ArticlePDF Available

Abstract and Figures

'Resistant starch' (RS) is defined as starch and starch degradation products that resist the action of amylolytic enzymes. The effect of multiple heating/cooling treatments on the RS content of legumes, cereals and tubers was studied. The mean RS contents of the freshly cooked legumes, cereals and tubers (4.18%, 1.86% and 1.51% dry matter basis, respectively) increased to 8.16%, 3.25% and 2.51%, respectively, after three heating/cooling cycles (P< or =0.05) with a maximum increase of 114.8% in pea and a minimum of 62.1% in sweet potato (P< or =0.05). Significant positive correlations were observed between the RS content and amylose (y=0.443x-5.993, r=0.829, P< or =0.05, n=9) as well as between the percentage increase in RS and insoluble dietary fiber content (y=2.149x-24.787, r=0.962, P< or =0.05, n=9). A differential scanning calorimeter study showed an increase in the T(0), T(p), T(c) and DeltaH values of the repeatedly autoclaved/cooled starches. The intact granular structure was also observed disappear, as studied using scanning electron microscopy.
Content may be subject to copyright.
This article was downloaded by:
[Yadav, Baljeet S.]
9 October 2009
Access details:
Access Details: [subscription number 914740650]
Informa Healthcare
Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House,
37-41 Mortimer Street, London W1T 3JH, UK
International Journal of Food Sciences and Nutrition
Publication details, including instructions for authors and subscription information:
Studies on effect of multiple heating/cooling cycles on the resistant starch
formation in cereals, legumes and tubers
Baljeet S. Yadav a; Alka Sharma b; Ritika B. Yadav a
a Department of Food Science & Technology, Ch. Devi Lal University, Sirsa, Haryana, India b Department of
Food Technology, Guru Jambheshwar University of Science & Technology, Hisar, Haryana, India
Online Publication Date: 01 January 2009
To cite this Article Yadav, Baljeet S., Sharma, Alka and Yadav, Ritika B.(2009)'Studies on effect of multiple heating/cooling cycles on
the resistant starch formation in cereals, legumes and tubers',International Journal of Food Sciences and Nutrition,60:1,258 — 272
To link to this Article: DOI: 10.1080/09637480902970975
Full terms and conditions of use:
This article may be used for research, teaching and private study purposes. Any substantial or
systematic reproduction, re-distribution, re-selling, loan or sub-licensing, systematic supply or
distribution in any form to anyone is expressly forbidden.
The publisher does not give any warranty express or implied or make any representation that the contents
will be complete or accurate or up to date. The accuracy of any instructions, formulae and drug doses
should be independently verified with primary sources. The publisher shall not be liable for any loss,
actions, claims, proceedings, demand or costs or damages whatsoever or howsoever caused arising directly
or indirectly in connection with or arising out of the use of this material.
Studies on effect of multiple heating/cooling cycles on
the resistant starch formation in cereals, legumes and
Department of Food Science & Technology, Ch. Devi Lal University, Sirsa, Haryana, India,
Department of Food Technology, Guru Jambheshwar University of Science & Technology,
Hisar, Haryana, India
‘Resistant starch’ (RS) is defined as starch and starch degradation products that resist the action
of amylolytic enzymes. The effect of multiple heating/cooling treatments on the RS content of
legumes, cereals and tubers was studied. The mean RS contents of the freshly cooked legumes,
cereals and tubers (4.18%, 1.86% and 1.51% dry matter basis, respectively) increased to
8.16%, 3.25% and 2.51%, respectively, after three heating/cooling cycles (P50.05) with a
maximum increase of 114.8% in pea and a minimum of 62.1% in sweet potato (P50.05).
Significant positive correlations were observed between the RS content and amylose (y
0.443x5.993, r0.829, P50.05, n9) as well as between the percentage increase in RS
and insoluble dietary fiber content (y2.149x24.787, r0.962, P50.05, n9). A
differential scanning calorimeter study showed an increase in the T
and DHvalues of
the repeatedly autoclaved/cooled starches. The intact granular structure was also observed
disappear, as studied using scanning electron microscopy.
Keywords: Resistant starch, amylose, gelatinization, retrogradation, insoluble dietary fiber
Starch occurs as insoluble and tightly packed granules in plant cells storing the
carbohydrates (Imberty et al. 1991). Besides being a major plant metabolite, starch is
an extremely important dietary component in the form of carbohydrates in the human
diet (Bjorck et al. 1994; Skrabanja et al. 1999). Recently, the research on starch has
been focused on its peculiar form, which is indigestible in vitro and in vivo (i.e.
resistant starch [RS]) (Sievert and Pomeranz 1989; Siljestrom et al. 1989; Gormley
and Walshe 1999; Tharanathan and Tharanathan 2001; Hoover and Zhou 2003;
Brouns et al. 2007; Englyst et al. 2007; Cummings and Stephen 2007; Sharma et al.
2008; Murphy et al. 2008; Grabitske and Slavin 2009). The digestion of starch is
mainly mediated by alpha-amylases (a-1,4-glucan hydrolase [EC3.2.1.1]), which act
on both amylose and amylopectin in an endo fashion releasing glucose, maltose,
oligosaccharides and higher dextrins into the lumen of small intestine. The glucose is
absorbed directly through the intestinal mucosa, whereas the oligosaccharides and
Correspondence: Dr Baljeet Singh Yadav, Lecturer, Department of Food Science & Technology, Ch. Devi
Lal University, Sirsa, Haryana 125055, India. E-mail:
ISSN 0963-7486 print/ISSN 1465-3478 online #2009 Informa UK Ltd
DOI: 10.1080/09637480902970975
International Jour nal of Food Sciences and Nutrition,
September 2009; 60(S4): 258272
Downloaded By: [Yadav, Baljeet S.] At: 03:47 9 October 2009
other dextrins are acted upon by the membrane bound glucosidases. These enzymes
include glucoamylase that cleaves a-1,4-glucan links from the non-reducing ends.
However, an increasing volume of evidence suggests that, with very few exceptions,
only a proportion of total ingested nutrients in a diet or in food is available, and the
term ‘availability’ has come into use. During food processing, derivatization of
nutrients and formation of cross-linkages occur, making the food inaccessible for
digestion and/or metabolism.
Englyst et al.’s (1982) studies on measurement of non-starch polysaccharides first
recognized the presence of a starch fraction resistant to enzymic hydrolysis. The term
‘resistant starch’ was first used to describe the incomplete digestion of starch in vitro that
had been cooked and cooled (Berry 1986). Now this term includes all starch and starch
degradation products that resist small intestinal digestion and enter the large bowel in
normal humans (Asp 1992). RS has been categorized into four types: RS
and RS
represents tightly bound starch molecules that are physically inaccessible
to digestive enzymes as these are wrapped in a fiber shell (Bird et al. 2000; Haralampu
2000) and it is found in partly milled grains and seeds. RS
is ungelatinized starch
granule, which is inaccessible to amylolytic enzymes due to its compact and unhydrated
structure. RS
is the retrograded or recrystallized starch and is found in most of the heat-
processed foods (Muir ad O’ Dea 1992; Haralampu 2000). RS
is the chemically
modified form; for example, esterified and cross-bonded starches that cannot be broken
down, since the modification process renders the structure inaccessible to digestion by
alpha-amylase (Cummings et al. 1996; Haralampu 2002).
RS is being examined both for its potential health benefits as well as functional
properties to produce high-quality foods. The beneficial short-chain fatty acids,
including mainly butyrate, acetate and propionate produced from the fermentation of
RS in the colon, may play an important role in the prevention of gastrointestinal
disorders including colon cancer, diverticulitis and hemorrhoids (Bird et al. 2000). RS
has been reported to lower the glycemic values, decrease serum cholesterol and
triglyceride levels, and increase fecal bulk and prebiotic effects (Nugent 2005; Sajilata
et al. 2006; Sharma et al. 2008).
