Nutritional Composition of Black Potato (Plectranthus rotundifolius (Poir.) Spreng.) (Synonym: Solenostemon rotundifolius)

Abstract

Plectranthus rotundifolius (synonym: Solenostemon rotundifolius) (black potato) is an underutilised nutrient-rich crop that has the potential to contribute to food and nutritional security. We examined the macronutrient and selected mineral content of black potato bought at a morning market located in the state of Pahang, Peninsular Malaysia. The proximate composition of the tubers observed in % were, moisture (78.14 ± 0.84); crude protein (0.84 ± 0.06); crude fat (0.48 ± 0.06); crude fibre (2.03 ± 0.12); ash (1.63 ± 0.13); carbohydrate (18.92 ± 0.73) and energy in kcal/100g (83.32 ± 3.46). The mineral content observed in mg/kg were calcium (336.57 ± 21.71), iron (48.20 ± 3.64), potassium (12025.07 ± 485.33), magnesium (1346.63 ± 101.24), sodium (68.23 ± 2.62), manganese (6.67 ± 0.21) and phosphorus (978.00 ± 7.72). Comparison of black potato with some popular tubers such as potato, sweet potato and cassava found that black potato had less crude protein and crude fat. The carbohydrate and the energy contents of black potato were within the same range as potato and sweet potato but lower than those observed in cassava. The ash content of black potato was higher than that of potato, sweet potato and cassava and it also had a higher mineral content. Compared with popular tuber crops such as potato, sweet potato and cassava, black potato was observed to have higher mineral content that fulfils the requirements of the Recommended Nutrient Intake as outlined in the Dietary Guideline for American male and female aged between 31 to 50.

Full text

Nutritional Composition of Black Potato
(Plectranthus rotundifolius (Poir.) Spreng.)
(Synonym: Solenostemon rotundifolius)
Gomathy Sethuraman1,4, Nur Marahaini Mohd Nizar1, Fatin Nadia Muhamad1, Tengku Adhwa Syaherah Tengku Mohd Suhairi1,
Ebrahim Jahanshiri1, Peter J. Gregory2,3, Sayed Azam-Ali2
1Crops For the Future Research Centre (CFFRC), Jalan Broga, 43500 Semenyih, Selangor, Malaysia
2Crops For the Future UK, 76-80 Baddow Road, Chelmsford, Essex, England CM2 7PJ
3School of Agriculture, Policy & Development, University of Reading, Earley Gate, Reading, RG6 6AR, UK
4Institute of Biological Sciences, Faculty of Science, University Malaya, 50603 Kuala Lumpur, Malaysia
Abstract: Plectranthus rotundifolius (synonym: Solenostemon
rotundifolius) (black potato) is an underutilised nutrient-rich crop that
has the potential to contribute to food and nutritional security. We
examined the macronutrient and selected mineral content of black
potato bought at a morning market located in the state of Pahang,
Peninsular Malaysia. The proximate composition of the tubers
observed in % were, moisture (78.14 ± 0.84); crude protein (0.84 ±
0.06); crude fat (0.48 ± 0.06); crude fibre (2.03 ± 0.12); ash (1.63 ±
0.13); carbohydrate (18.92 ± 0.73) and energy in kcal/100g (83.32 ±
3.46). The mineral content observed in mg/kg were calcium (336.57 ±
21.71), iron (48.20 ± 3.64), potassium (12025.07 ± 485.33),
magnesium (1346.63 ± 101.24), sodium (68.23 ± 2.62), manganese
(6.67 ± 0.21) and phosphorus (978.00 ± 7.72). Comparison of black
potato with some popular tubers such as potato, sweet potato and
cassava found that black potato had less crude protein and crude fat.
The carbohydrate and the energy contents of black potato were within
the same range as potato and sweet potato but lower than those
observed in cassava. The ash content of black potato was higher than
that of potato, sweet potato and cassava and it also had a higher
mineral content. Compared with popular tuber crops such as potato,
sweet potato and cassava, black potato was observed to have higher
mineral content that fulfils the requirements of the Recommended
Nutrient Intake as outlined in the Dietary Guideline for American male
and female aged between 31 to 50.
