Chestnuts, a “Comfort” Healthy Food?
I. Mujić1, V. Agayn2, J. Živković3, D. Velić4, S. Jokić4, V. Alibabić1 and A. Rekić1
1 Biotechnical faculty, University of Bihac, Kulina bana 2, 77000 Bihac, Bosnia and
2 Innoso bv, The Netherlands
3 Faculty of Medical Sciences in Nis, Department of Pharmacy, Bulevar Zorana Djindjica
81, 18000, Nis, Serbia
4 Faculty of Food Technology, University J.J. Strossmayer of Osijek, F. Kuhaca 18,
31000 Osijek, Croatia
Keywords: Catanea sativa Mill., resistant starch, storage, celiac disease, blood sugar
Chestnut has been a staple food since ancient times and after being set aside
for several centuries, it has finally regained appreciation within the group of
patisserie connoisseurs and has been expanded among health conscious consumers.
Being relatively cheap in a modern agricultural practice, a chestnut deserves a
better appreciation as a source of valuable nutrients and in terms of its composition
and properties which positively affect human health when included in various
modern foods. Also, it contains a very large amount of vitamin C, considerable
vitamin B6, thiamin, folate and riboflavin, large amounts of manganese, potassium,
copper, phosphorus, magnesium and iron, a small amount of valuable unsaturated
fatty acids and 40% of its dry matter is composed of non-resistant and resistant
starch. Chestnut is gluten-free and that makes it useful as a food for celiac patients
who suffer from gluten intolerance manifested in stomach discomfort and diarrhea,
fatigue and many other symptoms. On the other hand, resistant starch, which
survives the small intestines and decomposes in the rectum, serves as a bulking agent
to provide a feeling of satiety and it transfers sugar to the blood via a sort of
controlled-released mechanism. Results from investigations on the health benefits of
chestnuts in modern foods in general and the effects on the well-being of celiac
patients in particular are reviewed: patient’s comfort, satiety, and blood sugar
levels. The effect of storage conditions and the chestnut cultivar on starch
digestibility are studied in a two-month period. A decrease of up to 30% regarding
resistant starch composition is observed for some cultivars when stored at 20°C as
opposed to storage at -18°C. This study shows that different storage conditions affect
the content of non-resistant and resistant starch.
Classical celiac disease (CD), (glutensensitive enteropathy, or GSE) is a small
intestinal inflammatory disease that is characterized by global malabsorption of nutrients,
minerals, and vitamins. It is triggered by the gluten proteins of wheat, barley, and rye
(Schuppan et al., 2005). In patients with celiac disease ingestion of the gliadin fraction of
wheat gluten and similar molecules (prolamins) causes damage to the intestinal
epithelium. Therapy of CD is a lifelong gluten-free diet. The National Food Authority has
recently redefined the term “gluten-free“, and now that term now means no gluten, and
<0.02% is currently labelled “low gluten” (Fassano and Catassi, 2001).
An association of diabetes with GSE has been observed since the late 1960s. In
recent years, it has become clear that the incidence of GSE in patients with type 1
diabetes is substantial. The incidence of type 1 diabetes and celiac disease occurring
together is about 7 to 12% in persons with either celiac disease or diabetes (Aktay et al.,
2001; Cronin et al., 1997). Both diseases require dietary modifications for proper
management. The control or elimination of certain foods will keep the person with either
The glycemic index or GI describes difference by ranking carbohydrates
European Congress on Chestnut - Castanea 2009
Eds.: G. Bounous and G.L. Beccaro
Acta Hort. 866, ISHS 2010
according to their effect on blood glucose levels. Choosing low GI carbs, the ones that
produce only small fluctuations in our blood glucose and insulin levels, provoke reducing
risk of heart disease and diabetes.
Chestnuts are very low in fat (99% fat free and no cholesterol), low in salt contain
and are a great source of smart carbohydrates (mostly starch). They are also high in
dietary fibre and rich in minerals like potassium and calcium and in B group vitamins, all
of which enhance health in general. Chestnuts have low glycemic index (GI 54 for
crushed uncooked chestnut kernels), and no gluten (ion the starch). There is the added
advantage of providing specific health benefits for diabetics and coeliacs.