Very little uncooked raw starch is consumed in normal diets and most of the
processed foods invariably involve the application of heat and moisture for varying
periods. During processing, the starch molecules undergo several physical modifica-
tions depending upon the type of starch and severity of the conditions applied (Goni
et al. 1996), leading to the formation of resistant starch. The amylase RS (RS
formed in foods processed under relatively high moisture contents with cooking,
baking or autoclaving (Sagum and Arcot 2000; Tharanathan and Tharanathan 2001;
Habana et al. 2004; Katyal et al. 2005; Mahmood et al. 2006). Bravo et al. (1998)
studied the effect of different processing treatments on RS formation in moth beans,
horse gram and black gram. Vasanthan and Bhatty (1998) used annealing as a means
of increasing the RS content of pea and lentil starches from 8.4% to 14.1% and from
6.5% to 9.5%, respectively. Increases in the baking temperature and baking time were
found to result in increases in the RS contents of bakery products (Kale et al. 2002).
Three heating and cooling cycles resulted in increase in the RS content of potato
(Gormley and Walshe 1999). Sievert and Pomeranz (1989) described the use of
autoclaving/cooling cycles to produce RS from high-amylose maize varieties. Elevated
processing temperatures such as those used in canning enhance the effect of heating
and cooling. Canning/autoclaving has a greater depressive effect on the digestibility of
Multiple heating/cooling cycles and resistant starch formation 259
Downloaded By: [Yadav, Baljeet S.] At: 03:47 9 October 2009
starch and it is only partially ameliorated by reheating. It is important to study the
effect of multiple heating and cooling as foods such as potatoes and legumes may be
subjected to more than one cook/cool sequence as component of ready meals.
Although there have been different studies on RS formation during heating/cooling
treatments in food crops having high amylose content, like amylomaize, high amylose
barley, and so forth, very little and raw information is available on the effects of such
processing treatments on the RS formation in normally consumed food crops*
particularly in India. In view of the above, the present study aims to evaluate the
effect of multiple heating and cooling cycles on the RS content of some commonly
consumed cereals, legumes and tubers.
Materials and methods
Seeds of bengal gram or chickpea (Cicer arietinum), pea (Pisum sativum), lentil (Lens
esculenta), kidney beans (Phaseolus vulgaris), grains of wheat (Triticum aestivum), rice
(Oryza sativa), barley (Hordeum vulgare) and tubers of potato (Solanum tubersum) and
sweet potato (Ipomea batatas) were procured from the local market. The legume crops
were milled to dhals with the help of the locally available dhal mill. The flours (60
mesh particle size) from various legume and cereal crops were prepared using
Navdeep flourmill.
All chemicals used were of analytical grade. The enzymes used for analytical purpose
were pepsin (No. 7190, 2002 FIP U/G; Merck, Darmstadt, Germany), pancreatic
alpha-amylase (A-3176; Sigma, St Louis, MO, USA), amyloglucosidase from Aspergil-
lus niger (No. 10115; Fluka, Buchs, Switzerland), glucose oxidase (SRL 074040; SRL,
Mumbai, India) from A. niger, peroxidase from horseradish (RM 664; Himedia,
Mumbai, India), heat-stable alpha-amylase (No. A 3306; Sigma Chemicals, St Louis,
MO, USA) and protease enzyme (No. P 3910; Sigma Chemicals, St Louis, MO, USA).
The raw materials were analyzed for their moisture, ash, fat and protein contents by
employing the standard methods of analysis (AOAC 1984). The amylose content was
determined using the rapid colorimetric method of Williams et al. (1970). The dietary
fiber contents were determined by the AOAC enzymatic-gravimetric method (AOAC
2000), except that no corrections were made for protein and ash in the undigested
residue. The total starch content was determined as the glucose released by the
enzymic hydrolysis after gelatinization of the samples in boiling water (Goni et al.
1997). Rice starch was isolated by alkali steeping method of Wang and Wang (2001).
The starch from potato was extracted using the method of Peshin (2001). Bengal
gram starch was isolated by the method of Abia et al. (1993).
Multiple heating/cooling of the foods
The effect of multiple heating/cooling was studied on pressure-cooked legume flours,
cereal flours and tubers (15 psi, 1218C for 15 min; sample to water ratio of 1:5 for
cereal flours, 1:3 for legume flours and 1:2 for tubers). Cooling of the samples was
done at 48C for 24 h and reheating was done over a boiling water bath for 10 min after
260 B. S. Yadav et al.
Downloaded By: [Yadav, Baljeet S.] At: 03:47 9 October 2009
bringing the samples to the room temperature. Up to three heating/cooling cycles were
given to the samples.
Determination of resistant starch content
The RS was determined using the enzymic method of Goni et al. (1996). One
hundred milligrams of dry-milled sample or 400500 mg wet homogenized sample
was weighed in a 50 ml centrifuge tube. Pepsin solution (0.2 ml, 1 g pepsin/10 ml
KClHCl buffer, pH 1.5) was added to deproteinize the sample (408C for 60 min).
The cooled sample was treated with pancreatic alpha-amylase (A-3176; Sigma) (1.0
ml, 40 mg alpha-amylase per 1 ml Tris maleate buffer, 378C for 16 h) to hydrolyze
digestible starch. The pellet obtained after centrifugation (15 min, 3,000g) was
washed with distilled water and centrifuged again to discard supernatant. The pellet
was dispersed with 3.0 ml distilled water and 3.0 ml of 4 M KOH and mixed well with
a magnetic stirrer along with constant shaking for 30 min at room temperature. After
the complete dispersion of sample, 5.5 ml of 2 M HCl and 3 ml of 0.4 M sodium
acetate buffer (pH 4.75, pH adjusted with 2 M HCl) and 80 ml amyloglucosidase
(5 mg/ml acetate buffer pH 4.75) were added and the sample placed in a water bath at
608C for 45 min with constant shaking. The contents were centrifuged (15 min,
3,000g), and supernatant collected in a 500 ml volumetric flask. The residue was
washed with 10 ml distilled water, centrifuged again and the supernatant was
combined with previously obtained one. The volume was made to 250500 ml
depending upon the RS content. The amount of glucose was determined using
glucose oxidaseperoxidase reagent.
RS (percentage of the sample as is) was calculated as:
% RS contentglucose concentration from standard curve 0:9
volume correctionx 1=1;000 100=w
The% RS content was calculated on a dry matter basis.
Resistant starch preparation from native starches
RS formation was studied using differential scanning calorimetery and scanning
electron microscopy in the repeatedly autoclaved/cooled starches isolated from rice,
bengal gram and potato. The isolated starch (25g, as is basis) of each crop was
suspended with distilled water with a starch/water ratio of 1:3.5 in a 500 ml beaker.
The suspensions were autoclaved in a thermostatically controlled autoclave at 128C
for 1 h. After autoclaving, the samples were allowed to cool at room temperature and
stored overnight in a refrigerator at 48C. The autoclaving/cooling cycles were repeated
five times and the treated samples were wet-milled in a pestle and mortar, and dried in
a vacuum oven at 558C. The dried material was ground in a blender and allowed to
pass through a sieve with 250 mm openings.
Differential scanning calorimetry
The thermal properties of isolated native and repeatedly heated/cooled starches
isolated from bengal gram, rice and potato were analyzed using a differential scanning
calorimeter (DSC-821; Mettler Toledo, Schwerzenbach, Switzerland) equipped with
a thermal analysis data station. Starch (10 mg, dry matter basis) was weighed in
Multiple heating/cooling cycles and resistant starch formation 261
Downloaded By: [Yadav, Baljeet S.] At: 03:47 9 October 2009
aluminum pan (ME 27331; Mettler Toledo). About 20 ml distilled water was added
with the help of a Hamilton microsyringe to achieve a starch-water suspension
(Szczodrak and Pomeranz 1991). The pans were sealed hermetically and allowed to
stand for 1 h at room temperature before heating in the differential scanning
calorimeter. A pan with water served as reference. The samples were heated at the rate
of 108C/min from 20 to 1808C.
Scanning electron microscopy
Scanning electron micrograms of native and repeatedly heated/cooled starches
isolated from bengal gram, rice and potato were obtained with a scanning electron
microscope (Jeol JSM-6100; Jeol Ltd, Tokyo, Japan). For examination by scanning
electron microscopy, finely ground and ethanol dehydrated samples were placed on an
aluminum stub and the samples were coated with a thin film of gold, with the help of
the Jeol ion sputter (JFC-1100). An acceleration potential of 10 kVA was used during
Statistical analysis
A randomized complete block design with three replications was used to analyze changes
in RS content during multiple heating/cooling cycles. Data were analyzed using two-way
analysis of variance procedures. Statistical analysis was performed using the OPSTAT
software version opstat1.exe (Hisar, India). Correlation studies were performed using
SPSS 11.0 software (SPPS 11.0 Chicago, Illinois).