Index Terms: Plectranthus rotundifolius, Solenostemon rotundifolius,
black potato, ubi kemili, underutilised, nutritional composition, mineral
content
1 INTRODUCTION
Tuber crops rank second after cereals and grain
legumes as food crops providing carbohydrate [1],[2],[3],[4]
and contribute about six percent of the world’s dietary
energy [5] with an annual global production of
approximately 836 million tonnes [2]. Tuber crops have
edible carbohydrate-rich storage organs or `tubers’ that
develop wholly or partly underground from the stems
[2],[3]. Potato, sweet potato and cassava are among the
popular tuber crops that are widely consumed around the
world contributing to 90% of the global production [2].
Among such tubers is a rare tuber, Plectranthus rotundifolius
(synonym: Solenostemon Rotundifolius) [6],[7]; an
underutilised tuber crop that is gaining interest due to its
nutritional content and dietary potential
[8],[9],[10],[11],[12]. Studies have been conducted to
evaluate its potential to; improve diet quality [8];
antioxidant properties [13],[14],[15]; glycaemic response
[16],[17]; prebiotic quality [18] and development of food
products and functional food properties [12],[19],[20]
because of its untapped potential as an alternative food
source and to augment income [7],[9],[12].
Black potato originates from tropical Africa, where it is
still found as a native plant in East Africa, but can now be
found cultivated in other parts of the world including
countries like Sri Lanka, India, Indonesia, Thailand and
Malaysia [6],[7],[9],[11],[21],[22],[23],[24],[25],[26]. Common
names of this potato include Black potato, Hausa potato,
Country potato, Coleus potato, Chinese potato, Zulu
potato, Frafra potato, Sudan potato and “ubi kemili”
[6],[17],[22],[24],[27]. Black potato is a perennial herbaceous
crop belonging to the Lamiaceae mint family [17],[21],[24].
It is noted to be tolerant to high temperature and rainfall
and prefers well-drained, loose or sandy soil with direct
sunlight [6],[21],[24],[25],[27]. It is a smallholder crop,
mainly cultivated by women as subsistence food where the
tubers are grown, dried and stored for times of shortage
[24]. It is not primarily a cash crop, but part of the harvest is
sold, from which African women have derived
considerable income [6],[11],[24].
Black potato tubers are smaller than the commercial
potato and are oval-shaped (Fig.1). They have dark brown
skin with pale yellow flesh. The tubers are mostly eaten
boiled, sautéed, mashed or peeled and fried [9],[12]. They
are also milled into flour and made into various food
products including breakfast porridge [6],[23],[24],[26]. Its
products have been cited for use in treating burns, wounds,
sores, insect bites and allergies [21]. Other uses include
treatment for stomach pain, nausea, vomiting, diarrhoea,
mouth and throat infections and are used as purgative,
carminatives and as antihelmintic [6],[9],[10],[28]. Black
potato is also noted for its antioxidant content which has
been studied for its potential to mediate cancer cells
[14],[15]. Due to its low glycaemic index, black potato can
also reduce the risk of diabetes and obesity [19],[23],[25].
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a)
b)
Fig 1. Plectranthus rotundifolius, a) photo taken at the
morning market where the tubers were procured; b) size
comparison to a Malaysian 10 cent coin (18.8 mm in
diameter).
It has been reported that 100 g of black potato has 21 g
of carbohydrate, slightly higher than the same portion of
potato (17 g) and sweet potato (20 g) [9],[22],[23],[25].
Compared with other tubers, a standard serving provides a
large percentage of the daily required calcium, vitamin A
and more than the daily required iron [9],[12],[24]. The
absence of gluten in these tubers may serve as an
advantage as it can be an alternative food source for those
who are sensitive to gluten products or are celiac [16].
Studies on black potato indicate that this underutilised
crop has the potential as an alternative food and nutrition
source and may generate income. To the best of the
authors’ knowledge, there is little data on the crop obtained
from Malaysia. The objective of this research was to
investigate the nutritional composition of the crop which
would further supplement the existing knowledge on the
nutritional implications as a food source. For this, the
macronutrient and selected mineral content were
benchmarked against some popular tubers already on the
market.
