160
DOI 10.1002/star.201500186
Starch/Stärke 2016, 68, 160–168
RESEARCH ARTICLE
Isolation of starches from different tubers and study of their
physicochemical, thermal, rheological and morphological
characteristics
Sakshi Sukhija, Sukhcharn Singh and Charanjit S. Riar
Department of Food Engineering and Technology, Sant Longowal Institute of Engineering and Technology, Longowal,
Punjab, India
Isolation of starches from various tubers such as elephant foot yam (NYS), taro (NTS), ginger
(NGS), green banana (NBS) and lotus stem (NLS) was carried out for studying various
characteristics viz. physicochemical, differential scanning calorimeter (DSC), rapid visco
analyzer (RVA), rheological, morphological and colour in order to explore their end use potential.
A significant variation was observed in pasting properties of isolated starches. X-ray
diffractometery (XRD) showed a B-type crystal pattern of banana starch, while yam, taro,
ginger and lotus starches had A-type crystal pattern. Scanning electron microscope (SEM)
revealed that taro starch possessed the smallest granule size having cluster pattern while lotus
starches have the largest granular size with hemispherical facets having dents or hollows at one
end. Thermal properties of isolated starches revealed that NLS had lowest To, Tp, Tc values i.e.
68.3, 72.0 and 76.8°C, respectively. Similarly the lowest gel characteristics such as hardness,
gumminess, chewiness and adhesiveness 3.09 g, 1.45, 1.27, 8.42 gs, respectively, were also found
in NLS. L values of NTS and NYS starches were the highest i.e. 93.36, 93.29 with no significant
difference whereas the lowest i.e. 89.917 in NGS.
Received: July 21, 2015
Revised: August 16, 2015
Accepted: August 20, 2015
Keywords:
Morphological characteristics / Non-conventional starches / SEM / Starch isolation /
Texture profile analysis
1
Introduction
Starch is a semi-crystalline biopolymer and comprises as a
major carbohydrate source from agricultural raw materials
including cereals, roots and tubers, rhizomes, stems and
fruits. Till date cereal starches (wheat, rice, maize) and
tubers (potato, cassava and sweet potato) have been the
major focus for research and industrial application.
However, non-conventional and underutilised starch sources such as tubers (elephant foot yam, taro), rhizomes
(ginger, lotus stem) and fruits (green banana) are still to be
explored for their potential use in food and non-food
applications.
Correspondence: Dr. Charanjit S. Riar, Sant Longowal Institute of
Engineering and Technology, Longowal, Punjab 148106, India
E-mail: charanjitriar@yahoo.com
Fax: þ91-1672-280057
ß 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Tubers are considered to be the third important staple food
crops after cereals and legumes. These are grown and
consumed throughout the world in hot and humid regions.
These contain 70–80% water, 16–24% starch and less
quantities about <4% protein. Yam and other tuber crops
have not been exploited for industrial application because of
difficulty in pure starch extraction [1]. Elephant foot yam
(Amorphophallus paeoniifolius) has nutritional and medicinal
value and is consumed as vegetable by millions of people in
India. Elephant foot yam contains up to 18% starch, 1–5%
protein and 2% fat. Taro (Colocasia esculenta) contains 12–25%
starch content from different Indian varieties [2]. Due to small
granule size of taro starch (1–5 mm) it can be used as filling
agent for biodegradable packaging films, bread or noodles
making and in baby food as well as a fat substitute and
encapsulation of flavors [3–5]. Englberger et al. [6] reported that
these starchy tubers contain wide variety of minerals and trace
elements like iron, calcium, potassium and magnesium.
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Starch/Stärke 2016, 68, 160–168
Ginger (Zingiber officinale) is a popular spice being
cultivated and used for its medicinal value throughout
India. It is a perennial reed-like plant with annual leafy
stems, about a meter tall. Annual production in India is
estimated up to 795.028 tons [7]. Ginger contains up to
40% starch on dry basis [8]. The rhizomes are smooth,
reddish-brown or white in colour and measure about
15–25 cm in length. Edible portion contains starch,
protein, fiber, sugars and minerals. The fresh root
contains about 15% starch. Green banana (Musa paradidiaca L.) is the most widely grown tropical fruit and
India contributes 27% of the world’s production [9]. It
contains 68% moisture, up to 11% starch, 1–2.5% protein,
1% fat, 0.7–1.2% pectin, vitamins and minerals. Green
banana contains resistant starch and non-starch polysaccharides having low glycemic index and digestibility
which makes it excellent ingredient for functional and
convenience foods (like cookies and chips) [10, 11].
Native starches are highly variable depending upon the
origin and variability in terms of granule morphology (size
and shape), degree of crystallinity, amylose and amylopectin content [12]. Starches find their application as
thickeners, adhesives, gelling agents, stabilizers, bulking
agents and base material for formation of edible coatings
and biodegradable packaging films. Starch from sources
(roots and tubers, rhizomes, fruits etc.) have not been
commercialised yet due to the lack in study of their starch
yield, purity of isolated starch and molecular information.