Results and discussion
Starch and dietary fiber profile of food crops
Among legumes, bengal gram showed the highest value of total starch content
(percentage dry matter basis); that is, 60.26%. The values of the total starch content
for pea and chickpea were comparable with those found by Rosin et al. (2002). The
amylose content of legumes was higher than that of cereals and tubers in general. The
amylose content of legumes was in agreement with those observed by Rosin et al.
(2002). The total starch content of different cereal food crops varied from 65.54% for
barley to 81.42% for rice. Among cereals, the amylose content calculated as the
percentage of total starch was the highest for wheat (25.85%) and lowest for rice
(20.66%). The total dietary fiber (TDF) values of legumes varied from 17.18%
(percentage dry matter basis) for kidney beans to the highest value of 24.92% for
bengal gram. Bravo et al. (1999) also observed comparable value of TDF for bengal
gram. The observed values of insoluble dietary fiber (IDF) and TDF for lentil,
common bean and pea in this study were in agreement with the values observed by
Almeida Costa et al. (2006). Among cereals, barley was found to show the highest
value of TDF; that is, 15.02%.
Resistant starch content of repeatedly heated/cooled foods
The RS content of the freshly cooked legumes was the highest, followed by cereals and
tubers in general. The RS content of rice was the minimum and was 1.24%, compared
262 B. S. Yadav et al.
Downloaded By: [Yadav, Baljeet S.] At: 03:47 9 October 2009
with a maximum RS content of 4.89% in freshly cooked flour of kidney beans (Table
I). In general, legume starches differ from cereal and tuber starches both in their
chemical composition and granular structure (Doublier 1987; Hoover and Zhou
2003). The reduced bio-availability of starch and hence the greater RS content of
legumes can be attributed to the presence of intact tissue/cell structures enclosing
starch granules, a high level of amylose (2233% in this study), a high content of
viscous soluble dietary fiber components, the presence of large number of antinu-
trients, ‘B’-type crystallites and strong interactions between amylose chains (Wursch
et al. 1986; Siddhuraju and Becker 2001; Mahadevamma et al. 2003). Permanence of
intact starch granules trapped within the cells in the pre-cooked legume flour was
observed by Tovar et al. (1991) even after extensive homogenization and pepsin
treatment. This could account for the higher RS content in the freshly cooked
legumes. The lower RS content of cereals could be expected from their polymorph
starch type. Cereal starches are ‘A’-type starches (Gernat et al. 1990; Cairns et al.
1997) always having a low RS fraction of starch. The tubers such as potato and sweet
potato in their natural state contain sufficient water to allow full gelatinization of their
starch content during heat treatment as demonstrated by their low RS content. The
rapid expansion of tuber starch as it gelatinizes in the presence of excess water loosens
the cellular architecture of most potato products, which allows easy access for starch-
degrading enzymes.
Multiple heating/cooling greatly increased the RS content of foods (Table I). The
mean RS content of the freshly boiled food crops was 2.81% and the mean value of RS
Table I. RS content (percentage dry matter basis) of repeatedly heated/cooled foods.
Food crop Control
Wheat 1.7690.14
Rice 1.2490.09
Barley 2.5790.09
Bengal gram 4.5590.20
Pea 3.1690.11
Lentil 4.8990.27
Kidney bean 4.1290.08
Potato 1.7090.08
Mean 2.81
Data presented as mean9standard deviation of three independent determinations at 5% level of
significance (PB0.05). Values in parentheses show the percentage increase over the control value. Values
with different uppercase superscript letters in the column (mean values) differ significantly.
Multiple heating/cooling cycles and resistant starch formation 263
Downloaded By: [Yadav, Baljeet S.] At: 03:47 9 October 2009
in the thrice-heated/cooled foods was observed to be 5.27%, indicating a significant
increase of about 87.5% (P50.05). The RS content of the once-heated, twice-heated
and thrice-heated/cooled foods was significantly different (P50.05). A significant
interaction (P50.05) was also observed between heating/cooling treatments and
crops; that is, the effect of three successive heating/cooling treatments on the RS
content was more pronounced in legumes as compared with cereals and tubers. A
maximum increase of 114.0% in the RS content was observed in case of thrice-heated/
cooled pea flour. Among thrice-heated/cooled food crops, sweet potato reported a
minimum increase of 62.1% in RS content. Although rice showed a higher increase in
the RS content as compared with sweet potato at every stage of heating/cooling, no
significant difference was observed in the RS content of rice and sweet potato at any
stage of heating/cooling (PB0.05).
Szczodrak and Pomeranz (1991) observed the formation of RS in high amylose
barley starch with increasing number of autoclaving/cooling cycles. The percentage
yield of RS was 5.8 in once-heated/cooled barley starch and it increased to 25.8 after
20 heating/cooling cycles. However, the percentage RS content of repeatedly heated/
cooled barley flour observed in the present study was less because of low amylose
content of the barley cultivar used and the lesser number of heating/cooling cycles,
resulting in formation of lesser retrograded starch. Sievert and Pomeranz (1989) also
observed a pronounced effect of the number of heating/cooling cycles on the RS
content of wheat, maize, potato, pea, waxy maize and amylomaize. The starch/water
ratio and autoclaving temperature affected the formation of RS in amylomaize VII
starch also. Gruchala and Pomeranz (1993) reported an increased yield of RS in
repeatedly autoclaved/cooled amylomaize starch. A consistent increase in the yield of
RS content was observed up to four autoclaving/cooling cycles, and it increased from
20.7% after one heating/cooling cycle to 31.7% after four cycles. RS was also found to
develop and increase in bengal gram and red gram dhals autoclaved/cooled for four
cycles (Mahadevamma et al. 2003). A similar increase in the RS content has been
observed in multiple heated/cooled potatoes by Kingmann and Englyst (1994). The
findings of the present study are also in agreement with the observations reported by
Gormley and Walshe (1999) in multiple cooked/cooled potatoes.
The percentage increase in the RS content of repeatedly heated/cooled tubers was
less in comparison with that of legumes and cereals. The two possible reasons for this
may be the low amylose content in tuber crops as amylose plays an important role in
the formation and development of RS during heating/cooling treatments and,
secondly, the tuber crops used in this study were not in the form of flours as in the
case of cereals and legumes. In the case of flours the starch is gelatinized more
uniformly and intensively, and hence is retrograded more as compared with intact
grains or tubers.
RS is formed during retrogradation or recrystallization of the gelatinized starch,
particularly amylose. Each successive cooking increases the degree of starch gelatiniza-
tion and each cooling promotes more retrogradation. The gelatinized starch recrys-
tallizes into a more ordered solid state that is less susceptible to the action of pancreatic
amylase. Most of the crystallized starch chains are re-dispersed by reheating, leading to
restoration of digestibility, but a small fraction of mainly retrograded amylose (RS
remains resistant (Englyst et al. 1982). During each reheating and cooling cycle a bit
more RS
is formed, leading to an increased percentage of RS content each time in
repeatedly heated/cooled foods. Autoclaving is more effective in increasing the RS
264 B. S. Yadav et al.
Downloaded By: [Yadav, Baljeet S.] At: 03:47 9 October 2009
content of most of the starches, presumably because it mobilizes the starch polymers by
swelling of the native granules ultrastructure and thereby allowing separation of the
amylose domain that crystallizes more readily upon cooling (Russell et al. 1989). A
positive and significant correlation (y0.443x5.993, r0.829, P50.05, n9) was
observed between the RS of repeatedly heated/cooled foods and amylose. Figure 1
depicts the RS content of repeatedly heated/cooled foods as affected by amylose. Sagum
and Arcot (2000) also observed a higher amount of RS for mation in the pressure-cooked
rice cultivars having higher amylose content (1.6% RS with 20% amylose and 2.8% RS
with 31% amylose). Rosin et al. (2002) also observed a positive significant correlation
between the RS of cooked foods and amylose (r0.631). The percentage increase in the
IDF of repeatedly heated/cooled foods (Figure 2) was also observed to relate positively
with the amylose content (y2.149x24.787, r0.962, P50.05, n9), suggesting
that retrogradation of amylose occurred in repeatedly heated/cooled foods, resulting in
enhanced levels of RS content. A positive significant correlation (r0.81) between IDF
and RS content was also observed by Thed and Phillpps (1995) in potatoes.