2 MATERIALS AND METHODS
2.1 Raw material
Black potatoes (Plectranthus rotundifolius) were
procured from a morning market; Pasar Pagi Maran,
Pahang, Malaysia in November 2019. The materials were
reportedly grown in Bachok, Kelantan, Malaysia. Black
potatoes are found to be diverse in shape, size and colour.
The procured tubers had blackish brown skin with pale
yellow flesh (Fig. 2a & 2b). The dimension of the tubers
ranged between 3.0 and 5.0 cm long and 1.0 and 2.0 cm
diameter.
a)
b)
c)
Fig 2. Plectranthus rotundifolius, a) washed and cleaned; b) sliced
c) dried at 105 °C
2.2 Sample preparation
The tubers (≈ 2 kg) were cleaned under running tap
water to remove soil particles and debris. Fine roots were
removed to leave only tubers. The tubers were sliced and
dried in an oven at 105 °C for 24 h or until the sample
reached a constant weight (Fig. 2c). The dried tubers were
ground using a household dry blender in batches and
pooled. The ground samples were stored in labelled airtight
containers before analysis. Proximate analysis was carried
out using standard methods outlined by the National
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Technical Working Group of Malaysia Food Composition
Database [29]. Selected mineral content was determined for
the dried sample in accordance with AOAC methods by an
ISO/IEC 17025 accredited laboratory, UNIPEQ, Malaysia.
Triplicate samples were carried out for all the analysis.
2.3 Analytical Analysis
Moisture: Approximately 5 g of fresh sample was dried in a
laboratory oven (Venticell VC55) at 105 °C for 16 h or until
constant weight was achieved.
Crude Protein: Protein content was measured by
estimating the nitrogen content in the sample using a semi-
automated Kjeldahl method. This involved three steps,
manual digestion; automatic distillation and titration.
Approximately 2 g of sample was digested in 20 ml
concentrated sulphuric acid (> 98 % H2SO4) with one
mineralised catalyst on a conventional digester (Gerhardt,
KI 11/26) for at least 2 h or until the solution became
clear/colourless. This was followed with second step,
distillation; 50 ml deionized water (dH2O) and 70 ml 32 %
sodium hydroxide (NaOH) was added into the colourless
digested sample and distilled into 60 ml 2 % boric acid
(H3BO3) using automated distillation equipment (Gerhardt,
Vapodest 400). In the final step, the distillate with borate
ion was titrated against standardized 0.1 M hydrochloric
acid (HCl) using an automatic titrator (Metrohm, 877
Titrino plus) to obtain the nitrogen percentage and the
protein was calculated by multiplying by 6.25.
Crude Fat: Crude fat was determined using a continuous
solvent extraction method with a standard Soxhlet setup
from Gerhardt. Approximately 2 g of dried sample was
wrapped in a filter paper and inserted into a cellulose
thimble and then placed in an extraction chamber.
Approximately 200 ml petroleum ether was added into a
pre-weighted - pre-dried boiling flask with 2-3 pieces of
boiling stones. The extraction was carried out for 3 h. After
the extraction was complete, the solvent was collected in
the boiling flask. The boiling flask was placed in a water
bath (70 °C) to evaporate the solvent, the flask is further
dried in the oven (105 °C). The crude fat content was
calculated as the weight of the fat removed from the
sample.
Crude Fibre: The crude fibre was measured using Fibrebag
System (Gerhardt, Fibretherm FB6). There were four steps
involved. Step one; approximately 2 g of the sample was
de-fatted by rinsing with petroleum ether to obtain a clear
solution. Step two involved two separate digestion
processes, acid digestion using 0.13 mol/L H2SO4 (to
remove free sugar and starch) and alkaline digestion using
0.23 mol/L NaOH (to remove protein and carbohydrate).
The sample was further digested for 30 mins and rinsed
with hot water twice after each digestion process. After
digestion was completed, the sample was dried overnight
at 105 °C (Venticell, VC55) and incinerated in a muffle
furnace (Thermolyne, F6010) at 550 °C for 4 h.
Ash: Ash was determined by incinerating 5 g of the sample
in a muffle furnace (Thermolyne, F6010) at 550 °C for 4 h.
Carbohydrate: Carbohydrate was obtained by difference
calculation, 100 – (sum of percentage in moisture, ash,
protein and fat).