Dietary starch that escapes digestion in the small intestine may be quantitatively
more important than dietary fiber as a substrate for fermentation (Cummings and Englyst,
1987). Resistant starch and other types of starch that escape digestion in the small
intestine may quantitatively be more important as substrates of fermentation than non
starch polysaccharide (NSP). Also, resistant starch is the major substrate for colonic
butyrate production. This compound is probably the short-chain fatty acid with the
strongest protective effect against colorectal cancers. Furthermore, recent epidemiological
data show a negative relationship between starch and colorectal cancer risk (Cassidy et
The population of Bosnia and Herzegovina and Croatia mainly used cereals in
nutrition, as well as flour of cereals origin. As a result, for people who suffer from celiac
disease it is very difficult to find appropriate food. At the same time, special products
assigned for diabetics are often too expensive. In consideration that chestnuts are wide-
spread in the investigated area, we investigated the possibility of applying chestnuts and
chestnuts flour as crude material in making dietetics products for patient who suffer from
diabetes and celiac disease. Previously, we investigated the influence of three different
storage regimes (-18°C, 4°C and 20°C) on digestibility of starch in three chestnut
cultivars, grown in different locations in Croatia and Bosnia and Herzegovina. The
examination of action of products gained from chestnut floor occurred in two target
populations of patients who suffer from diabetes (planned diet experiment) and celiac
disease (sensory evaluation of products).
MATERIAL AND METHODS
The objects of our study were three separate investigations of application and
characterization of chestnut and chestnut products.
Experiment 1 - Influence of Storage Period and Storage Conditions on Starch
In the investigation of digestibility of starch, three Castanea sativa Mill. cultivars
were included: chestnut grown in north-western part of Bosnia (Bosnian chestnuts),
chestnut grown in Slavonija (Slavonian chestnuts), and marrone grown in the north-
western part of Bosnia (Bosnian marron). Influence of storage period and conditions on
starch properties was determined by analysis of chestnut samples at the beginning of
storage, after a period of one and two months, at three temperatures: 20°C, 4°C and -8°C.
Dry matter content was determined by drying at 70°C in a vacuum oven. Before analysis
chestnuts were peeled and grinded.Resistant starch content was determined by AOAC
Method 2002.02. Samples were incubated with α-amylase (Sigma no. A3306; Sigma
Chemical Co., St. Louis, MO) and amyloglucosidase (Sigma no. A3514; Sigma Chemical
Co., St. Louis, MO) (AMG) (37°C, 16h). Samples were washed with ethanol, and
resistant starch (RS) residues were melted in 2M KOH and incubated with AMG (50°C,
30 min). Resulting glucose was determined colorimetrically by spectrophotometer
Hewlett Packard 8452, after reaction with GOPOD (glucose oxidase-peroxidase-4-
aminoantipyrine) reagent (also purchased from Sigma Chemical) (50°C, 20 min). All the
other used chemicals and solvents were of a high analytical grade and obtained from
Experiment 2 - Planned Diet for Patients Who Suffer from Diabetes
1. Preparation of Chestnut Products. Premium nuts were selected and peeled before
use, then boiled and crumbled. Preparation of samples was performed by previously
defined recipes. Preparation of diet products based on chestnut flour was made by using
the artificial sweeteners and the fats of vegetable origin (margarine and olive oil), with the
intention to obtain products of low caloric value, which will cause minimum oscillations
of blood glucose. Two types of cake were made: honeycomb with jam and chestnut cake.
2. The Planned Diet of Patients. A group of six patients who suffer from diabetes
mellitus, of different age and sex participated in the experiment. The examination was
conducted to determine the effects of chestnut flour in parameters of blood analysis
before and after the diet. The planned diet of the examinee took a total of 12 days. The
following schedule was applied:
a) The first four days the patients consumed products made of chestnut flour as follows:
before food intake, in the morning at 7pm a blood sample were taken. Then 30 g
products of chestnut flour were consumed (the first two days the patients ate the
honeycomb with dietary jam, and next two days they consumed chestnut cake). After
two hours, the procedure of blood sampling was repeated. The 30 g sample of cookies
contained 1.70 g resistant starch.
b) During the next four days, they consumed 30 g of rye bread, containing 0.055 g
resistant starch. The procedure of blood sampling before and after the meal was the
same. In that manner we compared the effects of chestnut and rye to the level of blood
glucose in diabetes. The rye was taken according to its low glycemic index.
c) During the last four days the patients consumed food of their normal diet. The
monitoring schedule was kept the same.
3. Monitoring of Blood Glucose, Cholesterol and Triglycerides Levels Before and
After Chestnut Diet. The blood samples were analyzed for blood glucose and cholesterol
level, and content of triglycerides by standard clinical blood tests.
Experiment 3 - Sensory Evaluation of Chestnut Biscuits of Patient Who Suffer from
This experiment included:
a) preparing gluten-free product based on chestnut flour by previously established
b) sensory analysis and assessment of acceptability of products by patients who suffer
from celiac disease.