0 10203040
lose content (% starch)
%RS (dmb)
% RS
Linear (% RS)
Figure 1. RS content of repeatedly heated/cooled foods as affected by amylose content (r0.82). dmb, dry
matter basis.
0 50 100 150
%Increase in RS content
% Increase in IDF content
%Increase in IDF
Linear (%Increase in IDF)
Figure 2. Percentage increase in IDF content versus percentage increase in the RS content of repeatedly
heat-treated and cooled food crops (r0.91).
Multiple heating/cooling cycles and resistant starch formation 265
Downloaded By: [Yadav, Baljeet S.] At: 03:47 9 October 2009
Differential scanning calorimetric study
The gelatinization transition temperatures T
(onset), T
(peak), T
(completion) and
enthalpy of gelatinization (DH) of native and heated/cooled starches of bengal gram,
potato and rice are presented in Table II. The values of transition temperatures (T
for the native starches were found to be lower than the normal expected values, which
may be due to difference in the starchwater ratios or experimental set-up. The
difference in the transition temperatures of the different starches suggests that
the starches may differ with respect to their crystallite size and/or the degree of
crystallite association within the granule. The differences in DHamong different
starches probably reflect differences in the number of double helices (within
amorphous and crystalline regions of granule) unraveling and melting during
gelatinization (Levine and Slade 1988). Cooke and Gidley (1992) have also shown
by X-ray spectroscopy that DHvalues reflect mainly the loss of double-helical order
rather than crystalline regions. An increase in the T
and DHover that of native
starches was observed in multiple autoclaved/cooled starches. Mangala et al. (1999)
observed a similar increase in the transition temperatures and enthalpy values in the
autoclaved and cooled starches of rice and ragi. T
is an indication of structural
stability and resistance to gelatinization. The crystallinity of the heated/cooled starches
is governed by the cooling in between the heating steps. Autoclaved and cooled
starches develop more stabilized structures with increased degree of ordering. The
thermograms of native and repeatedly heated/cooled starches of potato, bengal gram
and rice are shown in Figure 3. The melting enthalpy values for native starches varied
from 2.65 to 3.29 J/g, whereas for autoclaved/cooled starches the values varied from
7.99 to 12.79 J/g. The higher melting enthalpies of heated/cooled starches might be
related to the stabilization of the starch molecules through retrogradation and
compact structures formation. The thermograms of amylomaize preparations also
showed that an increase in the number of autoclaving/cooling cycles was associated
with an increase in melting enthalpies. The corresponding RS residue also exhibited
sharper endotherms over a broader temperature range [Sievert and Pomeranz 1989].
Scanning electron microscopy
The structural differences between the native and heat-treated starches were
illustrated using scanning electron microscopy. Native starches of potato, rice and
Table II. Thermal properties of the native and repeatedly heated/cooled starches.
Transition temperature (8C) DH(J/g)
Starch T
Bengal gram 45.37 56.96 68.36 3.29
Bengal gram
64.25 68.89 73.46 7.99
Potato 48.21 58.99 70.77 2.65
60.20 69.12 80.6 7.62
Rice 55.11 63.45 74.70 2.66
56.69 60.85 69.37 12.79
Temperature at which gelatinization of starch starts; T
Tis temperatures measures the thermal
stability of starch; T
The temperature at which gelatinization concludes; DHenthalpy associated with
gelatinization process.
266 B. S. Yadav et al.
Downloaded By: [Yadav, Baljeet S.] At: 03:47 9 October 2009
bengal gram consist of granules of varying diameter. Figures 4 and 5 respectively show
the structural features of native and repeatedly heated/cooled starches. The starches
showed completely different images after repeated autoclaving/cooling treatment. The
intact granular structure disappeared and bigger irregularly shaped particles with a
continuous sponge like porous network with some compact structures appeared. The
Figure 3. Differential scanning calorimetery endotherms of (line A) native and (line B) repeatedly heated/
cooled (I) potato, (II) bengal gram and (III) rice starch.
Multiple heating/cooling cycles and resistant starch formation 267
Downloaded By: [Yadav, Baljeet S.] At: 03:47 9 October 2009
higher melting enthalpies of repeatedly heated/cooled starches might be related to this
stabilization. This transformation of the structure of the starch granules upon heating
and cooling make them resistant to amylolytic attack, and it is generally also
acknowledged that alpha-amylase preferentially attacks amorphous regions of starch
and that solid regions of starch are hydrolyzed at a slower rate (Vasanthan and Bhatty
1998). The findings of the present study are in agreement with those of Sievert and
Pomeranz (1989).
Figure 4. Scanning electron micrographs of (a) native rice starch, (b) bengal gram starch and (c) potato
268 B. S. Yadav et al.
Downloaded By: [Yadav, Baljeet S.] At: 03:47 9 October 2009
From the results it has been concluded that repeated heating/cooling of foods results
in an increase in their RS content. Although a linear correlation (r0.829) between
amylose content and RS content has been observed, the increasing RS is not
proportional to the increasing amylose content. It implies that along with amylose
content there are some other factors that also influence the RS content, and these may
Figure 5. Scanning electron micrographs of (a) repeatedly heated/cooled rice starch, (b) bengal gram starch
and (c) potato starch.
Multiple heating/cooling cycles and resistant starch formation 269
Downloaded By: [Yadav, Baljeet S.] At: 03:47 9 October 2009
include amylose chain lengths, granule size, type of crystalline polymorphs, physical
insulation of starch by thick-walled cells, porosity and physical distribution of starch in
relation to the dietary fiber components, and so forth. In fact, RS formation is a very
complex process that involves several parameters simultaneously which must be
properly quantified in foods. Similarly, an increase in RS content is also not strictly
proportional to the increasing IDF content. This also once again signifies that the
enzymic-gravimetric method for the estimation of dietary fiber is not reliably inclusive
of RS in the IDF fraction. It is therefore significant to redefine dietary fiber. However,
it could act as an incentive for food manufacturers in raising levels of RS in processed
foods as a means of generating extra ‘dietary fiber’. It is important to study such
effects since foods are often cooked and held chilled, as in potato-salad manufacture.
In distilleries and breweries, such studies may be of great importance as cooking and
cooling operations are repeated and there occurs formation of RS in the residue if
cooker vessels are not emptied or cleaned properly. The RS formed may cause
problems of filtration and haze formation in beer. It is important to emphasize here
that RS should be included in the food composition database as it plays important
physiological roles in the body.
Abia R, Buchanan CJ, Saura-Calixto F, Eastwood MA. 1993. Structural changes during the retrogradation
of legume starches modify the in vitro fermentation. J Agric Food Chem 41:18561863.
Almeida Costa GE, Queiroz-Monici KS, Reis SMPM, Oliveira AC. 2006. Chemical composition, dietary
fiber and resistant starch contents of raw and cooked pea, common bean, chickpea and lentil legumes.
Food Chem 94:327330.
AOAC. 1984. Official methods of analysis. 14th ed. Arlington, VA: Association of Official Analytical
AOAC. 2000. Method 991.3. Total dietary fiber, enzymatic-gravimetric method. In: Official methods of
analysis of Association of Official Analytical Chemists International. 7th ed. Gaithersburg, MD:
Association of Official Analytical Chemists.
Asp NG. 1992. Resistant starch: Proceedings from the second plenary meeting of EURESTA: European
FLAIR Concerted Action, 11 on physiological implications of the consumption of resistant starch in man.
Eur J Clin Nutr 46:S1.
Berry CS. 1986. Resistant starch: Formation and measurement of starch that survives exhaustive digestion
with amylolytic enzymes during determination of dietary fibre. J Cereal Sci 4:301314.
