Coconut - Tropical and Subtropical Fruits: Postharvest Physiology, Processing and Packaging - page 165

in the formulation. It has been reported that noodles with
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Table 9.8. Composition of fresh and defatted
coconut kernel (per 100 g).

20% DCF did not exhibit good textural properties (Gu-
nathilake and Abeyrathne, 2008).

Parameter Fresh Defatted

Utilization of mature nut water
The taste of mature nut water differs considerably from that
of tender nut water. During the cause of maturation of nuts,
various chemical and biochemical properties of nut wa-
ter change due to the changing composition. For instance,
with the increasing maturity, the concentration of total sug-
ars decreases that leads to a decline in sweetness and fla-
vor (Ranasinghe et al., 2003). Generally, nut water from
copra and desiccated coconut processing is turbid with a
pH of 6-7.
Mature coconut water contains 2.5-3.0% sugar, which
can be utilized as a fermentation substrate for the produc-
tion of vinegar. Since the amount of fermentable sugars
present in the starting material is low, it is supplemented
from the external sources. By using a generator, the total
fermentation time can be reduced to 1-2 weeks. When vine-
gar reaches 4% acidity, it is allowed to age before bottling
(Gunathilake and Fernando, 2007).

Moisture 45.00 4.50

Fat 37.00 13.55

Protein 4.00 19.70

Ash 4.00 4.90

Total carbohydrates 1 10.00 57.35

1 By difference.
Source: Thampan (1981); Baensch et al (2004).

Other edible products
Defatted kernel residue
The defatted oil cake left after the oil extraction is an im-
portant by-product. Its quality can be variable depending
on the type of technology or process used for oil extrac-
tion. The oil cake coming out of commercial oil expellers,
which use copra as raw material is often inferior in qual-
ity. Owing to the high pressure and friction in commercial
oil expellers, the oil cake becomes partially burnt; being
known as Poonac, it is only suitable for animal or poultry
feed due to its somewhat poor quality. In contrast, the de-
fatted oil cake coming out of VCO extraction is found to be
superior. As the method of oil recovery is either aqueous
process or low-temperature extraction, the physical appear-
ance and organoleptic characteristics of the defatted kernel
residue are far better than those of the traditional Poonac.
Proximate analyses presented in Table 9.8 show that it is
found to possess 13-15% fat and 18-20% proteins. When
compared to fresh kernel, there was significant decrease in
the fat content with the concurrent increase in the protein
content. Hence, it could be used as a base material for the
preparation of low-fat food products with high protein and
fiber content (Baensch et al., 2004).
There has been much interest in utilizing defatted co-
conut flour (DCF) in various food product formulations
(Ramaswamy, 2006). The purpose would be to enrich the
dietary fiber content by partial supplementation to wheat
flour. The amount of DCF to be added might vary depend-
ing on the type of food as well as the consumer preferences.
In biscuit formulation, the flour mix having more than 40%
DCF is reported to give undesirable gritty mouth-feel. For
products with better consumer acceptance, incorporation of
20-30% DCF is ideal (Marikkar et al., 2007b). Incorpora-
tion of DCF would be also desirable in products such as
noodles. The proportion of DCF in noodles should be kept
≤ 20%; otherwise, it will lower the proportion of gluten

Coconut sap and its products
Coconut sap is a sugar-rich fluid that drips out when cut-
ting the edge of an unopened inflorescence of coconut trees.
The sap can be collected in clay pots (Fig. 9.5) or a poly-
thene bag. The fermented sap contains variable amounts of
sucrose, proteins, vitamins, and minerals. Since sap has a
sugar content of about 13-15%, it may be processed into
brown sugar or sap syrup. Of the total sugars present in
the fresh sap, sucrose is always the most predominant con-
stituent followed by fructose and glucose (Purnomo and
Mufida, 2004). Sap can also be hydrolyzed into reducing
sugars by the invertase activity. If left standing, the fluid
may become fermented in a few days to yield an alcoholic
drink commonly known as Toddy. From Toddy, pure alcohol
can be recovered through a partial distillation method, or
if left to stand, fermentation may continue until it becomes
vinegar.
If a sugary product is desired from coconut sap, it is
necessary to control the invertase activity and the onset
of fermentation. In the rural areas, smoke curing of the
collection pot and application of a little amount of slaked
lime (hydrated calcium hydroxide) on the inner surface of
the collection pot are adopted. Use of sodium metabisulfite
in place of slaked lime is also found to be effective for the
preservation of coconut sap (Samarajeewa et al., 1985). Be-
sides chemical additives, several plant materials were also
found to be effective in preserving coconut sap. Finely cut