Pasting, thermal, morphological, rheological and other
characteristics may help in knowing the industrial
application of the starch from these sources. Keeping in
view the above facts, present study was focused on
isolation and characterization of starch from different
underutilised and non-conventional sources.
2
Materials and methods
2.1 Materials
Raw materials such as elephant foot yam (Amorphophallus paeoniifolius), taro (Colocasia esculenta), ginger
(Zingiber officinale), lotus stem (Nelumbo nucifera) and
green banana (Musa paradidiaca L.) were procured from
Punjab Agriculture University, Ludhiana, Punjab and
Haryana Agriculture University, Hissar, Haryana, India.
Elephant foot yam, ginger and green banana were
procured during the months of December and January.
Taro and lotus stem were available in the months of
May–June and July–August, respectively. All the raw
materials were fresh and of good quality i.e. free of cuts,
and internal defects. The chemicals were purchased from
S.D. Fine Chemicals Ltd., Mumbai, India and were of AR
grade.
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Characterization of tuber starches
161
2.1.1 Isolation of starch
2.1.1.1 Isolation of elephant foot yam, taro and lotus
stem starch
Starches were isolated from elephant foot yam, taro and lotus
stem by little modifications in the method as described by
Singh et al. [13]. The tubers were washed, peeled and shredded.
Shreds were put in plain water for further washing. After that
the shreds were put into the solution for one hour; containing
potassium metabisulphite (KMS)þcitric acid solution viz.
(0.25% þ 0.12%) for elephant foot yam, (0.5% þ 0.25%) for
taro and lotus stem. The shreds were ground with addition of
water in a lab grinder for 1 min. The slurry was filtered through
100, 200 and 300 mesh (BSS) sieve using slurry:water ratio of
1:4, 1:3 and 1:5 for elephant foot yam, lotus stem and taro,
respectively. The filtrate was then allowed to stand at 4°C for
90 min to allow the starch to settle down. Supernatant was
decanted off and the sediment was washed repeatedly,
dispersed in 0.2% NaOH solution and allowed to settle.
Precipitated starch was then washed 3–5 times with
demineralized water till neutral pH was obtained. Starch
was then centrifuged at 3000 rpm for 10 min for further
purification of starch by scratching the top layer. Starch cakes
thus obtained were transferred to trays and dried overnight in a
cabinet drier at 40°C.
2.1.1.2 Isolation of ginger starch
Ginger starch was extracted using the method of Kolawole [14] and clarification of starch was carried out by the
method as described by Policegourda [15]. Fresh roots of
ginger were peeled and washed with plain water. The sample
was cut into small pieces and dipped into KMS (potassiummeta-bi-sulphite) solution (1% w/v) at room temperature for
1 h. The soaked sample was then ground in a lab grinder
(Sujata, India) for 1 min for preparation of slurry. The slurry
was then filtered through 100, 200 and 300 mesh (BSS)
sieves using slurry:water ratio of 1:4. The filtrate was then
allowed to settle at 4°C for 3–4 h. Top layer was decanted off
and precipitates were washed with distilled water, 5–6 times
for the removal of impurities. Thereafter, starch suspension
was centrifuged at 3000 rpm for 15 min to scrap off the
yellow layer. Further clarification of ginger starch was carried
out by stirring the starch with petroleum ether and acetone
(1:1, v/v) for 1 h using magnetic stirrer followed by washings
with distilled water. The starch was then allowed to settle and
dried at 40°C overnight in a cabinet drier.
2.1.1.3 Isolation of green banana starch
Green banana starch was isolated using the method of
Vatanasuchart et al. [16]. Green banana was peeled, washed
and macerated for one min with 0.05 N NaOH solution using
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S. Sukhija et al.
a lab grinder. Homogenate was passed through 100, 200 and
300 (BSS) mesh sieves using slurry:water ratio of 1:4. The
filtrate was allowed to stand for 2 h at 4°C. After that
supernatant was decanted off and starch precipitates were
washed 3-4 times with distilled water to neutral pH. Starch
slurry was then centrifuged at 3000 rpm for 15 min to scratch
the top layer of impurities. Clarified starch was then
transferred to trays and dried overnight at 40°C in a cabinet
drier.
After drying, all the starches were ground in a pestle and
mortar and passed through 150 mesh sieve and stored in an
air tight package under refrigeration till used for further
analysis.
Starch/Stärke 2016, 68, 160–168
Netherlands). Diffractometer was operated at 30 mA and
40 kV with a scanning speed of goniometer at 4°/min from 4
to 40°. Origin 9.1 software was used to determine the relative
crystallinity of starch samples quantitatively. It was estimated
as the ratio of crystalline area (Ac) and the total area drawn
under the major diffraction peaks [19].
2.5 Colour
Colour of different starches was determined using Hunter
Lab Colorimeter (D-25, Hunter Associates Laboratory,
Ruston, USA) after calibration using Hunter Lab colour
standards. ‘L’ (Lightness), ‘a’ (redness to greenness) and ‘b’
(yellowness to blueness) values of starches were measured.