Bird AR, Brown IL, Topping DL. 2000. Starches, resistant starch the gut microflora and human health.
Curr Issues Intestinal Microbiol 1(1):2537.
Bjorck IM, Granfeldt Y, Liljerberg H, Tover J, Asp NG. 1994. Food properties affecting the digestion and
absorption of carbohydrates. Am J Clin Nutr 59:699705.
Bravo L, Sidduraju P, Saura-Calixto F. 1998. Effect of various processing methods on the in vitro starch
digestibility and resistant starch content of Indian pulses. J Agric Food Chem 4:46674674.
Bravo L, Siddhuraja P, Saura Calixto F. 1999. Composition of underexploited Indian pulses: comparison
with common legumes. Food Chem 64:185192.
Brouns F, Arrigoni E, Langkilde AM, Verkooijen I, Fassler C, Andersson H, Kettlitz B, Nieuwenhoven MV,
Philipsson H, Amado R. 2007. Physiological and metabolic properties of a digestion-resistant
maltodextrin, classified as type 3 retrograded resistant starch. J Agric Food Chem 55:15741581.
Cairns P, Bogracheva TY, Ring SG, Hedley CL, Morris VJ. 1997. Determination of the polymorphic
composition of smooth pea starch. Carbohydr Polym 32:275282.
Cooke D, Gidley MJ. 1992. Loss of crystalline and molecular order during starch gelatinization: Origin of
the enthalpy transition. Carbohydr Res 227:103112.
Cummings JH, Beatty ER, Kingmann SM, Bingham SA, Englyst HN. 1996. Digestion and physiological
properties of resistant starch in human bowel. Br J Nutr 75:733747.
Cummings JH, Stephen AM. 2007. Carbohydrate terminology and classification. Eur J Clin Nutr 61(1):
270 B. S. Yadav et al.
Downloaded By: [Yadav, Baljeet S.] At: 03:47 9 October 2009
Doublier JL. 1987. A rheological comparison of wheat, maize, faba bean and smooth pea starches. J Cereal
Sci 5:247262.
Englyst HN, Wiggins HS, Cummings JH. 1982. Determination of the non-starch polysaccharides in plant
foods by gas-liquid chromatography of constituent sugars as alditol acetates. Analyst 107:307318.
Englyst KN, Liu S, Englyst HN. 2007. Nutritional characterization and measurement of dietary
carbohydrates. Eur J Clin Nutr 61(1):S19S39.
Gernat C, Radosta S, Damaschun G, Schierbaum F. 1990. Supramolecular structure of legume starches
revealed by X-ray scattering. Starch 42:175178.
Goni L, Garcia-Dia Manas E, Saura-Calixto F. 1996. Analysis of resistant starch: A method for foods and
food products. Food Chem 56(4):455459.
Goni I, Garia-Alonso A, Saura-Calixto F. 1997. A starch hydrolysis procedure to estimate glycemic index.
Nutr Res 17:427437.
Gormley R, Walshe T. 1999. Effects of boiling, warm holding, mashing and cooling on the levels of enzyme-
resistant potato starch. Int J Food Sci Technol 34:281286.
Grabitske HA, Slavin JL. 2009. Gastrointestinal effects of low-digestible carbohydrates. Crit Rev Food Sci
Nutr 49:327360.
Gruchala L, Pomeranz Y. 1993. Enzyme resistant starch: studies using differential scanning calorimetery.
Cereal Chem 70:163170.
Habana LL, Hernandez AP, Acevedo EA, Tovar J, Perez B. 2004. Effect of cooking procedures and storage
on starch bioavailability in common beans (Phaseolus vulgaris L.). Plant Foods Hum Nutr 59:133136.
Haralampu SG. 2000. Resistant starch*a review of the physical properties and biological impact of RS3.
Carbohydr Polym 41:285292.
Haralampu SG. 2002. Physiological effects of resistant starch. Available online at: http// www. (accessed 20 September 2002).
Hoover R, Zhou Y. 2003. In vitro and in vivo hydrolysis of legume starches by alpha amylase and resistant
starch formation in legumes*a review. Carbohydr Polym 54:401417.
Imberty A, Buleon A, Tran V, Perez S. 1991. Recent advances in knowledge of starch structure. Starch
Kale CK, Kotecha PM, Chavan JK, Kadam SS. 2002. Effect of processing conditions of bakery products on
formation of resistant starch. J Food Sci Technol 39(5):520524.
Katyal D, Ghugre PS, Udipi SA. 2005. Resistant starch in selected raw and processed legumes. J Food Sci
Technol 42(6):506510.
Kingmann M, Englyst HN. 1994. The influence of food preparation methods on the in vitro digestibility of
starch in potatoes. Food Chem 49:181186.
Levine H, Slade L. 1988. Water as a plasticizer: Physicochemical aspects of low-moisture polymeric systems.
In: Franks F, editor. Water science reviews Vol. 3. water dynamics. Cambridge, UK: Cambridge
University Press. pp 79185.
Mahadevamma S, Prashanth KVH, Tharanathan RN. 2003. Resistant starch derived from processed
legumes(purification and structural characterization. Carbohydr Polym 54:215219.
Mahmood I, Ghugre PS, Udipi SA. 2006. Resistant starch in raw and processed roots and tubers. J Food Sci
Technol 43(3):282285.
Mangala SL, Vidyasanker K, Tharanathan RN. 1999. Resistant starch from processed cereals. The
influence of amylopectin and non-carbohydrate constituents on its formation. Food Chem 64:391396.
Muir IG, O, Dea K.. 1992. Measurement of resistant starch: Factors affecting the amount of starch escaping
the digestion in vitro. Am J Clin Nutr 56:123127.
Murphy MM, Douglass JS, Birkett A. 2008. Resistant starch intakes in the United States. J Am Diet Assoc
Nugent AP. 2005. Health properties of resistant starch. Nutr Bull 30:2754.
Peshin A. 2001. Characterization of starch isolated from potato tubers (Solanum tuberosum L.). J Food Sci
Technol 38(5):447449.
Rosin PM, Lajolo FM, Menezesm EW. 2002. Measurement and characterization of dietary starches. J Food
Compos Anal 15:367377.
Russell PL, Berry CS, Greenwell P. 1989. Characterization of resistant starch from wheat and maize. J
Cereal Sci 9:115.
Sagum R, Arcot J. 2000. Effect of domestic processing methods on the starch, no-starch polysaccharides
and in vitro starch and protein digestibility of three varieties of rice with varying levels of amylose. Food
Chem 70:107111.
Multiple heating/cooling cycles and resistant starch formation 271
Downloaded By: [Yadav, Baljeet S.] At: 03:47 9 October 2009
Sajilata MG, Singhal RS, Kulkarni PR. 2006. Resistant starch(a review. Compr Rev Food Sci Food Saf 5:
Sharma A , Yadav BS , Ritika. 2008. Resistant starch: Physiological roles and food applications. Food Rev
Int 24:193234.
Siddhuraju P, Becker K. 2001. Effect of various domestic processing methods on antinutrients and in vitro
protein and starch digestibility of two Indigenous varieties of Indian tribal pulse Mucana pruriens Va r.
utilis. J Agric Food Chem 49:30583067.
Sievert D, Pomeranz Y. 1989. Enzyme-resistant starch I. Characterization and evaluation by enzymatic,
thermoanalytical and microscopic methods. Cereal Chem 66(4):342347.
Siljestrom M, Eliasson AC, Bjorck I. 1989. Characterization of resistant starch from autoclaved wheat
starch. Starch/ Staerke 4:147151.
Skrabanja V, Liljeberg HGM, Hedleym CL, Kreft I, Bjorck IME. 1999. Influence of genotype and
processing on the in vitro rate of starch hydrolysis and resistant starch hydrolysis in peas (Pisum sativam
L.). J Agric Food Chem 47:20332039
Szczodrak J, Pomeranz Y. 1991. Starch and enzyme resistant starch from high-amylose barley. Cereal Chem
Tharanathan M, Tharanathan RN.. 2001. Resistant starch in wheat-based products: Isolation and
characterization. J Cereal Sci 34:7384.