Energy: The total energy content was determined by the
sum of fat, protein and carbohydrate multiplied with
factors 9.0, 4.0 and 4.0 respectively, the result was
expressed in kilocalories per 100 g sample.
3 RESULTS AND DISCUSSION
3.1 Proximate composition
Table 1 shows the proximate composition of black
potato compared with the values reported by Leung et al.
[30] and other tuber crops: potato, sweet potato and
cassava. In this study, the proximate data differed from that
reported by Leung et al. [30]. We found crude protein
(0.84%) to be lower whereas all other proximate data were
within the same range or slightly higher than previously
reported.
It was found that 100 g of black potato had 21 g of
carbohydrate, slightly higher than the same portion of
potato (17 g) and sweet potato (20 g) [22]. This study
reports lower carbohydrate (18.9 g) than cited by Enyiukwu
et al. [22], but still slightly higher than that found in potato
which also contributes to a slightly higher energy content.
A notable attribute of the black potato is the ash content
compared to the other tubers. Black potato (1.63 %) was
observed to have the highest ash content compared with
potato (1.11 %); sweet potato (0.99 %) and cassava (0.62 %).
This higher ash content contributed to the higher mineral
content which is discussed below.
3.2 Mineral composition
Table 2 presents the mineral composition of black
potato compared with potato, sweet potato, cassava and the
Recommended Nutrient Intake (RNI) for adult male and
female aged 31 to 50 [31]. Black potato had a higher
composition of all the analysed minerals compared to the
other tubers. Potassium and magnesium are notably high;
potassium (12025 mg/kg) almost three times more than
potato and six times more than cassava and magnesium
(1347 mg/kg) is higher by five times compared to all the
listed tubers. Phosphorus (978 mg/kg) was observed to be
nearly double that of potatoes but almost four times that of
cassava. The mineral content observed in black potato
meets the recommended nutrient intake for both female
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and male aged between 31 to 50 for most of the nutrient
except for calcium and sodium.
Minerals are essential for bodily function, macro-
minerals (calcium, potassium, magnesium, sodium,
phosphorus) are needed in a larger quantity compared to
the micro-minerals (iron and manganese). These two
groups of minerals are equally important and cannot be
synthesized biochemically by the body. Mineral
deficiencies have been associated with stunting, wasting,
anemia and other disorders [32],[33]. It was reported that
the number of undernourished people has increased from
777 million in 2015 to 815 million in 2017 with an estimated
155 million children having stunted growth [8].
4 CONCLUSION
Underutilised tuber crops offer an important
agronomic advantage as staple foods because of their
favourable adaptation to diverse soil and environmental
conditions and as part of the diversification of farming
systems with minimum agricultural inputs. The tuber
Plectranthus rotundifolius, known as ubi kemili by the local
community in Malaysia was examined for its proximate
composition and selected mineral. The analysis shows that
the crop has untapped potential uses in the human diet
particularly in addressing the recommended nutrient
intake requirements.
Table 1. Proximate Composition of Plectranthus rotundifolius compared to other tubers
Component
This study
Leung et al. 1968
Potato1
Sweet potato1
Cassava1
Moisture (%)
78.14 ± 0.84
75.60 - 78.00
79.25
77.28
59.68
Crude protein (%)
0.84 ± 0.06
1.30 - 1.90
2.05
1.57
1.36
Crude fat (%)
0.48 ± 0.06
0.20 - 0.40
0.09
0.05
0.28
Crude fibre (%)
2.03 ± 0.12
1.00 - 1.10
ND
ND
ND
Ash (%)
1.63 ± 0.13
0.90 - 1.00
1.11
0.99
0.62
Carbohydrate (%)
18.92 ± 0.72
18.80 -21.90
17.49
20.12
30.06
Energy (kcal/100g)
83.33 ± 3.42
84.00 - 94.00
77.00
86.00
160.00
Values in this study are expressed as mean ± standard deviation (n = 3); ND – No data; Fat, Protein and Carbohydrate
multiplied with factors 9.0, 4.0 and 4.0; 1Source: USDA [34]
Table 2. Mineral Composition of Plectranthus rotundifolius compared to other tubers
Component
This study
Potato1
Sweet
Potato1
Cassava1
RNI (Age 31 - 50)
Female
(1800)2
Male
(2200)2
Calcium (mg/kg)
337
120
300
160
1000
1000
Potassium (mg/kg)
12025
4250
3370
2710
4700
4700
Magnesium (mg/kg)
1347
230
250
210
320
420
Sodium (mg/kg)
68
60
550
140
2300
2300
Phosphorus (mg/kg)
978
570
470
270
700
700
Iron (mg/kg)
48
8.1
6.1
2.7
18
8
Manganese (mg/kg)
7
1.53
2.58
3.84
1.8
2.3
Values in this study are expressed as mean ± standard deviation (n = 3); 1Source: USDA [34]; 2Source: USDA [31]
AUTHORS CONTRIBUTIONS
Gomathy Sethuraman: Investigation, Resources, Data
Curation, Writing – Original Draft. Nur Marahaini Mohd
Nizar: Resources, Data Curation, Writing - Editing. Fatin
Nadia Muhamad: Resources, Data Curation. Ebrahim
Jahanshiri: Funding acquisition. Peter J. Gregory:
Conceptualization, Supervision, Writing - Review and
Editing. Sayed Azam-Ali: Funding acquisition, Project
Administration, Writing - Review and Editing.