2.2 Chemical composition of isolated starches
2.6 Textural properties of starch gels
The analyses of starches were carried out for moisture, crude
protein, crude fat and ash contents by the official methods of
AACC [17]. Amylose content of isolated starches was
determined according to the method of Morrison and
Laignelet [18]. A 70 mg starch sample was placed in a test
tube followed by addition of 10 mL of urea (6M)-DMSO
solution (1:9) with continuous stirring. After heating for
10 min in boiling water, samples were placed in an oven at
100°C for 1 h and then cooled at room temperature. Then
0.5 ml of the solution was taken into a volumetric flask
containing 25 mL distilled water þ 1 mL of I2/KI (100 mg I2
and 1000 mg KI in 50 mL distilled water) and made volume
up to 50 mL with distilled water and mixed thoroughly.
Absorbance of the samples was measured against a blank
(prepared by allowing chemicals and distilled water to
stabilize for 15 min) at 635 nm in a UV spectrophotometer (I
D 5000 HACH, USA).
Absorbance 100
Blue value ¼
100
2 g solution mg starch
% Amylose ¼ Blue value 28:414
2.3 Morphological studies
Morphology of starch granules was studied using scanning
electron microscope (SEM) (JEOL JSM-7500, USA). Starch
was directly deposited on aluminum stub using double-sided
adhesive carbon conductive tape and starch was coated with a
thin gold-palladium (60:40). An accelerating potential of
20 kV was used during micrography.
The starch gels obtained from rapid visco analyzer (RVA-4,
Newport Scientific, Warriewood, Australia) were further
stored at 4°C to cause gelation. The texture profile analyses
(TPA) of stored gels were studied according to the method
described by Sandhu and Singh [20] using texture analyzer
(TAXT-2i) (Stable Micro Systems, UK). Each canister was
placed upright on the metal plate and the gel was
compressed at speed of 0.5 mm/s to a distance of 10 mm
with a cylindrical plunger (diameter 5 mm). The compression was repeated twice to generate force-time curve from
which hardness (height of first peak) and springiness (ratio
between recovered height after the first compression and the
original gel height) were determined. Adhesiveness was
termed as the negative area of the curve during retraction of
the probe. Cohesiveness was calculated as the ratio between
the area under the second peak and the area under the first
peak [21, 22]. Gumminess was determined by multiplying
hardness and cohesiveness. Chewiness was determined by
multiplying gumminess and springiness.
2.7 Pasting properties
The pasting properties of the starches were evaluated with
rapid visco analyzer (RVA-4, Newport Scientific, Warriewood,
Australia). Viscosity profiles of different starches were recorded
using 3 g of starch sample in 25 g of water. A programmed
heating and cooling cycle was used, where the samples were
held at 50°C for 1 min, heated to 95°C at 10°C/min, held at
95°C for 2.5 min, before cooling from 95 to 50°C at 10°C/min
and holding at 50°C for 2 min. Parameters recorded were
pasting temperature, peak viscosity, trough viscosity, final
viscosity, breakdown viscosity and setback viscosity.
2.4 X-ray diffractometry
2.8 Thermal properties
X-ray diffraction patterns of fully moistened starch granules
were recorded by a copper anode X-ray tube using an
Analytical Diffractometer (Panalytical, X’pert PRO, The
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Thermal characteristics of isolated starches were determined
using a differential scanning calorimeter (DSC, model-821e,
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Starch/Stärke 2016, 68, 160–168
Characterization of tuber starches
Mettler-Toledo, Switzerland). The starch (3.5 mg, dry weight)
was loaded into a 40 ml capacity aluminum pan and distilled
water was added with the help of a Hamilton micro-syringe
to achieve a starch-water suspension containing 70% water.
The samples were hermetically sealed and allowed to stand
for 2 h at room temperature before heating in the DSC. The
DSC analyzer was calibrated using indium and an empty
aluminum pan was used as reference. The sample pans were
heated at a rate of 10°C/min from 20 to 100°C. Onset
temperature (To); peak temperature (Tp); conclusion temperature (Tc) and enthalpy of gelatinization (DHgel) were
calculated automatically. The gelatinization temperature
range (R) was computed as (TcTo), as described by
Vasanthan and Bhatty [23], Krueger et al. [24].
2.9 Statistical analysis
The data presented in the tables represent average of
triplicate observations, () standard deviation and subjected
to one way analysis of variance (ANOVA) by Duncan’s test
(p < 0.05) using Statistica-7 (M/s. StatSoft Inc., OK, USA).