1. Chestnut Biscuits. Five types of biscuits were made from chestnut flour: honey cake,
peanut biscuit, snow cookies, vanilla cookies and chocolate truffles. The producer of
chestnut flour is “Mulino di Zanonova Zanonova Giamalmigi” from Italy. Flour was
bought on the market of Croatia. Some sorts of cookies were prepared using chestnut
flour composited with wheat flour in the following proportions: 85:15%. In preparation
adding of artificial sweetener was included if necessary.
2. Sensory Analysis and Assessment of Acceptability. In the sensory analysis and
assessment of acceptability, seven celiac patients of different age and sex were included.
The sensory evaluation was conducted at a specialized laboratory and tasting was done
according to methods of ISO Sensory analyses. The sensory rating included estimation of
appearance, colour, texture, aroma and taste. The assessment of products was graded as
totally acceptable, acceptable, nor acceptable nor not acceptable, not acceptable and
totally not acceptable.
RESULTS AND DISCUSSION
The formation of RS is influenced by: crystallinity of starch, granular structure,
amylose:amylopectin ratio, retro gradation of amylose, moisture, presence of other
nutrients, processing and storage conditions (Sajilata et al., 2006). The results of
investigation of digestibility of starch in Castanea sativa Mill. cultivars stored at different
temperatures are shown in Table 1.
The most considerable changes of dry matter and starch content were detected
during storage at 20°C. At this temperature Slavonian chestnuts were stable for one
month only. At 20°C within a 2-month period, non resistant starch content in some
cultivars increased even 30%. During a 1-month period, changes in starch and dry matter
content are not marked, but in the second month non resistant starch content decreased for
35-40%, excluding Bosnian chestnut. Also, changes in resistant starch content were
observed. Since the lowest changes in dry matter content and starch digestibility occurs at
-18°C, this is the most suitable temperature regime for storage of all cultivars.
A small preliminary study (6 patients) of the effects of systemic use of chestnut
products on the level of some parameters in blood analysis was done (Fig. 1, Table 2).
After conducting systematic nutrition it seems that resistant starch from chestnut
and rye decrease the glycemic index of food. Blood tests of patients show positive results
of glucose level (Table 2).
In the investigated group 83.33% patients showed a decrease for glucose level
(66.44%), (Fig. 1). The influence of planned diet was not so distinctive in cholesterol and
triglycerides content in blood samples (Figs. 2 and 3).
Results in Table 3 and Figure 4 express judgement of consumer (celiac patient)
about sensorial properties of cakes made with chestnut flour.
In Figure 5 the final results of sensory rating of the products acceptability is
shown. The maximum estimation for sensory characteristics got honey cake (119), then
vanilla cookies (118), while the lowest score had snow cookies (104), (Fig. 4). The
estimation of acceptability following this trend, honey cake graded as totally acceptable
(100%) and vanilla cookies TA (85.71%). Snow cookies were described as acceptable
(57.14%). Toward opinon of celiac patients who participated in evaluation, all the
investigated samples demonstrated considerable good sensorial prorerties.
Chestnuts and chestnut flour have low GI, high RS content and represent gluten
free products. The preliminary results of our research of possible application of chestnuts
and chestnuts flour in celiac and diabetic patients nutrition were promising and demand
Aktay, A.N., Lee, P.C., Kumar, V., Parton, E., Wyatt, D.T. and Werlin, S.L. 2001. The
prevalence and clinical characteristics of celiac disease in juvenile diabetes in
Wisconsin. J. Pediatr. Gastroenterol. Nutr. 33:462-465.
Australian Chestnut Industry Strategic Plan. 2006-2010. Version 8. 03.02.2007.
Cassidy, A., Bingham, S.A. and Cummings, J.H. 1994. Starch intake and colorectal
cancer risk: An international comparison. Br. J. Cancer 69:937-942.
Cronin, C.C., Feighery, A., Ferriss, J.B., Liddy, C., Shanahan, F. and Feighery, C. 1997.
High prevalence of celiac disease among patients with insulin-dependent (type I)
diabetes mellitus. Am. J. Gastroenterol. 92:2210-2212.
Cummings, J.H. and Englyst, H.N. 1987. Fermentation in the human large intestine and
the available substrates. Am. J. Clin. Nutr. 45:1243-1255.
Fassano, A. and Catassi, C. 2001. Current approaches to diagnosis and treatment of celiac
disease: an evolving spectrum. Gastroenterology 120(3):636-651.