ACKNOWLEDGEMENT
The authors would like to thank Crops For the Future
Research Centre (CFFRC) colleagues for support and
assistance in this study; especially to Mrs. Hilda Hussin
who organised a portion of the funding for this study.
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FUNDING
This project was funded by internal funding and CFFRC
was financially supported by the Malaysian Government.
The Proximate Analysis equipment and Product
Development Laboratory at CFFRC were obtained with
sponsorship from the Sime Darby Foundation
CORRESPONDING AUTHOR
Gomathy Sethuraman1,2
1Crops For the Future Research Centre (CFFRC), Jalan
Broga, 43500 Semenyih, Selangor, Malaysia
2Institute of Biological Sciences, Faculty of Science,
University Malaya, 50603 Kuala Lumpur, Malaysia.
Email: gomathy@um.edu.my
REFERENCES
[1] Allemann, J., Laurie, S.M., Thiart, S., Vorster, H.J., &
Bornman, C.H. (2004). Sustainable production of root
and tuber crops (potato, sweet potato, indigenous
potato, cassava) in southern Africa. South African
Journal of Botany, 70(1), 60–66.
https://doi.org/10.1016/S0254-6299(15)30307-0
[2] Chandrasekara, A., Kumar, T.J. (2016). Roots and
tuber crops as functional foods: A review on
phytochemical constituents and their potential health
benefits. International Journal of Food Science, 2016.
https://doi.org/10.1155/2016/3631647
[3] Gregory, P.J., & Wojciechowski, T. (2020). Chapter one
- Root systems of major tropical root and tuber crops:
Root architecture, size, and growth and initiation of
storage organs. In D.L. Sparks (Ed.), Advances in
Agronomy (Vol. 161, pp. 1–25). Academic Press.
https://doi.org/10.1016/bs.agron.2020.01.001
[4] John, K.S., George, J., Beegum, S.U.S., Shivay, Y.S.
(2016). Soil fertility and nutrient management in
tropical tuber crops - an overview. Indian Journal of
Agronomy, 61(3), 263-273.
[5] Suja, G., & Nedunchezhiyan, M. (2018). Crop
diversification with tropical tuber crops for food and
livelihood security. Journal of Root Crops, 44(1), 3–11.
[6] Morton, J.K. (2004). Solenostemon Rotundifolius (Poir).
In G.J.H. Grubben, & O.A. Denton (Eds.). Plant
Resources of Tropical Africa 2. Vegetables (pp.508-511).
Wageningen, Netherlands: Backhuys Publishers,
PROTA Foundation.
[7] Reddy, P.P. (2015). Chinese Potato, Plectranthus
rotundifolius. In P.P. Reddy (Ed.), Plant Protection in
Tropical Root and Tuber Crops (pp. 235–251). Springer
India. https://doi.org/10.1007/978-81-322-2389-4_6
[8] Andrias, D.R., Fahmida, U., Adi, A.C. (2019).