3
Results and discussion
3.1 Chemical composition of isolated starches
The chemical composition of isolated starches from different
sources is presented in Table 1. The moisture content of
isolated starches ranged between 10.5–10.9% and did not
differ significantly as the time and temperature for drying was
same for all the starch extraction processes. The ash content of
ginger starch (NGS) was found highest i.e. 0.29% and that of
elephant foot yam starch (NYS) was minimum (0.19%) among
the starches analyzed. The final fat content (0.44%) was also
high in NGS as the ginger itself contains higher amount of
lipid content as compared to other sources used in the present
study. Although clarification process was used during starch
extraction from ginger rhizome still ginger starch contained
higher amount of fat comparatively. The protein content was
found higher in taro starch (NTS) i.e. 0.42% which might be
163
due to strong binding of starch with mucilage which had
created hindrance in protein removal during starch extraction
process. Lotus stem starch (NLS) had high amylose content i.e.
20.6% followed by green banana starch (NBS) 19.2% which
may render these starches to have film forming properties and
other food applications. Taro starch having low amylose
content (4.3%) may have its application in the preparation of
noodles and also its small granule size extends its application
in the formulation of baby foods.
3.2 Morphological characteristics
The starches isolated from different sources had shown
variation in shape and granule size depending upon the
botanical origin of the starch. The starch granules of
elephant foot yam starch (NYS) as shown in Fig. 1a were
hemispherical with 3–4 facets with smooth surface having
no pores or channels. Taro starch (NTS) granules (Fig. 1b)
were seen having present in the form of packed clusters with
irregular or cuboidal and polygonal shape. The starch
granules of ginger starch (NGS) Fig. 1c, were elliptical in
shape and aligned like layers. Green banana starch (NBS)
granules (Fig. 1d) were elongated and cylindrical, oval in
shape. The shape of lotus stem starch (NLS) Fig. 1e was rod
shaped, hemispherical with facets and oval, whereas, some
granules had dents or hollows at one end. Rasper [25]
reported that granule size, structure and their distribution
are important because functional properties of starch may be
affected. Ginger, green banana and lotus stem starches
(NGS, NBS, NLS) were observed having surfaces covered
with minute surface pores. The presence of surface pores in
corn, sorghum and millet starches are formed by tube like
channels present in the granule matrix that open to external
surface Fannon et al. [26]. The average granule size of taro
starch (NTS) was the smallest and that of native lotus stem
starch (NLS) was largest among the starches analyzed
(Table 2). The relationship between granule size and
digestibility as earlier reported by Cone and Wolters [27];
Riley [28] confirms that the smaller granule size improves
the digestibility because smaller granules have greater
surface area and are readily digested by enzymes.
Table 1. Chemical characteristics of isolated starchesa)
Sample
Moisture (%)
Ash (%)
Protein (%)
Fat (%)
Amylose (%)
NYS
NTS
NGS
NBS
NLS
10.70.12ab
10.90.12a
10.90.24a
10.50.19b
10.80.27a
0.190.02c
0.240.01b
0.290.01a
0.240.01b
0.200.01c
0.230.02c
0.420.06a
0.340.03b
0.180.01d
0.150.02d
0.120.00c
0.230.02b
0.440.02a
0.110.02c
0.110.01c
14.00.05c
4.30.06e
12.50.04d
19.20.20b
20.60.40a
NYS, native elephant foot yam starch; NTS, native taro starch; NGS, native ginger starch, NBS, native green banana starch; NLS, native lotus starch.
a) n ¼ 3, Results are expressed as mean values standard deviations. Values with similar letters in the same column do not differ significantly
(p < 0.05).
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Starch/Stärke 2016, 68, 160–168
Figure 1. Scanning electron micrographs (SEM) of: a) native elephant foot yam starch, b) native taro starch, c) native ginger starch, d) native
green banana starch, and e) native lotus starch.
Table 2. Granule size distribution, colour characteristics and degree of crystallinity of isolated starchesa)
Starch granule size
Sample
Length (mm)
Width (mm)
La)
aa)
ba)
NYS
NTS
NGS
NBS
NLS
17.50.74c
1.90.26d
22.60.24bc
33.20.54b
47.90.13a
13.10.27b
1.60.23c
15.20.09b
12.70.61b
25.90.17a
93.140.28a
93.360.15a
90.040.24c
90.560.14b
91.750.12b
0.070.02e
0.260.02d
1.010.04a
0.810.01b
0.380.03c
1.590.11e
1.680.01d
3.930.01b
5.380.07a
2.540.09c
Degree of crystallinity (%)
32.560.03b
34.640.09a
32.610.54b
26.740.37c
28.120.36d
NYS, native elephant foot yam starch; NTS, native taro starch; NGS, native ginger starch; NBS, native green banana starch; NLS, native lotus starch.
a) n ¼ 3, Results are expressed as mean values standard deviations. Values with similar superscript letters in the same column do not differ
significantly (p < 0.05).