ISO Sensory analysis; ISO 11037:2002 (E), General guidance and test method for
assessement of the colour of foods; ISO 3972:2002 (E), Methodology-Method of
investigating sensitivity of taste; ISO 5496:1992 (E), Methodology-Initiation and
training of assessors in the detection and recognition of odours; ISO 6564:2002 (E),
ISO 4121:1987 Methodology-Evaluation of food products by methods using scales;
Methodology-Flavour profile methods.
Sajilata, M.G., Singhal, R.S. and Kulkarni, P.R. 2006. Resistant starch - a review.
Comprehensive Reviews in Food Science and Food Safety 5:1-17.
Schuppan, D., Dennis, M.D. and Kelly, C.P. 2005. Celiac disease: epidemiology,
pathogenesis, diagnosis, and nutritional management. Nutrition in Clinical Care
Table 1. Digestibility of starch in chestnut cultivars stored at different temperatures.
Stored at 20°C Stored at 4°C Stored at -18°C
Cultivar Parameter 0 1 month 2 month 1 month 2 month 1 month 2 month
Dry matter (%) 48.14 72.41 93.51 44.85 49.22 47.03 47.17
RS** (% d.m.*) 26.84 27.33 16.34 27.30 26.88 27.30 28.12
NRS*** (% d.m.) 27.69 20.77 27.12 31.71 31.03 31.71 32.66
TS**** (% d.m.) 54.53 48.10 43.46 59.01 57.91 59.01 60.78
RS/TS (%) 49.22 56.82 37.60 46.26 46.42 46.26 46.26
Dry matter (%) 42.78 73.45 93.96 43.27 43.40 41.48 40.30
RS (% d.m.) 11.28 12.05 8.56 15.54 12.38 5.99 8.97
NRS (% d.m.) 53.33 34.72 32.31 63.22 34.49 65.89 59.47
TS (% d.m.) 64.61 46.76 40.87 78.77 46.87 71.88 68.45
RS/TS (%) 17.46 25.76 20.94 19.73 26.41 8.33 13.11
Dry matter (%) 56.47 88.53 52.30 57.61 56.44 54.07
RS (% d.m.) 22.52 6.04 39.85 40.91 31.39 35.60
NRS (% d.m.) 30.68 60.71 31.59 18.14 17.83 12.43
TS (% d.m.) 53.19 66.75 71.44 59.05 49.22 48.03
RS/TS (%) 42.33 9.05 55.78 69.28 63.77 74.12
*d.m.- dry matter
**RS - resistant starch
***NRS - nonresistant starch
****TS – total starch
Table 2. The results of glucose, cholesterol and triglyceride content in blood before and
Glucose (mmol/L) Cholesterol (mmol/L) Triglyceride (μmol/L)
Patient Before ex* After ex Before ex After ex Before ex After ex
1. 20.7 17 5.1 6.1 1.35 2.20
2. 17.6 9.1 6.5 6.8 2.26 1.76
3. 13.8 13.6 4.8 5.8 7.01 5.16
4. 18.1 9.8 7.9 7.0 3.17 3.78
5. 6.0 4.6 6.2 5.3 1.92 1.43
6. 12.7 17.9 5.7 6.5 1.09 2.06
*ex - experiment
Table 3. Sensory rating of chestnut cakes.
Appearance (max 14) 14 14 12.5 13 13.5
Colour (max 21) 21 21 18.5 19.5 20.5
Texture (max 28) 28 27.5 26 25.5 20
Aroma (max 21) 21 21 20 20 19.5
Taste (max 35) 35 34.5 34.5 33 30.5
Total score (max 119) 119 118 111.5 111 104
0% 20% 40% 60% 80% 100%
Diabetics who have decreased glucose levels
Diabetics who have increased glucose levels
Fig. 1. The ratio of diabetics with reduced blood glucose levels after the final testing.
0% 20% 40% 60% 80% 100%
Diabe tics who have increased cholesterol leve ls
Diabetics who have decreased cholosterol levels
Fig. 2. The ratio of diabetics with reduced content of triglycerides in blood after the final
0% 20% 40% 60% 80% 100%
Diabetics who have triglycerides decreased
Diabetics who have triglycerides increased
Fig. 3. The ratio of diabetics with reduced blood triglycerides levels after the final testing.
Honey cake Vanilla c ookies Penaut biscuit
Chocolate truffles Snow cookies
Fig. 4. Total sensory rating of chestnut cakes.
The acceptability of products
Vanilla cookies (TA)
Penaut biscuit (A)
Chocolate truffles (A)
Snow cookies (A)
A - Acceptable; TA -
Fig. 5. Total sensory acceptability of chestnut cakes.