lemon, litchi, pineapple, guava, strawberry, mango, chilli, chilli-pepper, lemon-mint, etc were tried and are found suitable for the candy. The mixture is then kept for 10-12 hours for the absorption of flavour and colour.
The treated haustorium slices are removed from the syrup and drained completely. The drained slices are finally dried in a hot air oven at 70-80°C temperature until it attains 3% moisture level. The novel product, haustorium candy had an excellent taste and appearance. It is sweet, chewy, and in a ready-to-eat form.
Packaging
Haustorium candy is hygroscopic. Therefore, the selection of high moisture barrier packing materials is essential. Since the candy has an attractive appearance, transparent packaging materials are preferred.
Chronological sequence of Haustorium candy manufacturing
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Table I: Conversion ratio of fresh haustorium to candy
| Wt. of Raw haustorium | Weight with respect to raw haustorium | ||
|---|---|---|---|
| Sliced haustorium | Slices after
Osmotic Dehydration with sugar syrup |
Haustorium candy | |
| 99.2 g | 96 g (96.7%) | 121.7 g (122.6%) | 91.66 g (92.4%) |
Table II: Nutritional evaluation of Haustorium Candy
| S.no | Parameter | Value (%) |
|---|---|---|
| 1 | Moisture | 3 |
| 2 | Fat | Nil |
| 3 | Total ash(Minerals) | 0.3 |
| 4 | Carbohydrates | 94.2 |
| 5 | Protein | 0.2 |
| 6 | Crude fibre | 0.7 |
(Data generated at CIT, Aluva)
Protein Health Mix
Health mix has been formulated using Coconut haustorium and VCO residue as major ingredients. Freshly harvested haustoria are washed, sliced, and blanched in 0.05% KMS solution. Ingredients used are arrowroot powder (22%), Haustorium powder (20%), Virgin Coconut Oil residue (20%), Sprouted green gram powder (8%), Milk powder (10%), Sugar (20%), flavor, and salt. All the ingredients were dried separately at 90°C for 1-2 hours in a hot air oven dryer. The dried ingredients are then powdered and packed in laminated aluminium foil pouches.
Table III: Nutritional evaluation of Protein health mix
| S.no | Parameter | Value (%) |
|---|---|---|
| 1 | Moisture | 6 |
| 2 | Fat | 4.5 |
| 3 | Total ash(Minerals) | 2.71 |
| 4 | Carbohydrates | 68 |
| 5 | Protein | 17.5 |
| 6 | Crude fibre | 0.9 |
(Data generated at CIT, Aluva)
Coconut haustorium can be used as a source of dietary protein due to its nutritional significance. More studies need to be undertaken at the pilot- scale level for identifying the possibilities for commercial exploitation of this product.
[Content shared by Aneeta Joy (Food Technologist), Praseetha. K.C (Chemist), CIT, Aluva, Toffiya Sunil (Student, CFRD, Konni)]