3.3 X-ray diffractometery
3.4 Colour
The Hizukuri et al. [29]; Zobel [30] reported that most of the tuber
starches exhibit ‘B’ type X- ray pattern with reflections centered
at 5.5–5.6°, 15.0°, 17.0°, 19.7°, 22.2° and 24.0° 2u angles. Whereas,
cereal starches exhibit ‘A’ type pattern with reflections at 15.3°,
17.0°, 18.0°, 20.0° and 23.4° 2u angles. A ‘C’ type starches exhibit
superposition of ‘A’ and ‘B’ type patterns [31]. In present study
(Fig. 2), native green banana starch (NBS) exhibited B-type X- ray
pattern with reflections at 5.8°, 14.9°, 17° and 24° 2u angles where
as the NYS, NTS, NGS and NLS starches exhibited A-type
pattern with reflections at 15.1°, 17.0°, 18.1°, 23.2°; 15.1°, 17.1°,
18.1°, 20.2°, 23.2°; 15.1°, 17.1°, 18.1°, 23.3° and 15.0°, 16.9°, 18.0°,
19.9°, 23.0° 2u angle on diffractogram, respectively. The degree of
crystallinity (%) (Table 2) of different starches ranged between
26.74 and 34.64 (%) and as indicated that the starches with lower
amylose content showed higher crystallinity. Similar results
were earlier reported by Chavez-Murillo et al., [32] for Mexican
rice cultivars.
The colour values (L , a , b ) are represented in Table 2 with
significant difference in their values in some cases. The L
values of native taro starch (NTS) and native elephant foot
yam (NYS) starches were found maximum i.e. 93.36, 93.29
with no significant difference, however the L value of
native ginger starch (NGS) differs significantly at 89.917.
The lighter colour of these isolated starches suggests their
use in various food applications where uniformity in colour
is recommended. The a values of native ginger starch
(NGS) was maximum (1.01) towards greenness whereas
that of native elephant foot yam (NYS) was found
minimum. The b values of native banana starch was
maximum (5.38) i.e. more yellowness whereas that of native
elephant foot yam (NYS) starch was minimum (1.47). L
value of banana starch i.e. 90.9 was similar as reported by
Pelissari et al., [33] and recommended banana starch for
clear starchy products.
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Characterization of tuber starches
165
Figure 2. X-ray diffractometry overlay of: NYS, native elephant foot yam starch; NTS, native taro starch; NGS, native ginger starch; NBS,
native green banana starch; NLS, native lotus starch.
3.5 Textural properties
The textural properties of starch gels from different sources
varied significantly (p < 0.05) as represented in Table 3.
Native lotus starch (NLS) exhibited maximum gel hardness
(3.05 g) which may be attributed to its higher amylose
content (Table 1). Mua and Jackson [34] reported that the
starches forming harder gels tend to have higher amylose
content and longer amylopectin chains. The values of
gumminess and adhesiveness were also highest for NLS and
minimum for NTS among other starches analyzed.
Biliaderis [35] reported that the mechanical properties of
starch gels depend upon the rheological characteristics of
amylose matrix, the volume fraction, interactions between
dispersed and continuous phase of matrix and rigidity of
gelatinized starch granules which are in turn dependent on
amylose content and structure of amylopectin [36].
3.6 Pasting characteristics
The pasting characteristics of the starches are shown in Table 4.
A significant difference (p < 0.05) was observed between peak
viscosity (PV), breakdown viscosity (BV), trough viscosity (TV),
final viscosity (FV), setback viscosity (SV) and pasting
temperature (PT) of starches from different sources. This
difference in parameters may be attributed to source of origin
of starches. Highest peak viscosity was observed for native
green banana starch (NBS) among other starches indicating its
more water-holding capacity [37] followed by NLS, NGS, NYS
and NTS. The final viscosity in case of native ginger starch
(NGS) was observed higher resulting in shear resistant paste
which can form more rigid gel [38], however, for the NYS, NTS,
NBS and NLS the results were reverse. The native lotus stem
starch was having highest breakdown viscosity (BV) which
may be attributed to its large granule size which attributed an
increase in the fragility of granule in shear field [39]. Abera
et al. [40] reported a higher degree of swelling and subsequent
disintegration of starch sample which contributes to their
higher breakdown viscosity.
3.7 Thermal properties
The gelatinization temperatures (To, onset; Tp, peak; Tc,
conclusion), enthalpy of gelatinization DHgel, and gelatinization
temperature range (R) are represented in Table 5. In this study,
the native ginger starch (NGS) had shown highest To, Tp, Tc
values indicating that the more energy is required for initiation
of gelatinization of starch [20] followed by, NTS, NYS, NBS and
NLS. A high melting temperature of starch had been reported to
be related to higher degree of crystallinity in turn results a stable
structure and making granule more resistant towards gelatinization [41, 42]. In present study, it was observed that NGS
possessed lower degree of crystallinity than NTS but higher To,
Tp, Tc values. This had resulted because of higher content of lipid
complexes chains in the native ginger starch (NGS) which
decreased the extent of hydration in amorphous region, thereby
Table 3. Textural characteristics (TPA) of starch gelsa)
Sample
Hardness (g)
Cohesiveness
Gumminess
Springiness
Chewiness
NYS
NTS
NGS
NBS
NLS
2.540.04c
1.640.05e
2.350.06d
2.860.08b
3.050.03a
0.380.01d
0.660.00a
0.490.00b
0.260.03e
0.470.02c
1.250.00b
1.080.02c
0.890.00d
0.540.03e
1.450.03a
0.840.05c
0.950.04a
0.690.07d
0.270.02e
0.870.08b
1.060.00b
1.020.00c
0.630.03d
0.140.02e
1.270.03b
Adhesiveness (gs)
3.510.01d
3.970.00c
2.460.04e
5.450.03b
8.420.02a
NYS, native elephant foot yam starch; NTS, native taro starch; NGS, native ginger starch; NBS, native green banana starch; NLS, native lotus starch.