Thed ST, Phillips RD. 1995. Changes of dietary fiber and starch composition of processed potato products
during domestic cooking. Food Chem 52:301304.
Tovar J, de Francisco A, Bjorck A, Asp NG. 1991. Relationship between microstructure and in vitro
digestibility of starch in precooked leguminous flours. Food Struct 10:1926.
Vasanthan T, Bhatty RS. 1998. Enhancement of resistant starch (RS
) in amylomaize, barley, field pea and
lentil starches. Starch 50:286291.
Wang L, Wang YJ. 2001. Comparison of protease digestion at neutral pH with alkaline steeping method for
rice starch isolation. Cereal Chem 78:690692.
Williams PC, Kuzina FD, Hlynka I. 1970. A rapid colorimetric procedure for estimating the amylose
content of starches and flours. Cereal Chem 47:411420.
Wursch Dal Vedovo PS, Koellreuter B. 1986. Cell structure and starch nature as key determinants of the
digestion rate of starch in legume. Am J Clin Nutr 43:2529.
This paper was first published online on iFirst on 25 June 2009.
272 B. S. Yadav et al.
Downloaded By: [Yadav, Baljeet S.] At: 03:47 9 October 2009
... A shorter time of the glycemic peak has also been observed in the CR group, suggesting a beneficial effect to the glycemic control, as the delayed glycemic peak could improve the activity of the short-acting insulin analogues. Yadav et al. [49]] have also found that the content of RS was increased in starch products with multiple heating/cooling cycles, while the content of digestible carbohydrates was reduced. Haini et al. [50] found that, compared with the control group, the 2-h postprandial glucose of healthy female subjects was lower in the high-amylose maize starch 30 (HM30) group. ...
Full-text available
In recent years, the prevalence of diabetes is on the rise, globally. Resistant starch (RS) has been known as a kind of promising dietary fiber for the prevention or treatment of diabetes. Therefore, it has become a hot topic to explore the hypoglycemic mechanisms of RS. In this review, the mechanisms have been summarized, according to the relevant studies in the recent 15 years. In general, the blood glucose could be regulated by RS by regulating the intestinal microbiota disorder, resisting digestion, reducing inflammation, regulating the hypoglycemic related enzymes and some other mechanisms. Although the exact mechanisms of the beneficial effects of RS have not been fully verified, it is indicated that RS can be used as a daily dietary intervention to reduce the risk of diabetes in different ways. In addition, further research on hypoglycemic mechanisms of RS impacted by the RS categories, the different experimental animals and various dietary habits of human subjects, have also been discussed in this review.
... Steaming, extrusion, boiling, cooling, and drying gluten-free noodles can raise RS3 noodle levels (Yadav et al., 2009). Food containing RS3 can be antiinflammatory, antidiabetic, and immune-boosting (Higgins and Brown, 2013;Sun et al., 2018). ...
The purpose of this research was to find out the chemical composition, bioactive compound content, antioxidant activity, and sensory evaluation of gluten-free noodles made from organic red rice. The study was carried out by creating three formulations using germinated organic red rice flour, germinated Vigna radiata flour, and tapioca flour. Proximate analysis, resistant starch and dietary fibre were used to analyze the chemical composition. Phenolic and flavonoid compounds were among the bioactive compounds studied. The DPPH method was used to assess antioxidant activity. The findings revealed that all three formulations of gluten-free organic red rice noodles, formulations I, II, and III, had high fibre content, resistant starch, bioactive compounds, and antioxidant activity. According to sensory evaluation, gluten-free organic red rice noodles formulation I have the highest acceptance rate compared to organic red rice noodles formulations II and III. The amount of soluble dietary fibre was 0.79±0.08%, the amount of insoluble dietary fibre was 6.73±0.18%, and the amount of resistant starch was 7.56±0.02%. Total phenolics content (TPC) was 49.16±0.27%, total flavonoids content (TFC) was 53.36±0.86%, and the IC50 was 9665.84±72.39. The content of bioactive compounds and the IC50 of glutenfree organic red rice noodles have a significant and positive correlation. According to the study's findings, gluten-free organic red rice noodle formulation could be developed as a functional food high in dietary fibre, resistant starch, and antioxidants.
... This could be caused by the amylose content of the cornstarch (39.75%) which was higher than in the corn starch (32.47%). The higher the amylose content in a material, the higher the RS content produced (58)(59)(60). High amylose content in a material affects the formation of RS during the autoclaving-cooling process. The starch retrogradation process that occurs in autoclaving-cooling is mainly caused by amylose interactions, because hydrogen bonds between amylose are easily formed. ...
Full-text available
Autoclaving-cooling is a common starch modification method to increase the resistant starch (RS) content. The effect of this method varies depending on the type of crop and treatment condition used. The objectives of this study were to verify the autoclaving-cooling treatment based on a meta-analysis result and to evaluate the physicochemical properties of modified starches. The meta-analysis study used 10 articles from a total of 1,293 that were retrieved using the PRISMA approach. Meta-analysis showed that the optimal treatments of autoclaving-cooling process that increase the RS content significantly, was in starch samples from the cereal group (corn, oats, rice) (SMD: 19.60; 95% CI: 9.56–29.64; p < 0.001), with water ratio 1:4 (SMD: 13.69; 95% CI: 5.50–21.87; p < 0.001), using two cycles of autoclaving-cooling (SMD: 16.33; 95% CI: 6.98–25.67; p < 0.001) and 30 min of autoclaving heating (SMD: 12.97; 95% CI: 1.97–23.97; p < 0.001) at 121°C (SMD: 12.18; 95% CI: 1.88–22.47; p < 0.001). Verification using corn flour and corn starch showed a significant increase in RS contents from 15.84 to 27.78% and from 15.27 to 32.53%, respectively, and a significant decrease in starch digestibility from 67.02 to 35.74% and from 76.15 to 28.09%, respectively. Treated sample also showed the pasting profile that was stable under heating and stirring.
... It is related to the phenomenon of resistant starch formation during the cooling of starch products [19,20]. Yadav et al. showed that multiple heating/cooling cycles of starch products increased the resistant starch content even more [21]. In the present study, the test meal was cooled for 24 h. ...
Full-text available
Introduction Carbohydrates are one of the macronutrients which have the most substantial influence on glycemic response. The cooling of rice after cooking causes retrogradation of starch, which becomes a non-absorbable product in the human digestive tract. Aim of the study This study aimed to assess whether cooling of rice affects postprandial glycemia in subjects with type 1 diabetes. Materials and methods The study included 32 patients with type 1 diabetes. Each participant of the study consumed two standardized test meals consisting of long-grain white rice. One of the test meals was served immediately after preparation, and another was cooled for 24 h at 4 °C after preparation and reheated before being served. Postprandial glycemia was measured for 3 h using the FreeStyle Libre flash glucose monitoring system for each patient. Results After consumption of the test meal containing rice subjected to the cooling process when compared to fresh rice, a significantly lower value of maximum glycemia (11 vs. 9.9 mmol/L, p = 0.0056), maximum glycemic increase (2.7 vs. 3.9 mmol/L, p < 0.0001), areas under the glycemic curve (135 vs. 336 mmol/L * 180 min, p < 0.0001) and significantly shorter time to peak (35 vs. 45 min, p = 0.031) was observed. There was a significantly higher number of hypoglycemic episodes among the patients after consuming test meals with cooled rice compared to fresh ones during 180 min of observation (12(38) vs. 3(9), p = 0.0039). Conclusions Consumption of rice subjected to the cooling process results in a lower increase of postprandial blood glucose in subjects with type 1 diabetes. At the same time it increases the risk of postprandial hypoglycemia using a standard insulin dose.
... However, our study found that RS increment is not proportional to the increase of amylose content which may include other factors such as amylose chain lengths, granular size, and crystalline polymorphs. The formation of RS highly depends on the temperature, heating and cooling cycles, and storage condition [65,66]. Our study reveals that HMT contribute to the SDS and RS increase through the rearrangement of amylose-amylose and amylose-amylopectin chains during the breakdown and re-association of starch molecules in the starch gelatinization process. ...