Nutritional potential of underutilised food crops to
improve diet quality of young children in food
insecure prone areas of Madura Island, Indonesia.
Asia Pacific Journal of Clinical Nutrition, 28(4), 826-836.
[9] Kwarteng, A.O., Ghunney, T., Amoah, R.A., Nyadanu,
D., Abogoom, J., Nyam, K.C., Ziyaaba, J.Z., Danso,
E.O., Whyte, T., Asiedu, D.D. (2018). Current
knowledge and breeding avenues to improve upon
frafra potato (Solenostemon rotundifolius (Poir.) J. K.
Morton). Genetic Resources and Crop Evolution, 65, 659 -
669. https://doi.org/10.1007/s10722-017-0581-6
[10] Safwan, I.I., Mohammed, U.A. (2016). Review on the
nutritional value, cultivation and utilization potential
of some minor and under-utilized indigenous root
and tuber crops in Nigeria. International Journal of
Advanced Research, 4(3), 1298-1303.
[11] Sugri, I., Kusi, F., Kanton, R.A.L., Nutsugah, S.K.,
Zakaria, M. (2013). Sustaining frafra potato
(Solenostemon rotundifolius Poir.) in the food chain;
current opportunities in Ghana. Journal of Plant
Sciences, 1(4), 68-75.
https://doi.org/10.11648/j.jps.20130104.14
[12] Tortoe, C., Akonor, P.T., Kusi, F., Anabire, P.A.,
Owusu, R.K., Boateng, C. (2018). Unearthing the
potential of the frafra potato (Solenostemon
rotundifolius) flour in culinary application: sensory and
nutritional analysis of its pastry products. Journal of
Culinary Science & Technology, 18(1), 1-12.
https://doi.org/10.1080/15428052.2018.1495588
[13] Joy, J.K., & Siddhuraju, P. (2017). Studies on
nutritional profile and antioxidant potential of
different Dioscorea sp. with plectranthus rotundifolius.
International Journal of Current Pharmaceutical Research,
9(4), 65–74.
https://doi.org/10.22159/ijcpr.2017v9i4.20959
[14] Murthy, H.N., Herlekar, V.V., Joseph, K.S., Payamalle,
S., Shinde, S. (2018). Phenolic content, antioxidant and
antibacterial activities of Plectranthus rotundifolius
tuber extracts. Journal of Herbs, Spices & Medicinal
Plants, 24(2), 213-220.
https://doi.org/10.22159/ijcpr.2017v9i4.20959
[15] Nugraheni, M., Santoso, U., Suparmo, Wuryastuti, H.
(2011). Potential of coleus tuberosus as an antioxidant
and cancer chemoprevention agent. International Food
Research Journal, 18(4), 1471- 1480.
[16] Lakmali, H.M.K., Eashwarage, I.S., Gunathilake,
K.D.P.P. (2019). Glycemic response of two composite
flours: wheat-innala (Plectranthus rotundifolius) and
wheat-kiri ala (Xanthomonas sagittifolium). Annals. Food
Science and Technology, 20(3), 585-590.
[17] Eleazu, C.O., Eleazu, K.C., Iroaganachi, M.A., Kalu,
W. (2017). Starch digestibility and predicted glycemic
indices of raw and processed forms of hausa potato
(Solenostemon rotundifolius Poir). Journal of Food
International Journal of Scientific & Engineering Research Volume 11, Issue 10, October-2020
ISSN 2229-5518
1149
IJSER © 2020
http://www.ijser.org
IJSER

Biochemistry, 2017, 41:e12355.
https://doi.org/10.1111/jfbc.12355
[18] Jayatilake, S., Chandrasekara, A., Madhujith, A.
(2008). Effect of potential prebiotics on the survival of
probiotic Lactobacillus acidophilus. Tropical Agricultural
Research, 20, 162-167.
[19] Hasna, T., Muchlisyiyah, J., Wardani, S., Estiasih, T.