a) n ¼ 3, Results are expressed as mean values standard deviations. Values with similar superscript letters in the same column do not differ
significantly (p < 0.05).
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Table 4. Pasting properties of isolated starchesa)
Sample
NYS
NTS
NGS
NBS
NLS
PV (cP)
5195.7
2893.0
5274.0
6622.7
6214.3
1.06d
2.42e
1.46c
1.50a
1.57b
TV (cP)
2592.7
1938.3
4686.3
3558.3
2091.3
BV (cP)
1.57c
1.50e
1.06a
2.07b
1.34d
2580.0
939.0
562.7
3029.7
4123.0
FV (cP)
1.71c
2.11d
2.04e
1.01b
1.09a
3863.7
2741.0
7993.0
4072.3
2894.0
1.63c
1.73e
1.44a
1.90b
2.58d
SV (cP)
1270.7
792.3
3310.3
476.3
976.0
2.51b
1.50d
1.02a
2.00e
1.14c
Ptemp (°C)
86.3
85.9
90.4
75.2
77.5
0.55b
0.25b
0.10a
0.06d
0.07c
NYS, native elephant foot yam starch; NTS, native taro starch, NGS, native ginger starch; NBS, native green banana starch; NLS, native lotus
starch. PV, peak viscosity; TV, trough viscosity; BV, breakdown viscosity; FV, final viscosity; SV, setback viscosity; Ptemp, pasting
temperature.
a) n ¼ 3, Results are expressed as mean values standard deviations. Values with similar superscript letters in the same column do not differ
significantly (p < 0.05).
increased the amount of thermal energy required for crystallite
melting [43]. The native lotus stem starch was having minimum
values for To, Tp, Tc among the analyzed starches which may be
attributed to its higher amylose content and lower degree of
crystallinity. Flipse et al. [44] also reported that the presence of
high amylose lowers the melting point of crystalline regions and
the energy for starting gelatinization. The highest R-value
(gelatinization temperature range) of NBS indicated the
presence of crystallites of varying stability within crystalline
domains of its granules [45]. The difference in thermal
properties of these starches may be related to difference in
amylopectin content, degree of crystallinity of starch and
presence of crystalline regions of different strength in starch
granules [46].
4
Conclusions
Starches from non-conventional and underutilised sources like elephant foot yam, taro, ginger, green banana and
lotus stem were isolated and characterised for possible
application in food and other industries. These isolated
starches exhibited a different thermal, pasting and
molecular characteristics depending upon their botanical
origin. The green banana and lotus stem starches had
higher amylose contents and harder gel textures which
explore their film forming properties and as source of
resistant starch for different food applications. Elephant
foot yam starch could also find its application in film
preparation and food products formulation because of its
moderate granule size, amylose content and gelatinization
temperature range. Higher gelatinization temperature of
native ginger starch resembles it to modified starches and
can be exploited for its thermal and textural properties at
high processing temperatures. Small size of taro starch
granules can finds its application in baby foods
formulations.
The authors thank the Department of Food Engineering and
Technology for providing facilities in carrying out the research.
The authors have declared no conflict of Interest.
5
Table 5. Thermal properties of isolated starchesa)
Sample
NYS
NTS
NGS
NBS
NLS
To (°C)
Tp (°C)
Tc (°C)
79.70.31ab
78.40.17b
81.10.48a
66.50.34c
68.30.48c
82.20.04b
82.30.48b
86.20.19a
72.90.24c
72.00.32c
86.00.04c
90.10.11b
91.90.19a
77.90.28d
76.80.36e
1
DHgel (Jg )
R
12.50.19d
4.90.17d
c
13.50.13
7.80.29c
13.80.18ab 10.20.09b
13.20.29c 12.70.01a
13.70.19a
7.50.04c
NYS, Native elephant foot yam starch; NTS, native taro starch;
NGS, Native ginger starch; NBS, native green banana starch; NLS,
native lotus starch To, onset temperature; Tp, peak temperature,
Tc, conclusion temperature; DHgel, enthalpy of gelatinization; R,
gelatinization range 2 (TpTo).
a) n ¼ 3, Results are expressed as mean values standard deviations. Values with similar superscript letters in the same column do
not differ significantly (p < 0.05).
