Preserved Coconut Sap

                 

Coconut sap (Neera) is a sweet juice or sap, obtained by tapping the unopened spadix of the coconut palm. The tapping involves the collection of exuded sap from the inflorescence that yields sweet sap. Tapping methods vary from country to country and even within the country.
In India, the spathe is considered ready for tapping when the mature one bursts or is just about to burst. The female flower within the unopened spadix causes a swelling at the base and its appearance indicates the appropriate stage for tapping. The yield of sap gradually increases and when it reaches the maximum, the collection is made twice in a day. The flow of the sap from the inflorescence continues for about one month or even more. During this period, the second spathe is also brought into production.
The tapping is usually continued for a period of six months with a possibility of three spathes on the same tree being tapped at the same time. The maximum yield of Neera is usually obtained in the third month after the commencement of tapping.
Neera is rich in carbohydrates with sucrose as its main constituent and has a specific gravity of 1.058-1.077. Other constituents of Neera are:

  • Total solids (g/100 ml) : 15.2-19.7

  • Sucrose (g/100 ml) : 12.3 -17.4

  • Total ash (g/100 ml) : 0.11-0.41

  • Protein (g/100 ml) : 0.23-0.32

  • Ascorbic acid (mg/100 ml) : 16-30

Preservation and processing of Neera required a suitable technology, since it is highly susceptible to fermentation. DRDO has developed a technology for processing and preservation of Neera in its natural form. The technology helps to retain the vitamins, sugar and other nutrients beneficial for health. Heat preservation methods such as pasteurisation and sterilisation are necessary to preserve and extend the shelf life of the product. Temperature requirement for thermal processing of the Neera was found to be more than 95 °C. Thermal stress could be reduced by the addition of bio-preservative “nisin” at a minimum concentration of 10 ppm both for in-pack pasteurisation and retort processing. Furthermore, Neera is highly photosensitive due to the presence of ascorbic acid, hence foil-based multi-layer packaging material such as PET/aluminium foil/cast pp was found suitable to prevent the adverse effect of light. In order to increase the product appeal, the suspended particles in Neera were removed by centrifugation at 4000 rpm for 10 min.
The product as such without any additive treatment as well as heat processing was stable up to 72 hr. When the product was processed either by in-pack pasteurisation or through retort pouch processing, the shelf life was about one year under refrigerated condition and 30 days under ambient conditions. No difference was observed between retort processed samples and in-pack pasteurised samples. The latter was found to be cost-effective.
The estimated cost of 200 ml processed Neera in PET/aluminium foil/cast pp is about Rs 9. It also compares well with other natural drinks like fresh fruit juice, nectar and ready-to-serve drinks.

Salient Features

  • Production of consistent quality product

  • Enhancing shelf stability of the product

  • Improving the rural economy by value addition

  • Increasing rural shelf employment