Full-text available
In general, modified starches provided a desirable feature so that they can be used in the food industry like food additive products. The awareness of eating healthy has become very evident. The food industry is willing to produce foods and food ingredients that not only maintain nutrition but also promote health and safety. Tartary buckwheat starch has been isolated to assess the effect of HMT on its digestibility, morphological structure, pasting, thermal and textural properties and compared with common buckwheat, sorghum, and broomcorn millet. HMT changed significantly the granular structure of native starches. The complete starch granular structure increased the size and changed into an irregular shape, with a rough surface. The modified starches exhibited higher onset and peak temperatures, while their amylose content, solubility, swelling power, gel hardness, and enthalpy of gelatinization were significantly reduced. In pasting properties, tartary buckwheat and sorghum modified starch had the highest thermal treatment stability with lower setback and breakdown viscosity. Moreover, after three hours of starch hydrolysis; Resistant (RS) starch was higher in tartary buckwheat followed by broomcorn millet and lastly sorghum. In this study, we reported that tartary buckwheat modified starch is more useful in the preparation of food with thermal stability combined with a high amount of resistant starch.
... Penggunaan autoclaving-cooling untuk meningkatkan kadar pati resisten telah banyak diaplikasikan pada berbagai kelompok pangan. Beberapa studi memperlihatkan bahwa proses autoclaving-cooling meningkatkan kadar pati resisten pada berbagai kelompok pangan tinggi karbohidrat seperti serealia (jagung, beras, oat), umbi-umbian (umbi garut) dan kacang-kacangan (kacang polong, kacang merah) (Yadav, Sharma & Yadav, 2009;Kim et al., 2010;Faridah, 2011;Ashwar et al., 2016;Astuti, Widaningrum, Asiah, Setyowati, & Fitriawati, 2018). Namun seberapa besar pengaruh proses autoclaving-cooling terhadap masing-masing kelompok pangan tersebut belum diketahui. ...
Full-text available
ABSTRAK: Autoclaving-cooling merupakan salah satu metode modifikasi pati fisik yang banyak digunakan untuk meningkatkan kadar pati resisten. Namun metode ini memiliki pengaruh yang berbeda-beda pada tiap jenis pangan tinggi karbohidrat. Studi ini bertujuan untuk menganalisis jenis pangan karbohidrat yang memiliki pengaruh signifikan dalam peningkatan kadar pati resisten akibat proses autoclaving-cooling 2 siklus. Studi ini menggunakan 9 artikel yang diseleksi melalui metode panduan PRISMA dari total 279 artikel yang diperoleh. Data dianalisis berdasarkan nilai ukuran efek Hedges'd (standardized mean difference/SMD) dan nilai selang kepercayaan (CI) menggunakan perangkat lunak Meta-Essentials. Studi meta-analisis menunjukkan bahwa metode autoclaving-cooling pada pangan serealia memiliki efek signifikansi yang lebih tinggi dalam meningkatkan kadar pati resisten (SMD: 7,39; 95% CI: 2,8 s.d 11,97; p<0,001) dibandingkan kacang-kacangan dan umbi-umbian. Dalam kelompok serealia, jenis sampel oat (SMD: 10,91; 95% CI: 3,89 s.d 17,94; p<0,001) berpengaruh signifikan terhadap peningkatan kadar pati resisten dibandingkan sampel beras. Kesimpulan dari studi ini yaitu metode autoclaving-cooling 2 siklus memiliki pengaruh yang signifikan (tingkat kepercayaan 95%) dalam peningkatan kadar pati resisten pada kelompok pangan serealia, yaitu oat. Kata kunci: autoclaving-cooling, meta-analisis, modifikasi pati, pati resisten, serealia ABSTRACT: Autoclaving-cooling is one of the physical starch modification methods that widely used to increase the resistant starch content. However, the effect of this method varies with each type of high carbohydrates foods. The aim of this study was to analyze the type of carbohydrate foods that have the significant effect in increasing the resistant starch content due to the autoclaving-cooling 2 cycles process. This study used 9 articles that were selected through PRISMA method from 279 articles retrieved. The data were analysed by the effect size value using Hedges'd (standardized mean difference/SMD) and confidence interval (CI) utilizing Meta-Essentials software. Meta-analysis showed that autoclaving-cooling on cerealia has a higher significant effect (SMD: 7.39; 95% CI: 2.8 to 11.97; p<0.001) than those of lentils and tubers. In cereal groups, oat (SMD: 10.91; 95% CI: 3,89 to 17.94; p<0.001) has the significant effect in increasing the resistant starch content compared to rice. In conclusion, the autoclaving-cooling 2 cycles method has significant effect (level of confidence 95%) to increase the resistant starch content in cereal groups, namely oats.
Background and aims: The global prevalence of diabetes mellitus is on the increase, and Africa, particularly Nigeria is not left out. The management of the disease using a diabetes drug is often a hard choice to make for many. Information on the right food is inevitably important, as eating some type of food and avoiding or limiting some could help manage diabetes. Therefore, this study investigated glycemic indices of commonly consumed staples in Nigeria. Methods: Databases like PubMed, ScienceDirect, Google scholars, African journal online and Nigerian journal online was used to search for relevant information. Keywords like: nutritional management, diabetes in Nigeria, quality of life, prevalence, glycemic index, foods and diabetes, macronutrients and diabetes, were used separately or combined to obtain the relevant information. Results: Findings from literature search revealed that the glycemic indices of many staples such as Rice dough (Tuwo shinkafa), maize dough (tuwo masara), millet dough (tuwo gero), yam/cassava flour (amala), pounded fermented cassava (fufu, akpu), garri (eba), african salad (abacha), pounded yam (ema, iyan), rice (shinkafa, isesi), beans (wake, ewa, Agwa), and plantain (Ojoko, Ogbagba, Ogede) that are consumed in different parts of Nigeria are high (75.0%-97.0%). However, available information revealed that less commonly consumed foods like, Maize pudding (igbangwu), dried beef floss (dambu), Fonio (acha), bean pudding (moi-moi) and Tom Brownvita (Turnbrown) exhibit lower glycemic indices (14.1%-52.9%). Conclusions: This study revealed the few among several local foods in Nigeria that are low in glycemic indices that could be useful in the management of Type-2 diabetes. However, these foods may require further certification by appropriate authorities and agencies to enable persons with diabetes, particularly in Nigeria make informed choices on the right food to consume.
A starch‐rich portion is produced as a by‐product of black Tartary buckwheat processing. The effect of enzymatic combined with autoclaving–cooling cycles (one, two, or three times) on the physicochemical and structural properties of black Tartary buckwheat type 3 resistant starch (BRS) was evaluated. The autoclaving–cooling cycles enhanced solubility and reduced swelling, with the BRS content increasing from 14.12% to 25.18%. The high crystallinity of the BRS reflected a high molecular order. However, increasing the number of autoclaving–cooling cycles did not result in higher BRS content. The highest BRS yield in the autoclaved starch samples was 25.18% after double‐autoclaving–cooling cycles. Furthermore, the autoclaving–cooling cycles altered the crystalline structure of black Tartary buckwheat, and the subsequent crystallinity changed from 36.33% to 42.05% to 38.27%. Fourier‐transform infrared spectroscopy shows that the number of cycles results in more efficient double‐helical packing within the crystalline lamella. Principal component analysis showed that the autoclaving–cooling cycle treatment leads to significant changes in the molecular structure of resistant starch (RS). These results indicated that autoclaving–cooling cycles might be a feasible way for producing RS from black Tartary buckwheat starch with better structural stability to expand their application range.
The property changes of sorghum starch during multiple cycles of gelatinization and fermentation were studied. This study simulated the gelatinization and fermentation process of raw starch in strong-flavor Baijiu production (Sorghum as raw material, the distillers' grains as a control). The results showed that the starch content of the same batch of sorghum after five cycles of gelatinization and fermentation was 9.98% (Cannot continue to be used for fermentation), and about 60% of the starch was consumed in the first three cycles of gelatinization and fermentation. The gel properties of sorghum starch gradually decreased during fermentation but slightly increased after gelatinization. After five cycles of gelatinization and fermentation, the sorghum starch has a uniform size and a thin and small fragment structure. At the same time, sorghum starch does not form new groups. The recrystallization of starch caused by multiple cycles of gelatinization and fermentation increased the onset gelatinization temperature (from 61.6 to 114.4 °C), peak gelatinization temperature (from 78.5 to 139.5 °C), and gelatinization enthalpy (from 7.980 to 17.121 J/g) of sorghum starch. The crystalline structure of sorghum starch changed from the initial type A to type A + V, type A + B + V, and finally to type B.