ß 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
References
[1] Moorthy, S. N., Physicochemical and functional properties of
€rke 2002, 54,
tropical tuber starches: A Review. Starch/Sta
559–592.
[2] Edison, S., Unnikrishnan, N., Vimala, B., Pillai, S. V.,
Biodiversity of tropical tuber crops in India. NBA Scientific
Bulletin, 7, 60. National Biodiversity Authority, Chennai,
Tamilnadu, India, 2006.
[3] Lim, S., Jane, J., Rajagopalan, S., Seib, P. A., Effect of
starch granule size on physical properties of starch-filled
polyethylene film. Biotechnol. Prog. 1993, 8, 51.
[4] Zhao, J., Whistler, R. L., Spherical aggregates of starch
granules as flavor carriers. Food Technol. 1994, 48,
104–105.
[5] Aprianita, A., Purwandri, U., Watson, B., Vasiljecie, T.,
Physico-chemical properties of flours and starches from
selected commercial tubers available in Australia. Food Res.
Int. 2009, 16, 507–520.
www.starch-journal.com
Starch/Stärke 2016, 68, 160–168
Characterization of tuber starches
167
[6] Englberger, L., Aalbersberg, W., Ravi, P., Bonnin, E., et al.,
Further analyses of Micronesian green banana, taro, breadfruit and other foods for provitamin A carotenoidsand
minerals. J. Food Compost. Anal. 2003, 16, 219.
[24] Krueger, B. R., Knutson, C. A., Inglett, G. E., Walker, C. E.,
A differential scanning calorimetry study on the effect of
annealing on gelatinization behavior of corn starch. J. Food
Sci. 1987, 52, 715–718.
[7] Mathew, A. G., Future of spice and floral extracts. Indian
Perfumer 2004, 48, 35–40.
[25] Rasper, V., Investigations on starches from major starch
crops grown in Ghana III Particle size and particle size
distribution. J. Food Sci. Agr. 1971, 22, 572–580.
[8] Moreschi, S. R. M., Petenate, A. J., Meireles, M. A. A.,
Hydrolysis of ginger bagasse starch in subcritical water and
carbon dioxide. J. Agric. Food Chem. 2004, 52, 1573.
[26] Fannon, J. E., Shull, J. M., BeMiller, J. N., Interior channels
of starch granules. Cereal Chem. 1993, 70, 611–613.
[9] Debabandya, M., Sabyasachi, M., Namrata, S., Green
banana and its by-product utilization: An overview. J. Sci.
Ind. Res. 2010, 69, 323–329.
[27] Cone, J. W., Wolters, G. E., Some properties and
€rke
degradability of isolated starch granules. Starch/Sta
1990, 42, 298–301.
[10] Lehmann, U., Robin, F., Slowly digestlible starch-its
structure and health implications: a review. Trends Food
Sci. Technol. 2007, 18, 346–355.
[28] Riley, C. K., In vitro digestibility of raw starches extracted
from five yam species grown in Jamaica. Starch/St€
arke
2004, 56, 69–73.
[11] Aparicio-Saguilan, A., Sayago-Ayerdi, S., Vargas-Torres,
G. A., Tovar, J., et al., Slowly digestible cookies prepared
from resistant starch-rich lintnerized banana starch. J. Food
Compos. Anal. 2007, 20, 175–181.
[29] Hizukuri, S., Kaneko, T., Takeda, Y., Measurement of the
chain length of amylopectin and its relevance to the origin of
crystalline polymorphism of starch granules. Biochim.
Biophys. Acta 1983, 760, 188–191.
[12] Wang, S. J., Gao, W. Y., Liu, H. Y., Chen, H. X., et al.,
Studies on the physicochemical, morphology, thermal and
crystalline properties of starches separated from different
Dioscorea opposita cultivars. Food Chem. 2006, 99, 38–44.
[30] Zobel, H. F., Molecules to granules—a comprehensive starch
review. Starch/St€
arke 1988, 40, 44–50.
[13] Singh, S., Raina, C. S., Bawa, A. S., Saxena, D. C., Effect of
heat-moisture treatment and acid modification on rheological,
textural and differential scanning calorimeter characteristics
of sweet potato starch. J. Food Sci. 2005, 70, 374–378.
[14] Kolawole, S. A., Igwemmar, N. C., Bello, H. A., Comparison
of the physicochemical properties of starch from ginger
(Zingiber officinale) and maize (Zea mays). Int. J. Sci. Res.
2013, 2, 71–75.
[15] Policegourda, R. S., Aradhya, S. M., Structure and
biochemical properties of starch from an unconventional
source—Mango ginger (Curcuma amada Roxb.) rhizome.
Food Hydrocolloids 2007, 22, 513–519.
[16] Vatanasuchart, N., Niyomwit, B., Wongkrajang, K., Resistant starch content, in vitro starch digestibility and physicchemical properties of flour and starch from Thai green
bananas. MAEJO Int. J. Sci. Tech. 2012, 6, 259–271.