(2020). Effect of pre-gelatinization on physicochemical
and functional properties of Solenostemon rotundifolius
flour. IOP Conference Series: Earth and Environmental
Science, 524. https://doi.org/10.1088/1755-
1315/524/1/012014
[20] Ukpabi, U.J., Oti, E., Ogbogu, N.J. (2011). Culinary
and sensory characteristics of hausa potato
(Solenostemon rotundifolius) and livingstone potato
(Plectranthus esculentus) tuber in Nigeria. Journal of
Stored Products and Postharvest Research, 2(16), 301-304.
https://doi.org/10.5897/JSPPR11.062
[21] Anbuselvi, S., Balamurugan, T. (2013). Nutritional and
anti-nutritional constituents of Manihot esculentus and
Plectranthus rotundifolius. International Research Journal
of Pharmacy. 4(9), 97-99. https://doi.org/10.7897/2230-
8407.04919
[22] Enyiukwu, D., Awurum, A.N., Nwaneri, J. (2014).
Potentials of hausa potato (Solenostemon
rotundifolius (Poir.) J. K. Morton and management of
its tuber rot in Nigeria. Greener Journal of Agronomy,
Forestry and Horticulture, 2(2), 027-037.
https://doi.org/10.15580/GJAFH.2014.2.010314008
[23] Khairinisa, F., Purnomo, Maryani (2018). Diversity
and phenetic relationship of black potato (Coleus
tuberosus Benth.) in Yogyakarta based on
morphological and leaf anatomical characters. AIP
Conference Proceedings 2002, 020025.
https://doi.org/10.1063/1.5050121
[24] National Research Council. (2006). Lost Crops of
Africa: Volume II: Vegetable. Washington, DC: The
National Academies Press.
https://doi.org/10.17226/11763.
[25] Paramita, V., Kusumayanyi, H., Yulianto, M.E.
Rachamawati, D.A., Hartati, I., Ardi, P.R. (2019).
Drying kinetics modelling of dried black potato
(Plectranthus rotundifolius) cultivated in Indonesia. IOP
Conference Series: Materials Sciences and Engineering,
845. https://doi.org/10.1088/1757-899X/845/1/012045
[26] Prematilake D.P. (2005). Inducing genetic variation of
innala (Solenostemon rotundifolius) vis in vitro callus
culture. Journal of the National Science Foundation, 33(2),
123-131.
[27] Manikandan, S., Lakshmanan, G.M.A., Chandran, C.
(2016). Phytochemical screening and evaluation of
tuber extract of Plectranthus rotundifolius Spreng. by
GC-MS and FT-IR spectrum analysis. International
Journal of Herbal Medicine, 4(2), 36-40.
[28] Anbuselvi, S. & Priya, M.H. (2013). Nutritional and
anti-nutritional constituents of Plectranthus
rotundifolius. International Journal of Pharmaceutical
Sciences Review and Research, 22(1), 213-215.
[29] National Technical Working Group of Malaysian Food
Composition Database. (2011). Protocol For Sampling
And Methods Of Analysis For Malaysian Food
Composition Database.
[30] Leung, T.W., Busson, F., Jardin, C. (1968). Food
Composition Table for Use in Africa. Rome: Food and
Agriculture Organization of the United Nations.
[31] USDA (2015). 2015–2020 Dietary Guidelines for
Americans. 8th Edition. December 2015. Retrieved 5
August 2020, from
http://health.gov/dietaryguidelines/2015/guidelines/
[32] Caulfield, L.E., Richard, S.A., Rivera, J.A., Musgrove,
P., Black, R.E. (2006). Stunting, Wasting, and
Micronutrient Deficiency Disorders. In D.T. Jamison,
J.G. Breman, A.R. Measham, G. Alleyne, M. Claeson,
D.B. Evans, P. Jha, A. Mills, & P. Musgrove (Eds.),
Disease Control Priorities in Developing Countries (2nd
ed.). World Bank.
http://www.ncbi.nlm.nih.gov/books/NBK11761/
[33] Rivera, J.A., Hotz, C., González-Cossío, T., Neufeld,
L., García-Guerra, A. (2003). The effect of
micronutrient deficiencies on child growth: A review
of results from community-based supplementation
trials. The Journal of Nutrition, 133(11 Suppl 2), 4010S-
4020S. https://doi.org/10.1093/jn/133.11.4010S
[34] USDA (2019). FoodData Central. Retrieved August 16,
2020 from: https://fdc.nal.usda.gov/
International Journal of Scientific & Engineering Research Volume 11, Issue 10, October-2020
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