Background Hot extrusion is widely used to produce iron-fortified rice, but heating may increase resistant starch and thereby decrease iron bioavailability. Cold-extruded iron-fortified rice may have higher bioavailability but has higher iron losses during cooking. Thus, warm extrusion could have nutritional benefits, but this has not been tested. Whether the addition of citric acid and trisodium citrate (CA/TSC) counteracts any detrimental effect of high extrusion temperature on iron bioavailability is unclear. Objective Our aim was to assess the effects of varying processing temperatures on the starch microstructure of extruded iron-fortified rice and resulting iron solubility and iron bioavailability. Methods We produced extruded iron-fortified rice grains at cold, warm and hot temperatures (40°C, 70°C and 90°C), with and without CA/TSC at a molar ratio of iron to CA/TSC of 1:0.3:5.5. We characterized starch microstructure using small- and wide-angle X-ray scattering and differential scanning calorimetry, assessed color over 6 mo, and measured in vitro iron solubility. In standardized rice and vegetable test meals consumed by young women (n = 22, mean age 23 y, geometric mean plasma ferritin, 29.3 μg/L), we measured iron absorption from the fortified rice grains intrinsically labeled with 57ferric pyrophosphate (57FePP), compared to ferrous sulfate (58FeSO4) solution added extrinsically to the meals. Results Warm and hot extrusion altered starch morphology from native type-A to type-V and increased of retrograded starch. However, extrusion temperature did not significantly affect iron solubility or iron bioavailability. The geometric mean fractional iron absorption of iron from fortified rice extruded with CA/TSC (8.2%; 95%CI: 7.9, 11.0%) was more than twice that from extruded without CA/TSC (3.0%; 95% CI: 2.7, 3.4%; P < 0.001). Conclusions Higher extrusion temperatures did not affect iron bioavailability from extruded rice in young women, but co-extrusion of CA/TSC with FePP sharply increased iron absorption independently from extrusion temperature.
Full-text available
Interest in water will continue to grow for a long time to come. It will continue to spread over a large number of disciplines and technologies. Research into water in all its aspects has become so diverse that even those with a direct interest find it impossible to keep up with the original literature beyond a very limited range. On the other hand, scientists want to keep in touch with a wide spectrum of basic and applied research on water and the role played by aqueous solvents in physical, chemical, biological, technological and environmental processes. Water Science Reviews contains three or four critical reviews of the type previously published in the seven volume work Water - A Comprehensive Treatise. Some reviews update previously published topics, while others feature areas of Water Sciences that have never yet been reviewed. A common focus is the central position adopted by water in the systems and processes described.
The resistant starch (RS) content of Bengal gram (Cicer arietinum), field pea (Pisum sativum), lentil (Lens esculenta), red gram (Cajanus cajan), green gram (Phaseolus aureus Roxb) and cow pea (Vigna catjang) ranged from 9.00 to 19.5 g/100 g; maximum in lentil and minimum in Bengal gram. The RS content differed with variety, the coefficient of variation (CV) ranged from 3 to 26%. The RS content of decorticated legumes was higher (14.2-21.5 g/100 g) than the whole legumes. Pressure-cooking of decorticated legumes increased the RS content, the increase being 153.9% for red gram and 66.5% for green gram. Storage of pressure-cooked decorticated red gram at 4°C for 12 and 24 h further increased the RS content. Reheating resulted in a reduction. Germination, dehydration and frying resulted in a decrease in RS content by 32.1, 1.7 and 18.3%, respectively. Legumes contain appreciable amounts of RS, which may be influenced by variety and may be further modified by different processing techniques.
The effects of baking temperature and time, levels of shortening fat and water in recipe and storage at ambient conditions on the changes in insoluble dietary fibre (IDF) and resistant starch (RS) in breads, sweet buns, toasts and cookies were investigated. Increments in both baking temperature and time were found to increase IDF and RS in the products. The higher levels of dough water lowered IDF and RS in bread or sweet buns, while the increase in shortening fat in recipe exhibited a non-significant effect on IDF and RS in breads, toasts and cookies. The storage of breads or sweet buns at ambient conditions resulted in an increase in both IDF and RS, perhaps due to retrogradation of starch.
Starch was purified from five Indian potato genotypes and a few important physico-chemical properties were determined. Starch yield was found to vary from 9 to 12.6% on fresh weight basis. Scanning electron microscopy (SEM) studies of 'Kufri Jyoti' variety showed that potato starch granules were relatively large and oval to elliptical in shape. The mean particle size of potato starch granules varied from 40 to 60 μm among different cultivars. The total amylose content in potato starch ranged between 17.2 and 23.7%. Potato starch contained high phosphorus content of 0.09 to 0.10%. The swelling volume of 1% potato starch paste ranged from 20 ml to 40 ml/g starch. Viscosity of potato starch paste was much higher compared to cereal and other tuber crop starches. X-ray diffraction studies of potato starch extracted from 'Kufri Jyoti' showed typical B-type pattern with a maximum peak at 17.1°2θ. The other significant peaks were observed at 5.7°2θ, 22.°2θ and 24°2θ.
Resistant starch (RS) was estimated in potato (Solanum tuberosum), colocasia (Colocasia antiquorum), elephant yam (Amorphophallus camapanulatus), sweet potato (Ipomea batata) and tapioca (Manihot esculenta). The RS content of raw roots/tubers varied from 1.1 to 2.9% fresh weight. The content of RS in descending order was tapioca>colocasia>sweet potato>potato>yam. RS comprised less than 11% of the total starch. Boiling of all roots/tubers increased the RS content, the increase being highest for potato and least for sweet potato. Pressure-cooking of potato and sweet potato increased RS content by 18.9 and 11.3%, respectively. Refrigeration of pressure-cooked potato at 4°C for 12 h increased RS content by 55%. Sautéing followed by cooking reduced RS content by 45.8% in colocasia and 55.5% in elephant yam. Frying of potato decreased RS content, maximum decrease being with shallow frying.
Measured with an enzymic method, the starch content of a raw red kidney bean (Phaseolus vulgaris) flour (RBF) was higher than that of a cooked and blended (CBB) and of a cooked, freeze-dried, and milled (CBF) preparation of the seeds. Wet homogenization as well as pepsin pretreatment of CBP increased the starch yield, indicating that starch in the cooked samples is not completely available to enzymic degradation unless cell wall entrapped granules are released by mechanical or enzymatic disruption of the fibrous walls. Solubilization of resistant starch in CBF with 2 N KOH resulted in a further increase in measured starch, which reached the RBF value. Influence of encapsulated and resistant starch fractions on dietary fiber values was also noticed, CBF showed remarkably low values of in vitro amylolysis rate and starch digestibility index in a digestion/dialysis system, features that seemed to depend also on the integrity of cell walls.
A Glacier variety selection with a 43% amylose content was used for isolation and purification of barley starch. The starch was separated into two fractions that varied in granule size, and the two fractions were assayed using chemical, microscopic (scanning electron microscopy), and thermoanalytical methods. Large and small barley starch granules were different in both chemical composition and endothermic properties; the small starch granules were higher in amylose than the large granules. Heat-moisture treatment (autoclaving at 121 C) with subsequent cooling was used to produce amylase-resistant starch (RS) from purified high-amylose starch samples. The formation of RS in barley starch was strongly affected by the number of autoclaving-cooling cycles; increasing the number of cycles from one to 20 raised the RS yield from 6 to 26%. Differential scanning calorimetry thermograms showed that all isolated RS preparations exhibited an endothermic transition over a similar temperature range (116-177 C), with a mean peak temperature at 158 C, which could apparently be attributed to the melting of RS amylose crystallites. The maximum melting enthalpy for RS from barley, 37 J/g, was achieved by 12 repeated autoclaving-cooking cycles. The thermodynamic data indicated that changes in the quality of RS occurred during autoclaving- cooling cycles.