[17] AACC, Approved method of analysis, 11th edn. American
Association of Cereal Chemists International, St. Paul, MN
2010.
[18] Morrison, W. R., Laignelet, B., An improved colorimetric
procedure for determining apparent and total amylose in
cereal and other starches. J. Cereal Sci. 1983, 1, 19–35.
[19] Nuwamanya, E., Baguma, Y., Emmambux, N., Rubaihayo,
P., Crystalline and pasting properties of cassava starch are
influenced by its molecular properties. Afr. J. Food Sci.
2010, 4, 8–15.
[20] Sandhu, K. S., Singh, N., Some properties of corn
starches II: Physicochemical, gelatinization, reterogradation, pasting and gel textural properties. Food Chem.
2007, 101, 1499–1507.
[21] Bourne, M. C., Texture profile of ripening pears. J. Food Sci.
1968, 33, 223–226.
[22] Friedman, H. H., Whitney, J. E., Szezesniak, A. S., The
texturometer- a new instrument for objective texture
measurement. J. Food Sci. 1968, 28, 390–396.
[23] Vasanthan, T., Bhatty, R. S., Physicochemical properties of small and large granule starches of waxy, regular
and high amylose barley. Cereal Chem. 1996, 73,
199–207.
ß 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
on, A., Colonna, P., Planchot, V., Ball, S., Starch
[31] Bule
granules: Structure and biosynthesis. Int. J. Biol. Macromol.
1998, 23, 85–112.
[32] Chavez-Murillo, C. E., Mendez-Montealvo, G., Wang, Y. J.,
Bello-Perez, L. A., Starch of diverse Mexican rice cultivars:
Physicochemical, structural and nutritional features. Starch/
St€
arke 2012, 00, 1–12.
[33] Pelissari, F. M., Andrade-Mahecha, M. M., Sobral, P. J. A.,
Menegalli, F. C., Isolation and characterization of the flour
and starch of plantain bananas (Musa paradisiaca). Starch/
€rke 2012, 64, 382–391.
Sta
[34] Mua, J. P., Jackson, D. S., Relationships between functional
attributes and molecular structures of amylose and amylopectin fractions of corn starch. J. Agric. Food Chem. 1997,
45, 3848–3854.
[35] Biliaderis, C. G., Polysaccharide association structures in
food, in: Walker R. H. (Ed.), Marcel Dekker, Inc., New York
1998, pp. 57–168.
[36] Yamin, F. F., Lee, M., Pollak, L. M., White, P. J., Thermal
properties of starch in corn variants isolated after chemical
mutagenesis of inbred line B73. Cereal Chem. 1999, 76,
175–181.
[37] Sekine, M., Measurement of dynamic viscoelastic behavior
of starch during gelatinization in a xanthan-gum solution. J.
Jpn. Soc. Food Sci. 1996, 43, 683–688.
[38] Zhang, Z., Niu, Y., Eckhoff, S. R., Feng, H., Sonication
€rke 2005, 57,
enhanced cornstarch separation. Starch/Sta
240–245.
[39] Yuan, Y., Zhang, L., Dai, Y., Yu, J., Physicochemical
properties of starch obtained from Dioscorea nipponica
Makino comparison with other tuber starches. J. Food Eng.
2007, 82, 436–442.
[40] Abera, S., Rakshit, S. K., Comparison of physicochemical and
functional properties Cassava starch extracted from fresh root
and dry chips. Starch/ St€
arke 2003, 55, 287–296.
[41] Tester, R. F., Morrison, W. R., Swelling and gelatinization of
cereal starches. I. Effect of amylopectin, amylose and lipids.
Cereal Chem. 1990, 67, 551–557.
[42] Barichello, V., Yada, R. Y., Coffin, R. H., Stanley, D. W., Low
temperature sweetening in susceptible and resistant
www.starch-journal.com
168
S. Sukhija et al.
potatoes: Starch structure and composition. J. Food Sci
1990, 54, 1054–1059.
Starch/Stärke 2016, 68, 160–168
Absence of amylose has a distinct influence on the physicochemical properties of starch. Theor. Appl. Genet. 1996, 91,
121–127.
[43] Jayakody, L., Hoover, R., Liu, Q., Weber, E., Studies on
tuber and root starches. I. Structure and physicochemical
properties of innala (Solenostemon rotundifolius) starches
grown in Sri Lanka. Food Res. Int. 2005, 38, 615–629.
[45] Hoover, R., Li, Y. X., Hynes, G., Senanayake, N.,
Physicochemical characterization of mung bean starch.
Food Hydrocolloids 1997, 11, 401–408.
[44] Flipse, E., Keetels, C. J. A. M., Jacobson, E., Visser.,
R. G. F., The dosage effect of the wild type GBSS allele is
linear for GBSS activity, but not for amylose content:
[46] Singh, J., Singh, N., Studies on the morphological, thermal
and rheological properties of starch separated from some
Indian potato cultivars. Food Chem. 2001, 75, 67–77.
ß 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.starch-journal.com